Chrysin mitigated obesity by regulating energy intake and expenditure in rats

Chrysin is a flavonoid found in plant extracts from Passiflora species, honey and propolis. It has demonstrated anti-adipogenic activity in vitro but there are no studies substantiating the anti-obesity activity of chrysin in vivo.

The pancreatic lipase (PL) inhibitory potential of chrysin was determined by preliminary in silico screening and further confirmed by in vitro PL inhibitory assay and oral fat tolerance test (OFTT). The effect of chrysin on acute feed intake and sucrose preference test was determined in normal rats. Obesity was induced by feeding of high fructose diet (HFD) to the rats. The rats were divided into six groups: normal control, HFD control, orlistat and three doses of chrysin (25, 50 and 100 mg/kg body weight). Body weight, body mass index (BMI), abdominal circumference/thoracic circumference (AC/TC) ratio, calorie intake, adiposity index, fecal cholesterol, locomotor activity and histopathology of the adipose tissue of the rats were evaluated.

Chrysin showed good affinity to PL with competitive type of inhibition. It significantly reduced serum triglycerides in OFTT. Chrysin also significantly reduced acute feed intake and sucrose preference in rats. Chrysin significantly decreased the body weight, BMI, AC/TC ratio, adiposity index, calorie intake while it significantly increased the fecal cholesterol and locomotor activity of the rats. Chrysin was found to reduce the size of the adipocytes when compared to the HFD control group.

Thus, chrysin exerted anti-obesity effect by inhibiting PL, reducing sucrose preference, reducing calorie intake and increasing the locomotor activity of rats.