Casearia decandra leaves present anti-inflammatory efficacy in a skin inflammation model in mice

Abstract

Ethnopharmacological relevance: Casearia decandra (guaçatonga) is popularly used as an anti-inflammatory. We investigated the antioxidant and anti-inflammatory effect of C.decandra leaves (CdE) ethanolic extract and of the rutin standard (present in the CdE).

Materials and methods: Male adult Swiss mice were used (25-30 g; 5-6 animals by a group). CdE phytochemical analysis was performed by HPLC method. The antioxidant potential of CdE and rutin was assessed by different methods. Topical anti-inflammatory effect of CdE (0.001-1mg/ear) and rutin (0.003-0.03mg/ear) was evaluated by ear edema formation and inflammatory cells infiltration (MPO activity and histology) on a skin inflammation model induced by topical application of croton oil (1mg/ear).

Results: Rutin (27.81 ± 1.11 mg/g) was identified in CdE by HPLC analysis. The required amounts of CdE, rutin and ascorbic acid to reduce the initial concentration of radical DPPH by 50% (IC₅₀) were 7.77 (6.31-9.57) μg/mL, 3.62 (3.26-4.01) μg/mL and 3.74 (3.37-4.14) μg/mL with a radical DPPH reduction of 91 ± 1.2%, 91 ± 0.5%, and 96 ± 0.44% (at 30 μg/mL), respectively. Moreover, CdE and rutin presented H₂O₂ scavenging activity with H₂O₂ levels reduction of 41 ± 7% and 46 ± 6%, respectively and SOD-like activity of 60 ± 4% and 51 ± 14%, respectively. On the other hand, just rutin presented nitric oxide scavenging activity of 54 ± 6%. CdE and rutin topically applied inhibited the ear edema with a maximum inhibition of 70 ± 5% (1 mg/ear) and 78 ± 10% (0.03 mg/ear), respectively. Treatments reduced the MPO activity (42 ± 4% to CdE; 1mg/ear and 30 ± 8% to rutin; 0.03 mg/ear). Histologically, the topical treatments also reduced the dermis thickness and the inflammatory cells infiltration.

Conclusion: We demonstrated the antioxidant and anti-inflammatory effect of C.decandra leaves and rutin. Its antioxidant potential may contribute to inflammatory process attenuation, supporting the C.decandra leaves used as a promising alternative in the therapy of the inflammatory diseases.

Keywords: Anti-inflammatory; Antioxidant; Ear edema; Guaçatonga; Rutin.