ABSTRACT
We have previously shown that the flowers of neem tree (Azadirachta indica A. Juss, family Meliaceae), Thai variety, strongly induced the activity of glutathione S-transferase (GST) while resulting in a significant reduction in the activities of some cytochrome P(450)-dependent monooxygenases in rat liver, and possess cancer chemopreventive potential against chemically-induced mammary gland and liver carcinogenesis in rats. In the present study, 2 chemicals possessing strong QR inducing activity were fractionated from neem flowers using a bioassay based on the induction of QR activity in mouse hepatoma Hepa 1c1c7 cultured cells. Spectroscopic characteristics revealed that these compounds were nimbolide and chlorophylls, having CD (concentration required to double QR specific activity) values of 0.16 and 3.8 mug/ml, respectively. Nimbolide is a known constituent of neem leaves, but was found for the first time here in the flowers. Both nimbolide and chlorophylls strongly enhanced the level of QR mRNA in Hepa 1c1c7 cells, as monitored by northern blot hybridization, indicating that the mechanism by which these constituents of neem flowers induced QR activity is the induction of QR gene expression. These findings may have implication on cancer chemopreventive potential of neem flowers in experimental rats previously reported.
Subject(s)
Animals , Azadirachta/chemistry , Biological Assay , Blotting, Northern , Carcinoma, Hepatocellular/pathology , Chlorophyll/isolation & purification , Enzyme Induction , Flowers , Limonins/isolation & purification , Liver Neoplasms/pathology , Mice , NAD(P)H Dehydrogenase (Quinone)/biosynthesis , Plant Extracts/pharmacology , Tumor Cells, CulturedABSTRACT
A randomized controlled trail to assess the efficacy of Aloe vera Linn. for the topical treatment of minor burns was conducted in 38 patients admitted to two community hospitals. Twenty patients were treated with fresh mucilage prepared from Aloe vera Linn. and 18 were treated with silfadiazine. The baseline characteristics of the patients in both groups were not significantly different. The success rates were observed in 95 and 83 percent of the patients in the Aloe vera Linn. group and the silver sulfadiazine group, respectively. About one third of the patients in both groups experienced irritation at the sites of topical treatment