Effects Of Entophytic Fungus MF24 On Protocorm Of Dendrobium Candidum And Studies On Chemical Constituents And Bioactivity Of Herba Dendrobii

Dendrobium candidum Wall, ex Lindl., an orchidaceous epiphytic perennial herb, is a famous traditional medicine used as tonic in China. Because of the low breeding ratio and long growing cycle for natural D. candidum, it has been ranked in the Catalog of Chinese Wild Endangered Plants since 1987. Recent years, researches have revealed that some fungal elicitors could enhance the contents of some activity compounds in plant cells. The protocorm, which is a kind of tissue cultures from D. candidum elicited by entophytic fungus (MF24), was studied and applied as the substitute of medicinal D. candidum in this thesis. Moreover, the chemical constituents and bioactivity of Herba Dendrobii (the protocorm of D. candidum, D. nobile Lindl., D. longicornu lindl.) was studied.Ⅰ. In vitro pharmacological evaluation indicated the MF24 fungal elicitor could improve the lymphocyte proliferation activity and free radical scavenging ability of protocorms.At 100μg/ml, the methanol extract of protocorms treated by fungal elicitor could stimulate mouse B lymphocyte proliferation with the proliferation ratio 9.36%, the controlled protocorms showed no significant proliferative stimulation and natural D. candidum inhibited B lymphocyte proliferation intensively. Fungal elicitor also could enhance the ability of stimulate mouse T lymphocyte proliferation of the methanol extract of protocorms by 84.8% than that of controlled protocorms.