The investigation on an ethnic medicinal plant of Elsholtiza bodinieri Vaniot: Chemical constituents, acute, 28-day subacute and 90-day subchronic toxicity evaluation.

Ethnopharmacological Significance: Elsholtiza bodinieri Vaniot, belonging to the family Lamiaceae, has important medicinal value in Yunnan province of China. Traditionally, its aerial parts have been used as an ethnomedicine to treat diaphoresis, headache, fever, cough, pharyngitis, dyspepsia, and hepatitis. However, the safety assessment of E. bodinieri is still unexplored.

Aim Of The Study: This study aimed to investigate the phytochemical constituents of the hot water extract from E. bodinieri (HEEB) and evaluate the 14-day acute, 28-day subacute and 90-day subchronic toxicity by oral administration in Sprague-Dawley (SD) rats.

Materials And Methods: The chemical constituents of HEEB were analyzed by UHPLC-ESI-HRMS/MS. Firstly, SD rats were chosen for a single oral administration of the maximum dose of 5000 mg/kg to evaluate toxicity. Subsequently, consecutive 28-day subacute and 90-day subchronic toxicity assessments of HEEB were conducted on Sprague-Dawley (SD) rats through repeated doses of 2500, 1250, 625, and 312.5 mg/kg for the former, and 1500, 1000, and 500 mg/kg for the latter. For toxicity evaluation, hematology and serum biochemical indicators were determined, and major organs of the rats were collected to calculate organ coefficients. Additionally, hematoxylin-eosin (H&E) staining was performed on the collected tissues to assess histopathological changes induced by repeated oral administration of HEEB.

Results: A total of 23 compounds were identified by UHPLC-ESI-HRMS/MS analysis. Acute toxicity assessment revealed that oral administration of HEEB did not induce mortality and unnormal behavior changes in female rats over a 14-day period, suggesting that the approximate lethal dose (ALD) was higher than 5000 mg/kg. In consecutive 28-day and 90-day toxicity evaluations, HEEB doses of 2500 mg/kg and 1500 mg/kg resulted in hepatic and kidney tissue damage in both female and male rats, which was verified by the increased levels of AST, ALT, BUN, Na, and Cl.

Conclusions: After the acute, 28-day subacute and 90-day subchronic toxicity evaluation, the No Observed Adverse Effect Level (NOAEL) was determined as 1000 mg/kg/day. These findings not only provided a safety information for its medicinal and edible application, but also promoted the further comprehensive development of this plant.