Pomelo peel contains a lot of important bioactive compounds having benefits for human health. This pomelo peel (Citrus grandis L.) products have important health benefits, so pomelo peel tea has been produced in order to enhance this great value. In-vitro and in-vivo studies on Nam Roi pomelo peel tea extract combined with identified acute toxicity in white male mice at a single oral dose of 5000 mg/kg body weight suggests that this is a safe product and has a high antioxidant effect as well as helps reduce the activity of glucose in the blood. This kind of extract had reduced blood sugar to normal levels (126.00±16.89 mg/dL, 100% survival) at a dose of 400 mg/kg weight of male white mice. There was no significant difference with the physiological control mice, which were more effective than those treated with glucophage (187.2±11.87 mg/dL). This extract also exhibited moderate antioxidant activities with EC₅₀ value of 80.81 ± 0.91; 93.61 ± 0.31; 106.52 ± 0017; 114.41 ± 1.01 μg/mL according to ABTS·+, FRAP, RP and DPPH methods, respectively. However, the exception of EC₅₀ values up to 349.31 ± 0.14 μg/mL when using the TAC method.

Key–words: acute toxicity, antioxidant, aqueous extract, blood glucose, Citrus grandis L. peels tea.