Synergistic effect of Trikatuk, a traditional Thai formulation, on antioxidant and alpha-glucosidase inhibitory activities

Oxidative stress and hyperglycemia are known to be responsible for several diseases, including diabetes. To prevent these diseases, efforts are ongoing to identify novel antioxidants with hy-poglycemic effects. Trikatuk is a traditional Thai formulation composed of three herbs in equal quantities: the fruits of Piper nigrum and Piper retrofractum and the rhizomes of Zingiber officinale. This formulation has been reported to have antioxidant activity and the three individual herbs have been traditionally used for managing diabetes. Therefore, the present study aimed to investigate the phytochemical contents, antioxidant activity (DPPH and ABTS radical scavenging assays), and alpha-glucosidase inhibitory activity of Trikatuk. As Trikatuk is a combination of herbs, the synergistic effect and two different preparation methods from powder or extract mixtures were also explored. The results revealed that Trikatuk, particularly prepared from a mixture of extracts, exhibited high contents of piperine, total phenolics and total flavonoids, as well as significant antioxidant and alpha-glucosidase inhibitory activities. Trikatuk also exhibited additive or synergistic effects in all experiments. Overall, Trikatuk is potentially an alternative traditional medicine and dietary supplement offering antioxidant activity and diabetes management.