Inhibitory effect on lipid accumulation and body weight reduction of rambutan and santol peel extracts in high sugar intake Drosophila melanogaster

Abstract

Obesity is the major risk factor for chronic diseases, which are the major health problems globally including Thailand. The previous report has demonstrated that santol (Sandoricum koetjape Merr.) and rambutan (Nephelium lappaceum L.) peel extracts showed to inhibit lipase activity in vitro. However, the experimental prove in vivo is limited. Therefore, this study aims to evaluate the inhibitory effect of both peel extracts on the lipid accumulation in Drosophila melanogaster. The crude extracts was obtained by using the maceration method with 95% ethanol. The extracts were used for testing the gustatory, toxicity and lipid accumulation in Drosophila by mixing in the diet and feeding ad libitum for 7 days. The study groups were divided into 6 group: 1) the control group 2) the high sugar diet group 3-4) the groups that were fed with santol peel extract at the concentrations of 10 and 20 mg/mL mixed with high sugar diet and 5-6), the groups that were fed with rambutan peel extract at the concentrations 10 and 20 mg/mL mixed with high sugar diet. The results showed that the food intake of all groups was not different. The toxicity test results showed that all groups had a survival rate of more than 95%. The lipid accumulation results demonstrated that the mean change in body weight after the experiment, triglyceride content, and fat score in the abdominal area of the Drosophila fed with rambutan extract at the concentration of 20 mg/mL mixed with high sugar diet were significantly lower than other groups. This study's results can be used as a promising data to test in mammal models and to further develop a drug or dietary supplement for inhibition of lipid accumulation.