Efeito antinociceptivo e anti-inflamatório da Scoparia dulcis Linn na osteoartrite experimental

Abstract

Introduction: Pain in osteoarthritis causes disability and functional impairment of the affected joint, and its management is considered a major challenge. In search of new therapies, comes Scoparia dulcis, popularly known as broom, whose anti-inflammatory, antinociceptive and antioxidant properties are scientifically proven and have not been studied so far in controlling joint pain in osteoarthritis. Objective: To evaluate the antinociceptive, antiinflammatory and antioxidant effect of crude extract and chloroform fraction of Scoparia dulcis Linn in an experimental model of osteoarthritis. Material and Methods: In the first moment of the research, knee osteoarthritis was induced by intraarticular injection of sodium monoiodoacetate. Twenty-five Wistar rats were divided into five groups with five animals each: healthy group, saline group, crude extract group, chloroform fraction group and meloxicam group. Clinical parameters of pain (joint disability, motor activity, tactile sensitivity, joint edema and spontaneous pain) were evaluated on days zero, five, ten, fifteen and twenty days after induction. Secondly, the percentage of cyclooxygenase inhibition, chemical analysis, molecular coupling and quantification of the cytokines IFN-γ, IL-6 and IL-10 of the synovial fluid were evaluated. Polyphenol values and total flavonoid contents, antioxidant activity (DPPH •, FRAP and ABTS • + methods) were quantified. The enzymes superoxide dismutase, catalase and glutathione peroxidase were evaluated. Histopathological evaluation was done on articular cartilage with safranin O staining and on synovial fluid with hematoxylin and eosin staining. Results: Therapeutic treatment for 15 days with crude S. dulcis extract and chloroform fraction (500 mg / kg / day) reduced edema, spontaneous pain and peripheral nociceptive activity in the right knee with OA, attenuating histological changes in the membrane. synovial and articular cartilage with lower synovial levels of IL-6 and IFN-γ, and higher levels of IL-10, possibly due to their anti-inflammatory action. The tested concentration of 50 μg / mL showed the highest inhibition for COX-1 and COX-2 in the crude extract. All compounds showed high parameter affinity with COX-2 structure, highlighting suspensaside and nicotiflorin and performed interactions with important residues of the active site of COX, such as Arg120 and Glu524 and with neighboring residues. The extract and chloroform fraction showed antioxidant activity by the DPPH •, FRAP and ABTS • + methods and by the enzymes superoxide dismutase, catalase and glutathione peroxidase. Conclusion: The crude extract and chloroform fraction of S. dulcis have therapeutic potential for the treatment of osteoarthritis due to its anti-inflammatory, antinociceptive and antioxidant action.