The Hong Kong Polytechnic University, PR China
Hui-Hui Xiao is a Scientific Officer in The Hong Kong Polytechnic University. She received her PhD in Natural Product Chemistry from Shenyang Pharmaceutical University, China in 2011 and finished Post-doctoral studies from Jinan University in 2014. She has published more than 10 papers in reputed journals and obtained one authorized patent of invention. Her research interests are in the areas of preclinical study about the therapeutic effects of Traditional Chinese Medicine (TCM) on Osteoporosis, the chemical components of TCM and the involved mechanism in anti osteoporosis.
Sambucus williamsii Hance, as a fork herbal medicine has been used in China on treatment of bone and joint diseases for thousands of years. Our previous studies clearly demonstrated that a fraction composed of 50% and 95% ethanol eluate from S. williamsii exerted protective effects on trabecular bone and cortical bone without side effects on uterus in ovariectomized mice and rats. The fraction is rich in lignans and 55 lignans were isolated and identified in this fraction. Among them, 44 lignans were characterized as bioactive components by in vitro activity screening. In the present study, PPD, a typical norlignan was selected for mechanism investigation involved in the anabolic effects of S. williamsii. The results showed that PPD exerted beneficial effects in osteoblasts and its effects were abolished by co-incubation with ICI 182,780 or U0126. It failed to bind to either ERα or ERβ at the concentration up to 10-6 M and did not activate estrogen response element (ERE)-ludiferase activities via ER. PPD induced the phosphorylation of ERK and ERα at serine 118. The data indicated that PPD exerts oestrogen-like actions in ostoblast-like cells via ligand-independent, ERE-independent and mitogen-activated protein (MAP) Kinase-mediated rapid nongenomic ER signalling pathway. In order to elucidate the real bioactive components in body, we further study the metabolites of DDA, a major norlignan in the bioactive fraction. In rats model, 14 metabolites were identified in the plasma, urine and feces administrated with DDA. The final metabolite was enterodiol. However, the metabolic pathway was still in study.