Background: The plant Aster koraiensis has long been used as an ingredient in folk medicine. It has been reported that Aster koraiensis extract (AKE) prevents the progression of diabetes-induced retinopathy and nephropathy. However, although these beneficial effects of AKE on diabetes complications have been identified, the antidiabetic effects of AKE have not yet been completely investigated and quantified. In the present study, the glucose-lowering and antioxidant effects of aqueous and ethanolic AKEs were evaluated.
Methods and Results: The glucose-lowering effects of aqueous and ethanolic (30%−, 50%−, and 80%-ethanol) AKEs were investigated via α-glucosidase inhibitory assays. The mode of inhibition by AKEs on α-glucosidase was identified through kinetic analysis. The total antioxidant capacity of each of the 4 AKEs was evaluated by assessing their conversion rate of Cu2+ to Cu+. The content of chlorogenic acid and 3,5-di-O-caffeoylquinic acid, the bioactive compounds in AKE, in each extract were analyzed by high performance liquid chromatography (HPLC). The AKEs showed potent α-glucosidase inhibitory activity with mixed inhibition mode, and significant antioxidant capacity.
Conclusions: These results of this study suggested that the AKEs tested had α-glucosidase inhibitory and antioxidant effects. Among the extracts, the 80% ethanol extract showed the most significant α-glucosidase inhibitory activity, with a half maximal inhibitory concentration (IC50 value) of 1.65 ± 0.36㎎/㎖ and a half maximal effective concentration (EC50 value) for its antioxidant activity of 0.42 ± 0.10㎎/㎖. It can therefore be used as a source of therapeutic agents to treat diabetes patients.

ABSTRACT
 서 언
 재료 및 방법
  1. 시약 및 재료
  2. 추출방법
  3. Total antioxidant capacity (TAC) 측정
  4. α-glucosidase 억제 활성 측정
  5. α-glucosidase 억제 방식 결정
  6. 분석용 검액의 제조
  7. 표준 용액의 제조 및 검량선 작성
  8. HPLC 분석조건
  9. 통계분석
 결과 및 고찰
  1. 벌개미취 추출물의 항산화능 측정
  2. 벌개미취 추출물의 α-glucosidase 억제 활성 측정
  3. 벌개미취 추출물의 α-glucosidase 억제 방식 결정
  4. HPLC 분석 조건의 확립
  5. 검량선, 검출한계 및 정량한계 작성
  6. 벌개미취 추출물의 주요 성분 함량분석
 REFERENCES

• 이태구(한국한의학연구원 임상의학부) | Tae Gu Lee (Clinical Medicine Division, KIOM)
• 현수왕(한국한의학연구원 한약연구부) | Soo Wang Hyun (Herbal Medicine Research Division, KIOM)
• 이익수(한국한의학연구원 한약연구부) | Ik Soo Lee (Herbal Medicine Research Division, KIOM)
• 박봉균(한국한의학연구원 임상의학부) | Bong Kyun Park (Clinical Medicine Division, KIOM)
• 김진숙(한국한의학연구원 한약연구부) | Jin Sook Kim (Herbal Medicine Research Division, KIOM)
• 김찬식(한국한의학연구원 임상의학부) | Chan Sik Kim (Clinical Medicine Division, KIOM) Corresponding author