Two new acylated triterpenoidal saponins from Gleditsia caspica Desf. and the effect of its saponin content on LPS-induced cognitive impairment in mice

Abstract

• Two new triterpenoid saponins were isolated from Gleditsia caspica Desf. • Structures of saponins were determined using spectral and chemical means. • MEGC and SFGC were able to significantly improve memory and learning in mice dose dependently. Two bisdismosidic triterpenoidal saponins, caspicaoside A 1 (1) and caspicaoside B 1 (2) , were isolated from Gleditsia caspica fruit methanolic extract. The structures of 1 and 2 were determined using chemical and spectral techniques. Gleditsia caspica fruit methanolic extract (MEGC) and its saponin containing fraction (SFGC) at the two dose levels 45 and 90 mg/kg b.wt. were studied comparatively for their effect on LPS-induced cognitive impairment in mice using Ginkgo biloba (100 mg/kg b.wt.) as a standard drug. Neurobehavioral tests (Morris Water Maze and Novel Object Recognition tests) were conducted to prove that MEGC and SFGC at the two levels were able to significantly improve memory and learning in mice dose dependently. Also, the two test drugs were able to significantly decrease the levels of proinflammatory cytokines (Tumor necrosis factor alpha and Interleukin 1-beta) in addition to reducing the extra-cellular deposition of amyloid beta 42 in a dose dependent manner.