Evaluation of in vivo and in vitro biological activities of Gardenia latifolia Ait leaf

Gardenia latifolia Ait. belonging to the family Rubiaceae is a flowering plant with high ethnomedicinal practices in Bangladesh. The current study evaluates analgesic, antipyretic, α-amylase enzyme inhibition, membrane stabilizing, antioxidant effect and antimicrobial potentials of G. latifolia. The analgesic and antipyretic activity of ethanol extract of G. latifolia (EGL) leaves were evaluated by hot plate reaction model and brewers’ yeast-induced hyperthermia model in mice, respectively. The a-amylase inhibiting activity, membrane stabilizing activity, antioxidant activity and antimicrobial activity of EGL along with its hexane (HSGL) and chloroform (CSGL) soluble fractions were measured employing the starch-iodine method, hypotonic induced hemolysis assay, DPPH free radical scavenging assay and minimum inhibitory concentration (MIC) determination method, respectively. Here, EGL exhibited dose-dependent pain relieving activity in experimental mice. EGL also significantly (p<0.05) reduced the yeast-induced hyperthermia in mice over the experimental period. During the α-amylase enzyme inhibition assay, the EGL at dose of 500 µg/mL showed maximum α-amylase inhibitory activity (65.95%). In membrane stabilizing assay, EGl, HSGL and CSGL were found to be effective for stabilizing erythrocyte membrane in hypotonic solution. During antioxidant assays, dose-response curve of DPPH radical scavenging activity of the different soluble fractions of G. latifolia was obtained. Besides, these plant samples also displayed substantial antimicrobial activity against test microorganisms with MIC value ranged from 15.62 to 250 μg/mL. In summary, the plant G. latifolila possesses a significant biological activity which validates its use in Bangladesh folk medicinal practices.