title: Neuroprotective activity of two active chemical constituents from Tinospora hainanensis.
abstract: OBJECTIVE
  To determine the chemical structure of the new compound and investigate the protective effects of Tinosporaic acid A and B towards in-vitro neuro.
  
  
  METHODS
  The structures of two new compounds were established by analyzing its 1D and 2D NMR spectra as well as HRESIMS. Their neuroprotective effects with respect to the antioxidant properties were evaluated by radical scavenging tests and hydrogen peroxide-injured oxidative stress model in PC12 cell lines. Cell morphology of treated PC12 cells was observed by phase contrast microscopy. In-vitro MTT assay, lactate dehydrogenase activity assay and oxidative stress markers (intracellular ROS production, MDA level, and caspase-3 activity) were used to evaluate the protective effects against hydrogen peroxide induced cytotoxicity in PC12 cells.
  
  
  RESULTS
  The two new compounds, named Tinosporaic acid A and B, were isolated and identified from the stem bark of Tinospora hainanensis. Cell viability studies identified a representative concentration for each extract that was subsequently used to measure oxidative stress markers. Both extracts were able to reverse the oxidative damage caused by hydrogen peroxide, thus promoting PC12 cells survival. The concentration of Tinosporaic acid A and B were 86.34 μg/mL and 22.06 μg/mL respectively, which is neuroprotective for EC50. The results indicated that both of them significantly attenuated hydrogen peroxide-induced neurotoxicity.
  
  
  CONCLUSIONS
  The two new compounds isolated from ethanol extracts of Tinospora hainanensis are the promising natural ones with neuroprotective activity and needed for further research.
authors.affiliation: Department of Pharmacology, School of Pharmaceutical Science, Hainan Medical University, School of Pharmaceutical Science, Haikou 571199, China.
authors.forename: Dao-Rui
authors.initials: DR
authors.lastname: Yu
authors.affiliation: Department of Pharmacology, School of Pharmaceutical Science, Hainan Medical University, School of Pharmaceutical Science, Haikou 571199, China; Department of Pharmacology, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China.
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Ji
authors.affiliation: Research Center of Basic Medicine, Hainan Medical University, Haikou 571199, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.affiliation: Research Center of Basic Medicine, Hainan Medical University, Haikou 571199, China.
authors.forename: Xi-Nan
authors.initials: XN
authors.lastname: Yi
authors.affiliation: Research Center of Basic Medicine, Hainan Medical University, Haikou 571199, China.
authors.forename: Guo-Hui
authors.initials: GH
authors.lastname: Yi
authors.affiliation: Department of Pharmacology, School of Pharmaceutical Science, Hainan Medical University, School of Pharmaceutical Science, Haikou 571199, China.
authors.forename: Tong
authors.initials: T
authors.lastname: He
authors.affiliation: Department of Pharmacology, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China.
authors.forename: Yong-Xiao
authors.initials: YX
authors.lastname: Cao
authors.affiliation: Department of Pharmacy, Sichuan Provincial People's Hospital, Chengdu 610072, China. Electronic address: dragon984169@126.com.
authors.forename: En-Wu
authors.initials: EW
authors.lastname: Long
authors.affiliation: Department of Pharmacology, School of Pharmaceutical Science, Hainan Medical University, School of Pharmaceutical Science, Haikou 571199, China. Electronic address: yxybing@163.com.
authors.forename: Qi-Bing
authors.initials: QB
authors.lastname: Liu
keywords: HRESIMS; NMR; Neuroprotective activity; Phytochemical analysis; Tinospora hainanensis