Investigation of the antioxidant and aldose reductase inhibitory activities of extracts from Peruvian tea plant infusions

•Antioxidant effects of 24 Peruvian infusion tea plants were investigated.•Aldose reductase inhibitory effects of the 24 plants were also investigated.•Aldose reductase ultrafiltration-high pressure liquid chromatography was developed.•Phoradendron sp. is a potent functional food ingredient.

In the present study, the antioxidant and aldose reductase inhibitory activities of 24 Peruvian infusion tea plants were investigated by 2,2′-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and aldose reductase assays. Phoradendron sp. showed the highest inhibition of aldose reductase (IC50, 1.09 ± 0.06 μg/mL) and considerable antioxidant (IC50 of DPPH, 58.36 ± 1.65 μg/mL; IC50 of ABTS, 9.91 ± 0.43 μg/mL) effects. In order to identify the antioxidants and aldose reductase inhibitors of Phoradendron sp., DPPH-high performance liquid chromatography (HPLC) and ultrafiltration-HPLC assays were performed. Chlorogenic acid, 3,5-di-O-caffeoylquinic acid, and 1,3,5-tri-O-caffeoylquinic acid were identified as the antioxidants and aldose reductase inhibitors; apigenin was identified as the antioxidant. Finally, Phoradendron sp. and its aldose reductase inhibitors also showed a dose-dependent anti-inflammatory effect without cellular toxicity. These results suggested that Phoradendron sp. can be a potent functional food ingredient as an antioxidant, aldose reductase inhibitor and anti-inflammatory agent.