Wound healing and antibacterial properties of methanolic extract of Pupalia lappacea Juss in rats

BACKGROUND Wound healing is a natural process that enables tissue repair after an injury. To shorten its duration and minimize associated complications, wounds are treated with medications. Currently there is a growing interest in the use of alternative wound dressing agents such as plant extracts. One plant used traditionally in wound treatment is Pupalia lappacea. In view of its use in wound care, we investigated the wound healing activities of 80% methanolic leave extract of Pupalia lappacea using excision, incision and dead space wound models. Also its effects on three common wound contaminants were investigated. METHODS Excision wounds were created, contaminated with microbes and treated with ointments (10% and 20% w/w) prepared from Pupalia lappacea. Incision and dead space wounds were also created in rats which were subsequently dosed orally with the extract. The wound healing activities of Pupalia lappacea ointment on excision wound was assessed by rates of wound contraction and epithelialization as well as its antibacterial effects. The effects of Pupalia lappacea on incision and dead-space wounds were determined by the wound breaking strengths and weights of the granuloma tissues formed, respectively. RESULTS Pupalia. lappacea ointments significantly (p<0.05) accelerated wound healing with 20% ointment having the highest percentage wound contraction and rate of epithelialization. At 4, 7 and 14 days post treatment, mean total viable bacterial count of excision wounds of the extract treated groups were significantly (p<0.05) lower compared against the control. Wound breaking strengths and weights of granuloma tissues formed in the extract treated groups were significantly (p<0.05) higher than those of the control group. The minimum inhibitory concentration values obtained for the Pupalia lappacea extract against Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis were 9 mg/ml, 4 mg/ml and 3 mg/ml, respectively, while the corresponding minimum bactericidal concentrations were 10 mg/ml, 8 mg/ml and 7 mg/ml. CONCLUSION The results obtained showed that Pupalia. lappacea has good wound healing and antibacterial activities. These findings validate the use of this plant in traditional medicine for treatment of wounds.