Hepatoprotective Activity on Ethanol-induced Injury by Polyphenolic Extracts From Litchi (Litchi chinensis Sonnerat)

• Main Authors: Cheng-Wei Chang, 張証維
• Other Authors: Bor-Chun Weng
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/7g75xk

碩士 === 國立嘉義大學 === 生物醫藥科學研究所 === 97 === Alcoholism (chronic ethanol consumption) is one of primary medical problems with significant socio-economic consequence worldwide. Currently, silymarin from the milk thistle herb is the first-line drug used clinically on the alcohol liver disease (ALD). However, it has plenty side effects and uncertainties in curing some of liver diseases. Finding novel drug is in need to improve the efficiency on ALD therapy. Litchi is a precious tropical fruit originating from southern China enriched with phenolic compounds and flavonoids in its pericarp. It is traditionally documented as herbal medicine with hepatoprotective property. However, lack of scientific data to fulfill the wisdom of ancestral practice. In this study, we extracted and purified polyphenolic compounds of litchi pericarp. Cytotoxicity assay was performed for each fractionation of extract on various cell lines including the murine embryonic liver cell line (BNL CL.2). The model of ethanol induced cell injury in BNL CL.2 cells was adapted and showed litchi extracts were effectively protecting cells from ethanol induced reactive oxygen species (ROS). In addition, regenerative capacity of injured liver cells was analyzed. Using high performance liquid chromatography (HPLC) and NMR, two major compounds from litchi extracts, the epicatechin and proanthocyanidin A2, were identified, purification procedures were carried out subsequently. Flow cytometry analysis indicated the hepatoprotection of proanthocyanidin A2 was at least due to the strengthening mitochondria detoxification to ethanol induced excessive ROS. Moreover, there was a decrease percentage in the accumulated sub-G1 phase of ethanol treated liver cells and a faster regenerative proliferation with treatment of proanthocyanidin A2. To compare with silymarin, the litchi extracts had more protective effects on ethanol induced damages. In summary, we have discovered litchi pericarp extracts, possessing effective hepatoprotective properties on ethanol (EtOH)-induced liver cells BNL CL.2 injury. Two major compounds, epicatechin and proanthocyanidin A2 were identified in responsible for the results. Litchi pericarp may be promoted as complementary alternative medicines in ALD therapy.