• Nutrition Research and Practice
• /
• 제11권3호
• /
• pp.198-205
• /
• 2017

BACKGROUND/OBJECTIVES: The anti-diabetic activity of pear through inhibition of ${\alpha}-glucosidase$ has been demonstrated. However, little has been reported about the effect of pear on insulin signaling pathway in obesity. The aims of this study are to establish pear pomace 50% ethanol extract (PPE)-induced improvement of insulin sensitivity and characterize its action mechanism in 3T3-L1 cells and high-fat diet (HFD)-fed C57BL/6 mice. MATERIALS/METHODS: Lipid accumulation, monocyte chemoattractant protein-1 (MCP-1) secretion and glucose uptake were measure in 3T3-L1 cells. Mice were fed HFD (60% kcal from fat) and orally ingested PPE once daily for 8 weeks and body weight, homeostasis model assessment of insulin resistance (HOMA-IR), and serum lipids were measured. The expression of proteins involved in insulin signaling pathway was evaluated by western blot assay in 3T3-L1 cells and adipose tissue of mice. RESULTS: In 3T3-L1 cells, without affecting cell viability and lipid accumulation, PPE inhibited MCP-1 secretion, improved glucose uptake, and increased protein expression of phosphorylated insulin receptor substrate 1 [p-IRS-1, ($Tyr^{632})$)], p-Akt, and glucose transporter type 4 (GLUT4). Additionally, in HFD-fed mice, PPE reduced body weight, HOMA-IR, and serum lipids including triglyceride and LDL-cholesterol. Furthermore, in adipose tissue, PPE up-regulated GLUT4 expression and expression ratio of p-IRS-1 ($Tyr^{632})/IRS$, whereas, down-regulated p-IRS-1 ($Ser^{307})/IRS$. CONCLUSIONS: Our results collectively show that PPE improves glucose uptake in 3T3-L1 cells and insulin sensitivity in mice fed a HFD through stimulation of the insulin signaling pathway. Furthermore, PPE-induced improvement of insulin sensitivity was not accompanied with lipid accumulation.

• The Korean Journal of Physiology and Pharmacology
• /
• 제17권4호
• /
• pp.315-320
• /
• 2013

Here, we show that radicicol, a fungal antibiotic, resulted in marked inhibition of inducible nitric oxide synthase (iNOS) transcription by the pancreatic beta cell line MIN6N8a in response to cytokine mixture (CM: TNF-${\alpha}$, IFN-${\gamma}$, and IL-$1{\beta}$). Treatment of MIN6N8a cells with radicicol inhibited CM-stimulated activation of NF-${\kappa}B$/Rel, which plays a critical role in iNOS transcription, in a dose-related manner. Nitrite production in the presence of PD98059, a specific inhibitor of the extracellular signal-regulated protein kinase-1 and 2 (ERK1/2) pathway, was dramatically diminished, suggesting that the ERK1/2 pathway is involved in CM-induced iNOS expression. In contrast, SB203580, a specific inhibitor of p38, had no effect on nitrite generation. Collectively, this series of experiments indicates that radicicol inhibits iNOS gene expression by blocking ERK1/2 signaling. Due to the critical role that NO release plays in mediating destruction of pancreatic beta cells, the inhibitory effects of radicicol on iNOS expression suggest that radicicol may represent a useful anti-diabetic activity.

• 대한본초학회지
• /
• 제30권4호
• /
• pp.101-108
• /
• 2015

Objectives : Positive effects of Ginseng has great research attentions such as anticancer, anti-diabetic, antiaging, liver, immune function, CNS, etc. In this study, we investigated Hydroponic-cultured Ginseng Folium fermented byBacillus subtilisto establish fermentation conditions for enhancing functionality.Methods : Ginseng Folium were cultivated hydroponic-cultured and were extracted with methanol. We inoculateBacillus subtilisfor fermentation by adding to 0%, 3% and 5% sugar respectively and checked antioxidant activities, total phenolic content and total saponin content in 2 days intervals during 11 days. The antioxidant activities were studied by the 1,1-diphenyl-2-picryl hydrazyl(DPPH) radical, 2, 2'-Azino-bis(3-ethylbenzothiazoline-6 sulfonic acid) diammonium salt(ABTS) radical scavenging assay and Reducing power assay. We analyzed the Total phenol content, crude saponin content and ginsenoside content. Moreever, Hepatoprotective effects by Glutamic oxaloacetic transaminase(GOT) and Glutamic pyruvic transaminase(GPT) in Sprague-Dawley rat.Results : The results of DPPH and ABTS were 66.89% and 96.72%, respectively. The reducing power was resulted in optical density of 0.7312 with 3% sugar after 9 days of fermentation. and the concentration at 200 ㎍/㎖. Total phenol content was 36.92㎎/g with 3% sugar after 9 days of fermentation, in which crude saponin content wasn't changed, and ginsenoside content such as Rg3, Re and Rb was increased. Activities of GOT and GPT concentration were decreased in rat.Conclusions : This study suggests that hydroponic-cultured Ginseng Folium fermented byBacillus subtilisin 9 days showed significant efficacy of hepato-protection as well as antioxidant compared to the others. In addition, it shows not only improved value but also utilized hydroponic-cultured Ginseng Folium by fermentation.

• BMB Reports
• /
• 제51권10호
• /
• pp.538-543
• /
• 2018

Pancreatic beta cell destruction and dysfunction induced by cytokines is a major cause of type 1 diabetes. Paraoxonase 1 (PON1), an arylesterase with antioxidant activity, has been shown to play an important role in preventing the development of diabetes in transgenic mice. However, no studies have examined the anti-diabetic effect of PON1 delivered to beta cells using protein transduction. In this study, we expressed the cell-permeable PON1 fused with PEP-1 protein transduction domain (PEP-1-PON1) to investigate whether transduced PEP-1-PON1 protects beta cells against cytokine-induced cytotoxicity. PEP-1-PON1 was effectively delivered to INS-1 cells and prevented cytokine-induced cell destruction in a dose-dependent manner. Transduced PEP-1-PON1 significantly reduced the levels of reactive oxygen species (ROS) and nitric oxide (NO), DNA fragmentation, and expression of inflammatory mediators, endoplasmic reticulum (ER) stress proteins, and apoptosis-related proteins in cytokine-treated cells. Moreover, transduced PEP-1-PON1 restored the decrease in basal and glucose-stimulated insulin secretion induced by cytokines. These data indicate that PEP-1-PON1 protects beta cells from cytokine-induced cytotoxicity by alleviating oxidative/nitrosative stress, ER stress, and inflammation. Thus, PEP-1-mediated PON1 transduction might be an effective method to reduce the extent of destruction and dysfunction of pancreatic beta cells in autoimmune diabetes.

• Toxicological Research
• /
• 제35권2호
• /
• pp.181-190
• /
• 2019

Lentinus squarrosulus (Mont.) is an edible wild mushroom with tough fruiting body that belongs to the family Polyporaceae. It is used in ethnomedicine for the treatment of ulcer, anaemia, cough and fever. Recent studies have demonstrated its anticancer, anti-diabetic and antioxidant properties. However, little or no information is available regarding the bioactive components and toxicological study of wild dried L. squarrosulus. Therefore, this study investigated the bioactive components of aqueous extract of boiled wild dried L. squarrosulus and its toxicological effects in rats. The extract of L. squarrosulus was subjected to GC-MS analysis. The acute toxicity test was performed by oral administration of a single dose of up to 5,000 mg/kg extract of L. squarrosulus. In subacute study, the rats were orally administered extract of L. squarrosulus at the doses of 500, 1,000 and 1,500 mg/kg body weight daily for 14 days. The haematological, lipid profile, liver and kidney function parameters were determined and the histopathology of the liver and kidney were examined. The GC-MS analysis revealed the presence of bioactive compounds; 1-tetradecene, fumaric acid, monochloride, 6-ethyloct-3-yl ester, 9-eicosene, phytol, octahydropyrrolo[1,2-a]pyrazine and 3-trifluoroacetoxypentadecane. In acute toxicity study, neither death nor toxicity sign was recorded. In the sub-acute toxicity study, significant differences (p < 0.05) were observed on creatinine, aspartate aminotransferase, alanine aminotransferase, total cholesterol, triglycerides and high-density lipoprotein cholesterol. Whilst no significant differences (p > 0.05) were observed on packed cell volume, heamoglobin, red blood cell, white blood cell and alkaline phosphatase, in all the tested doses. No histopathological alterations were recorded. Our findings revealed that aqueous extract of L. squarrosulus may have antimicrobial, antinocieptive and antioxidant properties based on the result of GC-MS analysis. Results of the toxicity test showed no deleterious effect at the tested doses, suggesting that L. squarrosulus is safe for consumption at the tested doses.

• Journal of Ginseng Research
• /
• 제45권1호
• /
• pp.86-97
• /
• 2021

Background: Panax ginseng Meyer has been used as a nourishing edible herb in East Asia for thousands of years. 25-OH-PPT was first discovered as a natural rare triterpenoid saponin in ginseng stems and leaves by our group. Research found that it showed strong inhibitory effects on α-glucosidase and protein tyrosine phosphatase 1B, and protected cardiocytes (H9c2) through PI3K/Akt pathway. Methods: In the research, in order to optimize the 25-OH-PPT enrichment process, optimal macroporous resins and optimal purification conditions were studied. Meanwhile, the hypoglycemic effect and mechanism of 25-OH-PPT were evaluated by using STZ to establish insulin-dependent diabetic mice and the spontaneous type 2 diabetes DB/DB mice. Results and Conclusion: Research found that 25-OH-PPT can reduce blood glucose and enhance glucose tolerance in STZ model mice. It increases insulin sensitivity by upregulating GLUT4 and AMPK in skeletal muscle, and activating insulin signaling pathways. In DB/DB mice, 25-OH-PPT achieves hypoglycemic effects mainly by activating the insulin signaling pathway. Meanwhile, through the influence of liver inflammatory factors and lipids in serum, it can be seen that 25-OH-PPT has obvious anti-inflammatory and lipid-lowering effects. These results provide new insights into the study of ginseng as a functional food.

• 대한약침학회지
• /
• 제26권4호
• /
• pp.319-326
• /
• 2023

Objectives: The study's goal was to find out whether Chrysanthemum rubellum extract has anti-diabetic properties by concentrating on α-glucosidase and the PTP-1B signaling pathway. C. rubellum flowers were used for extraction using Methanol/water (80/20) as solvent. Methods: LC-MS techniques was used to check the presence of phytoconstituents present in C. rubellum extract. In vitro antidiabetic activity was evaluated using α-glucosidase inhibitory activity and PTP-1B signaling pathway. On Streptozotocin (STZ)-induced rats with diabetes, the in vivo antidiabetic efficacy was assessed using a test for oral glucose tolerance. Results: The phytoconstituents identified in the extract of C. rubellum were apigenin, diosmin, myricetin, luteolin, luteolin-7-glucoside, and Quercitrin as compound 1-6, respectively. Results showed that diosmin exhibited highest α-glucosidase inhibitory activity i.e. 90.39%. The protein level of PTP-1B was lowered and the insulin signalling activity was directly increased by compounds 1-6. The maximum blood glucose levels were seen in all groups' OGTT findings at 30 minutes following glucose delivery, followed by gradual drops. In comparison to the control group, the extract's glucose levels were 141 mg/dL at 30 minutes before falling to 104 mg/dL after 120 minutes. The current study has demonstrated, in summary, that extract with phytoconstituents reduce blood sugar levels in rats. Conclusion: This finding suggests that extract may reduce the chance of insulin resistance and shield against disorders like hyperglycemia.

• 한국식품과학회지
• /
• 제52권3호
• /
• pp.274-283
• /
• 2020

본 연구에서는 국내 주요 토종 향신료로 활용되는 초피(Zanthoxylum piperitum)와 산초(Zanthoxylum schinifolium)가 갖는 in vitro 항당뇨 활성과 뇌신경세포 보호 효과를 확인하고 이에 영향을 주는 주요 생리활성물질을 분석하고자 하였다. 추출 용매에 따른 차이를 비교하기 위하여 총 페놀함량을 측정한 결과, 공통적으로 40% 에탄올의 초피 추출물(EZP)과 산초 추출물(EZS)에서 뛰어난 함량을 나타냈으며, ABTS/DPPH 라디칼 소거 활성과 MDA 생성 억제 효과에 대해서도 상대적으로 우수한 항산화 활성을 보였다. 초피 추출물(EZP)와 산초 추출물(EZS)의 당뇨 관련 효소에 대한 저해 효과를 비교한 결과, 초피 추출물(EZP)는 α-amylase 및 α-glucosidase와 같은 효소를 직접적으로 억제하는 능력이 뛰어났으며, 산초 추출물(EZS)는 비효소적 반응으로 단백질과 당의 결합을 막아 최종당화산물의 생성을 억제하는 능력이 뛰어난 것으로 나타났다. 또한, MC-IXC 뇌신경세포에 고당을 처리하여 산화적 스트레스를 유발시켰을 때 생성되는 ROS의 함량과 뇌신경세포 사멸에 대해 우수한 보호 효과를 보여주었다. 이러한 초피 추출물(EZP)와 산초 추출물(EZS)의 생리활성물질을 확인하기 위해 UPLC IMS-QTOF/MS^E 분석을 실시한 결과, 초피 추출물(EZP)의 경우 3-CQA, 4-CQA, quercetin-3-O-glucoside 및 quercetin-3-O-rhamnoside가 주요 물질임을 확인하였으며, 산초 추출물(EZS)의 경우 protocatechuic acid glucoside, 5-CQA 및 rutin이 주요 물질임을 확인하였다. 이상의 결과로부터 초피와 산초는 식후 혈당의 급격한 상승을 지연 또는 개선하고 이로 인해 야기되는 산화적 스트레스로부터 뇌신경세포를 보호하여 고혈당으로 인한 퇴행성 뇌질환과 같은 당뇨 및 그 합병증을 예방할 수 있는 천연 유래 건강기능식품 소재로의 산업적 활용 가능성을 확인하였다.

• 한국식품과학회지
• /
• 제38권1호
• /
• pp.114-120
• /
• 2006

백련 뿌리 및 잎과 조릿대는 과거부터 약용으로 사용해 왔지만 아직까지 연구도 많이 이루어지지 않았고, 항당뇨 효과에 대한 연구도 거의 없었다. 본 연구에서는 백련 뿌리 및 잎과 조릿대의 추출물과 분획물이 in vitro에서 인슐린 작용, 인슐린 분비 또는 탄수화물의 소화에 효과적인지를 조사함으로 항당뇨에 효과적인지 여부를 조사하였다. 백련 뿌리 및 잎과 조릿대의 추출물은 각각 물로 추출하여 항당뇨 효과를 조사하였다. 또한 백련 뿌리 및 잎과 조릿대의 3 : 2 : 3으로 혼합하여 물로 추출한 후 이를 메탄올과 물을 섞은 용액으로 단계별로 XAD-4 column으로 분획하였다. 백련 뿌리 및 잎과 조릿대의 추출물과 혼합물의 분획물은 고농도(1 mg/mL)에서도 MTT 방법으로 측정하였을 때 세포 독성을 나타내지 않았다. 백련 뿌리와 조릿대 물추출물은 인슐린 작용을 향상시키는 효능이 있었고, 백련잎 물추출물은 ${\alpha}-amylase$를 억제하여 탄수화물의 소화 흡수를 지연시켰다. 이에 백련 뿌리 및 잎과 조릿대를 3 : 2 : 3으로 혼합하였을 때 20과 80% 메탄올층은 3T3-L1 지방세포에 처리하였을 때 인슐린의 작용을 향상시켜 포도당의 흡수를 증가시키는 효과가 인슐린을 10 nM을 처리한 것 만큼 효과적으로 포도당 흡수를 증가시켰다. 이 층에는 3T3-L1 섬유아세포에 분화 유도물질과 함께 처리하였을 때 $PPAR-{\gamma}$ agonist인 rosiglitazone과 마찬가지로 지방 세포로의 분화를 촉진시키고 지방의 축적도 증가시켰다. 그러므로 80% 메탄올 층에는 $PPAR-{\gamma}$ agonist로 작용하는 물질이 함유되어 있을 가능성이 높다. 베타세포라인인 Min6 세포에 백련 뿌리 및 잎과 조릿대의 혼합물의 분획물을 처리한 후 저농도와 고농도 포도당 자극시 인슐린 분비를 측정하였을 때 두 농도에서 모두 인슐린 분비에 영향을 미치지 않았다. 또한 백련 뿌리 및 잎과 조릿대의 혼합물의 20, 60과 80% 메탄올 분획층은 탄수화물의 소화에 작용하는 효소인 ${\alpha}-amylase$의 활성을 16% 정도를 억제하는 효과가 있었다. 결론적으로 백련 뿌리 및 잎과 조릿대의 추출물과 분획물에는 인슐린 분비나 탄수화물의 소화에 관여하는 성분이 없지만, 인슐린 작용을 향상시키는 인슐린 민감성 물질이 함유되어 있을 가능성이 높다.

• 생명과학회지
• /
• 제30권11호
• /
• pp.965-972
• /
• 2020

한국, 중국, 일본에 분포한 지렁쿠나무는 관절염 치료제로 동양의 민간요법에 사용되었다. 본 연구에서는 지렁쿠나무의 건강기능성 식품, 화장품 및 식품 보존료 등의 기능성 소재로 개발하기 위한 기초자료를 제공하고자 연구를 수행하였다. 지렁쿠나무의 잎, 가지 부위를 메탄올 추출물로 제조하여 총 폴리페놀 및 총 플라보노이드 함량을 측정하고, 항산화 활성, α-glucosidase 저해 활성 및 tyrosinase 저해 활성과 항염증 활성을 검증하였다. 지렁쿠나무 추출물의 총 폴리페놀 및 플라보노이드 함량은 1.52±0.1 mg/g and 1.73±0.1 mg/g로 측정되었고, DPPH와 ABTS radical 소거 활성은 처리 농도가 증가함에 따라 농도 의존적으로 소거 효과를 나타냈으며, 각각 IC₅₀ 값이 124.0 ㎍/ml (DPPH), 85.6 ㎍/ml (ABTS)로 높은 항산화 효과를 나타내었다. 또한, α-glucosidase 저해활성 및 tyrosinase 저해 활성은 각각 IC₅₀ 값이 183.5 ㎍/ml와 323.9 ㎍/ml로 우수한 억제 활성을 보였다. 게다가 RAW 264.7 cell에서 LPS로 염증을 유발시켜 nitric oxide (NO) 억제효과 실험에서 지렁쿠나무 추출물의 IC50 값을 측정하였을 때 NO 생성을 농도의존적으로 저해하는 농도는 36.7 ㎍/ml이고, 추출물 100 ㎍/ml의 농도에서도 독성을 나타내지 않는 것으로 확인되었다. 이상의 결과로부터 지렁쿠나무 추출물은 항산화, 항염증, 미백, 및 항당뇨 효능을 확인할 수 있었으며, 이는 지렁쿠나무가 기능성 식품, 화장품 및 의약품 소재로서의 활용 가능성을 시사한다. 또한, 지렁쿠나무로부터 생리활성물질의 분리 동정과 메커니즘 규명에 관한 연구가 수행되어야 할 것으로 판단된다.