31-36-Wei Zhang - Shouxin

Ginkgo biloba leaf is the leaf of Ginkgo biloba L. in the genus Ginkgo of family Ginkgoaceae. It has the actions of benefiting heart, astringing lung, resolving dampness and stopping diarrhea, which can be used in the treatment of chest distress and pain, palpitation, phlegm panting and cough, diarrhea, dysentery, leucorrhea and other symptoms. Main active constituents of Ginkgo biloba leaves are lactones and flavonoids. To investigate the extraction process of lactones from Ginkgo biloba leaves. To study the effects of Ginkgo biloba leaf extract on serum levels of superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (NO) and protein kinase C (PKC) in rat model of schizophrenia. With the total contents of three types of lactones in Ginkgo biloba leaves as the indicators, the influences of four factors, extraction time (A), extraction temperature (B), ethanol concentration (C) and ethanol amount (D), on the extraction yield of Ginkgo biloba leaves were investigated. Schizophrenia model was established, SD rats were randomly divided into five groups: normal group (A), model group (B), Ginkgo biloba leaf extract highdose group (C), Ginkgo biloba leaf extract medium-dose group (D) and Ginkgo biloba leaf extract low-dose group (E), changes in serum SOD, MDA and NO levels were determined by biochemical methods, and serum PKC level by avidin-biotin complex-ELISA (ABC-ELISA). The optimal extraction process of lactones from Ginkgo biloba leaf was determined to be A3B1C3D1. Compared with the model group, each Ginkgo biloba leaf extract group was all able to improve the general condition of rats in different degrees, and significantly lower serum MDA, NO levels (P<0.05 or P<0.01), increase SOD activity (P<0.05 or P<0.01), and reduce the pathological damage caused by oxygen free radicals. Each Ginkgo biloba leaf extract group could significantly lower serum PKC level (P<0.05 or P<0.01). The process was capable of effectively extracting lactones from Ginkgo biloba leaves. Ginkgo biloba leaf extract can reduce pathological damage in schizophrenic model rats, and plays a protective role in the damage caused by oxygen free radicals; it can decrease serum concentration of PKC, and thus plays a regulatory role in the gap junctional intercellular communication (GJIC) functionality.