Easing mitochondrial stress in chronic Chlamydia pneumoniae infections: the use of dietary supplements

David Wheldon

Introduction

In health a balanced diet provides all the vitamins and antioxidants necessary to maintain vigour, and supplementation cannot reasonably be recommended.

In disease states, however, the situation is different. Chronic persistent infections with Chlamydia pneumoniae are characterized by high levels of oxidative stress as a result of complex inflammatory processes. Multiple Sclerosis is no exception. The concentrations of reactive oxygen and nitrogen species - superoxide, nitric oxide and peroxynitrite, a toxic metabolite of nitric oxide - increase dramatically in MS not only because of bacterial activity but because of the pro-inflammatory immune response to this activity.

The antioxidant buffering capacity within the brain is known to be limited. Oligodendrocytes seem to be particularly vulnerable to oxidative stress. Unresolved oxidative stress can damage the lipids, proteins and nucleic acids of cells and mitochondria; mitochondrial DNA is particularly vulnerable. [reviewed by Smith KJ, Kapoor R, Felts PA. Demyelination: the role of reactive oxygen and nitrogen species. Brain Pathol. 1999 Jan;9(1):69-92.]

Levels of isoprostane are increased in the CSF and brain tissue in inflammatory states and in MS. [Greco A, Minghetti L, Levi G. Isoprostanes, novel markers of oxidative injury, help understanding the pathogenesis of neurodegenerative diseases. Neurochem Res. 2000 Oct;25(9-10):1357-64.] These authors comment: 'Isoprostanes are prostaglandin-like compounds which are formed by free radical catalysed peroxidation of arachidonic acid esterified in membrane phospholipids. They are emerging as a new class of sensitive, specific and reliable markers of in vivo lipid peroxidation and oxidative damage.'

There is some evidence that the progression of MS is more severe in those who have a genetically-determined relative inability to remove the toxic products of oxidative stress. [Mann CL et al., Glutathione S-transferase polymorphisms in MS: their relationship to disability. Neurology. 2000 Feb 8;54(3):552-7.]

Antioxidants are depleted in the serum and CSF of MS patients. [reviewed by Besler HT, Comoglu S. Lipoprotein oxidation, plasma total antioxidant capacity and homocysteine level in patients with multiple sclerosis. Nutr Neurosci. 2003 Jun;6(3):189-96.] These authors found that, during MS relapses, there was a significant increase in the levels of autoantibodies against oxidized low-density lipoproteins, a strong decrease in plasma total antioxidant capacity and an elevated plasma homocysteine level. (Elevated homocysteine levels are also found in inflammatory arterial disease, and are associated with coronary thrombosis.)

There is evidence that damage in MS is not limited to the plaque areas. The current view is that considerable biochemical alterations are present in both grey matter and in normal-appearing white matter. Might an ongoing intracerebral Chl. pneumoniae infection cause widespread oxygen depletion in the brain? Graumann and colleagues found up-regulation of genes involved in maintenance of cellular homeostasis, and in neural protective mechanisms known to be induced upon ischemic preconditioning in MS. [Graumann U, et al., Molecular changes in normal appearing white matter in multiple sclerosis are characteristic of neuroprotective mechanisms against hypoxic insult. Brain Pathol. 2003; 13(4): 554-73.] Haemodynamic disorders have been found in MS, with decreased grey matter and increased white matter perfusion. [Rashid W et al., Abnormalities of cerebral perfusion in multiple sclerosis. J Neurol Neurosurg Psychiatry. 2004; (9): 1288-93.]

The damage caused by free radicals may be multifactorial, synergic and unexpected. In 1982 Amaducci and co-workers described an increased incidence of MS in leather workers exposed to organic solvents. [Amaducci L et al., Multiple sclerosis among shoe and leather workers: an epidemiological survey in Florence. Acta Neurol Scand. 1982 Feb;65(2):94-103.] A raised incidence of MS has also been found in nurse-anaesthetists, who are exposed to volatile anaesthetic agents. [Flodin U et al., Multiple sclerosis in nurse anaesthetists. Occup Environ Med. 2003 Jan;60(1):66-8]

Are there any dangers of supplementation? Disappointment follows undue expectation: the remarkable claims made for vitamin C in malignancy in the 1970's are now known to have been based on the comparison of groups of patients whose diagnoses were made under different circumstances and so were not comparable. [Cameron E, Pauling L. Supplemental ascorbate in the supportive treatment of cancer: Prolongation of survival times in terminal human cancer. Proc Natl Acad Sci USA. 1976 Oct;73(10):3685-9.] This has generated not a little antipathy amongst physicians; recollection of this punctured bubble has tended to eclipse the more modest findings that antioxidants may be of help in slowing the rate of progress of Alzheimer's disease.

Supplements may not be standardized and may not be present in the same physiological form in which they are in the body; they are not necessarily controlled by their manufacturers and are not assayed by the state. But this is also true of prescription drugs: in the case of some generics the patient may not receive what the physician has prescribed. One should go for quality in both.
There is a theoretical risk, during treatment of malignancies with radiotherapy or chemotherapy, that antioxidants such as Vitamins C and E may help protect tumour cells against purposefully-made free radicals. [reviewed by D'Andrea G, Use of antioxidants during chemotherapy and radiotherapy should be avoided. CA Cancer J Clin. 2005 55(5):319-21.] On reading this paper I was left with the feeling that the author is against antioxidant supplementation in general; the argumentation is a little disingenuous. Were it really believed, recommendation of a junk-food diet would be the next logical step.

The risks of supplementation are present but small. The possible benefits - by counteracting chronic endotoxicity and unrelenting inflammatory damage, by restoring a range of depleted antioxidants, and by preventing mitochondrial degradation before this becomes irreversible - are very great.

Vitamin C

Humans cannot make Vitamin C (ascorbic acid) and require a dietary source.

Vitamin C is required for the synthesis of collagen, which is a component of arterial walls, tendons, ligaments and bronchioles. Persistent infection with Chlamydia pneumoniae damages arterial and bronchial walls [Theegarten G et al. The role of chlamydia in the pathogenesis of pulmonary emphysema. Electron microscopy and immunofluorescence reveal corresponding findings as in atherosclerosis. Virchows Arch. 2000 Aug;437(2):190-3.]. Cross-linkages occur in collagen and elastin with stiffening. These cross-linkages are capable of reversal [Vaitkevicius PV et al., A cross-link breaker has sustained effects on arterial and ventricular properties in older rhesus monkeys. Proc Natl Acad Sci USA. 2001 Jan 30;98(3):1171-5.]

Vitamin C is also a powerful antioxidant, able to protect proteins, carbohydrates and nucleic acids (DNA and RNA) against damage by free radicals and reactive oxygen species that can be generated during normal cellular metabolism; this damage is increased enormously on exposure to bacterial endotoxins and ensuing inflammation.

Vitamin C has the capacity to regenerate other antioxidants such as vitamin E [Chan AC. Partners in defense, vitamin E and vitamin C. Can J Physiol Pharmacol. 1993 Sep;71(9):725-31.]

Vitamin C helps make the neurotransmitter noradrenaline (norepinephrine).

Vitamins C and E in combination are particularly active, and, if taken as supplements, may protect against the onset of certain diseases; elderly men who took supplements of both vitamin C and E were found to have an 88% reduction in the frequency of vascular dementia (but not Alzheimer's dementia) compared with men who did not take the supplements. The protective effect was substantially greater in men who reported long-term use of both vitamins. [Masaki KH et al., Association of vitamin E and C supplement use with cognitive function and dementia in elderly men. Neurology. 2000 Mar 28;54(6):1265-72.]

Vitamin B2, B6, B12 and Folate

Vitamin B2 (Riboflavin), Vitamin B6 (pyridoxal phosphate), Vitamin B12 (as oral methylcobalamin) and folate are also important. Low concentrations of these vitamins are found in persons with excess plasma homocysteine. Homocysteine is an amino acid whose metabolism is involved with remethylation, which requires folic acid and B-12, and transsulphuration, which requires B-6. [Data from the Framingham studies, reviewed by Selhub, J. J. Nutr. 136:1726S - 1730S] Hyperhomocysteinaemia, due to interference with the methionine pathway, is also found in chronic infections with C. pneumoniae [Nabipour I, et al. Heart Lung Circ. Correlation of hyperhomocysteinaemia and Chlamydia pneumoniae IgG seropositivity with coronary artery disease in a general population. 2007 Dec;16(6):416-22.] and is a feature of diseases as diverse as adult onset asthma, arteriopathy and dementia. Elevated homocysteine levels are found in the plasma of persons with MS even when the disease is in remission [Ramsaransing GS, et al. J Neurol Neurosurg Psychiatry. 2006 Plasma homocysteine levels in multiple sclerosis. Feb;77(2):189-92. Raised homocysteine damages proteins, most notably in the endothelium, and may be responsible for some of the vascular changes seen in MS [D'haeseleer M, Lancet Neurol. 2011 Jul;10(7):657-66.]

Supplementation with vitamin B complex is thus recommended.

Note: There is evidence that the cellular uptake of Vitamin B12 and folate is greatly improved by supplementation with low-dose lithium compounds. Lithium orotate is the preferred form. [Reviewed in depth by Marshall T M, Lithium as a nutrient. Journal of American Physicians and Surgeons 2015 20 (4) 104-109.]

Bioflavonoids

Bioflavonoids are a large, heterogenous group of pigmented plant molecules; in evolutionary terms they may have emerged because of their ability to cope with the immense free radical load associated with photosynthesis. They are polyphenols, but beyond that they have a wide structural diversity. Over 4000 bioflavonoids have been described. They have been divided into 7 different families according to their chemical structure. Though they are efficient antioxidants, tissue and cellular levels may be too low for this to be their prime benefit. Williams and colleagues suggest that flavonoids, and their in vivo metabolites, may not act as conventional hydrogen-donating antioxidants but may exert modulatory actions in cells through actions at protein kinase and lipid kinase signalling pathways. [Williams RJ, Spencer JP, Rice-Evans C. Flavonoids: antioxidants or signalling molecules? Free Radic Biol Med. 2004;36(7):838-849.]

Quercetin is a ubiquitous bioflavonoid with powerful activity against the production of proinflammatory cytokines in macrophages stimulated by lipopolysaccharide. [Cho SY, Park SJ, Kwon MJ, et al. Quercetin suppresses proinflammatory cytokines production through MAP kinases andNF-kappaB pathway in lipopolysaccharide-stimulated macrophage. Mol Cell Biochem. 2003;243(1-2):153-160.] A mixture of bioflavonoids from Waltheria indica, a plant used for centuries in India for inflammatory disorders, was found to significantly and dose-dependently inhibit the production of the nitric oxide (NO) and the cytokines tumor necrosis factor-a and interleukin (IL)-12, in lipopolysaccharide and g interferon activated murine peritoneal macrophages, without displaying cytotoxicity. The major constituent of extracts of this were quercetin. [Rao YK, Fang SH, Tzeng YM. Inhibitory effects of the flavonoids isolated from Waltheria indica on the production of NO, TNF-a and IL-12 in activated macrophages. Biol Pharm Bull. 2005 May;28(5):912-5.]

The ability of bioflavonoids to enter the CNS in man is uncertain, but dietary anthocyanin from blueberries has been found to enter the CNS of aged rats, with some evidence that memory was improved. [Andres-Lacueva C, Shukitt-Hale B, Galli RL, Jauregui O, Lamuela-Raventos RM, Joseph JA. Anthocyanins in aged blueberry-fed rats are found centrally and may enhance memory. Nutr Neurosci. 2005 Apr;8(2):111-20.] This is of particular interest, as the authors found the anthocyanin in several parts of the brain, including the hippocampus, which is concerned with the processing of experiences into memories, which are stored elsewhere. The hippocampus is often the first area to be damaged in Alzheimer's disease. In another aged rat study, again using blueberries, short-term but not long-term memory was significantly enhanced. [Ramirez MR, Izquierdo I, Raseira MD, Zuanazzi JA, Barros D, Henriques AT. Effect of lyophilised Vaccinium berries on memory, anxiety and locomotion in adult rats. Pharmacol Res. 2005 Aug 9. Epub ahead of printing.]

Pomegranate juice appears to have remarkable properties, with recently reported benefits in coronary artery disease, [Aviram M et al., Pomegranate juice consumption for 3 years by patients with carotid artery stenosis reduces common carotid intima-media thickness, blood pressure and LDL oxidation. Clin Nutr. 2004 Jun;23(3):423-33.; Sumner MD et al., Effects of pomegranate juice consumption on myocardial perfusion in patients with coronary heart disease. Am J Cardiol. 2005 Sep 15;96(6):810-4. ] hyperlipidaemia in diabetics, [Esmaillzadeh A et al., Concentrated pomegranate juice improves lipid profiles in diabetic patients with hyperlipidemia. J Med Food. 2004 Fall;7(3):305-8.] prostatic cancer [Malik A et al., Pomegranate fruit juice for chemoprevention and chemotherapy of prostate cancer. Proc Natl Acad Sci U S A. 2005 Sep 28; [Epub ahead of print] and hypertension. [Aviram M, Dornfeld L. Pomegranate juice consumption inhibits serum angiotensin converting enzyme activity and reduces systolic blood pressure. Atherosclerosis. 2001 Sep;158(1):195-8.] This new work is promising.

Vitamin E

The term vitamin E describes a family of eight antioxidants - four tocopherols and four tocotrienols. Deficiency is rare, but it is quite possible that relative deficiency may occur in chronic Chlamydia pneumoniae infection, due to increased oxidative stress and consequent demand for antioxidants.

a-tocopherol, the commonest E vitamin, is fat soluble and protects fats from oxidative degeneration. Fats are an integral part of cell membranes - including myelin - and are vulnerable to destruction through oxidation by free radicals. Endotoxin can also bind to them. When a molecule of a-tocopherol neutralizes a free radical, it is itself neutralized. However, other antioxidants, such as vitamin C, are capable of regenerating its antioxidant capacity. [Chan AC. Partners in defense, vitamin E and vitamin C. Can J Physiol Pharmacol. 1993; 71(9): 725-31.] Deficiency of vitamin E results in neurological symptoms, notably vertigo, ataxia and peripheral neuropathy.

Chronic Chlamydia pneumoniae infection has been linked with Alzheimer's dementia, which is characterised by intracerebral oxidative damage; one controlled study showed that supplementation of individuals who had moderate neurological impairment with 2,000 IU of synthetic a-tocopherol daily for two years resulted in a significant slowing of the progression of Alzheimer's dementia. [Sano M et al. N Engl J Med. 1997 Apr 24;336(17):1216-22.] The mechanism for this protection may be inhibition of the sphingomyelin-ceramide cascade which results in oxidative stress and cell-death. [Ayasolla K et al., Inflammatory mediator and beta-amyloid (25-35)-induced ceramide generation and iNOS expression are inhibited by vitamin E. Free Radic Biol Med. 2004 Aug 1;37(3):325-38.] This cascade can be initiated by lipopolysaccharides amongst other agents.

Many commercial preparations calling themselves 'Vitamin E' contain synthetic a-tocopherol only. There is evidence that all eight members of the vitamin E family are required in health. The tocotrienols (which until recently have been largely ignored) may be particularly important. Abnormal angiogenesis occurs in chronic C. pneumoniae infection and in other degenerative diseases (it is a serious component of the pathology in diabetes mellitus for instance), and the tocotrienols have been shown in vivo to act against new vessel formation. [Nakagawa K, et al., In vivo angiogenesis is suppressed by unsaturated vitamin E, tocotrienol. J Nutr. 2007 137(8): 1938-43.] Tocotrienols are neuroprotective, particularly against oxidative stress, possibly more so than tocopherols [Khanna S, Roy S, et al., Characterization of the potent neuroprotective properties of the natural vitamin E alpha-tocotrienol. J Neurochem. 2006 Sep;98(5):1474-86. pdf available]. Sources and properties of the tocotrienols are discussed in this excellent review [Sen CK, Khanna S, Roy S. Tocotrienols: Vitamin E beyond tocopherols. Life Sci. 2006 78(18): 2088-98. pdf available]. Natural scources of balanced tocopherols and tocotrienols may be preferable to synthetic sources. Wheat-germ and wheat-germ oil are ideal sources.

Omega 3 oil

Omega 3 oils are polyunsaturated; they include a-linolenic acid which is found in plant oils, particularly flax-seed oil. Fish-derived Omega 3 oils include eicosapentaenoic (EPA) and docosahexaenoic acids (DHA); EPA and DHA can also be synthesised in the body from a-linolenic acid.

Eicosanoids are chemical messengers derived from 20-carbon polyunsaturated fatty acids. They play critical roles in immune and inflammatory responses. They are fabricated from EPA. They are also fabricated from arachidonic acid. Arachidonic acid-derived eicosanoids differ from EPA-derived eicosanoids in being more potent inducers of inflammation and clotting. The average Western diet, poor in oily fish, tends to allow a chronic imbalance of eicosanoids and creates an unfavourable ratio of arachidonic acid- and EPA-derived eicosanoids. Oily fish or Omega 3 oils correct this balance and protect against cardiovascular disease. [Kris-Etherton PM et al. Fish consumption, fish oil, omega-3 fatty acids, and cardiovascular disease. Circulation. 2002;106(21):2747-2757; Calder PC, Proc Nutr Soc. 2002 Aug;61(3):345-58.] Chlamydia pneumoniae is known to have an input into cardiovascular disease.

Fish-derived Omega 3 oils inhibit graft-versus-host reactions in animal studies; the same studies showed an inhibition of the production of Tumour-Necrosis Factor alpha (TNF-a). [Grimm, H et al., Immunoregulation by parenteral lipids: impact of the n-3 to n-6 fatty acid ratio. J Parenter Enteral Nutr. 1994 Sep-Oct;18(5):417-21.] TNF-a has a complex pro-inflammatory cytokine; it is a component of the innate immune response. Raised TNF-a levels have been found to be associated with fatigue in MS patients. [Flachenecker P, et al. Cytokine mRNA expression in patients with multiple sclerosis and fatigue. Mult Scler. 2004 Apr;10(2):165-9.] TNF-a is produced in large amounts in response to bacterial endotoxins.

Evening Primrose Oil

Evening primrose oil contains linoleic acid (LA) and gamma-linoleic acid (GLA). LA is plentiful in oils derived from nuts and seeds, and, in health, GLA is readily synthesized from it in the body. Thus GLA supplementation is unnecessary in health. However, in disorders which have an autoimmune component - as may be the case with MS - there is some evidence that the ability to synthesize GLA is impaired. GLA may defend against endotoxin damage. This has been shown in cell-culture [Crutchley DJ, Hydroxyeicosatetraenoic acids and other unsaturated fatty acids inhibit endotoxin-induced thromboplastin activity in human monocytes. Biochem Biophys Res Commun. 1985 Oct 15;132(1):67-73.] and in animal studies. [Karlstad MD et al., Effect of intravenous lipid emulsions enriched with g-linolenic acid on plasma n-6 fatty acids and prostaglandin biosynthesis after burn and endotoxin injury in rats. Crit Care Med. 1993 Nov;21(11):1740-9.]
GLA has been found to increase bone density in the elderly. [Kruger MC et al., Calcium, g-linolenic acid and eicosapentaenoic acid supplementation in senile osteoporosis. Aging (Milano) 1998 Oct;10(5):385-94.] This may be important, as osteoporosis is often problematic in MS, where falls can be disastrous.

GLA has a beneficial effect in the treatment of peripheral neuropathy; [Keen H et al., Treatment of diabetic neuropathy with g-linolenic acid. The g-Linolenic Acid Multicenter Trial Group. Diabetes Care. 1993 Jan;16(1):8-15.] This may be of relevance; peripheral neuropathy is seen in severe chronic infection with Chlamydia pneumoniae and may well be caused by endotoxin release. Experimentally, endotoxin has been shown to cause peripheral neuropathy in an animal model. [Brown RF et al., Bacterial lipopolysaccharide induces a conduction block in the sciatic nerves of rats. Lab Anim Sci. 1999 Feb;49(1):62-9.]

N-acetyl cysteine ~ Selenium

Reduced glutathione (GSH) neutralizes peroxides in the presence of a peroxidase which has 4 atoms of selenium (Se) bound as seleno-cysteine moieties. During this process GSH is oxidized and is then regenerated by a reductase. Glutathione reductase is increased in the CSF of patients with MS. [Calabrese V et al., Changes in cerebrospinal fluid levels of malondialdehyde and glutathione reductase activity in multiple sclerosis. Int J Clin Pharmacol Res. 1994; 14(4): 119-23.] By contrast, low levels of glutathione peroxidase were found in MS patients. [Mai J et al., High dose antioxidant supplementation to MS patients. Effects on glutathione peroxidase, clinical safety, and absorption of selenium. Biol Trace Elem Res. 1990 Feb;24(2):109-17.] Taken together, these data suggest a disordered glutathione metabolism in MS, which accords with the evidence that oxidative stress is a part of this disease. Inherited glutathione synthetase deficiency has been described; it is accompanied by progressive peripheral and central neurological disorders. [Meister A, Larsson A. GSH synthetase deficiency and other disorders of the g-glutamyl cycle. In: Scriver CR, et al., eds. The Metabolic and Molecular Bases of Inherited Disease (Volume 1). New York: McGraw-Hill; 1995;1461-1495 (Chapter 43).]

GSH is a tripeptide composed of glutamate, cysteine and glycine. It is thought not to be absorbed intact from the gut and must be made in the body. Glutamate and glycine are well represented in the diet; cysteine less so. The concentration of this amino acid is thus the limiting factor in the synthesis of glutathione. The best form of supplementation is N-acetyl cysteine (NAC) which is safer than cysteine.

Supplementation of diet with NAC in MS patients elevates levels of GSH peroxydase. [Mai J et al., High dose antioxidant supplementation to MS patients. Effects on glutathione peroxidase, clinical safety, and absorption of selenium. Biol Trace Elem Res. 1990 Feb;24(2):109-17.] Selenium is required for the synthesis of GSH peroxydase (see above.) Selenium levels are low in patients with MS. Mai and colleagues (above) found that supplementation with selenium normalized the low levels of this element.

N-acetyl cysteine and selenium would seem to be useful supplements for restoring GSH stores; this is particularly important as GSH plays a part in the regeneration of other antioxidants.

Acetyl L-carnitine

Carnitine and acetyl L-carnitine (ALC) facilitate the transport of fatty acids across the mitochondrial membrane. The acetyl group of ALC is used in the biosynthesis of acetyl-CoA, a key intermediary in the generation of cellular energy. Depletion of ALC increases mitochondrial stress. Supplementation with ALC reduced fatigue in Chronic Fatigue Syndrome [Vermeulen RC, Scholte HR. Exploratory open label, randomized study of acetyl- and propionylcarnitine in chronic fatigue syndrome. Psychosom Med. 2004 Mar-Apr;66(2):276-82.] It also alleviated fatigue in MS. [Tomassini V et al., Comparison of the effects of acetyl L-carnitine and amantadine for the treatment of fatigue in multiple sclerosis: results of a pilot, randomised, double-blind, crossover trial. J Neurol Sci. 2004 Mar 15;218(1-2):103-8.]

Peroxynitrite is a strong oxidant capable of damaging target tissues, particularly the brain, which is known to be endowed with limited antioxidant buffering capacity. Inducible nitric oxide synthase is upregulated in the CNS in patients with MS. [Calabrese V et al., Disruption of thiol homeostasis and nitrosative stress in the cerebrospinal fluid of patients with active multiple sclerosis: evidence for a protective role of ALC. Neurochem Res. 2003 Sep;28(9):1321-8.] These authors comment: 'Western blot analysis showed in MS patients increased nitrosative stress associated with a significant decrease of reduced glutathione (GSH). Increased levels of oxidized glutathione (GSSG) and nitrosothiols were also observed. Interestingly, treatment of MS patients with ALC resulted in decreased CSF levels of NO reactive metabolites and protein nitration, as well as increased content of GSH and GSH/GSSG ratio. Our data sustain the hypothesis that nitrosative stress is a major consequence of NO produced in MS-affected CNS and implicate a possible important role for acetylcarnitine in protecting brain against nitrosative stress, which may underlie the pathogenesis of MS.'

ALC has many prophylactic properties. It was found to protect against acoustic damage to the inner ear in an animal model [Kopke R et al., Prevention of impulse noise-induced hearing loss with antioxidants. Acta Otolaryngol. 2005 Mar;125(3):235-43.]

Reviewing the literature, Ames and Liu conclude that trials of ALC in the treatment of mild cognitive impairment and mild Alzheimer's disease showed significant efficacy vs. placebo. [Ames BN, Liu J. Delaying the mitochondrial decay of aging with acetylcarnitine. Ann N Y Acad Sci. 2004 Nov;1033:108-16. Review.]

ALC treatment was found to be efficacious in alleviating symptoms, particularly pain, and improved nerve fiber regeneration and vibration perception in patients with established diabetic neuropathy. [Sima AA et al., Acetyl-L-carnitine improves pain, nerve regeneration, and vibratory perception in patients with chronic diabetic neuropathy: an analysis of two randomized placebo-controlled trials. Diabetes Care. 2005 Jan;28(1):89-94.]

In a cell culture study ALC was found to protect against damage caused by beta-amyloid (Abeta), a neurotoxic peptide which accumulates in the brain in Alzheimer's disease. [Dhitavat S, Ortiz D, Shea TB, Rivera ER. ALC protects against amyloid-beta neurotoxicity: roles of oxidative buffering and ATP levels. Neurochem Res. 2002 Jun;27(6):501-5.] These authors found that ALC attenuated oxidative stress and cell death induced by beta-amyloid neurotoxicity. They comment: 'Abeta depleted ATP levels, suggesting Abeta may induce neurotoxicity in part by compromising neuronal energy. ALC prevented ATP depletion; therefore, ALC may mediate its protective effect by buffering oxidative stress and maintaining ATP levels.' This is particularly interesting when considering chronic Chlamydia pneumoniae infection; the mechanism of accentuation of oxidative damage by ATP starvation may be similar. Electron microscopic studies have shown that replicating chlamydiae are always found in close proximity to mitochondria; they are obligate energy parasites, their metabolic function being a reversal of that of mitochondria. [reviewed by Stratton CW, The pathogenesis of systemic chlamydial infections: theoretical considerations of host-cell energy depletion and its metabolic consequences. Antimicrobics and infectious diseases newsletter. 1997; 16 (5) 33-38.]

Oxidative damage may be an important factor in neurone-loss associated with ageing. In an rat model Liu and colleagues demonstrated that oxidative damage to nucleic acids (8-hydroxyguanosine and 8-hydroxy-2'-deoxyguanosine) increased with age in the hippocampus, a region of the brain concerned with 'encoding' memory from the immediate circumstance. Oxidative damage to nucleic acids occurred predominantly in RNA. Dietary administration of ALC and / or a-lipoic acid significantly reduced the extent of oxidized RNA, the combination being the most effective. [Liu J et al., Memory loss in old rats is associated with brain mitochondrial decay and RNA/DNA oxidation: partial reversal by feeding acetyl-L-carnitine and/or R-a -lipoic acid. Proc Natl Acad Sci U S A. 2002 Feb 19;99(4):2356-61. Erratum in: Proc Natl Acad Sci U S A 2002 May 14;99(10):7184-5.]

Alpha-Lipoic acid

Alpha lipoic acid (ALA) plays an important role in mitochondrial energy production. It is also a powerful antioxidant. In health, sufficient can be synthesized in the body. However, in conditions of chronic oxidative stress it may become depleted; in depletion its role as an antioxidant is the first to be impaired. Strong antioxidant properties are shown by its reduced form, dihydrolipoic acid (DHLA). [reviewed by Biewenga GP et al., The pharmacology of the antioxidant lipoic acid. Gen Pharmacol. 1997 Sep;29(3):315-31]

ALA scavenges hydroxyl radicals, hypochlorous acid, peroxynitrite, and singlet oxygen. DHLA also scavenges superoxide and peroxyl radicals and can regenerate thioredoxin, vitamin C, and glutathione, which in turn can recycle vitamin E. [reviewed by Packer L et al., Molecular aspects of lipoic acid in the prevention of diabetes complications. Nutrition. 2001 Oct;17(10):888-95.]

ALA also has the ability to chelate to inorganic mercury and to increase the biliary excretion of this metal in animal experiments. [Gregus Z et al., Effect of lipoic acid on biliary excretion of glutathione and metals. Toxicol Appl Pharmacol. 1992 May;114(1):88-96.] ALA may also ameliorate oxidative damage caused by the toxic metal cadmium. [Bludovska M et al., The influence of a-lipoic acid on the toxicity of cadmium. Gen Physiol Biophys. 1999 Oct;18 Spec No:28-32] Cadmium and mercury are intensely toxic in the CNS.

Coenzyme Q10 (Ubiquinone)

Coenzyme Q10 (CoQ10, ubiquinone) is a lipid-soluble molecule active in the hydrophobic core of the phospholipid bilayer of the inner membrane of mitochondria where it effects electron transfer within the electron transport chain.

CoQ10 also serves as an important antioxidant, particularly within the mitochondrion.

CoQ10 is adequately synthesized in children and adolescents; however, the ability of the body to synthesize CoC10 begins to diminish surprisingly early in adult life. [Kalen A et al., Age-related changes in the lipid compositions of rat and human tissues. Lipids. 1989 Jul;24(7):579-84.] By mid-life most people are dependent on dietary sources.

Lipid peroxidation, caused by free radical damage, diminishes CoC10 levels in cells [Forsmark-Andree P et al., Lipid peroxidation and changes in the ubiquinone content and the respiratory chain enzymes of submitochondrial particles. Free Radic Biol Med. 1997;22(3):391-400.] When CoC10 levels become low, a vicious circle of lipid peroxidation and CoQ10 depletion begins, resulting in mitochondrial damage. Aejmelaeus and colleagues comment: 'The decline is most significant in males under 50 years; in older age groups the values remain stable at a low level. Q10 supplementation doubles the number of ubiquinol-10-containing low-density lipoprotein (LDL) molecules and may therefore have an inhibitory effect on LDL oxidation.' [Aejmelaeus R et al., Ubiquinol-10 and total peroxyl radical trapping capacity of LDL lipoproteins during aging: the effects of Q-10 supplementation. Molecular Aspects of Medicine 18(Suppl.) (1997), s113-s120.]

CoQ10 protected against toxic damage to neurones in animal studies. [Beal MF et al., Coenzyme Q10 and nicotinamide block striatal lesions produced by the mitochondrial toxin malonate. Ann Neurol. 1994 Dec;36(6):882-8] It also protected against neurological damage caused by endotoxins. [Chuang YC et al., Neuroprotective effects of coenzyme Q10 at rostral ventrolateral medulla against fatality during experimental endotoxemia in the rat. Shock. 2003 May;19(5):427-32.]

A combination of antioxidants (acetyl L-carnitine, CoQ10 and n-3 oils) was found to improve and stabilize vision in age-related macular degeneration (AMD). [Feher J et al., Improvement of visual functions and fundus alterations in early age-related macular degeneration treated with a combination of acetyl L-carnitine, n-3 fatty acids, and coenzyme Q10. Ophthalmologica. 2005 May-Jun;219(3):154-66.] AMD is a condition with a multifactorial aetiology, one factor being chronic infection with Chlamydia pneumoniae [Ishida O et al., Is Chlamydia pneumoniae infection a risk factor for age related macular degeneration? Br J Ophthalmol. 2003 May;87(5):523-4; Kalayoglu MV et al., Serological association between Chlamydia pneumoniae infection and age-related macular degeneration. Arch Ophthalmol. 2003 Apr;121(4):478-82; Robman L et al., Exposure to Chlamydia pneumoniae Infection and Progression of Age-related Macular Degeneration. Am J Epidem 2005 161(11):1013-1019.] AMD is a disorder characterized by mitochondrial depletion and damage. [Feher J et al., Mitochondrial alterations of retinal pigment epithelium in age-related macular degeneration.Neurobiol Aging. 2005 Jun 22.] AMD may be considered a paradigm of chronic progressive infections with Chlamydia pneumoniae and improvement following antioxidant treatment is significant.

Melatonin

Melatonin (MEL), an indole, was originally described as a hormone biosynthesized from L-tryptophan within the pineal gland in the brain; it was found to regulate sleep patterns. Since its discovery, this remarkable molecule has been found have numerous and diverse actions in the cell. MEL is a potent antioxidant, protecting mitochondria from oxidative stress [reviewed by Leon J, Acuna-Castroviejo D, Sainz RM, Mayo JC, Tan DX, Reiter RJ. melatonin and mitochondrial function. Life Sci. 2004 Jul 2;75(7):765-90.] MEL also acts directly on the electron transport chain, increasing ATP synthesis while preventing the oxidative damage associated with such an increase. [Acuna-Castroviejo D, Escames G, Leon J, Carazo A, Khaldy H. Mitochondrial regulation by melatonin and its metabolites. Adv Exp Med Biol. 2003;527:549-57.] These authors also found that MEL restored levels of the important antioxidant glutathione.

MEL is a readily diffusible mobile molecule and is able to pass into any tissue, cell or cell compartment with ease. [reviewed by Hardeland R, Pandi-Perumal SR. melatonin, a potent agent in antioxidative defense: Actions as a natural food constituent, gastrointestinal factor, drug and prodrug. Nutr Metab (Lond). 2005 Sep 10;2(1):22.] These authors observe that, unusually for a hormone, MEL is a normal dietary constituent, and is found in yeasts and plants; walnuts are a particularly rich source. Dietary MEL can markedly influence blood-levels. [Reiter RJ, Manchester LC, Tan DX.Melatonin in walnuts: Influence on levels of melatonin and total antioxidant capacity of blood. Nutrition. 2005; 21(9): 920-4.] The fact that MEL is a normal dietary constituent removes some of the hesitation which one may have in using it for supplementation.

MEL protects against endotoxin-induced lipid peroxidation. [Sewerynek E, Melchiorri D, Chen L, Reiter RJ. Melatonin reduces both basal and bacterial lipopolysaccharide-induced lipid peroxidation in vitro. Free Radic Biol Med. 1995 Dec;19(6):903-9.] This is very important in the CNS, where key lipids are relatively unprotected by other antioxidants.

Reiter and colleagues, in a comprehensive review, observe: 'Melatonin reduces oxidative stress by several means. Thus, the indole [melatonin] is an effective scavenger of both the highly toxic hydroxyl radical, produced by the 3 electron reduction of oxygen, and the peroxyl radical, which is generated during the oxidation of unsaturated lipids and which is sufficiently toxic to propagate lipid peroxidation. Additionally, melatonin may stimulate some important antioxidative enzymes, i.e., superoxide dismutase, glutathione peroxidase and glutathione reductase. In in vivo tests, melatonin in pharmacological doses has been found effective in reducing macromolecular damage that is a consequence of a variety of toxic agents, xenobiotics and experimental paradigms which induce free radical generation. In these studies, melatonin was found to significantly inhibit oxidative damage that is a consequence of paraquat toxicity, potassium cyanide administration, lipopolysaccharide treatment, kainic acid injection, carcinogen administration, carbon tetrachloride poisoning, etc., as well as reducing the oxidation of macromolecules that occurs during strenuous exercise or ischemia-reperfusion. In experimental models which are used to study neurodegenerative changes associated with Alzheimer's and Parkinson disease, melatonin was found to be effective in reducing neuronal damage. Its lack of toxicity and the ease with which melatonin crosses morphophysiological barriers and enters subcellular compartments are essential features of this antioxidant.' [Reiter RJ, Carneiro RC, Oh CS. Melatonin in relation to cellular antioxidative defense mechanisms. Horm Metab Res. 1997 Aug;29(8):363-72.]

MEL was found to inhibit the production of endotoxin-induced Tumour Necrosis Factor alpha. [Sacco S et al., Mechanism of the inhibitory effect of melatonin on tumor necrosis factor production in vivo and in vitro. Eur J Pharmacol. 1998 Feb 19;343(2-3):249-55.] and in an animal model was found to exert immunoregulatory effects via T-helper 2 (Th2) cell products. Th2 products may modulate the secretion and/or action of inflammatory cytokines, which play an important role in the development of septic shock associated with endotoxemia. [Maestroni GJ. melatonin as a therapeutic agent in experimental endotoxic shock. J Pineal Res. 1996 Mar;20(2):84-9.]

Post-mortem studies showed diminished levels of MEL in the ventricular CSF of those who had died with Alzheimer's disease (AD) compared with age-matched controls. However, CSF MEL levels were uniformly low in those who had died with advanced dementia, irrespective of their age. [Liu RY et al., Decreased melatonin levels in postmortem cerebrospinal fluid in relation to aging, Alzheimer's disease, and apolipoprotein E-epsilon4/4 genotype. J Clin Endocrinol Metab. 1999 Jan;84(1):323-7.] MEL depletion was found to be a very early event in the development of AD. [Zhou JN et al., Early neuropathological Alzheimer's changes in aged individuals are accompanied by decreased cerebrospinal fluid melatonin levels. J Pineal Res. 2003; 35(2): 125-30.] A loss of the diurnal rhythm of MEL levels may precede the first clinical signs of the disease. [Wu YH et al., Molecular changes underlying reduced pineal melatonin levels in Alzheimer disease: alterations in preclinical and clinical stages. J Clin Endocrinol Metab. 2003 Dec;88 (12): 5898-906.] MEL ameliorated evening agitation and improved cognitive and non-cognitive functions in patients with AD in small controlled trials. [Brusco LI et al., Melatonin treatment stabilizes chronobiologic and cognitive symptoms in Alzheimer's disease. Neuro Endocrinol Lett. 2000; 21(1): 39-42; Cardinali DP et al., The use of melatonin in Alzheimer's disease. Neuro Endocrinol Lett. 2002;23 Suppl 1:20-3; Asayama K, et al., Double blind study of melatonin effects on the sleep-wake rhythm, cognitive and non-cognitive functions in Alzheimer type dementia. J Nippon Med Sch. 2003; 70(4): 334-41.] Interestingly, it took several weeks for benefits to appear, suggesting an action other than sedation, which is immediate. Another, larger, multicentre study detected no benefits from melatonin in sleep disorders in Alzheimer's dementia. [Singer C, et al., Alzheimer's Disease Cooperative Study. A multicenter, placebo - controlled trial of melatonin for sleep disturbance in Alzheimer's disease. Sleep. 2003; 26(7): 893-901.] However, actigraphy, used in most studies of melatonin in sleeping disorders in Alzheimer's disease, does not give a direct measurement of sleep. Studies using polysomnography, which does measure sleep directly, but which is intrusive, would seem to be rare.

Sleep disorders are common in MS, with a flattening of the normal circadian sleeping/waking rhythm, leading to wakefulness at night and a tendency to somnolence during the day. [Fleming WE, Pollak CP. Sleep disorders in multiple sclerosis. Semin Neurol. 2005 Mar;25(1):64-8. Review.] This may due to decreased nocturnal biosynthesis of MEL. [Wu YH et al., Molecular changes underlying reduced pineal melatonin levels in Alzheimer disease: alterations in preclinical and clinical stages. J Clin Endocrinol Metab. 2003 Dec;88 (12): 5898-906.] Decreased MEL biosynthesis is associated with pineal calcification. [Kunz D et al., A new concept for melatonin deficit: on pineal calcification and melatonin excretion. Neuropsychopharmacology. 1999 Dec; 21(6):765-72.] Pineal calcification is common in MS. [Sandyk R, Awerbuch GI. The pineal gland in multiple sclerosis. Int J Neurosci. 1991 Nov;61(1-2): 61-7.] Indeed, nocturnal MEL levels were found to be lower than daytime levels in 11 of 25 patients with MS. [Sandyk R, Awerbuch GI. Nocturnal plasma melatonin and alpha-melanocyte stimulating hormone levels during exacerbation of multiple sclerosis. Int J Neurosci. 1992 Nov-Dec;67(1-4):173-86. Review] MEL is a major antioxidant in the brain, and chronic depletion would be expected to allow widespread oxidative damage in the CNS. [Reiter RJ et al., Reactive oxygen intermediates, molecular damage, and aging. Relation to melatonin. Ann N Y Acad Sci. 1998 Nov 20;854:410-24. Review.]

MEL may also correct disordered steroid metabolism. The hypothalamic - pituitary - adrenal (HPA) axis (an ancient pathway which releases cortisol in response to acute and chronic stress) is known to be disturbed in MS; activation of corticotropin releasing hormone (CRH) neurons and increased cortisol has been found in the cerebrospinal fluid (CSF) of MS patients, indicating activation of the HPA axis in this disease. [Huitinga I et al., The hypothalamo - pituitary - adrenal axis in multiple sclerosis. Ann N Y Acad Sci. 2003;992:118-28. Review] The basal level of cortisol is significantly increased in the CSF of MS patients. [Erkut ZA et al., Cortisol is increased in postmortem cerebrospinal fluid of multiple sclerosis patients: relationship with cytokines and sepsis. Mult Scler. 2002; 8(3): 229-36.] Chronically elevated cortisol levels due to activation of CRH neurons can be damaging, particularly to the hippocampus, the area of the brain where memory is processed. [Lupien SJ et al., The Douglas Hospital Longitudinal Study of Normal and Pathological Aging: summary of findings. J Psychiatry Neurosci. 2005;30 (5): 328-34.] In an animal study this atrophy was found to be reversible. [Magarinos AM, Deslandes A, McEwen BS. Effects of antidepressants and benzodiazepine treatments on the dendritic structure of CA3 pyramidal neurons after chronic stress. Eur J Pharmacol. 1999; 371(2-3): 113-22.] However, in another animal study, dietary MEL reduced hypothalamic CRH. [Konakchieva R et al., Chronic melatonin treatment and the hypothalamo - pituitary - adrenal axis in the rat: attenuation of the secretory response to stress and effects on hypothalamic neuropeptide content and release. Biol Cell. 1997; 89(9):587-96.] These authors comment 'MEL attenuates the adrenocortical response to stress and influences the biosynthesis, release and glucocorticoid responsiveness of hypothalamic ACTH secretagogues.' Depression is another disorder which can be set in motion by dysregulation of the HPA axis (perhaps acting in concert with pro-inflammatory cytokines.) [reviewed by Schiepers OJ, Wichers MC, Maes M. Cytokines and major depression. Prog Neuropsychopharmacol Biol Psychiatry. 2005; 29(2): 201-17.]

Melatonin would thus seem a valuable supplement in disease forms characterized by oxidative stress.

Concluding remarks

Easing mitochondrial stress by dietary supplementation in chronic infections with intracellular pathogens such as Chlamydia pneumoniae would seem a very reasonable and low-risk therapeutic strategy. Chronic release of endotoxins in an unresolved infection results in a strong pro-inflammatory immune reaction; this gives rise to a barrage of free radicals which cause profound oxidative damage and setting up vicious circles of antioxidant depletion and further free radical production. It is likely that release of endotoxins continues long after the organisms have been killed by antibiotics as host cells are broken down in programmes of cell replacement.

The risks of supplementation are low provided pure agents are used.

When the infection is resolved, and healing complete, supplementation may be reduced and an appropriately balanced diet continued.

Caveat

This reviewer is a medical practitioner and a microbiologist with no especial knowledge of cell-biology, nutrition, or biochemistry; this page gives only stop-gap information. Chronic infections quickly become multifactorial, and the demands of effective treatment transcend traditional medical disciplines.