Streptozotocin에 의해 유도된 당뇨모델동물에서 황칠나무 (Dendropanax morbifera Leveille)의 열수추출물과 에탄올추출물의 당뇨 질환 개선 효능

Anti-diabetic effects of aqueous and ethanol extract of Dendropanax morbifera Leveille in streptozotocin-induced diabetes model

본 연구는 황칠나무의 부위별 추출물의 항당뇨효능을 평가하기 위해, 황칠나무의 잎과 줄기의 열수추출물과 에탄올추출물을 분리하여 항산화능과 당뇨질환 개선효능을 측정하였다. 그 결과, total polyphenol과 total flavonoid의 농도는 DLW에서 가장 높게 나타났으며, 다음으로 DLE, DSW, DSE 순서로 나타났다. 또한, DPPH 소거능은 DLW가 대부분의 농도에서 가장 높게 나타났으며, DLE는 $500{\mu}g/mL$의 농도에서 가장 높은 DPPH 소거능을 나타내었다. 항산화능이 우수한 DLW와 DLE를 선정하여 STZ로 유도된 당뇨모델동물에 2주간 투여하여 항당뇨 효능을 분석하였다. 그 결과, 체중은 STZ/vehicle 처리군이 급격히 감소하였으나 STZ/DLW와 STZ/DLE 처리군에서 서서히 감소하였다. 혈당량은 STZ/vehicle 처리군에서 급격히 증가하였으며, STZ/DLW 처리군과 STZ/DLE 처리군에서만 유의적인 감소를 나타내었다. 그러나, 혈청 내 인슐린의 농도는 STZ/vehicle 처리군에 비하여 STZ/DLW와 STZ/DLE 처리군에서 증가하였으며, 특히 STZ/DEL-200 처리군에서 가장 높은 농도를 나타내었다. 이러한 변화는 췌장의 조직학적 변화와 면역염색의 결과에서도 동일하게 관찰되었다. 더불어, 뇨당 농도는 STZ/vehicle 처리군에서 급격히 증가하였으며, 오직 STZ/DLW-200 처리군과 STZ/DLE-200 처리군에서만 유의적으로 감소하였다. 이러한 결과는 황칠나무의 잎의 열수추출물과 에탄올추출물은 우수한 항산화효능과 베타세포의 사멸을 억제함으로서 당뇨질환을 개선하는 효능이 있음을 제시하고 있으며, 특히, 200 mg/kg의 농도가 우수한 효능을 나타내는 농도임을 제시하고 있다.

Purpose: Dendropanax morifera Leveille (DML) exhibits diverse biological and pharmacological activities, including anti-oxidative effect, anti-cancer activity, hepatoprotection, immunological stimulation, and bone regeneration. As part of the identification for novel functions of DML, we investigated the therapeutic effects of DML on diabetes induced by streptozotocine (STZ) treatment. Methods: First, the four extracts including the water extract of leaf (DLW), the ethanol extract of leaf (DLE), the water extract of stem (DSW), and the ethanol extract of stem (DSE) were collected from the leaf and stem of DML using a hot water and ethanol solvent. Alterations in body weight, glucose concentration, insulin level, and pancreatic islet structure were investigated in diabetic mice after treatment with extracts of DML for 2 weeks. Results: Among four extracts, the highest level of total polyphenols and total flavonoids was detected in DLW, while the lowest level of these was measured in DSE. The radical scavenging activity was also higher in DLW than in the other three extracts at the concentration of $25-100{\mu}g/mL$, although this activity was maintained at a constant level in all groups at the concentration of $500{\mu}g/mL$. Based on the results of anti-oxidant activity, DLW and DLE were selected for examination of anti-diabetic effects in a diabetes model. Body weight was gradually decreased in all STZ treated groups compared with the No treated group. However, four STZ/DML treated groups maintained a high level of body weight during 7-14 days, while the STZ/vehicle treated group showed a gradual decrease of body weight during the same period. Also, a significant decrease or increase in the concentration of glucose and insulin in the blood of the diabetes model was detected in a subset of groups, although the highest increase was detected in the STZ/DLE-200 treated group. In addition, the histological structure of pancreatic islet was significantly recovered after treatment with DLW and DLE. Conclusion: These results suggest that DLW and DLE may contribute to attenuation of clinical symptoms of diabetes as well as prevent the destruction of pancreatic ${\beta}$-cells in STZ-induced diabetes mice.