Acute and sub-acute toxicity evaluation of rhamnolipid derived from Stutzerimonas stutzeri PS1 in Wistar rats.

Rhamnolipid biosurfactants have gained attention due to their surface-active properties and applications in the pharmaceutical and food industries. However, toxicological profiling remains for their safe integration. This study assessed the purity of rhamnolipid by HPLC and evaluated its acute and sub-acute toxicity in Wistar rats. In the acute toxicity, a dose of 2000 mg/kg was administered, and animals were monitored for 14 days. In sub-acute toxicity study, rats received oral doses of 250, 500, and 1000 mg/kg for 28 days. Toxicity was assessed through clinical observation, hematological analysis, serum biochemistry, and histopathological examination of the liver and kidney. No mortality or abnormal signs were observed in any treated groups. The hematological parameters and serum biochemical markers (SGPT, SGOT, urea, and creatinine) showed no significant differences (p > 0.05) compared to the control group, indicating maintained hepatic and renal functions. Furthermore, histopathological analysis of liver and kidney sections revealed preserved cellular architecture with no evidence of inflammation, necrosis, or structural alterations across all doses. The No-Observed-Adverse-Effect Level (NOAEL) for hepatic and renal endpoints exceeded 1000 mg/kg/day. These findings suggest no hepatic or renal toxicity observed under tested conditions and support the suitability of this biosurfactant for pharmaceutical and biotechnological applications.