Safety and Antioxidant Potential of Traditional Thai Poly‑Herbal Tea “Phy‑Blica‑D” Used as a Rejuvenation Formula

Background: The rising popularity of phytonutrient consumption may be due to a vast number of scientific studies that have revealed their health benefits; however, concerns regarding the medical safety of herbal‑based products are increasing. Phy‑Blica‑O is Phyllanthus emblica‑based herbal tea used in Thai traditional medicine as a rejuvenating remedy. However, its consumption has been limited due to its strong bitter taste with unpleasant odor. Objective: The objective of this study is to evaluate the safety and antioxidant potential of Phy‑Blica‑D, the modified formula of Phy‑Blica‑O which gave high sensory acceptability scores. Materials and Methods: Subacute toxicity studies of Phy‑Blica‑D infusion was conducted by repeated oral administration of the extract at doses of 5, 50, and 300 mg/kg/day in Sprague‑Dawley rats. Results: The formula exhibited antioxidant activity with an IC50 of 0.243 ± 0.006, 0.486 ± 0.002 and 0.108 ± 0.004 mg/mL using 1,1‑diphenyl‑2‑picrylhydrazyl, 2,20‑azino‑bis‑3‑ethylbenzthiazoline‑6‑sulfonic acid and metal chelating assays, respectively. There was no significant treatment‑related toxicity as indicated by clinical signs, body weight, food consumption, serum biochemical and hematological parameters, organ weight, and histopathological examination of the animals treated with Phy‑Blica‑D infusion. These results suggest that the oral no‑observed‑adverse‑effectlevel of Phy‑Blica‑D extract is >300 mg/kg body weight/day, or ~3.7 L/kg body weight/day for both sexes. The calculated human equivalent dose value is 48.39 mg/kg/day, or ~600 mL/kg body weight/day. There were no target organs affected. Conclusion: This study demonstrates that Phy‑Blica‑D infusion can be regarded as safe and could potentially be used as a functional ingredient to reduce oxidative stress in non-communicable diseases.