Variations of endophytes in Tripterygium wildfordii due to geographical differences attribute to different biological effects

Tripterygium wilfordii Hook f. (TWHf) is a vice commonly grown in southern China and has long been used to treat various disorders such as rheumatoid arthritis. Its extract has been shown to exhibit immunosuppressive effects on the phytohemaglutinin stimulated proliferation of human peripheral blood mononuclear cells. Recent researches suggested that therapeutic effects derive from bioactive metabolites of some specific endophytic fungi. Hence, systematic and phylogenetic analyses of endophytic fungi may have practical implications on the discovery of new therapeutic drugs. In our recent studies, it was found 60 and 32 different genera, representing 343 and 88 fungal isolates, were identified in Tripterygium wilfordii (n=5) grown in Hong Kong and Taiwan respectively. Out of the 343 isolates from Hong Kong samples, 59 were Phomopsis (17%), 51 were Pestalotipsis species (15%), 36 were Glomerella species (10%), 23 were Phoma species (7%), 21 were Acremonium species (6%), 6 were Coelomycele species (2%) while in the Taiwan samples, out of 88 species, 30 (34%) were Collectriichum species, 29 (33%) were Glomerella species and 26 (30%) were Phomopsis species. The genera Acremonium and Pestalotiopsis isolated from Tripterygium wilfordii were only in Hong Kong but not in Twawan samples. Culture extracts from the former were significantly inhibitory on the growth of peripheral blood monuoclear cells. On the other hand, three major genera Colletotrichum, Glomerella and Phomopsis were isolated from Taiwan Tripterygium wildfordii and they didn’t show any anti-proliferative activity. Differences in compositions of the fungal endophytes and biological effects imply that these two events are correlated. It is concluded that because of the geographical difference, different types of endophyte may habitat with the host and produce difference metabolites which eventually generate different biological effects.