ABSTRACT
Eradication of tuberculosis seems to be a long way off especially with the growing of drug resistance tuberculosis and HIV co-infection tuberculosis. The gaps in our knowledge and the limited sensitive and specific biomarkers especially for latent tuberculosis infection make it defensive. The fate of tuberculosis treatment ranged from cured to failure and there are many risk factors involved apart from the immune state and age. Therefore, this review focuses on the understanding of tuberculosis disease progression and the associated risk factors of the events in the disease progression. This article also highlights the diagnostic and predictive marker that may predict the disease progression. In addition, this review highlights the potential use of rifabutin in tuberculosis treatment regimen. It is hoped that this review could give an overview on future directions of research in tuberculosis.
ABSTRACT
Palm tocotrienol-rich fraction (TRF), an extract from palm oil containing both tocotrienol and tocopherol, is known for its antioxidant effect. The present study investigated the effect of palm TRF on the stomach using a water immersion restraint stress (WRS) model. Fortytwo male Sprague-Dawley rats were divided into three groups and were administered 60 mg/kg/d of palm TRF, α-tocopherol or vehicle only for 28 days. At the end of the treatment period, half of the rats from each group were subjected to WRS for 3.5 hours, after which the rats were sacrificed. The stomachs were then examined for lesions and measured for thiobarbituric acid reactive substance content and xanthine oxidase activity. Rats exposed to WRS showed gastric mucosal lesions. Pretreatments of the palm TRF and α-tocopherol reduced the occurrence of the lesions. WRS also increased gastric malondialdehyde content and xanthine oxidase activity significantly, but the increase in the oxidative stress parameters were significantly suppressed by both vitamin E pretreatments. However, the effects of palm TRF and α-tocopherol on the parameters measured were not different. In conclusion, palm TRF has the ability to protect against gastric mucosal injury, likely via its ability to inhibit oxidative stress.
ABSTRACT
Phytosterols are plant sterols with a chemical structure similar to cholesterol. It has anti-cholesterol, anti-cancer and anti-oxidant properties which are probably mediated by suppression of lipid peroxidation. However, there are limited studies on the effects of phytosterols on lipid peroxidation. The aim of this study is to determine the effects of phytosterols on plasma and tissue malondialdehyde (MDA) of rats exposed to carbon tetrachloride. The rats were divided into four groups of normal control (NC), carbon tetrachloride (CCl4), phytosterol (P) and phytosterol+carbon tetrachloride (P+CCl4). The P and P+CCl4 groups were pretreated with subcutaneous phytosterol at 140 mg/kg once weekly for 5 weeks while the NC and CCl4 groups only received olive oil (vehicle). A single oral dose of carbon tetrachloride was then given to rats in the CCl4 and P+CCl4 groups to induce lipid peroxidation. After 24 hours, all the rats were sacrificed and the plasma and tissue MDA were measured. Our results showed carbon tetrachloride had caused significant elevations of the plasma and hepatic MDA of the CCl4 group compared to the NC group. Phytosterol pretreatment (P+CCl4 INTRODUCTION Phytosterols or plant sterols are a group of steroid alcohols, phytochemicals naturally occuring in plants. They have a chemical structure which is similar to cholesterol (Weihrauch & Gardner 1978) and exist in several forms in plants (Law 2000; Katan et al. 2003; Abumweis et al. 2007) including β-sitosterol, campesterol, stigmasterol and cycloartenol (Ostlund 2002). Phytosterols are natural compo-nents found in the human diet. It made up 0.1 to 0.5% w/w of vegetable oils or margerine (Kochlar 1983) and are also found in corn, wheat and rice. Phytosterol intake varies according to the type of diet taken. Europeans consume about 200-300 mg/day of phytosterol (Morton et al. 1995) while the vegetarian Japanese have a higher intake of phytosterol (Nair et al. 1984). group) were able to prevent the MDA elevations. Phytosterols treatments in normal rats (P group) were found to reduce the hepatic MDA level. The conclusion of this study was that phytosterols are effective suppressor of plasma and hepatic lipid peroxidation. They have potential as supplements to further reduce lipid peroxidation in healthy individuals.