1-Deoxynojirimycin (DNJ), an alpha-glucosidase inhibitor, has been used to prevent or treat type 2 diabetes. Low amounts of DNJ are found in mulberry leaf; however, a methodology is necessary to enhance the DNJ content of mulberry leaf extract (MLE) since increasing the amounts of DNJ is required for the prevention and treatment of type 2 diabetes. In this study, the DNJ content of MLE was increased through the optimization of the conditions for MLE fermentation by Lactobacillus plantarum SG-053, using response surface methodology (RSM). By single factor testing, the optimal conditions were identified as an inoculum concentration of 1%(v/v), an MLE concentration of 3°Bx, and no agitation. Based on a Plackett-Burman design, the following factors were considered to majorly affect the DNJ content in the MLE fermentation product: the initial pH, fermentation temperature, and fermentation time. By response surface methodology, the optimal conditions for MLE fermentation was found to have an initial pH of 5.5, a fermentation temperature of 31.9oC, and a fermentation time of 34 h. Under these optimal fermentation conditions, the DNJ content in MLE increased 3.59 times, or from 23.85 to 85.54 μg/mL.

This study was carried out to investigate the growth inhibition of Propionibacterium acnes by mycelial culture broth of Paecilomyces japonica in the Mulberry leaf extract. The results are as following. The growth inhibition effect of P. japonica mycelial culture broth against P. acnes in various concentration of Mulberry leaf extract was the most effective in 3% Mulberry leaf extract. The inhibition effect of P. japonica mycelial culture broth against P. acnes in Mulberry leaf extract according to the culture time was the moust effective for 25 days cultivation. As the treating volume of the mycelial culture broth was increased, the growth inhibition effect against P. acnes was increased as well. The growth inhibition effect of mycelial culture broth against P. acnes according to the time of heat treatment was active by 45min at 100℃, while it was inactive at more than 60min. Taken together P. japonica mycelial culture in the Mulbarry leaf extract has a possibility to be an element of skincare cosmetics regulating the acnes. This means that the enzyme may be used for health-care such as thrombosis without any hamful behavour in the blood vessel.

본 연구는 뽕잎 추출물에 눈꽃 동충하초 균사체(Paecilomyces japonica) 배양액의 Propionibacterium acnes에 대한 생육 억제 활성을 조사한 것이다. 배양 배지내의 뽕잎 추출물 농도는 3%일 때 가장 높은 여드름 균 생육 억제 활성이 나타났으며, 3% 농도의 뽕잎 추출물을 이용한 균사체 배양 날짜별 활성은 25일 배양시 가장 높은 여드름 균 생육 억제 활성을 확인 할 수 있었다. 또한 여드름 균에 생육 억제 활성을 가지는 물질은 동충하초 균사체의 2차 대사산물로 판단 할 수 있었다. 뽕잎 추출물에 동충하초 균사체 배양액의 처리농도별 여드름 활성은 처리 농도가 상승할수록 증가하였다. 그리고 5% 감자만을 넣고 배양하였을 경우 여드름 균의 활성이 나타나지 않았으며, 합성 배지인 PDB를 사용 시 뽕잎 추출물을 이용해 배양하였을 때보다 낮은 활성을 나타내었다. 또한 뽕잎 추출물에 동충하초 균사체 배양액의 여드름균 생육 억제 활성의 열 안정성을 확인하기 위한 열처리 결과, 100℃에서 45분 까지 열에 안정함을 확인 할 수 있었다. 이러한 결과로 볼 때 뽕잎 추출물에 동충하초 배양액의 여드름균 생육 억제 물질은 배당체 또는 peptide 인 것으로 판단된다. 따라서, 뽕잎 추출물을 이용한 동충하초 균사체 배양액은 여드름균 생육 억제 활성이 뛰어나며, 열에 안정한 천연 여드름 억제 화장품료 조성물로서의 이용가능성이 확인 하였다.

Background: The present study was carried out to asses whether mulberry leaves (MLs) have the potential to inhibit the mutagenic effect of cigarette smoke condensates (CSCs). Methods and Results: ML powder was extracted with 70% ethanol, and a yield of 35.1% by weight was obtained. The 70% ethanol extract of ML was further extracted sequentially using diethyl ether, chloroform, butanol, dichloromethane and water. The crude 70% ethanol extract of MLs and its solvent fractions did not show any mutagenic effect when tested at concentrations up to 1 ㎎/ plate against Salmonella typhimurium TA98. In contrast, the crude 70% ethanol extract showed an inhibitory activity against the mutagenicity of CSCs in the presence of S-9 mixture. Among the solvent fractions, the diethyl ether fraction showed the highest inhibitory activity, which increased in a dose-dependent manner, inhibiting mutagenesis by approximately 97.1% at a concentration of 1㎎/plate. Conclusions: In this study, we found that a crude 70% ethanol extract of MLs and the diethyl ether fraction themselves are potentially not mutagenic, but inhibit the mutagenic effect of CSCs.