A Preliminary Trial of Beta-Carotene in Subjects Infected with the Human Immunodeficiency Virus

Carotenoids: Therapeutic Strategy in the Battle against Viral Emerging Diseases, COVID-19: An Overview

Carotenoids, a group of phytochemicals, are naturally found in the Plant kingdom, particularly in fruits, vegetables, and algae. There are more than 600 types of carotenoids, some of which are thought to prevent disease, mainly through their antioxidant properties. Carotenoids exhibit several biological and pharmaceutical benefits, such as anti-inflammatory, anti-cancer, and immunity booster properties, particularly as some carotenoids can be converted into vitamin A in the body. However, humans cannot synthesize carotenoids and need to obtain them from their diets or via supplementation. The emerging zoonotic virus severe acute respiratory syndrome coronavirus 2, which causes coronavirus disease 2019 (COVID-19), originated in bats, and was transmitted to humans. COVID-19 continues to cause devastating international health problems worldwide. Therefore, natural preventive therapeutic strategies from bioactive compounds, such as carotenoids, should be appraised for strengthening physiological functions against emerging viruses. This review summarizes the most important carotenoids for human health and enhancing immunity, and their potential role in COVID-19 and its related symptoms. In conclusion, promising roles of carotenoids as treatments against emerging disease and related symptoms are highlighted, most of which have been heavily premeditated in studies conducted on several viral infections, including COVID-19. Further in vitro and in vivo research is required before carotenoids can be considered as potent drugs against such emerging diseases.

Non-Provitamin A and Provitamin A Carotenoids as Immunomodulators: Recommended Dietary Allowance, Therapeutic Index, or Personalized Nutrition?

Vegetables and fruits contain non-provitamin A (lycopene, lutein, and zeaxanthin) and provitamin A (β-carotene, β-cryptoxanthin, and α-carotene) carotenoids. Within these compounds, β-carotene has been extensively studied for its health benefits, but its supplementation at doses higher than recommended intakes induces adverse effects. β-Carotene is converted to retinoic acid (RA), a well-known immunomodulatory molecule. Human interventions suggest that β-carotene and lycopene at pharmacological doses affect immune functions after a depletion period of low carotenoid diet. However, these effects appear unrelated to carotenoids and retinol levels in plasma. Local production of RA in the gut-associated lymphoid tissue, as well as the dependency of RA-induced effects on local inflammation, suggests that personalized nutrition/supplementation should be considered in the future. On the other hand, the differential effect of RA and lycopene on transforming growth factor-beta suggests that lycopene supplementation could improve immune functions without increasing risk for cancers. However, such preclinical evidence must be confirmed in human interventions before any recommendations can be made.

The Relationship between Vitamin A Deficiency and Hiv Infection: Review of Scientific Studies

Review of the literature shows that in adults there are variations in the association of hyporetinemia with disease progression as well as variations in the response to supplementation. Populations that are likely to be deficient in vitamin A show the biggest responses. Additional vitamin A supplementation may not be necessary, and may even be harmful, in adults who already have a good dietary intake of vitamin A and who take many other vitamin supplements. Vitamin A supplementation does not appear to have any impact on mother-to-child transmission of HIV; nevertheless, vitamin A supplementation of pregnant women in the third trimester may be useful to reduce the incidence of low-birthweight and premature infants. the impact of vitamin A on mother-to-child transmission of HIV in preterm infants is awaiting further investigation. Vitamin A supplementation of HIV-infected children appears to be beneficial to reduce the incidence and severity of diarrhea in particular. Randomized, placebo-controlled trials in pregnant women and adults have shown that the association between vitamin A and HIV is probably an association of reverse causality.

Astaxanthin, a Carotenoid, Stimulates Immune Responses by Enhancing IFN-γ and IL-2 Secretion in Primary Cultured Lymphocytes in Vitro and ex Vivo

Astaxanthin, a potent antioxidant carotenoid, plays a major role in modulating the immune response. In this study, we examined the immunomodulatory effects of astaxanthin on cytokine production in primary cultured lymphocytes both in vitro and ex vivo. Direct administration of astaxanthin (70-300 nM) did not produce cytotoxicity in lipopolysaccharide (LPS, 100 µg/ mL)- or concanavalin A (Con A, 10 µg/ mL)-activated lymphocytes, whereas astaxanthin alone at 300 nM induced proliferation of splenic lymphocytes (p < 0.05) in vitro. Although astaxanthin, alone or with Con A, had no apparent effect on interferon (INF-γ) and interleukin (IL-2) production in primary cultured lymphocytes, it enhanced LPS-induced INF-γ production. In an ex vivo experiment, oral administration of astaxanthin (0.28, 1.4 and 7 mg/kg/day) for 14 days did not cause alterations in the body or spleen weights of mice and also was not toxic to lymphocyte cells derived from the mice. Moreover, treatment with astaxanthin significantly increased LPS-induced lymphocyte proliferation ex vivo but not Con A-stimulated lymphocyte proliferation ex vivo. Enzyme linked immunosorbent assay (ELISA) analysis revealed that administration of astaxanthin significantly enhanced INF-γ production in response to both LPS and Con A stimulation, whereas IL-2 production increased only in response to Con A stimulation. Also, astaxanthin treatment alone significantly increased IL-2 production in lymphocytes derived from mice, but did not significantly change production of INF-γ. These findings suggest that astaxanthin modulates lymphocytic immune responses in vitro, and that it partly exerts its ex vivo immunomodulatory effects by increasing INF-γ and IL-2 production without inducing cytotoxicity.

Ameliorating effect of β-carotene on antioxidant response and hematological parameters of mercuric chloride toxicity in Nile tilapia (Oreochromis niloticus)

The impact of different levels of dietary β-carotene to alleviate the effect of mercuric chloride toxicity in Nile tilapia was assessed. Semi-purified diets containing 0, 40, and 100 mg β-carotene kg(-1) dry diet were fed for 21 days, which were subjected to sublethal concentration of mercuric chloride (0.05 ppm). Hematological and biochemical parameters, lipid profile, and antioxidant response were examined. All hematological parameters of tilapia fish starting from second week of toxicity were significantly decreased. A significant increasing trend in liver enzymes (ALT and AST) were observed parallel to the time of toxicity and peroxide radicals (MDA) appearing significantly increased in toxicated group without carotene supplement, although carotene supplementation return all parameters within the control levels. Mercury accumulated significantly in fish liver and white muscles in toxicated group while it showed a significant reduction in dietary β-carotene-treated group. Overall, it can be used as immunostimulant and alleviate the suppression effect resulted from immune depressive stressful condition in farmed Nile tilapia.

Carotenoids modulate cytokine production in Peyer's patch cells ex vivo

This study investigated the effects of carotenoid and capsaicin constituents of Capsicum on intestinal immune responses in mice. Peyer's patch (PP) cells were isolated from mice orally administered with capsaicin, or one of three carotenoids (beta-carotene, beta-cryptoxanthin, or lycopene), at 5 mg/kg/day for 7 consecutive days. Collagenase-separated PP cells were then cultured in the presence or absence of concanavalin A (Con A). PP cells from mice treated with capsaicin, beta-carotene, or beta-cryptoxanthin all showed significantly enhanced interleukin (IL)-2 and interferon (IFN)-gamma production when costimulated with 5 microg/mL Con A, with capsaicin having the greatest effect (approximately two times greater than in normal mice). No increase in the production of IL-2 or IL-4 was observed when PP cells from mice were cultured without Con A. We further tested the combined efficacy of carotenoids and capsaicin on intestinal T-cell cytokine production. Oral administration of capsaicin with beta-carotene, both at 5 mg/kg/day for 7 days, increased IFN-gamma and IL-2 production in cultured PP cells costimulated with Con A. In contrast, oral administration of beta-cryptoxanthin counteracted the stimulatory effect of capsaicin treatment on T-helper cytokine production. Flow cytometric analysis revealed that the population of IFN-gamma(+) and IL-4(+) cells in PPs from mice administered capsaicin and/or carotenoids did not change, which suggested that the effects of carotenoids and capsaicin on cytokine production were not due to changes in the lymphoid population in PPs. These results indicate that carotenoids and capsaicin, which are common components of foods such as Capsicum, mutually modulate T-cell immune responses to exogenous or endogenous inducers such as antigens in PPs, without changing the lymphoid population. Carotenoids modulate the potentiality of cytokine production in T cells or indirectly activate T cells but have no triggering effect such as Con A.

Update: effects of antioxidant and non-antioxidant vitamin supplementation on immune function

The purpose of this manuscript is to review the impact of supplementation with vitamins E and C, carotenoids, and the B vitamins on parameters of innate and adaptive immune function as reported from clinical trials in humans. There is evidence to support causal effects of supplementation with vitamins E and C and the carotenoids singly and in combination on selected aspects of immunity, including the functional capacity of innate immune cells, lymphocyte proliferation, and the delayed-type hypersensitivity (DTH) response. Controlled intervention trials of B vitamin-containing multivitamin supplements suggest beneficial effects on immune parameters and clinical outcomes in HIV-positive individuals.

A community randomized controlled clinical trial of mixed carotenoids and micronutrient supplementation of patients with acquired immunodeficiency syndrome

OBJECTIVE

This clinical trial aims to evaluate if natural mixed carotenoids supplementation can improve the health and survival of acquired immunodeficiency syndrome (AIDS) patients.

DESIGN

A placebo-controlled, prospective, randomized, double-blind, multicenter clinical trial.

SETTING

Community, tertiary care human immunodeficiency virus (HIV) clinics of the Canadian HIV Trials Network (CTN).

PARTICIPANTS

Three hundred and thirty-one adults with advanced AIDS on conventional management were recruited during routine clinic visits.

INTERVENTIONS

All participants, including 166 controls, received daily oral specially formulated multivitamins including vitamin A and trace elements; 165 treatment group participants received additional daily oral natural mixed carotenoids, equivalent to 120,000 IU (72 mg) of beta-carotene daily. Follow-up was quarterly at routine clinic visits.

RESULTS

Mean (s.d.) follow-up was for 13 (6) months. Thirty-six participants died by 18 months. Serum carotene concentration <1.0 micromol/l was present in 16% participants at baseline. Despite variation in carotene content of the treatment medication, serum carotene concentrations increased significantly to twice the baseline levels to 18 months follow-up in participants who received carotenoids treatment compared with controls (P < 0.0001). Although not statistically significant, mortality was increased in participants who did not receive carotenoids treatment compared with those who did (HR time to death 1.76, 95% CI 0.89, 3.47, P = 0.11). In multivariate analysis, survival was significantly and independently improved in those with higher baseline serum carotene concentrations (P = 0.04) or higher baseline CD4 T-lymphocyte counts (P = 0.005). Adjusted mortality was also significantly and independently increased in those who did not receive carotenoids treatment compared with those who did (HR time to death 3.15, 95% CI 1.10, 8.98, P = 0.03).

CONCLUSIONS

Low serum carotene concentration is common in AIDS patients and predicts death. Supplementation with micronutrients and natural mixed carotenoids may improve survival by correction of a micronutrient deficiency. Further studies are needed to corroborate findings and elucidate mechanism of action.

Oxidative stress in viral hepatitis and AIDS

Dominant types of viral hepatitis are presently A, B, and C with prophylactic immunization available only for A and B. Hepatitis B and C and human immunodeficiency virus (HIV) infection constitute a worldwide scourge and treatment is far from satisfactory. Each produces severe oxidative stress (OS) and secondary cellular damage of varying severity and, as in toxic hepatitis, progression and regression are dependent on redox balance between oxidation and antioxidation. Experimental and clinical studies suggest that xenobiotics and co-infections exert cumulative, detrimental effects on their pathogeneses and further deplete antioxidants. It is proposed therefore that in the clinical management of these infections and especially in their early stages, considerable benefit should accrue from antioxidant repletion at dosages substantially above recommended daily allowances (RDAs) in conjunction with a nutritious high protein diet. Because plasma zinc and selenium concentrations are very low, their replenishment by high dosages is urgent and mandatory particularly in advanced HIV infections bordering on acrodermatitis enteropathica. Also recommended is their long-term continuance at high normal levels.

A clinical review of micronutrients in HIV infection

This article reviews current literature on the role of micronutrients in human immunodeficiency virus (HIV) infection. Deficiencies of micronutrients are common in HIV-infected persons. They occur due to malabsorption, altered metabolism, gut infection, and altered gut barrier function. There is a compelling association of deficiencies of micronutrients in HIV-infection with immune deficiency, rapid disease progression, and mortality. Also, there is increased risk of vertical HIV transmission from mother to child with deficiency of vitamin A, and of neurological impairment with vitamin B12. The last five years have been exciting in micronutrient research, and there is promise that some micronutrients may be key factors in maintaining health in HIV immunodeficiency, and in reducing mortality. Selenium appears important in reducing virulence of HIV and slowing disease progression. Vitamin A supplementation in pregnant women with HIV may reduce maternal mortality and improve birth outcomes. Supplementation in children with HIV may accelerate growth. Carotenoid supplementation is being evaluated. Vitamin B12 may slow HIV immune deficiency disease progression, and reverse neurological compromise. Clinical benefit of supplementation with some micronutrients may be measurable in the presence of pre-existing deficiency. Apart from improved general nutrition, the impact of micronutrient supplements on health and their optimal use in HIV infection is controversial because there are so few controlled clinical trials. Further research is needed to elucidate the role of micronutrient deficiencies on the course of HIV infection, and the preventive and therapeutic role of supplementation in its clinical management. Nevertheless, current knowledge supports the use of routine multivitamin and trace element supplementation as adjuvant to conventional antiretroviral drug treatment as a relatively low-cost intervention.

Carotenoid action on the immune response

Early studies demonstrating the ability of dietary carotenes to prevent infections have left open the possibility that the action of these carotenoids may be through their prior conversion to vitamin A. Subsequent studies to demonstrate the specific action of dietary carotenoids have used carotenoids without provitamin A activity such as lutein, canthaxanthin, lycopene and astaxanthin. In fact, these nonprovitamin A carotenoids were as active, and at times more active, than beta-carotene in enhancing cell-mediated and humoral immune response in animals and humans. Another approach to study the possible specific role of dietary carotenoids has used animals that are inefficient converters of carotenoids to vitamin A, for example the domestic cat. Results have similarly shown immuno-enhancement by nonprovitamin A carotenoids, based either on the relative activity or on the type of immune response affected compared to beta-carotene. Certain carotenoids, acting as antioxidants, can potentially reduce the toxic effects of reactive oxygen species (ROS). These ROS, and therefore carotenoids, have been implicated in the etiology of diseases such as cancer, cardiovascular and neurodegenerative diseases and aging. Recent studies on the role of carotenoids in gene regulation, apoptosis and angiogenesis have advanced our knowledge on the possible mechanism by which carotenoids regulate immune function and cancer.

Carotenoprotein complexes in entomostracan crustaceans (Streptocephalus dichotomus and Moina micrura)

The carotenoprotein complexes of a freshwater fairy shrimp (Streptocephalus dichotomus) and a daphnid (Moina micrura) were characterised and compared. Based on thin layer chromatography and mass spectral analysis, a variety of cartenoprotein complexes such as astaxanthin, canthaxanthin, antheraxanthin, lutein, beta-cryptoxanthin and violaxanthin were found. Both crustaceans had astaxanthin and canthaxanthin as predominant prosthetic groups. Amino acid analysis of the complexes further revealed high levels of asparagine, glutamine and glycine in both species. Our study highlights the presence of naturally available carotenoid species in both crustaceans and their possible inter-conversion in anostracans.

Low-dose supplementation with lycopene or beta-carotene does not enhance cell-mediated immunity in healthy free-living elderly humans

OBJECTIVE

To assess the effects of supplementation with the carotenoids, beta-carotene or lycopene, at levels achievable within a diet rich in fruit and vegetables, on immune function in a group of free-living healthy elderly.

DESIGN

A double-blind randomized placebo-controlled trial. T cell subsets and the expression of functionally associated cell surface molecules, quantified by flow cytometry, and lectin-stimulated lymphocyte proliferation, were compared before and following the treatment period.

SUBJECTS

Fifty-eight subjects aged over 65 y were recruited; 52 were included in the final analysis.

INTERVENTIONS

Participants received one placebo, one lycopene (13.3 mg) or one beta-carotene (8.2 mg) capsule daily for 12 weeks.

RESULTS

No significant differences were observed in any of the parameters examined following either lycopene or beta-carotene supplementation.

CONCLUSIONS

In well-nourished, free-living, healthy elderly individuals, supplementation with relatively low levels of beta-carotene or lycopene is not associated with either a beneficial or detrimental effects on several aspects of cell-mediated immunity.

Oxidative stress in HIV-1-infected injection drug users

Low serum antioxidant levels observed in many HIV-infected populations could be largely due to an increase in oxidative stress (defined as a disturbance in the equilibrium status of prooxidant/antioxidant systems of intact cells). In HIV infection, oxidative stress may be caused by both overproduction of reactive oxygen intermediates (ROIs) and a simultaneous deficiency of antioxidant defenses. Furthermore, injection drug use has been associated with increased levels of oxidative stress in animal models. Currently, there is widespread use of self-prescribed antioxidant supplementation among the HIV-infected population and a prevailing belief that high-dose supplementation is beneficial, or at the very least, not harmful. Data from our studies show that HIV-positive injection drug users (IDUs) who are on antiretroviral combination therapies including a protease inhibitor have significantly higher mean serum levels of several antioxidants, independent of dietary and supplemental intake, compared with both HIV-negative IDUs and HIV-positive IDUs not taking protease inhibitors. This suggests that oxidative stress may be reduced in patients taking protease inhibitors. Preliminary data suggest that the future of antioxidant supplementation therapy, if any, will be one in which different doses of supplements are recommended for HIV-infected patients on the various antiretroviral treatment regimens. More research is needed to determine the interactions among injection drug use, oxidative stress, antiretroviral therapy, and the use of antioxidant supplements in HIV infection. Until more is known, caution should be exercised when using or recommending high-dose antioxidant supplementation in HIV-infected individuals, particularly in those on protease inhibitors, since moderate levels of oxidative stress are involved in a number of useful physiologic processes.

Serum malondialdehyde: possible use for the clinical management of chronic hepatitis C patients

Serum lipid peroxidation products are increased in inflammatory liver disease and, as we previously reported, also in chronic hepatitis C. We have performed a specific assay of malondialdehyde, the reported most abundant product of lipid peroxidation, in serum of twenty four chronic hepatitis C patients, before, during, and after interferon treatment. Liver biopsies were performed in each patient before and after interferon treatment. The results show higher serum malondialdehyde values in chronic hepatitis C patients than healthy subjects (n = 68) before interferon treatment (p < .001). Mean value of serum malondialdehyde levels after interferon treatment was significantly lower than before it (p < .002). Associating the histopathological findings in each of the 48 biopsies performed, with serum malondialdehyde and alanine aminotransferase activity levels, of the sample obtained the same day of biopsy, a much better correspondence with the histopathological severity was observed for malondialdehyde concentration than for alanine aminotransferase activity. These levels decreased significantly after interferon treatment. However, when the patients were grouped in responding (group I; n = 9) and non-responding (group II; n = 15) to interferon treatment, according to the histopathological findings before and after interferon, the values of group I before interferon treatment were significantly higher than group II (p < .03). Thus, a potential predictive value could be ascribed to the serum malondialdehyde levels before interferon treatment in these patients. We propose the utility of the specific assay of malondialdehyde for the clinical management of chronic hepatitis C patients.

Effects of vitamin E and C supplementation on oxidative stress and viral load in HIV-infected subjects

OBJECTIVES

The HIV-infected population is known to be oxidatively stressed and deficient in antioxidant micronutrients. Since in vitro replication of HIV is increased with oxidative stress, this study assessed the effect of antioxidant vitamin supplementation on lipid peroxidation, a measure of oxidative stress, and viral load in humans.

DESIGN

A randomized placebo-controlled, double-blind study.

METHODS

Forty-nine HIV-positive patients were randomized to receive supplements of both DL-alpha-tocopherol acetate (800 IU daily) and vitamin C (1000 mg daily), or matched placebo, for 3 months. Plasma antioxidant micronutrient status, breath pentane output, plasma lipid peroxides, malondialdehyde and viral load were measured at baseline and at 3 months. New or recurrent infections for the 6-month period after study entry were also recorded.

RESULTS

The vitamin group (n = 26) had an increase in plasma concentrations of alpha-tocopherol (P < 0.0005) and vitamin C (P < 0.005) and a reduction in lipid peroxidation measured by breath pentane (P < 0.025), plasma lipid peroxides (P < 0.01) and malondialdehyde (P < 0.0005) when compared with controls (n = 23). There was also a trend towards a reduction in viral load (mean +/- SD changes over 3 months, -0.45 +/- 0.39 versus +0.50 +/- 0.40 log10 copies/ml; P = 0.1; 95% confidence interval, -0.21 to -2.14). The number of infections reported was nine in the vitamin group and seven in the placebo group.

CONCLUSION

Supplements of vitamin E and C reduce oxidative stress in HIV and produce a trend towards a reduction in viral load. This is worthy of larger clinical trials, especially in HIV-infected persons who cannot afford new combination therapies.

Nutrition and HIV infection in children

HIV infection has profound effects on a patient's nutritional status because it can modulate appetite, nutrient absorption and basal metabolic rate. In addition, HIV infection can lead to the depletion of a variety of vitamins and micronutrients including vitamins A, D, B2, B6, B12, L-carnitine, iron, zinc and selenium. This review article summarizes existing data regarding nutritional defects in HIV-infected patients and the results of clinical studies addressing the effects of nutritional supplementation in infected patients.

Vitamins and immunomodulation in AIDS

Acquired immune deficiency syndrome (AIDS) is a clinical disorder caused by a retrovirus infection and represents the end point in a progressive sequence of immunosuppressive changes. Vitamins can enhance disease resistance in animals and humans. As such they are important co-factors in optimal functioning of the immune systems. In this article, the immunological and nutritional modifications caused by AIDS are summarized. The effects of murine and human retrovirus infection on vitamin status are analyzed as co-factors in the development of severe immune dysfunction, AIDS. The properties of immunoenhancing antioxidative vitamins, vitamin A, B6, B12, C, E, and beta-carotene, which are frequently low in AIDS patients, are evaluated relative to the development of immunodeficiency during retrovirus infection. Vitamin A, E, and B12 deficiency accelerated the development of AIDS with low T cells, whereas their normalization retarded the development of immune dysfunction. The interactions between these vitamins and the immune system in human AIDS patients and animal models of AIDS are reviewed. Our purpose is to provide data on how retrovirus infection can cause nutritional deficiencies that accentuate immune damage and to evaluate the potential therapeutic role of vitamins in the treatment of immune dysfunctions in AIDS patients.

Nutrition and immunity with emphasis on infection and autoimmune disease

Nutrition and nutritional status can have profound effects on immune functions, resistance to infection and autoimmunity in man and other animals. Nutrients enhance or depress immune function depending on the nutrient and level of its intake. Protein-energy malnutrition and vitamin A deficiency are strongly associated with impaired immunity and infectious disease. The essential role vitamin A plays in infection and maintenance of mucosal surfaces has long been known. Recent evidence shows that T-cell subpopulations, cytokines and antibody subclasses are all affected by vitamin A. In animal studies supplementation with vitamin E protects against infection and is linked to stimulatory effects on the immune system. In man vitamin E and other anti-oxidants increase the number of CD4+ cells. Dietary lipids and zinc have a substantial impact on autoimmunity from protective to potentiation of immuno-pathological processes in animals. There is considerable potential to modify human autoimmune disease by manipulation of lipid nutrition. Deficiency of pyridoxine induces atrophy of lymphoid organs, marked reduction in lymphocyte numbers, impairs antibody responses and IL-2 production. Dietary copper is important in the prevention of infection in some animal species and T-cell function is defective under deficiency states due to an inability to produce IL-2. Selenium has been linked to viral infection, enhanced T-cell functions and TNF beta induced increase in natural killer cell activity. Understanding the molecular and cellular immunological mechanisms involved in nutrient-immune interactions will increase our applications for nutrition of the immune system in health and in disease

Fatty acids and plasma antioxidants in HIV-positive patients: correlation with nutritional and immunological status

OBJECTIVE

To investigate red blood cell (RBC) and plasma fatty acids (FA) in HIV-positive patients in relation to oxidative stress and nutritional or immunological status.

DESIGN AND METHODS

FA, plasma selenium, vitamins A and E were measured in 95 patients divided into four groups according to CD4 cells.

RESULTS

Poly- and di-unsaturated FA (PUFA, DUFA) decreased and saturated FA (SFA) increased in RBC in the patients below 400/mm3 and in plasma in the patients below 50/mm3. RBC SFA correlated to CD4 cells, PUFA to MDA. Unlike vitamin E, plasma vitamin A and selenium decreased in most groups. Plasma SFA and MUFA correlated negatively to selenium and PUFA and DUFA to vitamin E. No correlation was found between PUFA and nutritional markers.

CONCLUSION

FA seem to be modified during HIV infection by oxidative stress and disease evolution, but not by denutrition.

Effect of carotenoids on in vitro immunoglobulin production by human peripheral blood mononuclear cells: astaxanthin, a carotenoid without vitamin A activity, enhances in vitro immunoglobulin production in response to a T-dependent stimulant and antigen

The effect of carotenoids on in vitro immunoglobulin (Ig) production by peripheral blood mononuclear cells (PBMNC) was examined by employing blood samples from adult volunteers and full-term newborn babies (umbilical cord blood). Under carotenoid-supplemented culture conditions, cells were stimulated by polyclonal stimulants, neoantigens, and a recall antigen (Ag), and IgM, IgA, and IgG levels in the culture supernatant were measured. Beta-carotene and astaxanthin were used as representatives of carotenoids with and without vitamin A activity, respectively. Astaxanthin enhanced IgM production in response to T-dependent Ag (TD-Ag) and a T-dependent polyclonal stimulant. Astaxanthin also augmented IgG production in response to a recall Ag. IgA production without supplemental carotenoids was negligible for all stimuli. However, in carotenoid-supplemented cultures, IgA production was significantly higher in response to a T-dependent polyclonal stimulant than in unsupplemented cultures. IgM and IgA production was augmented at 10(-8) mol/l astaxanthin, whereas astaxanthin enhanced IgG production in response to a recall Ag at 10(-10)-10(-9) mol/l. Similar enhancing actions of astaxanthin on IgM production were observed in cord blood mononuclear cells (CBMNC), although CBMNC produced less IgM than adult PBMNC. Beta-carotene did not have a significant effect on human Ig production. The carotenoid actions were not demonstrated under serum-free culture conditions; serum is essential for solubilization of carotenoids. In summary, this study has shown for the first time that astaxanthin, a carotenoid without vitamin A activity, enhances human Ig production in response to T-dependent stimuli.

Clinical and lymphocyte responses to beta-carotene supplementation in 11 HIV-positive patients with chronic oral candidiasis

Eleven HIV-positive patients with chronic oral candidiasis were supplemented with 60 to 120 mg of beta-carotene daily for 3 to 7 months. Lymphocyte profiles were evaluated at intervals to help assess immune competence. Although there was a modest increase in some lymphocyte values at 2 months, there was a significant decrease in numbers of CD4 and CD8 cells and CD4 percentage of lymphocytes after 6 months of beta-carotene supplementation. Serum triglyceride and liver enzyme levels were not affected by the beta-carotene supplementation. No improvement was observed in the control of the oral candidiasis. Under the conditions of the study, there was no indication that daily beta-carotene supplements enhanced immune competence or was of benefit in managing oral candidiasis.

Nutrition: a cofactor in HIV disease

The relationships among nutritional status, infectious disease, and the immune system suggest that nutrition may be a cofactor in human immunodeficiency virus (HIV) progression. We examined nutrition as a cofactor in HIV disease by reviewing the current literature on the interactions of nutrition, infectious disease processes, and immune system dysfunction. Studies demonstrate that poor nutritional status and infection affect the immune system and interact with each other. This relationship leads to the development of opportunistic infections and malignancies, which may result in a diagnosis of acquired immunodeficiency syndrome. Moreover, evidence from our review indicates that nutritional status may play a role in HIV disease progression. We recommend that clinical trials be conducted to evaluate general malnutrition and the efficacy of supplementation with specific nutrients at various stages of HIV disease.

Could oxidative stress initiate programmed cell death in HIV infection? A role for plant derived metabolites having synergistic antioxidant activity

Evidence supports the premise that a pro-oxidant condition exists in HIV-seropositive patients, a result of an overabundance in production of reactive oxygen forms combined with a multilevel deficiency in nutritional and metabolic sources of antioxidants. Apoptosis (a programmed cell death) is recognized as a possible pathway of immune cell loss in patients with HIV infection and AIDS. The cascade of events that results from 'oxidative stress' (OS) is markedly similar to that which can initiate apoptosis and includes oxidation of cellular membranes, alteration of metabolic pathways, disruption of electron transport systems, depletion of cellular ATP production, loss of Ca2+ homeostasis, endonuclease activation and DNA/chromatin fragmentation. Downstream events secondary to these effects may also play a role in activation of latent virus and subsequent viral replication. Primary and secondary metabolites found in plants act as synergistic antioxidants, and can protect plants from oxidation-induced cell death. Experiments have shown that some of these same metabolites can inhibit cell killing by HIV. Can these compounds be useful in inhibiting viral activation and the death of immune cells in HIV/AIDS through their synergistic antioxidant properties? A brief review of the evidence for OS in HIV is presented and the potential basis for OS playing a role in the initiation of cell death and viral replication is explored. The functional antioxidant activities of plant metabolites are illustrated and the use of these synergistic antioxidants from plants are proposed as a mechanism by which viral replication and cell killing in HIV infection can be inhibited.

Oxidative stress and apoptosis in HIV infection: a role for plant-derived metabolites with synergistic antioxidant activity

The cascade of events resulting from 'oxidative stress' is markedly similar to that which can initiate apoptosis, a possible mechanism of immune-cell loss in patients with HIV infection and AIDS. Since primary and secondary metabolites found in plants can act as synergistic antioxidants, and can prevent oxidation-induced cell death, Howard Greenspan and Okezie Aruoma ask whether or not these compounds can be useful in inhibiting viral activation and the death of immune cells in HIV/AIDS.

Interferon decreases serum lipid peroxidation products of hepatitis C patients

Thiobarbituric acid reactive substances (TBARS) concentration in serum has been determined in healthy subjects and in patients suffering acute hepatitis and chronic cases of hepatitis C. Treatment with interferon of the chronic active hepatitis C patients, 5 x 10(6) U three times a week during 2 months, led in those patients whose SGPT activity normalized in serum, to a concomitant decrease in serum TBARS content. The possible theoretical involvement of peroxidation and antioxidants in this beneficial effect of interferon in hepatitis C patients is discussed. The results presented confirm the value of TBARS as laboratory test in the management of liver diseases and as a useful tool for the study of pathogenic and/or therapeutic mechanisms of this viral infection.

Role of carotenoids in the immune response

The well-established provitamin A activities of certain carotenoids have hampered past research into their possible specific functions. More recently, research interests on carotenoids have been revived, largely because of their anticancer activities. beta-Carotene and other carotenoids have been reported to possess immunomodulatory activities in humans and animals. These carotenoids enhance lymphocyte blastogenesis, increase the population of specific lymphocyte subsets, increase lymphocyte cytotoxic activity, and stimulate the production of various cytokines. In addition, carotenoids also stimulate the phagocytic and bacteria-killing ability of blood neutrophils and peritoneal macrophages. The action of these carotenoids is widely accepted to be independent of their provitamin A activity. The immunostimulatory action of carotenoids may be translated into improved health, including mammary and reproductive health in dairy cattle. More studies are needed to establish fully the beneficial effects of supplementation of different carotenoids on the health of dairy cattle. Furthermore, studies on carotenoids other than beta-carotene are needed.

Resistance to intestinal parasites during murine AIDS: role of alcohol and nutrition in immune dysfunction

A murine AIDS model with many similarities to human AIDS, LP-BM5 Murine Leukaemia, suppresses T and B cell numbers and functions in the intestine. This permits chronic colonization by Giardia and Cryptosporidium. Cocaine and the nutrient alcohol, which are immunosuppressive, further reduce resistance to intestinal parasites and intestinal lymphocyte numbers. Protein undernutrition, vitamin E supplementation, and alcohol use further modify immune dysfunction induced by the murine retrovirus infection. This suggests that both undernutrition and nutrient supplementation could affect parasite resistance during AIDS. Thus this murine model of human AIDS has great potential to accelerate studies of the role of nutrients in immune dysfunction and resistance to intestinal parasites.