The Pavonia xanthogloea (Ekman, Malvaceae): Phenolic compounds quantification, anti-oxidant and cytotoxic effect on human lymphocytes cells

Introduction: Pavonia xanthogloea is traditionally used as an antimicrobial and anti-tumour medicine in Southern Brazilian region. However, investigations about this species are still incipient. Hypothesis Tested: The study postulated that P. xanthologea specie present some phenolic compound and present some biological properties as anti-oxidant and cytoprotective effect against oxidative stress. Materials and Methods: The content of eight phenolic molecules in the crude ethanolic extract of the aerial part of P. xanthogloea and its five fractions (hexane, dichloromethane, ethyl-acetate, n-butanol, and water) was determined by heterotrophic plate count method. The anti-oxidant capacity of the extract and the fractions was determined by 1,1-diphenyl-2-picryl-hydrazyl assay. The potential anti-oxidant and cytoprotective effect was also analyzed in human lymphocyte culture treated with extract/fractions at different concentrations with and without oxidative stress generated by hydrogen peroxide (H 2 O 2 ) and sodium nitroprusside (SNP) exposition. Results: Tiliroside was the molecule detected in all extract. Water and ethyl-acetate fractions showed the highest radical-scavenging activity. The crude extract, hexane, water, and n-butanol reversed the higher reactive oxygen specie levels generated by H 2 O 2 and SNP to levels similar to those observed in the control group. In addition, crude extract, hexane, ethyl-acetate and n-butanol did not caused cytotoxicity, whereas water fraction was cytotoxic at higher concentration tested here (300 μg/mL). The cytotoxicity reversion caused by SNP exposition was concentration-dependent of the extract and fractions. However, dichloromethane fraction increased cell mortality in all concentrations investigated and was not able to decrease cell death in the lymphocytes exposed to SNP. Conclusion: The results suggest potential medicine use of this species.