Pharmacological Activities of Agave seemanniana and Isolation of Three Steroidal Saponins

Abstract

Aim: To investigate the analgesic, anti-inflammatory and ulceroprotective properties of Agave seemanniana methanolic leaf extract (MEAS) and its saponin containing fraction (SFAS), in animal models compared to standard drugs. In addition to separation and characterization of the major saponin fraction of Agave seemanniana leaves. Place and Duration of Study: The study was carried out at the Department of Pharmacognosy, Faculty of Pharmacy, Helwan University, Cairo, Egypt, between June 2011 and March 2013. Methodology: The analgesic activity was assessed using the hot plate method and aspirin being a positive standard, the anti-inflammatory activity was investigated using the standard carrageenan-induced paw edema method against indomethacin as standard and the ethanol induced ulcer was used to record the ulcer protective effect of methanolic leaf extract of Agave seemanniana (MEAS) and saponin fraction of Agave seemanniana (SFAS). Separation and characterization techniques were used for the phytochemical study of the saponin content of the extract. Results: The results of analgesic activity of MEAS and SFAS using the hot plate test, revealed significant increase in the reaction time at dose of 100mg/kg b.wt. The same dose of the two test drugs demonstrated significant ulcer protective activity. The results of anti-inflammatory activity revealed that the reduction of the carrageenan-induced paw edema was significant at a dose of 100mg/kg b.wt. Furthermore, SFAS contained mainly saponins of pregnane and furostanol types. The structures of three isolated and characterized saponins indicated that these saponins had a common oligosaccharide moiety linked to the aglycone C-3 position and identified as α-L- rhamnopyranosyl– (1→4)-β-D-glucopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucopyranosyl- (1→4)-β-D-galactopyranosyl.   Conclusion: This study contributes to the search for potent and locally available plant materials as analgesic, anti-inflammatory and ulcer protective drugs known for their high saponin content.