| Autor: |
Chagas VT; Department of Physiological Sciences, Federal University of Maranhão, 65080805 São Luís, MA, Brazil., Coelho RMRS; Department of Physiological Sciences, Federal University of Maranhão, 65080805 São Luís, MA, Brazil., Gaspar RS; Department of Physiological Sciences, Federal University of Maranhão, 65080805 São Luís, MA, Brazil., da Silva SA; Department of Physiological Sciences, Federal University of Maranhão, 65080805 São Luís, MA, Brazil., Mastrogiovanni M; Department of Biochemistry and Center for Free Radical and Biomedical Research, Faculty of Medicine, University de la República, 11800 Montevideo, Uruguay., Mendonça CJ; Department of Chemistry, Federal University of Maranhão, 65080805 São Luís, MA, Brazil., Ribeiro MNS; Department of Pharmacy, Federal University of Maranhão, 65080805 São Luís, MA, Brazil., Paes AMA; Department of Physiological Sciences, Federal University of Maranhão, 65080805 São Luís, MA, Brazil., Trostchansky A; Department of Biochemistry and Center for Free Radical and Biomedical Research, Faculty of Medicine, University de la República, 11800 Montevideo, Uruguay. |
| Abstrakt: |
Syzygium cumini (L.) Skeels has been reported to exert anti-inflammatory and cardiometabolic activities due to its high content of polyphenols. We characterized the chemical composition and assessed the antidiabetic effects of a novel polyphenol-rich extract (PESc) obtained from S. cumini leaf. Rats were injected with alloxan (150 mg/kg, ip, ALX group) and followed up for 7 days. Some were orally treated with PESc (50 mg/kg/day) for 7 days before and after diabetes induction (ALX-PP) or only for 7 days after alloxan injection (ALX-P). ALX-P and ALX-PP decreased fasting glycemia in 37 and 43%, respectively, as compared to ALX. Triglycerides and total cholesterol serum levels were also significantly reduced in comparison to ALX. PESc presented high polyphenol concentration (71.78 ± 8.57 GAE/100 g), with flavonoid content of 8.21 ± 0.42 QE/100 g. Upon HPLC-MS/MS and MS/MS studies, five main polyphenols-gallic acid, quercetin, myricetin, and its derivatives-were identified. Myricetin was predominant (192.70 ± 16.50 μ g/mg PESc), followed by measurable amounts of gallic acid (11.15 ± 0.90 μ g/mg PESc) and quercetin (4.72 ± 0.06 μ g/mg PESc). Kinetic assessment of total antioxidant capacity revealed PESc high potency, since maximum response was reached within 5 min reaction time in a concentration-dependent manner. Specific antioxidant activity of PESc was assessed against both DPPH • and ABTS •+ , showing strong activity (IC 50 : 3.88 ± 1.09 and 5.98 ± 1.19 μ g/mL, resp.). PESc also inhibited lipoxygenase activity (IC 50 : 27.63 ± 8.47), confirming its antioxidant activity also on biologically relevant radicals. Finally, PESc induced insulin secretion by directly stimulating INS-1E β cells in the absence of any cytotoxic effect. Overall, our results support that PESc is a potent antioxidant phytocomplex with potential pharmacological use as a preventive antidiabetic natural product. |
Plný text