ABSTRACT
Epaltes mexicana is a plant widely used in traditional medicine and as a food in Mexico; however, its phytochemical and pharmacological studies are limited. This study aimed to identify the active secondary metabolites of Epaltes mexicana and determine its cytotoxic activity on cancer cell lines. Three organic extracts were obtained by maceration using n-hexane, dichloromethane, and methanol. The n-hexane extract was fractioned by simple column chromatography. Eight terpenes were annotated in collection 6 (C6) by LC-QTOF-MS using a gradient elution and Electrospray Ionization (ESI) in positive ion mode: 1) Gibberellin A15, 2) farfugin A, 3) dehydromyodesmone, 4) eremopetasitenin A1, 5) hydroxyisonobilin, 6) anhydrocinnzeylanine, 7) nigakilactone H and 8) taxodione. On the other hand, C6 showed a concentration-dependent cytotoxic effect on cancer cell lines MCF-7 (Emax = 74.69 ± 6.19 % and IC50 = 6.31 µg/mL), MDA-MB-231 (Emax = 79.28 ± 12.12 % and IC50 = 124.21 µg/mL), and SiHa (Emax = 82.96 ± 6.02 % and IC50 = 124.31 µg/mL). The C6 did not show a cytotoxic effect against DU-145 and non-cancerous cells from the mammary glands MCF-10A. These results indicate cytotoxic specificity on cancer cell lines and support the hypothesis that terpenes identified in E. mexicana must be investigated and developed for non-clinical and clinical trials as potential anti-cancer drugs.
ABSTRACT
RESUMEN Analizamos el uso de microhábitat para las diferentes clases etarias entre épocas climáticas y comparamos la diversidad de presas consumidas por los machos y hembras adultas de Craugastor berkenbuschii en un arroyo tropical del sureste de México. Los datos fueron colectados en diez transectos de 100 x 15 m, separados entre sí por 25 m de distancia entre ellos. Los muestreos diurnos y nocturnos se realizaron mensualmente entre septiembre 2017 y agosto 2018. A cada individuo observado le registramos el sexo, la clase etaria y el microhábitat utilizado al momento del avistamiento. Las presas consumidas fueron extraídas mediante lavados estomacales in situ. Registramos un total de 437 individuos; 165 fueron adultos, 162 juveniles y 110 crías. Los microhábitats utilizados fueron roca, hojarasca, suelo, tronco, rama, hojas y raíz, de los cuales roca fue el más utilizado independientemente de la época del año y clases etarias. Se identificaron 21 órdenes de presas, 19 órdenes en hembras y 11 en machos. El índice de diversidad verdadera (1D), mostró valores similares para machos y hembras, con 9,67 y 9,08 respectivamente. El índice de distintividad taxonómica promedio (A+) determinó que las hembras consumen una mayor diversidad de presas que los machos, con 5,12 y 4,25, respectivamente. Los resultados muestran que las diferentes clases etarias de C. berkenbuschii aprovechan una gran variedad de microhábitats entre épocas climáticas y que existen diferencias entre las presas consumidas entre machos y hembras adultas.
ABSTRACT We analyzed microhabitat use for different age classes between climatic seasons and compared the diversity of prey consumed by adult males and females of Craugastor berkenbuschii in a tropical stream in southeastern Mexico. The data was collected in ten transects of 100 x 15 m, separated from each other by 25 m of the distance between them. Day and night sampling was carried out monthly between September 2017 and august 2018. For each observed individual, we recorded the sex, age class, and microhabitat used at the time of the sighting. The consumed prey was extracted by means of in situ stomach washings. We registered a total of 437 individuals; 165 were adults, 162 were juveniles, and 110 were young. The microhabitats used were rock, litter, soil, trunk, branch, leaves, and root, of which rock was the most used regardless of the time of year and age classes. Twenty-one orders of prey were identified, 19 orders in females and 11 in males. The true diversity index (1D) showed similar values for males and females, with 9.67 and 9.08 respectively. The average taxonomic distinctness index (A+) determined that females consume a greater diversity of prey than males, with 5.12 and 4.25, respectively. The results show that the different age classes of C. berkenbuschii take advantage of a wide variety of microhabitats between climatic seasons and that there are differences between the prey consumed between adult males and females.