Identification of a Huperzine A-producing endophytic fungus from Phlegmariurus taxifolius.

Highly prized huperzine A (Hup A), a natural alkaloid formerly isolated from the Chinese medicinal plant Huperzia serrata, has been widely used for the treatment of Alzheimer disease, inspiring us to search for endophytic fungi that produce this compound. In this study, we obtained the C17 fungus isolate from the Mexican club moss Phlegmariurus taxifolius, which produced a yield of 3.2 µg/g Hup A in mycelial dry weight, when cultured in potato dextrose broth medium. The C17 isolate was identified as belonging to the genus Fusarium with reference to the colony´s morphological characteristics and the presence of macroconidia and microconidia structures; and this was confirmed by DNA-barcoding analysis, by amplifying and sequencing the ribosomal internal transcribed spacer (rITS).

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 IC50 =5.32±0.8µg/mL and 0.74±0.05µg/mL; H. dichotoma displayed AChEI with IC50 values =14.11±2.1µg/mL and 0.64±0.09µg/mL; and H. linifolia presented IC50 =158.37±8.7µg/mL and 4.2±1.24µg/mL, respectively, compared to the control Hup A (IC50= 0.16±0.03µg/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 1H 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.

Anti-Helicobacter pylori, gastroprotective, anti-inflammatory, and cytotoxic activities of methanolic extracts of five different populations of Hippocratea celastroides collected in Mexico.

ETHNOPHARMACOLOGICAL RELEVANCE: The root barks of Hippocratea celastroides have been used for decades in Mexican traditional medicine to treat gastritis and ulcers. To investigate the anti-Helicobacter pylori, gastroprotective, anti-inflammatory, and cytotoxic activities of methanolic extracts obtained from the leaves, stems, and root bark of Hippocratea celastroides collected in five different localities in Mexico, during the winter of 2009, in order to establish differences in biological activities in terms of plant organs, as well as places of collection. MATERIALS AND METHODS: Whole individuals were collected in five separate localities in Mexico: La Mancha, Veracruz (VL), Yautepec, Morelos (MY), Jojutla, Morelos (MJ), Temalac, Guerrero (GT), and Landa de Matamoros, Querétaro (QL). Methanolic crude extracts from wild plant specimens were tested using in vivo ethanol-induced mice gastric ulcer model, and 12-O-tetradecanoylphorbol-13-acetate (TPA) induced ear edema in mice assay, and in vitro anti-Helicobacter pylori model, and carcinoma cell line cytotoxic assays. RESULTS AND CONCLUSIONS: The leaves, stems, and root bark from MY specimens, as well as the leaves and root bark of materials from VL, presented the highest activity against Helicobacter pylori (MIC values ranging from 7.81 to 31.25 µg/ml). Most gastroprotective effects were displayed by the leaves of plants collected in MY, with 89.85±1.91% of protection (300 mg/kg) and an ED50=27 mg/kg, which was corroborated by histological analysis. The root bark extracts from MY achieved the highest edema inhibition values (ED50=0.18 mg/ear), which were comparable to indomethacin (ED50=0.16 mg/ear). Finally, all extracts from MY (three plant parts) were cytotoxic against nasopharyngeal (KB), breast (MCF-7), and colon (HCT-116) carcinoma cell lines with IC50 values between 1.18 and 9.77 µg/ml, except that no activity was detected for root bark extracts against HCT-116 normal fibroblasts. The activities of methanolic extracts from leaves, stems and root bark of plants collected in five different locations varied considerably, representing a notable problem facing the quality control of the plant material from Hippocratea celastroides used for medicinal purposes. The ethnomedical information of this plant in regards to treating gastritis and ulcers was strongly evidenced by the findings of the experimental models employed in this study.