Atividades antioxidante, anti-inflamatória e antibacteriana dos extratos hexânico e etanólico das folhas da gravioleira (Annona muricata L.)

Abstract

Soursop (Annona muricata L.) is a tree of Annonaceae family widely distributed in all tropical regions of the world, produces fruit known as graviola and its leaves are used in traditional medicine as phytotherapy. Some compounds present in A. muricata have been related to antioxidant activity, anti-inflammatory and antimicrobial activities of this plant. This study aimed to evaluate the antioxidant, anti-inflammatory and antibacterial activities of hexane (HE) and ethanol (EE) soursop leaves extracts. To this end, we used soursop leaves for preparation of extracts for further analyzes of phytochemical composition, antioxidant capacity, ear edema assays in vivo and in vitro antibacterial activity. For analysis of the antioxidant activity of hexane and ethanol extracts were determined total polyphenols, yellows flavonoids and anthocyanins and total antioxidant capacity by ABTS●+ and DPPH methods. To evaluate the anti-inflammatory activity of the extracts was performed ear edema model induced by xylene or TPA in mice (Swiss females, 25-35g)-treated intragastrically (ig) for 7 consecutive days or topically (single dose) of different concentrations of the extracts (EE or HE):10, 100 and 1000 mg/kg. The antimicrobial activity of the extracts was evaluated against strains of Staphylococcus aureus (ATCC 14458), Listeria monocytogenes (ATCC 33090), Escherichia coli (ATCC 11775) and Salmonella choleraesuis (ATCC 14028). The extracts showed wide variety of phytochemical compounds, especially EE, and high antioxidant activity. Pretreatment via i.g. with the extracts was able to inhibit the edema induced by xylene, with a maximum percentage of inhibition of 61.72% for EE 10 and 57.08% for HE 100, but no effect on TPA-induced edema. The topical application with HE inhibited in a dose-dependent form the xylene-induced edema with maximum inhibition of 78.89% for HE1000, while for EE1000 was 67.95%, with no significant difference EE10 and EE100. As for the TPA-induced edema, HE (10, 100 and 1000 mg / kg) inhibited edema at 84.39%, 68.68% and 65.96%, while for EE (10, 100 and 1000 mg / kg ) the inhibition was 75%, 56% and 51%, respectively. Moreover, the extracts showed no antibacterial activity against all tested strains. The hexane and ethanol extracts of soursop leaves exhibit high differentiated antioxidant and anti-inflammatory activity compared to edema induced by xylene and TPA.