cytellin and Tuberculosis--Pulmonary

Although plant sterols (phytosterols) were chemically described in 1922, their biological role in human and animal health has been underestimated. Their ability to control cholesterol plasma levels in hypercholesterolimic patients was first described in 1983 when the structure of phytosterols implied that they could, by steric hindrance, inhibit the absorption of cholesterol from our diets. This has led to the development of functional foods containing high contents of these plant molecules or their esters as cholesterol controlling foods. Over the last 15 years, however, several reports have appeared in the literature indicating that phytosterols have some immunological activity as highlighted in animal models of inflammation or even in in-vitro and in-vivo models of cancer (colorectal and breast cancer). These findings were paralleled by epidemiological studies correlating the reduced risk of numerous diseases and the dietary intake of phytosterols. It is only in the last 10 years, however, that their direct immune modulatory activity on human lymphocytes has been proven and the mechanism of action in cancer cells has been elucidated. The use of phytosterols as supportive therapies in certain chronic conditions has been tested under clinical trial conditions. This review presents a summary of the in-vitro and in-vivo studies published to date.

Topics: Adjuvants, Immunologic; Animals; Cholesterol; Disease Models, Animal; HIV Infections; Humans; Hypercholesterolemia; Immune Tolerance; Intestinal Absorption; Neoplasms; Phytosterols; Phytotherapy; Sitosterols; Tuberculosis, Pulmonary; Tumor Cells, Cultured

Beta-sitosterol (BSS) and its glycoside (BSSG) are sterol molecules which are synthesized by plants. When humans eat plant foods phytosterols are ingested, and are found in the serum and tissues of healthy individuals, but at concentrations orders of magnitude lower than endogenous cholesterol. Epidemiological studies have correlated a reduced risk of numerous diseases with a diet high in fruits and vegetables, and have concluded that specific molecules, including b-carotene, tocopherols, vitamin C, and flavonoids, confer some of this protective benefit. However, these epidemiologic studies have not examined the potential effect that phytosterols ingested with fruits and vegetables might have on disease risk reduction. In animals, BSS and BSSG have been shown to exhibit anti-inflammatory, anti-neoplastic, anti-pyretic, and immune-modulating activity. A proprietary BSS:BSSG mixture has demonstrated promising results in a number of studies, including in vitro studies, animal models, and human clinical trials. This phytosterol complex seems to target specific T-helper lymphocytes, the Th1 and Th2 cells, helping normalize their functioning and resulting in improved T-lymphocyte and natural killer cell activity. A dampening effect on overactive antibody responses has also been seen, as well as normalization of the DHEA:cortisol ratio. The re-establishment of these immune parameters may be of help in numerous disease processes relating to chronic immune-mediated abnormalities, including chronic viral infections, tuberculosis, rheumatoid arthritis, allergies, cancer, and auto-immune diseases.

Topics: Adjuvants, Immunologic; Animals; Cats; HIV Infections; Humans; Immune Tolerance; Sitosterols; Tuberculosis, Pulmonary

To evaluate the adjuvant effect of beta-sitosterol and its glucoside in the treatment of culture proven pulmonary tuberculosis (PTB).. A blinded randomised placebo-controlled trial in culture proven drug sensitive PTB. Patients were hospitalised for the duration of treatment and evaluated at monthly intervals with regard to sputum culture positivity, chest radiography, weight gain, Mantoux test response, routine haematology and liver functions. STATISTICAL EVALUATION: General linear models for repeated measures (SAS GLM package) compared the interaction effects, group effects and time effects of findings in 19 patients receiving sitosterols with those in 18 patients receiving a placebo (talcum powder). Absolute values and change from baseline values were evaluated, although only the latter are reported.. Weight gain was significantly greater in the sitosterol group (mean weight gain 8.9 kg) than the placebo group (mean gain 6.1 kg) (P = 0.0023 group effects; P = 0.0001 for time effects). Speed of achieving culture negativity, radiological improvement and induration on Mantoux testing was similar in the two groups. Change in lymphocyte counts from baseline was significantly higher in the sitosterol group (P = 0.0001 and P = 0.0001 for group and time effects) as was the increase in eosinophil counts (P = 0.0001 and P = 0.0137 for group and time effects).. The study has shown significantly improved weight gain and higher lymphocyte and eosinophil counts in PTB patients receiving sitosterols in addition to an efficacious antituberculosis regimen. Sitosterols and their possible mode of action should now be evaluated in larger numbers of tuberculosis patients and in diseases with a similar immunopathogenesis.

Topics: Adjuvants, Immunologic; Adult; Antitubercular Agents; Humans; Leukocyte Count; Male; Sitosterols; Tuberculosis, Pulmonary; Weight Gain

Topics: Antitubercular Agents; Drug Therapy, Combination; Humans; Sitosterols; Treatment Outcome; Tuberculosis, Pulmonary; Weight Gain