Chemical and biological investigation of some Clerodendrum species cultivated in Egypt

Abstract

Context: Phytochemical investigation of Clerodendrum chinense (Osbeck) Mabberley (Lamiaceae) cultivated in Egypt and evaluation for anti-inflammatory, analgesic, and antipyretic effects of the methanol and chloroform extracts of Clerodendrum chinense, Clerodendrum indicum (L.) Kuntze, Clerodendrum glabrum E. Meyer.

Objective: The objective of this study was to investigate the anti-inflammatory, analgesic, and antipyretic effects of the methanol and chloroform extracts of Clerodendrum species under investigation.

Materials and methods: Air-dried powdered leaves of C. chinense were extracted with MeOH 80%. This extract was fractionated with successive portions of chloroform, ethyl acetate and n-butanol. By further fractionation through silica gel, polyamide and reversed phase column chromatography several compounds were isolated which were elucidated by nuclear magnetic resonance (NMR) and mass spectroscopy. For biological study, the powdered leaves of C. chinense, C. indicum and C. glabrum were extracted by chloroform and then extracted with methanol. The acute anti-inflammatory effect of tested extracts of the leaves of Clerodendrum species under investigation was estimated by carrageenan-induced rat paw edema. Antipyretic effect was evaluated and compared with that of paracetamol as standard using the yeast-induced hyperthermia method on female albino rats. Analgesic effect was evaluated and compared with that of Novalgin (metamizol sodium) as standard using an electric current anxious stimulus.

Results: Verbascoside, isoverbascoside, decaffeoylverbascoside, hispidulin, lupeol and icariside B5 were isolated from the leaves of C. chinense for the first time. Cornoside and rengyolone were also isolated. The methanol extract of the leaves of C. chinense and verbascoside showed significant analgesic, anti-inflammatory and antipyretic effects.

Conclusion: The present study provided a scientific validation of the traditional claims suggested for C. chinense.