추출방법에 따른 Neem의 항산화, 항균 활성 및 항염 효과 비교

Comparison of Antioxidant, Antimicrobial Activity and Anti-inflammatory effects of on Neem (Azadirachta indica) Extracts with Different Extraction Methods

In order to develop natural materials for the improvement of allergic and atopic skin diseases, this study compared antioxidative, antimicrobial and anti-inflammatory effects of neem leaves(Azadirachta indica) by different extraction methods. The extracts are WE(water extract at RT), EE(70% ethyl alcohol extract at RT) and USEE(heat process for 12 hours at 60℃ after ultrasonic extraction for six hours with 70% ethanol). As a result, the electron donating ability showing the antioxidant effect was 91.36% and 87.09% at 50 ㎍/㎖ of EE and USEE, respectively, and the ABTS radical scavenging ability was more than 99% at a concentration of 500 ㎍/㎖ for all extracts. Antimicrobial activity for S. aureus, S. epidermidis, E. coli and P. acnes was not observed in the water extract, but the EE and USEE showed high antimicrobial activity. In particular, USEE showed antimicrobial activity as 18.2±0.85 mm and 19.7±0.68 mm for S. aureus and P. acnes at a concentration of 1 ㎎/㎖, respectively. Cytotoxicity for RAW 264.7 cells was not observed in neem leaf extracts at a concentration of 1,000 ㎍/㎖. As a result of observing cytotoxicity for RAW 264.7 cells, no toxicity was observed up to 1,000 ㎍/㎖ of the sample. NO production inhibition showed a higher decrease of EE(32.8%) than WE and USEE at a concentration of 1,000 ㎍/㎖. In addition, the expression of iNOS and COX-2 was the highest at 500 ㎍/㎖ of EE. Therefore, it is considered that the ethanol extract of neem leaf can be used as a natural material for improving allergic and atopic skin diseases. Future study is necessary to understand the mechanism of anti-inflammation by separation and identification of substances.