Screening of stimulatory effects of dietary risk factors on mouse intestinal cell kinetics.

AIM: Although epidemiological and experimental studies validate influence of genetic, environmental and dietary factors in the causation of various types of cancers including colon, results from all these sources are inconclusive. Hypothesizing that high fat diet and obesity are among the major predisposing factors in the incidence of colon cancer, we evaluated the role of diet constituted with food material derived from a tropical plant, Tamarindus indica Linn (TI). METHODS: A two part randomized double-blind study was conducted employing inbred Swiss albino mice from a single generation for the whole investigation. One day-old neonates (n = 12) were subcutaneously administered with monosodium glutamate (MSG) to induce obesity (OB). At weaning these animals were maintained on modified AIN-76 diet supplemented with 10% TI and 10% fat bolus (w/w, TIFB) for 8 wk. Subsequently, in the second part of study, four groups of animals belonging to the same generation, age and gender (n = 12 per group), were maintained on: AIN-76 control diet (CD); AIN-76 mixed with 10% TI extract (TI); and, mixed with 10% TI and 10% FB (TIFB) for 8 wk, to determine intestinal crypt cell proliferation, functionally-specific enzyme activities, fermentation profile, and energy preferences. RESULTS: We observed a significant increase in the crypt cell production rate in distal colonic segment of experimental animals when compared with the controls. This segment also contained significantly low butyrate levels compared to control and TIFB groups. All the experimental groups showed a gross decrease in the enzyme activities viz., succinate dehydrogenase, acid-galactosidase and dipeptidyl amino peptidase IV demonstrating pathological stress caused by the test regimens, and an altered metabolic flux in the cellular environment. CONCLUSION: We have demonstrated a cumulative response to the three dietary factors, one of which (TI) is reported, herein, for the first time to modulate kinetics of large intestinal mucosa, contributing to total risk posed by these test agents.

Antioxidant activity of ethanolic extract of Terminalia chebula fruit against isoproterenol-induced oxidative stress in rats.

Antioxidant activity of ethanolic extract of fruits of Terminalia chebula (500 mg/kg body wt, orally for 30 days) against isoproterenol-induced oxidative stress was investigated in rats. The levels of serum lipid peroxides, iron, ascorbic acid, vitamin E, plasma iron-binding capacity, and the activities of ceruloplasmin and glutathione were assayed, in addition to the activities of the antioxidant enzymes--glutathione peroxidase, glutathione reductase, glutathione-S-transferase, superoxide dismutase and catalase in the heart tissue. Administration of isoproterenol increased the levels of lipid peroxides and iron, with corresponding decrease in the activities of the enzymic and non-enzymic antioxidants. The pre-treatment with ethanolic extract of fruits significantly prevented the alterations induced by isoproterenol, and maintained a near normal antioxidant status. Results suggest that the cardioprotective effect of T. chebula fruit may partly be attributed to its antioxidant properties.