Anticholinesterase activity and identification of huperzine A in three Mexican lycopods: Huperzia cuernavacensis, Huperzia dichotoma and Huperzia linifolia [Lycopodiaceae]

Huperzine A [Hup A], the alkaloid produced by the Chinese medicinal plant Huperzia serrata, has been documented to be a promising agent for the treatment of Alzheimer's disease due to its potent acetylcholinesterase inhibitory [AChEI] activity. The search for anticholinesterase natural products, as well as for alternative sources of Hup A in Mexican lycopods, prompted us to investigate these plants. The action of methanolic and alkaloidal extracts of three Huperzia species [H. cuernavacensis, H. dichotoma, and H. linifolia] was evaluated using an in vitro anticholinesterase activity assay. Also, chromatographic and spectroscopic analyses were employed to detect the presence of Hup A. Methanolic and alkaloidal extracts of H. cuernavacensis showed IC[50] =5.32+/-0.8micro g/mL and 0.74+/-0.05micro g/mL; H. dichotoma displayed AChEI with IC[50] values =14.11+/-2.1micro g/mL and 0.64+/-0.09micro g/mL; and H. linifolia presented IC[50] =158.37+/-8.7micro g/mL and 4.2+/-1.24micro g/mL, respectively, compared to the control Hup A [IC[50]= 0.16+/-0.03micro g/mL]. Hup A was identified in the extracts of H. dichotoma, but it was not detected in the extracts of H. cuernavacensis and H. linifolia by [1]H NMR techniques. This study reveals H. dichotoma as a new source of Hup A, and presents H. linifolia and H. cuernavacensis as potential candidates to obtain other anticholinesterase compounds useful in the Alzheimer's disease treatment

Radical scavenging, antioxidant, and cytotoxic activities of the methanolic extracts from different organs of Ternstroemia pringlei

Ternstroemia pringlei [Rose] Standl. [Theaceae] is widely used in Mexican traditional medicine to treat a diverse array of illnesses including rheumatoid pains, and is listed as one of the most consumed medicinal plants in the country. We selected T. pringlei given the strong relationship between oxidative stress and arthritis pathology, and investigated antioxidant potential of leaf, petal, fruit and seed methanolic extracts. Our method included assessing the in vitro free radical scavenger activity using the 2,2´-azino-bis[3-ethylbenzothiazoline-6-sulphonic acid] [ABTS] test, as well as the in vivo antioxidant action in the H[2]O[2] protection model with Saccharomyces cerevisiae. Leaves and fruits afforded the most active extract in the ABTS assay, with antiradical activity of IC[50]=33.91 and 38.09[micro]g/mL, respectively; while fruit extracts at 250[micro]g/mL proved the most protective action against H[2]O[2] oxidative stress. All extracts were noncytotoxic against HF-6 [colon], PC-3 [prostate], MCF-7 [breast], SiHa [cervical] cancer cell lines and also toward the HFS-30 fibroblast normal skin cell line [IC[50]>20[micro]g/mL]. Leaf methanolic extracts afforded ternstroside B, a known phenylethanoid glycoside with a strong free radical scavenging action. The presence of this kind of metabolites opens new research perspectives for the plant