Acute and subacute oral toxicity assessment of Karanjin in Sprague Dawley rats

Karanjin (KRN) is a benzofuran flavonoid derived from Pongamia pinnata seeds, known for its antihyperglycemic and anti-inflammatory properties. Despite its traditional use, comprehensive toxicological data are limited. This study evaluated the acute and subacute oral toxicity of KRN in Sprague Dawley rats. In the acute study, single doses of 5, 500, or 2000 mg/kg were administered, and animals were observed for 14 days. In the subacute study, daily doses of 5, 50, or 250 mg/kg were given for 28 days. Clinical signs, body weight, food and water intake were monitored throughout. At termination, organs (liver, kidney, heart, etc.) were weighed, blood was analysed for biochemical parameters (ALT, AST, ALP, total protein, albumin, lipids), and tissues were examined histopathologically. No mortality or treatment-related clinical signs occurred at any dose. Body weight, food/water intake, and organ weights did not differ significantly between treated and control groups. Serum biochemical values remained within normal limits, showing only minor, non-dose-dependent variations. Histopathology revealed normal architecture of major organs without evidence of necrosis, inflammation, or degeneration. These findings demonstrate a wide margin of safety for oral KRN and support its potential for further pharmacological development. • Karanjin, a furanoflavonoid from Pongamia pinnata , demonstrated excellent oral safety in both acute and subacute toxicity models in Sprague Dawley rats. • No mortality, clinical abnormalities, or behavioural changes were observed up to a single dose of 2000 mg/kg (acute) or repeated daily dosing of 250 mg/kg for 28 days (subacute). • Physiological parameters including body weight, food and water intake remained comparable to control throughout both studies, indicating normal metabolic function. • Liver, kidney, and heart histology were entirely normal at all dose levels, with no microscopic evidence of inflammation, necrosis, or structural alteration. • Serum biochemistry and lipid profiles remained within reference ranges, with no signs of organ toxicity or systemic disruption. • The No Observed Adverse Effect Level (NOAEL) of Karanjin exceeds the highest tested doses, supporting its advancement for pharmacological use.