Atividades antioxidantes, anti-Candida e inibitorias da lipoxigenase e alfa-amilase de espécies medicinais do gênero Plectranthus

Abstract

In the first article aimed to quantify the total phenolic compounds and evaluate the antioxidant and inhibitory potential of alpha-amylase of three medicinal species Plectranthus genus (Plectranhus amboinicus, Plectranthus ornatus and Plectranthus barbatus). Fresh leaves were used from three species as plant material. The aqueous extracts were prepared for refluxing during 60 minutes and infusion at a concentration of 5%. The hydroalcoholic extracts were prepared by turboextraction with ethanol 70% using 3 cycles of 10 minutes in an ice bath with 1-minute interval between them, also at a concentration of 5%. Quantification of total phenolics, and flavonoids dihidroflavonoides and evaluating the inhibitory activity of alpha-amylase was performed by spectrophotometry. The antioxidant activity was evaluated by the total antioxidant capacity methods (TAC) for the reduction of ammonium molybdate, chelating power, reducing power, inhibition of lipid peroxidation and scavenging activity of free radicals (ABTS and DPPH). It was observed that among the studied species the extract obtained by refluxing and turboextraction for P. barbatus showed high levels of phenolic components, antioxidant activity and inhibition of alpha-amylase. In the second article aimed to determine the chemical composition and antioxidant activities, anti-Candida and inhibitory of the lipoxygenase and alpha-amylase enzymes of the essential oil of P. amboinicus. For these evaluations, were tested plants grown on plat and in the greenhouse and collected in the morning and afternoon. The essential oil was obtained by hydrodistillation using a Clevenger type apparatus modified, and its percentage yield relative to dry weight of the plant ranged between 0.047 and 0.100%. Chromatographic analysis led to the identification of sixteen compounds carvacrol being the major component representing 68-75%. The total atioxidante capacity (TAC) and elimination of free radicals (DPPH and ABTS) essential oil showed significant results compared to the positive controls employed. The inhibitory activity of lipoxygenase and alpha-amylase enzymes was not significant. However, the P. amboinicus’s oil showed potential antiCandida activity in vitro.