Appraisal of anti-arthritic potential of Coronopus didymus (L.) Sm. aqueous extract and its safety study in Wistar rats.

The current study aimed to find out the anti-arthritic activity and safety study of Coronopus didymus aqueous extract (CDAE) as well as its chemical characterization by HPLC-DAD. Safety study including acute and subacute toxicity studies of the plant aqueous extract was also performed. In complete Freund's adjuvant-induced arthritic model (CFA), 0.15 ml CFA was injected in the left hind paw at day 1 in all rats except normal rats. Treatment with CDAE at 200, 400, and 800 mg/kg and methotrexate (1 mg/kg) was administered at day 8 and continued till 28th day using oral gavage. The CDAE considerably (p < 0.05) reduced the paw swelling and arthritic score, and reinstated the body weight and blood parameters. The CDAE considerably modulated superoxide dismutase, catalase, reduced glutathione, and malondialdehyde level in liver homogenate in contrast to disease control. The CDAE at 400 mg/kg considerably reduced IL-6, IL -1ß, COX-2, and NF-ĸß, whereas elevated IL-10, IL-4, and I-kappa ß as equated to disease and standard groups. The LD50 of CDAE > 2000 mg/kg. In subacute toxicity study, CDAE at 200-800 mg/kg did not exhibit clinical signs of toxicity, mortality, hematological, biochemical, and histological alteration in the liver heart, kidney, and lungs in contrast to the normal group. It was concluded that the presence of delphinidine-3-glucoside, diosmetin, 3-feruloyl-4,5-dicaffeoyl quinic acid, and gallic acid in CDAE might be accountable for its anti-arthritic activity and safe use for a long period.

HPLC -DAD analysis, anti-inflammatory and anti-arthritic potentials of Coronopus didymus (L.) Sm. extracts: effects on pro- and anti-inflammatory cytokines, COX-2, I-κß, NF-κß and oxidative stress biomarkers.

Coronopus didymus (L.) Sm. (CD) has been traditionally used to treat pain, rheumatism, and inflammation. This study was planned to appraise the anti-oxidant, anti-inflammatory and anti-arthritic potentials of CD (whole plant) aqueous ethanolic (CDAEE) and aqueous extracts (CDAE) and chemical characterization by high-performance liquid chromatography-diode array detector. In vivo anti-inflammatory (Carrageenan induced paw edema, and Xylene induced ear edema assays) and anti-arthritic potentials were evaluated in Wistar rats. Both extracts showed significant (p < 0.0001) in vitro free radical scavenging and in vitro anti-arthritic potentials by inhibition of protein denaturation and stabilization of the HRBC membrane and anti-oedematogenic potential, whereas more activity was expressed by CDAEE. In complete Freund's adjuvant-induced arthritic model, the CDAEE at 200, 400, and 800 mg kg-1 and methotrexate (1 mg kg-1) profoundly (p < 0.05) reduced the arthritic score and paw edema, restored body and immune organ weight, and altered blood parameters and oxidative stress biomarkers. The qRT-PCR analysis revealed that CDAEE at 400 mg kg-1 significantly (p < 0.0001) downregulated TNF-α (2.22 ± 0.16 fold), IL-6 (2.29 ± 0.05 fold), IL-1ß (2.10 ± 0.01 fold), COX-2 (2.45 ± 0.02 fold), and NF-Ä¸ß (2.72 ± 0.06 fold) and considerably upregulated IL-10 (58.84 ± 0.67%), IL-4 (76.16 ± 2.79%) and I-kß (75.45 ± 0.17%) in arthritic rats in contrast to disease control and methotrexate as evidenced from the joint histology. These findings suggested the antioxidant, anti-inflammatory and anti-arthritic activities of C. didymus, which might be due to the presence of quercetin, ferulic acid, dihydromyricetin, apigenin, vitexin, and kaempferol in CDAEE.