Abstract
Struthanthus quercicola, a hemiparasitic plant known as "seca palo," is used by Nahuatl traditional healers against diabetes, wounds, and rashes. We aimed to investigate the effects of different S. quercicola extracts, which were selected based on their traditional use in Tamazunchale, San Luis Potosí, on the cell viability and antioxidant activity in HeLa cell cultures. S. quercicola growing on Guazuma ulmifolia and Citrus sp. hosts was collected, and methanolic and ethanolic extracts as well as decoctions, infusions, and microwave-assisted extracts were obtained. The terpenoid, alkaloid, flavonoid, saponin, and tannin contents of each extract were evaluated qualitatively and quantitatively. The effects of different extracts on the viability of cervical adenocarcinoma (HeLa) cells were tested using an MTT assay. The differences in the total flavonoid and phenolic contents and free-radical scavenging activity in relation to the host and the extract were also determined. In assessments of the effects of the extracts on cell viability, eight organic extracts (4 from G. quercicola grown on Host 1 and 4 from G. quercicola grown on Host 2) were shown to decrease cell viability significantly in comparison with the control. However, the extract obtained by percolation (PMeOH) caused a significant increase in cell viability (p < 0.05), especially with the plant grown on Host 1. The microwave aqueous and methanolic extracts of the plants grown on both hosts showed a significant increase in the percentage of apoptosis (p < 005). In conclusion, different extracts of Struthanthus quercicola showed variable effects on cell viability and apoptosis. Isolation of the molecule or molecules with inhibitory and proliferative effects on cells should be conducted to evaluate their possible use as antineoplastic agents.