Anti-inflammatory and antioxidant properties of unripe papaya extract in an excision wound model.

CONTEXT

Carica papaya L. (Caricaceae) fruit was shown to exhibit wound healing properties.

OBJECTIVES

We investigated anti-inflammatory and antioxidant potential of papaya fruit phosphate-buffered saline extract (PE) during wound healing and enhancement of the potentials due to trace ions addition.

MATERIALS AND METHODS

Rat excision wounds were topically treated twice/day with 20 µL of PE (5 mg extract/mL), 0.5 µg Se(2+) added PE (PES), or 100 µM Zn(2+) added PE (PEZ). Control groups were treated with deionized water (negative) and deproteinized calf blood extract ointment (Solcoseryl®, positive). Lipid peroxidation (LPX), antioxidant, proinflammatory, and arginine metabolic enzymes were estimated in the wound excised on days 4 and 10 post wounding.

RESULTS

PE (5 mg/mL; 9.80 ± 0.33 d) and PES (PE + 0.5 µg Se(2+); 8.90 ± 0.23 d) significantly (p < 0.05) reduced the average time for complete wound closure compared with the negative (13.00 ± 0.37 d) and positive (9.80 ± 0.33 d) controls, respectively. Biochemical evaluations of LPX product (malondialdehyde), antioxidant (catalase, superoxide dismutase (SOD), and glutathione peroxidase (GPx)), and pro-inflammatory (cyclooxygenase-2 and myeloperoxidase (MPO)) enzyme activities and metabolites (nitrite and urea), on days 4 and 10 post wounding, confirmed the anti-inflammatory and antioxidant properties of PE and PES in this study.

DISCUSSION AND CONCLUSION

Treatment of excision wounds with papaya extract, especially with the addition of selenium for 10 d, reduced inflammation associated oxidative damage apparently via cyclooxygenase specific inhibition, arginine metabolism, and up-regulation of antioxidant enzymes.