The use of systemic corticosteroids in asthma management in Latin American countries

Oral sub-chronic toxicity of fingerroot (Boesenbergia rotunda) rhizome extract formulation in Wistar rats

Background

Boesenbergia rotunda (fingerroot) rhizome extract contains two major bioactive components, panduratin A and pinostrobin. In our previous study, we found the anti-inflammatory effects of the fingerroot extract against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in golden Syrian hamsters. In the present study, we evaluated the sub-chronic toxicity of a fingerroot extract formulation over 90 consecutive days of oral administration.

Methods

We enhanced the water solubility of a fingerroot extract by formulating it with cyclodextrin, containing panduratin A (29% w/w) and pinostrobin (32% w/w). This formulation was administered to male and female Wistar rats at doses of 25, 50, or 100 mg/kg/day for a duration of 90 days. Additionally, two recovery groups, comprising a control group and a high-dose group, were designated for a 14-day observation period to assess the persistence and reversibility of potential adverse effects. Throughout the experiment, we performed clinical and health observations, followed by hematological testing, clinical biochemistry analysis, necropsy examination, and histopathological evaluation at the end of the experiment.

Results

The administration of the fingerroot extract formulation at doses of 25, 50, or 100 mg/kg/day did not result in mortality or clinical signs of toxicity. No clinically significant findings were associated with the oral administration of the fingerroot extract formulation.

Conclusion

The fingerroot extract formulation showed no serious adverse effects at doses up to 100 mg/kg/day in Wistar rats under the experimental condition. Consequently, the No Observed Adverse Effect Level (NOAEL) was considered to be 100 mg/kg/day. This finding contributes significance for future developments involving fingerroot extract in herbal medicinal products targeting chronic inflammation.