구아바(Psidium guajava L.) 잎의 항산화 활성 및 tyrosinase 저해효과

Antioxidant activities and tyrosinase inhibitory effects of guava (Psidiumguajava L.) leaf

This research was designed to investigate the antioxidant activities and tyrosinase inhibitory effects of guava (Psidium guajava L.) leaf. Total phenol content was obtained from guava leaf extract of 19.0 (g/100g, D.W.). The crude extract exhibited significantly antioxidant activities (IC50value 102.5 μg/ml, free radical scavenging; 49.4 μg/ml, SOD like activity). The crude extract of guava leaf was fractionated into four partition layers; hexane (G-H), ethylacetate (G-E), butanol (G-B) and water (G-W) layer. The extracts of G-E, G-B, G-W showed high radical scavenging activities of over 50% at 100μg/ml. SOD like activities of G-E, G-B, G-Wwere revealed, as 81.8%, 84.7%, 65.3% at 100μg/ml, while those of G-H did not showed the effectively. The crude extract of guava leaf showed high tyrosinase inhibitory effect as 60.8% at 1mg/ml, the measurement of G-E, G-B, G-W were 65.2%, 62.8%, 51.6% and that of G-H was not effective. These results indicate that useful bioactive substances exist in the guava leaf extracts, especially G-E, G-B. And the guava leaf has the potential of being developed into health related products.