CHEMICAL CONSTITUENTS AND LIPASE INHIBITORY ACTIVITY OF Solanum torvum

Abstract

The ethanol and aqueous extracts of sixteen medicinal plants including Abelmoschus esculentus Linn., Allium sativum Linn., Alpinia galanga (L.) Willd., Boesenbergia rotunda (L.) Mansf., Carthamus tinctorius Linn., Curcuma longa Linn., Cymbopogon citrates Stapf., Garcinia atroviridis Griff., Hibiscus sabdariffa Linn., Metha cordifolia Opiz., Piper nigrum Linn., Rhinacanthus nasutus (Linn.) Kurz., Senna alexandrina P. Miller, Solanum torvum Swartz., Zingiber officinale Roscoe., and Ziziphus jujuba Mill. were measured lipase inhibitory activity. Among ethanol crude extract, fruit of S. torvum showed the strongest lipase inhibitory activity at 87.35 ± 2.37% while among aqueous crude extract, leaf of M. cordifola showed the strongest lipase inhibitory activity at 92.88 ± 2.99%. Therefore, S. torvum fruits were extracted with hexane, ethyl acetate, methanol, and aqueous, respectively. Then, they were evaluated for lipase inhibitory activity in vitro. Ethyl acetate crude extract showed the strongest lipase inhibitory activity at 67.23 ± 3.57%. Hexane crude extract showed moderate lipase inhibitory activity at 46.00 ± 6.71%, whereas methanol and aqueous crude extracts exhibited weak activity at 15.82 ± 1.13% and 8.51 ± 1.05%, respectively. Therefore, hexane and ethyl acetate crude extracts were isolated and purified to give Compound 60, as a mixture of 17-(1,5-dimethylhexyl)-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[α]phenanthren-3-ol, campesterol, stigmasterol and β-sitosterol and Compound 61, as 7-hydroxy-6-methoxycoumarin or scopoletin. Compounds 60 and 61 showed weak lipase inhibitory activity with IC50 values of 82.56 mg/mL and 91.98 mg/mL, respectively which were less than orlistat. Orlistat showed lipase inhibitory activity with IC50 value of 3.79 × 10-6 mg/mL.