Biological potential of Citharexylum myrianthum Cham. Leaves in vitro and phenolic profile by HPLC-ESI-MS/MS

Abstract

This study aimed to evaluate the antimicrobial, cytotoxic effects in vitro and phenolic profile of Citharexylum myrianthum Cham. leaves. Dried leaves were macerated with methanol and subjected to liquid-liquid partition with solvents of increasing polarity, furnishing the methanolic extract (ME), dichloromethane (DCMF) and ethyl acetate (EAF) fractions. They were subsequently analyzed by HPLC-ESI-MS/MS. Six strains of Mycoplasma, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, and Candida albicans, were used to determine the antimicrobial effects, and minimum inhibitory concentrations (MIC) values of less than 1000 μg.mL -1 were considered active. To evaluate the cytotoxic effects, the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay (MTT) test was conducted with colorectal adenocarcinoma (HT-29), non-small lung cancer (NCI-H460) and non-cancer fibroblast (MRC5) cell lines. HPLC-ESI-MS/MS analysis identified four main phenolic compounds, vanillic, p-coumaric and salicylic acids and hispidulin. All samples were considered active against Mycoplasmas, mainly against M. hominis, with MIC values of 250 μg.mL -1 . With respect to cytotoxicity, the ME and DCMF (100 μg.mL -1 ) reduced cell viability by 50% in both the HT-29 and NCI-H460 cell lines but were non-cytotoxic against the MRC5. These results in vitro showed that C. myrianthum Cham. may be a possible candidate as an antimicrobial and antitumor agent. However, further studies in vivo are needed to confirm its effects.