Hypericum silenoides Juss. and Hypericum philonotis Cham. & Schlecht. extracts: in-vivo hypolipidaemic and weight-reducing effects in obese rats.

OBJECTIVES: This study was carried out to assess the anti-obesity effect of Hypericum silenoides Juss. and Hypericum philonotis Cham. & Schlecht. in male Wistar rats fed with a cafeteria diet.

METHODS: Adult male Wistar rats with an initial body weight of 290-320 g were used in this trial. The rats were fed with a cafeteria diet for 77 days. Hypericum species were administered orally at a dose of 10, 30 or 100 mg/kg of body weight daily for 35 days. Body weight, food intake, anorexic effect and various biochemical parameters, such as serum glucose, lipid profile, alanine transaminase (ALT), aspartate transaminase (AST) and atherogenic index (AI), were assessed. Additionally, inhibitory lipase activity assay and forced swimming test were also carried out.

KEY FINDINGS: Oral administration of H. silenoides and H. philonotis extracts resulted in a significant decrease in body weight and serum glucose levels in obese male Wistar rats. Treatment with aqueous extract of H. silenoides showed anorexic and antidepressant effects and also significantly (P < 0.05) decreased total cholesterol, triglycerides and high-density lipoprotein-cholesterol, while low-density lipoprotein-cholesterol, AI, AST and ALT were not changed. The dichloromethane extract of H. silenoides (half maximal inhibitory concentration (IC₅₀ ) = 262.79 ± 0.09 μg/ml) and hexane extract of H. philonotis (IC₅₀  = 162.60 ± 0.02 μg/ml) showed the most potent lipase inhibitory activity.

CONCLUSION: Some H. silenoides and H. philonotis extracts showed a significant anti-obesity activity in cafeteria-diet-fed rats. This research provides the first scientific support for the use of the Hypericum genus for weight reduction in Mexican folk medicine.