Discovery of dihydro-β-agarofurans from Tripterygium wilfordii with their H2O2-induced SH-SY5Y cell protective effects

Neurotrophic Natural Products

Neurotrophins (NGF, BDNF, NT3, NT4) can decrease cell death, induce differentiation, as well as sustain the structure and function of neurons, which make them promising therapeutic agents for the treatment of neurodegenerative disorders. However, neurotrophins have not been very effective in clinical trials mostly because they cannot pass through the blood-brain barrier owing to being high-molecular-weight proteins. Thus, neurotrophin-mimic small molecules, which stimulate the synthesis of endogenous neurotrophins or enhance neurotrophic actions, may serve as promising alternatives to neurotrophins. Small-molecular-weight natural products, which have been used in dietary functional foods or in traditional medicines over the course of human history, have a great potential for the development of new therapeutic agents against neurodegenerative diseases such as Alzheimer's disease. In this contribution, a variety of natural products possessing neurotrophic properties such as neurogenesis, neurite outgrowth promotion (neuritogenesis), and neuroprotection are described, and a focus is made on the chemistry and biology of several neurotrophic natural products.

New dihydro-β-agarofuran sesquiterpenoids from Tripterygium wilfordii and their anti-inflammatory activity

Twenty seven dihydro-β-agarofuran sesquiterpenoids, including fifteen new congeners, wilforsinines I-W (1-9, 12-13, 24-27), and twelve known compounds were isolated from the dried root of Tripterygium wilfordii. The structures of the new sesquiterpenoids, wilforsinines I-W, were elucidated by extensive spectroscopic data analysis. The anti-inflammatory activity of isolates 1-27 were evaluated by examining their inhibitory effects on nitric oxide (NO) production in LPS-induced RAW 264.7 macrophage cells. Among them, wilforsinine K (3) and angulatin M (16) exerted optimal inhibitory effects on the production of NO in LPS-induced RAW 264.7 cells. Moreover, Western blot results revealed that their anti-inflammatory activities were correlated with the suppression of the expression of nitric oxide synthase (iNOS) and down-regulation of the level of NF-κB p65 phosphorylation.