Evaluation of Antimicrobial and Wound Healing Potential ofJusticia flavaandLannea welwitschii

Abstract

Microbial infections of various types of wounds are a challenge to the treatment of wounds and wound healing. The aim of the study is to determine the antimicrobial, antioxidant, and in vivo wound healing properties of methanol leaf extracts of Justicia flava and Lannea welwitschii. The antimicrobial activity was investigated using agar well diffusion and microdilution methods. The free radical scavenging activity of the methanol leaf extracts was performed using 1,1-diphenyl-2-picryl-hydrazyl (DPPH). The rate of wound contraction was determined using excision model. The test organisms used were Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 4853, Bacillus subtilis NTCC 10073, Staphylococcus aureus ATCC 25923, and clinical strains of Candida albicans. The MICs of methanol leaf extract of J. flava against test organisms were E. coli (7.5 mg/mL); P. aeruginosa (7.5 mg/mL); S. aureus (5 mg/mL); B. subtilis (7.5 mg/mL); and C. albicans (5 mg/mL). The MICs of methanol leaf extract of L. welwitschii against test organisms were E. coli (5 mg/mL); P. aeruginosa (10 mg/mL); S. aureus (5 mg/mL); B. subtilis (2.5 mg/mL); and C. albicans (2.5 mg/mL). The MBC/MFC of the extract was between 10 and 50 mg/mL. The IC50 of the reference antioxidant, α-tocopherol, was 1.5 μg/mL and the methanol leaf extracts of J. flava and L. welwitschii had IC50 of 65.3 μg/mL and 81.8 μg/mL, respectively. The methanol leaf extracts of J. flava and L. welwitschii gave a significant reduction in wound size as compared to the untreated. The rates of wound closure after the application of the extracts (7.5% w/w) were compared to the untreated wounds. On the 9th day, J. flava extract had a percentage wound closure of 99% (P < 0.01) and that of L. welwitschii exhibited wound closure of 95% (P < 0.05) on the 13th day compared to the untreated wounds. The two extracts significantly (P < 0.01) increased the tensile strength of wounds compared to the untreated wounds. The extracts treated wound tissues showed improved angiogenesis, collagenation, and reepithelialization compared to the untreated wound tissues. The preliminary phytochemical screening of J. flava and L. welwitschii leaf extracts revealed the presence of tannins, alkaloids, flavonoids, and glycosides. The above results indicate that methanol leaf extracts of J. flava and L. welwitschii possess antimicrobial and wound healing properties which may justify the traditional uses of J. flava and L. welwitschii in the treatment of wounds and infections.

Effect of Methanolic Extract of Justicia Flava on Petroleum-Induced Reduced Cell Division and DNA Damage

“…The medicinal ability of Justicia flava hinges on the presence of various phytochemicals with antioxidant properties [43]. This assertion is not surprising since earlier studies indicated that petroleum stimulated damages are preceded by the formation of free radicals that culminates in macromolecu-lar damage [44,45].…”

Acute Toxicological Evaluations of the Methanol Leaf Extract of Justicia flava (Vahl) Acanthaceae in Mouse Models

“…The methanol leaf extracts of J. flava have been reported to improve angiogenesis, collagenation, and reepithelialization in wound tissues. 4 The leaves of J. flava have also been reported to exhibit radical scavenging effect as well as inhibition of lipoxygenase activity. 2 The alpha-amylase inhibitory activity of the leaves of J. flava has also been reported 1 and has been proposed to have antiviral properties as well.…”

Medicinal Plants and Natural Products with Demonstrated Wound Healing Properties

“…Methanol leaf extract of L. welwitschii (7.5%, w/w) significantly (p < 0.05) reduced wound size as compared to the untreated in excision wound model in rats. The extract also significantly (p <0.01) increased the tensile strength, improved angiogenesis, collagenation, and re-epithelialization of wounds compared to the untreated wounds [16].…”