Repeat oral dose safety study of standardized methanolic extract of Boswellia sacra oleo gum resin in rats

The oleo gum resin of Boswellia sacra Fleuck. (Burseraceae) is widely consumed for treatment of several diseases and disorders. To determine the effect of repeated administration of this resin on liver and kidney functions, three different doses of standardized methanolic extract were administered orally to rats for 28 days. Apart from histological studies and determination of biomarkers of hepatotoxicity and nephrotoxicity, other parameters of sub-chronic toxicity such as behavioral change, food consumption and change in body weight were assessed. The extract contained about 36.91% of total boswellic acids; of which 11-keto beta boswellic acid, acetyl-11-keto beta boswellic acid, boswellic acids (α and β) and acetyl boswellic acid (α and β) were found to be 5.81%, 1.91%, 21.92% and 7.27% respectively. Oral administration of the extract for 28 consecutive days did not show any sign of behavioral toxicity and did not affect food consumption or weight gain significantly. Determination of biomarkers of hepatic and nephrotoxicity revealed that extract was safe at the tested doses as it did not produce any significant change in the studied biomarkers except producing a dose dependent increase in serum total protein levels. The histological examination supported biochemical findings. To conclude, methanolic extract of Boswellia sacra doen not produce any significant toxicity to liver and kidney up to doses of 100 mg/kg body weight. The results contradict earlier reports that members of boswellia species produce organ toxicity in rats.