Resumo A Curcuma longa é uma importante planta presente na dieta da população, pois possui diversas atividades farmacológicas, incluindo antioxidante, antimicrobiana, anti-inflamatória, anticancerígena, anticoagulante etc. O objetivo do presente estudo foi elucidar o perfil fenólico da Curcuma longa e determinar as atividades antioxidante e antidiabética in vitro do extrato. No cromatograma por HPLC do extrato de rizoma de Curcuma longa, foram identificados 15 compostos fenólicos: digaloil-hexosídeo, hexosídeo de ácido cafeico, curdiona, cumárico, ácido cafeico, ácido sinápico, quercetina-3-D-galactosídeo, casuarinina, bisdemetoxicurcumina, curcuminol, demetoxicurcumina, isoramnetina, bilactona de ácido valônico, curcumina e curcumina-O-glicuronídeo. O extrato etanólico apresentou um valor de IC50 de 37,1 ± 0,3 µg / mL em relação à alfa-glucosidase. O valor de IC50 da atividade de eliminação de radicais DPPH foi de 27,2 ± 1,1 μg / mL. Conclui-se que o extrato etanólico de Curcuma longa é uma rica fonte de curcumina e contém várias substâncias fenólicas importantes. O efeito antioxidante in vitro e inibidor da alfa-glucosidase da planta justifica seu uso popular na medicina tradicional.

Abstract Curcuma longa is an important dietary plant which possess several pharmacological activities, including antioxidant, antimicrobial, anti-inflamatory, anticancer and anti clotting etc. The aim of the present study was to determine the phenolic profile of Curcuma longa and in vitro antioxidant and antidiabetic activities. In HPLC chromatogram of Curcuma longa rhizome extract 15 phenolic compounds were identified namely Digalloyl-hexoside, Caffeic acid hexoside, Curdione, Coumaric, Caffeic acid, Sinapic acid, Qurecetin-3-D-galactoside, Casuarinin, Bisdemethoxycurcumin, Curcuminol, Demethoxycurcumin, and Isorhamnetin, Valoneic acid bilactone, Curcumin, Curcumin-O-glucuronide respectively. The ethanolic extract displayed an IC50 value of 37.1±0.3 µg/ml against alpha glucosidase. The IC50 value of DPPH radical scavenging activity was 27.2 ± 1.1 μg/mL. It is concluded that ethanolic extract of Curcuma long is rich source of curcumin and contain several important phenolics. The in vitro antioxidant and alpha glucosidase inhibitory effect of the plant justifies its popular use in traditional medicine.

Thirteen genotypes of sugarcane were exposed to different drought stress intensities followed by a period of stress relief. Different biomarkers were used to analyze the stress tolerance in leaves which include DPPH activity, proline, glycine betaine, lipid peroxidation and phenolic contents against different doses of Polyethylene glycol. Relatively the concentrations of all biochemical markers were increased when PEG concentration was increased. On the basis of lipid peroxidation, glycine betaine and proline contents, HSF-242, Lho-83, HSF-240, CP-77-400, CPF-198, NSG-45, NSG-60 and NSG-555 were found to be drought tolerant genotypes. In conclusion the drought stress-induced changes are reversible, at the cellular level in sugarcane.