Anti-obesity and anti-diabetic effects of Portulaca oleracea powder intake in high-fat diet induced obese C57BL/6 mice

국문 초록 (Abstract)

본 연구는 쇠비름분말의 항비만 및 항당뇨 효과가 있는지 알아보고자 5주령의 수컷 C57BL/6 마우스(n=32)를 대조군(CON), 고지방식이군(HFD), 고지방식이+쇠비름분말5%첨가군(HFD+PO5%), 고지방식이+쇠비름분말10%첨가군 (HFD+PO10%)의 4개의 군으로 나누어 12주간 사육하였다. 비만 관련하여 체중증가량, FER, 체지방량, 혈액지질분획 등을 분석하였고 혈당과 복강내 당부하 검사를 실시하여 혈당조절효과를 알아보고자 하였다. 또한, 지방대사 촉진(PPAR-α)과 혈당강하(GLUT4, PPAR-γ, TNF-α) 관련된 단백질 발현량을 분석하였다. 체중증가량은 HFD군보다 HFD+PO10%군이 34% 감소하였다(p<0.05). 한편, FER은 HFD군에 비해 HFD+PO5%군과 HFD+PO10% 군이 유의적으로 낮았다.
신장주변지방 및 부고환지방은 HFD군에 비해 HFD+PO10%군이 각각 6.3배, 1.5배 낮았다(P<0.05). HDL-cholesterol 함량은 HFD+PO5%군과 HFD+PO10%군이 HFD군보다 각각 1.3배, 1.2배 높았으나(p<0.05), LDL-cholesterol 함량은 HFD+PO10%군이 HFD군보다 16.2% 유의하게 감소하였다. 또한 TG는 HFD군보다 쇠비름분말을 섭취한 HFD+PO5%군과 HFD+PO10%이 유의하게 감소하였다. 동맥경화지수와 심혈관 위험인자의 경우 HFD군보다 쇠비름분말 5% 와 10% 섭취군 모두에서 유의적으로 낮았다. 무작위혈당은 0주차부터 8주차까지는 군간 유의적인 차이가 없었으나 10주와 12주에서 HFD군보다 HFD+PO5%군과 HFD+PO10%군이 유의적으로 낮았다. 또한, IPGTT에서 30분대비 120분의 혈당 농도는 HFD군은 39% 감소하였으나, CON군, HFD+PO5%군, HFD+PO10% 군은 각각 53%, 43%, 51%씩 감소하였다. HFD군보다 쇠비름 분말을 저농도 및 고농도 급여한군들의 지방구 크기가 감소하였다. 고지방식이군의 PPAR-α 단백질 발현량은 HFD+PO10%군이 HFD군보다 유의적으로 증가하였다. GLUT4 및 PPAR-γ의 단백질 발현량은 HFD+PO10%군이 CON군, HFD군 및 HFD+PO5%군보다 유의적으로 높게 발현되었으나 TNF-α의 단백질 발현량은 HFD군보다 쇠비름분말을 급여한 HFD+PO5%군과 HFD+PO10%군이 감소하였다(p<0.05). 본 연구결과, 쇠비름 분말 급여가 항비만 및 항당뇨 효과를 보였음을 확인하였으며, 비만 및 심혈관질환이나 당뇨병 등의 만성질환을 치료 및 예방하는데 효과적일 것으로 사료된다.

다국어 초록 (Multilingual Abstract)

In this study, Portulaca oleracea L. powder was added at low (5% purslane powder, HFD+PO5%) or high (10% purslane powder, HFD+PO10%) concentration, to a high fat diet and fed to male C57BL/6 mice (n=8) for 12 weeks. We analyzed blood lipid profile, blood glucose control factors, lipid metabolism (PPAR-α) and insulin resistance improvement (GLUT4 and PPAR-γ) of protein expression. Weight gain was reduced 34% in the HFD+PO10% group compared to the HFD group (p<0.05). FER was significantly lower in the HFD+PO5% and HFD+PO10% groups than it was in the HFD group. Perirenal fats and epididymal fats were shown to be decreased compared to the HFD group, of 6.3-fold and 1.5-fold, respectively in the HFD+PO10% group (p<0.05). HDL-cholesterol level increased, as compared to that of the HFD group, by 1.3-fold and 1.2-fold, in the HFD+PO5% and HFD+PO10% groups (p<0.05) respectively. LDL-cholesterol was reduced by 16.2 % the HFD+PO10% group as compared to the HFD group (p<0.05). TG and TG/HDL levels also decreased in the HFD+PO5% and HFD+PO10% groups compared to the HFD group (p<0.05). The HFD+PO5% and HFD+PO10% groups were significantly lower than the HFD group on AI and CRF. Random glucose level showed on difference from week 0 to week 8 but decreased in the HFD+PO5% and HFD+PO10% groups after week 10 and week 12 (p<0.05). HOMA-IR was lower in the HFD+PO10% group than it was in the HFD group. Furthermore, blood glucose level was decreased 39% in the HFD group, but the CON, HFD+PO5% and HFD+PO10% groups were reduced 53%, 43% and 51%, respectively, at 120 min versus 30 mins. PPAR-α was increased in the HFD+PO10% group as compared to the HFD group (p<0.05). GLUT4 and PPAR-γ protein expression were also increased in the HFD+PO10% group as compared to the HFD group. However, protein expression of TNF-α was reduced in the purslane groups than the HFD group. Given that these results show that the purslane powder to be effective at suppressing weight gain and reducing body fat and blood glucose level, it is predicted to show a positive effect on the treatment and prevention of obesity as well as diabetic- related adult disease.

목차 (Table of Contents)

• 1. Introduction 1
• 2. Material and Methods 5
• 2.1 Diet preparation and formula composition 5
• 2.2 Animal breeding and experimental design 7
• 2.3 Blood glucose measurement 7
• 2.4 Intraperitoneal glucose tolerance test 7
• 2.5 Blood and organ collection 8
• 2.6 Histopathological analysis 8
• 2.7 Blood chemicals analysis 8
• 2.8 Real-time RT-PCR 9
• 2.9 Western blot 9
• 2.10 Statistical analysis 10
• 3. Results 12
• 3.1 Final body weight, weight gain, food intake and Food efficiency ratio 12
• 3.2 Organ weight and unit organ weight 14
• 3.3 Blood chemical analysis 17
• 3.4 Random blood lucose 19
• 3.5 Intraperitoneal glucose tolerance test 22
• 3.6 Influence of a diet of purslane powder on liver morphology 25
• 3.7 Effects of purslane powder on the expression of TNF-α related to inflammation 27
• 3.8 Effects of purslane powder on fatty acid oxidation in the liver 30
• 3.9 Effects of purslane powder on the improvement of insulin resistance in the liver 31
• 4. Discussion 32
• 4.1 The effects on weight control of purslane powder 32
• 4.2 The effects of reducing body fat of purslane powder 33
• 4.3 The effects of purslane powder on reducing cardiovascular disease 36
• 4.4 The effects of blood glucose improvement of purslane powder 38
• 5. Conclusion 43
• References 44
• 국문초록 50