Acute and sub-acute toxicity assessment of methanolic extract from Clerodendrum infortunatum flowers.

BACKGROUND

The study evaluates the acute and sub-acute toxicity profiles of Clerodendrum infortunatum flower extracts (MECF) in animal models, addressing a critical gap in scientific research on this traditionally used medicinal plant. Systematic toxicity assessments are essential to bridge traditional knowledge with modern scientific validation and ensure the safe development of phytopharmaceuticals.

OBJECTIVE

To evaluate the acute and sub-acute oral toxicity of the methanolic flower extract of Clerodendrum infortunatum in Swiss albino rats and providing a foundation for its potential therapeutic applications and human use.

METHODS

Acute toxicity studies were conducted at doses up to 2500 mg/kg, mortality and visible signs of toxicity were monitored, while sub-acute toxicity assessments were performed over 28 days at doses up to 2000 mg/kg/day. Parameters evaluated included body weight, food and water intake, hematological and biochemical markers, and histopathological examinations of vital organs (heart, liver, kidneys, and brain).

RESULTS

Acute toxicity: MECF was well-tolerated at doses up to 2500 mg/kg, with no significant adverse effects except mild sedation at the highest dose. Sub-acute toxicity: No significant changes were observed in body weight, food and water intake, hematological parameters, or biochemical markers, indicating no adverse effects on liver, kidney, or other vital organ functions. Histopathological examinations confirmed the absence of tissue damage or cellular alterations.

CONCLUSION

The methanolic extract of Clerodendrum infortunatum flowers demonstrated no observable toxicity in rats at doses up to 2500 mg/kg in acute oral toxicity testing and up to 2000 mg/kg during sub-acute (28-day) exposure. Human equivalent doses were estimated by applying 10 × and 20 × safety margins to the preclinical data, using body surface area normalization for interspecies conversion providing a foundation for future preclinical and clinical studies. These findings suggest that the methanolic extract of flower is safe for oral administration in rats within the tested dose ranges.