In silico, anti-inflammatory and acute toxicological evaluation of an indigenous medicinal plant Pterospermum rubiginosum using Sprague-Dawley rats

Pterospermum rubiginosum has been traditionally used by the tribal inhabitants of Southern India for treating bone fractures and as a local anti-inflammatory agent; however, experimental evidence to support this traditional usage is lacking. The present study aimed to investigate the phytochemical characterization, in silico and in vitro anti-inflammatory evaluation, followed by in vivo toxicological screening of P. rubiginosum methanolic bark extract (PRME).

PRME administration significantly downregulated the gene expression of inflammatory markers, such as iNOS, IL-6, and IL-10. The molecular docking analysis of iNOS and IL-6 supports the in vitro study. In vivo toxicological study of PRME in SD rats was found to be non-toxic up to a concentration of 1000 mg/kg body weight for 14 days.

The LCMS evaluation revealed the presence of 80 significant peaks; nearly 50 molecules were identified using the LCMS database. In silico analysis showed notable interactions with inducible nitric oxide synthase (iNOS) and interleukin-6 (IL-6). In vitro gene expression study supported the docking results with significant down-regulation of iNOS, IL-6, and IL-10. PRME was administered orally to the SD rats and was found to be non-toxic up to 1000 mg/kg body weight for 14 days. The antioxidant enzymes catalase and sodium dismutase exhibited an increased value in PRME-administered groups, possibly due to the diverse phytochemical combinations in bark extract. Conclusions: PRME administration significantly downregulated the gene expression of inflammatory markers, such as iNOS, IL-6, and IL-10. The molecular docking analysis of iNOS and IL-6 supports the in vitro study. In vivo toxicological study of PRME in SD rats was found to be non-toxic up to a concentration of 1000 mg/kg body weight for 14 days.