Agroprocessing and Natural Products Division, National Institute for Interdisciplinary Science and Technology-CSIR, Thiruvananthapuram, Kerala 695019, India.
Nat Prod Res. 2012;26(17):1654-8. doi: 10.1080/14786419.2011.589386. Epub 2011 Oct 6.
A wide range of proteinaceous inhibitors are present in plants to protect themselves from hydrolytic enzymes. In this study, turmerin, a water-soluble peptide in turmeric rhizomes, was evaluated for its inhibitory potential against glucosidase and its antioxidant (AO) capacity. Turmerin inhibited α-amylase and α-glucosidase activities with IC₅₀ values 31 and 192 µg mL⁻¹, respectively. Under the experimental conditions, those values for a standard glucosidase inhibitor, acarbose, were 81 and 296 µg mL⁻¹, respectively. The AO capacity of turmerin was evaluated using in vitro assay systems. Turmerin showed good DPPH (IC₅₀ = 29 µg mL⁻¹) and superoxide (IC₅₀ = 48 µg mL⁻¹) and moderate ABTS (IC₅₀ = 83 µg mL⁻¹) radical scavenging and Fe(II) chelation (IC₅₀ = 101 µg mL⁻¹) capacities. The inhibitory potential showed by turmerin against enzymes linked to type 2 diabetes, as well as its moderate AO capacity, could rationalise the traditional usage of turmeric rhizome preparations against diabetes.
植物中存在广泛的蛋白质抑制剂，以保护自身免受水解酶的侵害。在这项研究中，姜黄根茎中的水溶性肽姜黄肽被评估其对葡萄糖苷酶的抑制潜力及其抗氧化（AO）能力。姜黄肽对α-淀粉酶和α-葡萄糖苷酶的抑制活性的 IC₅₀值分别为 31 和 192µg mL⁻¹。在实验条件下，标准葡萄糖苷酶抑制剂阿卡波糖的相应值分别为 81 和 296µg mL⁻¹。使用体外测定系统评估了姜黄肽的 AO 能力。姜黄肽显示出良好的 DPPH（IC₅₀=29µg mL⁻¹）和超氧化物（IC₅₀=48µg mL⁻¹）自由基清除能力，以及中等的 ABTS（IC₅₀=83µg mL⁻¹）和 Fe（II）螯合（IC₅₀=101µg mL⁻¹）能力。姜黄肽对与 2 型糖尿病相关的酶的抑制潜力及其适度的 AO 能力，可解释姜黄根茎制剂用于治疗糖尿病的传统用途。
