In vitro Antioxidant Activity and In vivo Anti-inflammatory Effect of Ricinus communis (L.) and Withania somnifera (L.) Hydroalcoholic Extracts in Rats

ABSTRACT

Abstract Ricinus communis L. and Withania somnifera L. have traditionally been used as analgesic and anti-inflammatory remedies. The current study was aimed to evaluate the in vitro antioxidant potential and anti-inflammatory activity of hydroalcoholic extract of R. communis leaves (RCE) and W. somnifera roots (WSE) in Wistar rats. Total phenolic and flavonoid contents were quantified and in vitro antioxidant activity of extracts was determined through DPPH* scavenging, superoxide anion scavenging and reducing power activities, while anti-inflammatory activity was observed by xylene-induced ear edema and paw edema induced by egg albumin and carrageenan. RCE and WSE demonstrated considerable antioxidant activity in DPPH* scavenging (IC50: 250.10 and 309.42 µg/mL), superoxide anion scavenging (IC50: 193.42 and 206.81 ug/mL), and reducing power (maximum absorbance: 1.47±0.01 O.D and 1.28±0.01 O.D at 500 ug/mL) activities, respectively, with high phenolic and flavonoid contents. Both extracts showed dose-dependent edema inhibition in inflammation models. A maximum ear edema inhibitions by RCE (51.49±2.54%) and WSE (49.28±1.90%) at 500 mg/kg were observed when compared to indomethacin (56.42±13.17%) in xylene-induced ear edema. RCE and WSE showed a maximum percentage of paw edema inhibitions of 46.62±8.98% and 43.00±12.44%, respectively as compared to chlorpheniramine (62.02±12.21%) after 4 h in the egg albumin model. In carrageenan-induced paw edema, RCE (72.88±13.79%) significantly inhibited paw edema in comparison to WSE (57.81±17.43%) against diclofenac (89.93±18.53%). Conclusively, both plants have shown plausible antioxidant and anti-inflammatory activities that might be due to high phenolic and flavonoid contents. Moreover, RCE demonstrated more promising effects than WSE.