Cardiovascular activity of the n-butanol fraction of the methanol extract of Loranthus ferrugineus Roxb

We investigated the vascular responses and the blood pressure reducing effects of different fractions obtained from the methanol extract of Loranthus ferrugineus Roxb. (F. Loranthaceae). By means of solvent-solvent extraction, L. ferrugineus methanol extract (LFME) was successively fractionated with chloroform, ethyl acetate and n-butanol. The ability of these LFME fractions to relax vascular smooth muscle against phenylephrine (PE)- and KCl-induced contractions in isolated rat aortic rings was determined. In another set of experiments, LFME fractions were tested for blood pressure lowering activity in anesthetized adult male Sprague-Dawley rats (250-300 g, 14-18 weeks). The n-butanol fraction of LFME (NBF-LFME) produced a significant concentration-dependent inhibition of PE- and KCl-induced aortic ring contractions compared to other fractions. Moreover, NBF-LFME had a significantly higher relaxant effect against PE- than against high K+-induced contractions. In anesthetized Sprague-Dawley rats, NBF-LFME significantly lowered blood pressure in a dose-dependent manner and with a relatively longer duration of action compared to the other fractions. HPLC, UV and IR spectra suggested the presence of terpenoid constituents in both LFME and NBF-LFME. Accordingly, we conclude that NBF-LFME is the most potent fraction producing a concentration-dependent relaxation in vascular smooth muscle in vitro and a dose-dependent blood pressure lowering activity in vivo. The cardiovascular effects of NBF-LFME are most likely attributable to its terpenoid content.

Hypolactasia & lactose intolerance among three ethnic groups in Malaysia.

BACKGROUND & OBJECTIVES: Prevalence of adult-type hypolactasia is known to vary among different countries and in different ethnic populations in the same country. The present study was undertaken to evaluate the prevalence of hypolactasia and lactose intolerance in three different ethnic populations living in similar environmental conditions in Malaysia. The correlation between different symptoms and lactose intolerance test was also studied. METHODS: A total of 300 Malaysian subjects from three different ethnic populations: Malays, Chinese and Indians (100 volunteers in each group, 18-49 yr old working or studying in a University) were included. Urine galactose excretion and gastrointestinal symptoms were measured after lactose intake (50 g). RESULTS: Based on galactose excretion, 88 per cent of the Malays, 91 per cent of the Chinese and 83 per cent of the Indians were hypolactasic. The differences were statistically not significant. When the symptoms were also considered, prevalence of lactose intolerance appeared to be significantly lowest among the Indians. When the subjects were divided into low, middle and high galactose excretion groups some correlation was found between the symptoms and galactose excretion. INTERPRETATION & CONCLUSION: There was no clear association between hypolactasia and gastrointestinal symptoms in all the study groups. However, the lactose intolerance was high in all the study groups indicating the increasing demand for low lactose dairy products in the Asian countries.