Safety and toxicological evaluation of NXT15906F6 (TamaFlex ® )

NXT15906F6 (TamaFlex ® ) is a food-derived herbal composition with synergistic anti-inflammatory properties and the potential to improve muscle–skeletal function in healthy populations. NXT15906F6 contains standardized ethanol/aqueous extracts of Tamarindus indica seeds and an ethanol extract of Curcuma longa rhizome in a 2:1 ratio. The present study was conducted to evaluate the broad-spectrum safety of NXT15906F6. All studies were conducted in compliance with good laboratory practice requirements and followed Organization for Economic Cooperation and Development Guidelines for Testing of Chemicals. The acute oral and acute dermal lethal dose of NXT15906F6 was greater than 2000 mg/kg body weight in Wistar rats. NXT15906F6 was classified as nonirritating to the skin and as a mild irritant to the eyes of New Zealand white rabbits. A repeated-dose 90-day subchronic study in Wistar rats was conducted. Groups of animals ( n = 20, 10 male and 10 female) were orally supplemented with 0, 250, 500, and 1000 mg/kg/day of NXT15906F6 for 90 days. In parallel, two separate groups of animals ( n = 10, five male and five female) were gavaged with 0 and 1000 mg/kg body weight of NXT15906F6 for 90 days and observed for another 28 days. No morbidity, mortality, or significant adverse events were observed during the study or the follow-up phase. The no observed adverse effect level for NXT15906F6 was 1000 mg/kg/day in both male and female rats. A bacterial reverse mutation test and an in vivo mouse bone marrow erythrocyte micronucleus test showed that the NXT15906F6 herbal blend is nonmutagenic and nongenotoxic. In summary, the safety studies conducted in various models demonstrate the broad-spectrum safety of NXT15906F6.