The effects of a newly developed flower thinning formulation (FTF) on the vitality of the honey bee Apis mellifera were examined by measuring the activities of various digestive enzymes in adult worker bees. First, direct spraying of the FTF solution did not cause any behavioral changes or lethal effects for the honey bees based on 24 h observation. Second, oral ingestion of a sugar solution containing the FTF did not produce any significant change in the activities of amylase, proteinases, lipase, or acetylcholine esterase (AChE) in the worker bees 6 h or 24 h after treatment. Meanwhile, a commercial formulation containing sulfur compounds showed slightly reduced activities for several digestive enzymes and AChE, although no behavioral disturbance. Thus, the results of the present study suggest that the FTF is not toxic for honey bees, in terms of contact and ingestion. Therefore, this newly developed FTF can be used for flower thinning without any detrimental effects on pollinating insects.

The black soldier fly (BSF), Hermetia illucens, is known as a beneficial insect and feeds on organic materials derived from animals and human, resulting in reduction of food waste and conversion of organic materials. Despite of a lot of study about the BSF, there is a less information about composition of digestive enzyme of the BSF larva. Experimentally, there is no evidence about characterization of digestive enzyme of the BSF. We investigated biochemical property of digestive enzyme released from the salivary and gut of the BSF. Through digestive enzyme assay, we found that the BSF has amylase, lipase and protease activity in gut extracts, resulting in that the BSF belong to polyphagous insect group. In the BSF gut, trypsin-like protease activity showed one peak at various temperature and pH condition. This result means the BSF has probably a similar form of trypsin-like enzymes. On study of comparison of enzyme activity between the BSF and the housefly using the apiZYM kit, the BSF had more strongly digestive enzyme activity than one of the housefly about leucine arylamidase, alpha-galactosidase, beta-galactosidase, alpha-mannosidase and alpha-fucosidase. This finding supports that the BSF can ingest raw waste far more efficiently than any other known species of fly as reported previously.

We evaluated the distribution pattern of tannin in 164 sorghum breeding lines and the inhibition rates of amylase, protease, and lipase in sorghum lines with different tannin concentrations. Tannin was existed in the testa of sorghum grain. The tannin content in whole grain of Nampungchal sorghum was 11.54 mg/g, and that in grain (milling rate 73%) and bran fractions was 4.57 mg/g and 28.71 mg/g, respectively. The inhibition rate of α-amylase, α-glucosidase, and β-glucosidase in sorghum lines with tannin was higher than that in sorghum lines without tannin. The inhibition rate of α-glucosidase was greater than 97% in sorghum lines with tannin. The inhibition rate of protease ranged from 20% to 70% in the sorghum lines, showing no discernable trends in tannin content. Lipase inhibition was either very low or not observed and did not seem to correlate with tannin concentration.

본 연구에서는 상백피의 소화효소 저해활성과 3T3-L1 전지방세포의 분화 억제능을 기반으로 항비만 효능소재로 서의 활용가능성을 평가하였다. 상백피의 에탄올 추출물 (MRE)은 α-amylase와 α-glucosidase, pancreatic lipase를 활 용한 소화효소 저해활성 평가 실험에서 각각 7.86±0.36, 0.12±0.03, 7.93±0.11 mg/mL 의 IC50 값을 보이며 우수한 억제 활성을 나타냈다. 또한 3T3-L1 전지방세포를 활용한 세포분화억제효능실험에서 MRE 처리군의 세포내 지방 축 적율은 농도 의존적으로 감소되었다. 상백피의 항비만 작 용 기전을 구명하기 위하여 adipogenesis 및 lipogenesis와 관련된 유전자 발현양상을 분석한 결과, 상백피 추출물 처 리군에서는 생체내 지방대사 조절에 중요한 역할을 하는 FAS와 ACC 뿐 아니라 adipogenesis와 lipogenesis와 관련된 주요 전사요소인 PPARγ와 C/EBPα, SREBP-1c의 유전자 발현이 현저하게 억제되었다. qRT-PCR 분석 결과, 상백피 추출물의 anti-adipogenesis 효능은 전사단계에서의 관련 유 전자 발현억제에 기인한다고 판단되었다. 본 실험결과 상 백피 추출물은 전지방세포의 분화와 세포내 지질합성을 저해하고 비만과 관련 된 소화효소에 대한 저해활성을 나타 내었다. 이러한 결과를 기반으로 상백피의 비만 예방 소재 로서의 잠재적인 가능성을 확인하였다.

Olive flounder (Paralichthys olivaceus) is a most important aquaculture species in Korea. Like most marine fishes, olive flounders are stomachless at first feeding and aquired gastric function during the metamorphosis, so food was mainly digested by pancreatic enzyme from first feeding to premetamorphosis. However, comprehensive analysis of pancreatic and gastric digestive enzyme of olive flounder at early developmental period is still unclear. In the expression study of pancreatic and gastric digestive enzyme by real-time PCR at early developmental stage, pancreatic enzyme such as chymotrypsinogen 2, preproelastase 2 and 4, pancreatic protein somatomedin-B domain (PPSB) mRNA expression were initiated at first feeding and strongly expressed in the pancreas developmental stage, while gastric digestive enzyme signal was not at all detected during same period. Although, trypsinogens were secreted from pancreas and have similar amino acid sequence, trypsinogen 3 expression induction was detected both pancreas and stomach developmental stage, while trypsinogen 2 expression was significantly increased only post-metamorphosis period. Pepsinogen mRNA expression was only detected at metamorphosis according to stomach differentiation. Lipid digestive enzyme, lipase and intestine fatty acid binding protein 1 (I-FABP 1), were already reached a certain level at beginning of hatching and more increased during early developmental stage and then gradually decreased before metamorphosis. These results suggested that feed ingestion of olive flounder was exclusive charged by pancreatic digestive enyme, lipid digestive enzyme and trypsinogen 3 from first feeding and then fully swiched by gastric digestive enzyme and trypsinogen 2 from metamorphosis period.