In vitro and In vivo Activity of Myrsine africana on Elastase Inhibition and Anti-wrinkle Activity

BACKGROUND: Myrsine africana (MA) is a plant traditionally used in South Africa to treat various diseases. OBJECTIVE: The ethanolic extract of MA, was used for in vitro and in vivo studies to determine its elastase inhibitory activity. MATERIALS AND METHODS: MA and its isolated compound, myrsinoside B, were tested in vitro for their elastase inhibitory activity. The MA extract was also evaluated for mutagenicity using two strains of Salmonella typhimurium (TA 98 and TA 100), microbial count, metal analysis, and stability. In vivo studies included irritancy and wrinkle reduction trials using Visioscan and Visioface. RESULTS: The leaf extract showed good elastase inhibition with a 50% inhibitory concentration (IC(50)) of 28.04 μg/ml. Myrsinoside B inhibited the elastase enzyme at an IC(50) of 4.68 ± 0.34 μg/ml. No colony growth observed during mutagenicity studies and it was concluded that MA ethanolic extract is a nonmutagen. MA extract was found to be a nonirritant during the patch test clinical trial. MA was found to contain negligible amounts of microorganisms and heavy metals. Gel cream containing MA crude extract was found to be stable for 2 years when kept at temperatures below 30°C. In clinical trials (in vivo), it was found that the test product containing 5% ethanolic extract of MA was effective in reducing wrinkles after application 2 times a day for 14 days and 28 days compared to the placebo aqueous cream. CONCLUSION: MA is effective in reducing the appearance of wrinkles. SUMMARY: This is a first time report of the elastase inhibitory potential of Myrsine africana and myrsinoside B and the anti-wrinkle potential of Myrsine africana. Myrsine africana ethanolic extract effectively inhibited the elastase enzyme. Myrsine africana was effective in in vivo studies to reduce the appearance of wrinkles after 14 days. [Image: see text] Abbreviations used: 4-NQO: 4-nitroquinoline, D14-BL: Baseline to day fourteen, D28-BL: Baseline to day twenty-eight, CFU: Colony forming units, IC(50): 50% inhibitory concentration, MA: Myrsine africana, MOU: Measurement of uncertainty, NaCl: Sodium chloride, NaH(2) PO(4).H(2)O: Sodium phosphate monobasic monohydrate, SEM: Standard error of the mean, TA 98: Salmonella typhimurium strain 98, TA 100: S. typhimurium strain 100, TLC: Thin layer chromatography, TMA: Total microbial activity, XVB salt: Vogel-Bonner medium E.