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Osmanović Barilar J, Babić Perhoč A, Knezović A, Homolak J, Virag D, Šalković-Petrišić M. The Effect of the Sodium—Glucose Cotransporter Inhibitor on Cognition and Metabolic Parameters in a Rat Model of Sporadic Alzheimer’s Disease. Biomedicines 2023; 11:biomedicines11041025. [PMID: 37189641 DOI: 10.3390/biomedicines11041025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 03/16/2023] [Accepted: 03/23/2023] [Indexed: 03/29/2023] Open
Abstract
Type 2 diabetes mellitus increases the risk of sporadic Alzheimer’s disease (sAD), and antidiabetic drugs, including the sodium–glucose cotransporter inhibitors (SGLTI), are being studied as possible sAD therapy. We have explored whether the SGLTI phloridzin may influence metabolic and cognitive parameters in a rat model of sAD. Adult male Wistar rats were randomized to a control (CTR), an sAD-model group induced by intracerebroventricular streptozotocin (STZ-icv; 3 mg/kg), a CTR+SGLTI, or an STZ-icv+SGLTI group. Two-month-long oral (gavage) SGLTI treatment (10 mg/kg) was initiated 1 month after STZ-icv and cognitive performance tested prior to sacrifice. SGLTI treatment significantly decreased plasma glucose levels only in the CTR group and failed to correct STZ-icv-induced cognitive deficit. In both the CTR and STZ-icv groups, SGLTI treatment diminished weight gain, decreased amyloid beta (Aβ) 1-42 in duodenum, and decreased the plasma levels of total glucagon-like peptide 1 (GLP-1), while the levels of active GLP-1, as well as both total and active glucose-dependent insulinotropic polypeptide, remained unchanged, compared to their respective controls. The increment in GLP-1 levels in the cerebrospinal fluid and its effect on Aβ 1-42 in duodenum could be one of the molecular mechanisms by which SGLTIs indirectly induce pleiotropic beneficial effects.
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Su YL, Liu D, Liu YJ, Ji YL, Liu GS, Wang JLT, Wang B, Wang H. Phlorizin alleviates cholinergic memory impairment and regulates gut microbiota in d-galactose induced mice. Exp Gerontol 2022; 165:111863. [PMID: 35660419 DOI: 10.1016/j.exger.2022.111863] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 04/24/2022] [Accepted: 05/28/2022] [Indexed: 02/06/2023]
Abstract
We explored the effect of phlorizin against cholinergic memory impairment and dysbacteriosis in D-galactose induced ICR mice. The control (CON) group, D-galactose model (DGM) group, and three groups (DG-PL, DG-PM, DG-PH) treated with phlorizin at 0.01%, 0.02%, and 0.04% (w/w) in diets were raised for 12 weeks. Supplementing with phlorizin reversed the loss of organ coefficient and body weight caused by D-galactose. The functional abilities of phlorizin on hippocampal-dependent spatial learning and memory, anti-oxidation, anti-inflammation were also observed. Meanwhile, phlorizin intervention upregulated the gene expression of Nrf2, GSH-PX, SOD1, decreased the gene expression of NF-κB, TLR-4, TNF-α, and IL-1β in the hippocampus, while enhanced the gene expression of JAM-A, Mucin2, Occludin in the caecum. Furthermore, a neurotransmitter of acetylcholine (ACh) was enhanced, while acetylcholinesterase (AChE) activity was inhibited by phlorizin administration. Moreover, phlorizin administration increased short-chain fatty acids (SCFAs) content, and reduced lipopolysaccharides (LPS) levels, which may relate to the rebuilding of gut microbiota homeostasis. Treatment with phlorizin may be an effective intervention for alleviating cognitive decline and gut microbiota dysbiosis.
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Affiliation(s)
- Yan-Ling Su
- Department of Biological Science and Technology, Jinzhong University, Jinzhong 030619, China; State Key Laboratory of Food Nutrition and Safety, College of Food Science and Engineering, Tianjin University of Science & Technology, Tianjin 300457, China
| | - Dong Liu
- State Key Laboratory of Food Nutrition and Safety, College of Food Science and Engineering, Tianjin University of Science & Technology, Tianjin 300457, China; Jiangsu Key Laboratory of Preventive and Translational Medicine for Geriatric Disease, Department of Nutrition and Food Hygiene, School of Public Health, Medical College of Soochow University, Suzhou 215123, China
| | - Yao-Jie Liu
- State Key Laboratory of Food Nutrition and Safety, College of Food Science and Engineering, Tianjin University of Science & Technology, Tianjin 300457, China
| | - Yang-Lin Ji
- State Key Laboratory of Food Nutrition and Safety, College of Food Science and Engineering, Tianjin University of Science & Technology, Tianjin 300457, China
| | - Gui-Shan Liu
- School of Food & Wine, Ningxia University, Yinchuan 750021, China
| | - Ji-Li-Te Wang
- Department of Agriculture, Hetao College, Inner Mongolia, Bayannur 015000, China
| | - Biao Wang
- College of Chemical Engineering and Material Science, Tianjin University of Science and Technology, Tianjin 300457, China.
| | - Hao Wang
- State Key Laboratory of Food Nutrition and Safety, College of Food Science and Engineering, Tianjin University of Science & Technology, Tianjin 300457, China.
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Liu Y, Liu Y, Guo Y, Xu L, Wang H. Phlorizin exerts potent effects against aging induced by D-galactose in mice and PC12 cells. Food Funct 2021; 12:2148-2160. [PMID: 33565551 DOI: 10.1039/d0fo02707c] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Phlorizin is the main active ingredient of apple peel and has potential utilization value. Some recent studies have suggested that phlorizin may have antioxidant capacity and protect the liver. The injection of a low dose of d-galactose can cause some changes that resemble accelerated aging in mice. This study explored the protective effects of phlorizin on d-galactose-induced mice and PC12 cells. In this study, ICR mice were divided into a normal group (NOR), a d-galactose model group (d-gal) and phlorizin treatment groups (100 mg kg-1, 200 mg kg-1 and 400 mg kg-1). In addition to the NOR group, four other groups were injected with d-galactose (120 mg kg-1) for 12 weeks. The results showed that phlorizin reduced the decline of strength, coordination and spatial memory caused by aging, increased the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), increased total antioxidant capacity (T-AOC), and reduced the content of malondialdehyde (MDA). On the other hand, phlorizin increased the levels of interleukin-2 (IL-2) and acetylcholine (ACh), reduced the release of interleukin-6 (IL-6), aspartate aminotransferase (AST) and alanine aminotransferase (ALT), and decreased the activity of acetylcholinesterase (AChE) in the brain, improved the expression of antioxidant genes related to the nuclear factor E2-related factor 2 (Nrf2) pathway, and reduced the occurrence of morphological lesions in the hippocampus and liver. In addition, phlorizin improved cell viability and reduced the cytotoxicity of d-galactose-induced oxidative stress in PC12 cells. Meanwhile, the protective effect of phlorizin was abolished in Nrf2 gene knockdown PC12 cells. Furthermore, molecular docking showed that phlorizin could bind Keap1 protein, which can interact with Nrf2 protein. Therefore, these results suggest that phlorizin may delay senescence and enhance antioxidant capacity through the Nrf2 pathway.
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Affiliation(s)
- Yaojie Liu
- State Key Laboratory of Food Nutrition and Safety, College of Food Science and Engineering, Tianjin University of Science & Technology, Tianjin 300457, China.
| | - Ying Liu
- State Key Laboratory of Food Nutrition and Safety, College of Food Science and Engineering, Tianjin University of Science & Technology, Tianjin 300457, China.
| | - Yatu Guo
- Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin 300384, China
| | - Lin Xu
- Pathology Department, Tianjin Municipal Public Security Hospital, Tianjin 300042, China
| | - Hao Wang
- State Key Laboratory of Food Nutrition and Safety, College of Food Science and Engineering, Tianjin University of Science & Technology, Tianjin 300457, China.
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Kamdi SP, Raval A, Nakhate KT. Phloridzin attenuates lipopolysaccharide-induced cognitive impairment via antioxidant, anti-inflammatory and neuromodulatory activities. Cytokine 2021; 139:155408. [PMID: 33476914 DOI: 10.1016/j.cyto.2020.155408] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 12/02/2020] [Accepted: 12/13/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Lipopolysaccharide (LPS) is known to produce neuroinflammation and memory impairment. Although phloridzin (a phenolic phytoconstituent) shows antioxidant- and anti-inflammatory activities, its ameliorative potential in LPS-mediated neuroinflammation and memory dysfunction remains unexplored. OBJECTIVES To investigate the protective effect of phloridzin against LPS-mediated memory impairment and neuroinflammation in mice. METHODS Different groups of mice were treated with LPS (250 μg/kg) via intraperitoneal (ip) route to induce cognitive impairments. The animals were administered with phloridzin (10-20 mg/kg, oral) or donepezil (1 mg/kg, intraperitoneal), and memory functions were evaluated by Morris water maze (MWM) and Y-maze. At the end of the behavioral experiments, the animals were sacrificed and different biochemical parameters like acetylcholinesterase (AChE), brain derived neurotropic factor (BDNF), tumor necrosis factor (TNF-α), interleukin-6 (IL-6), superoxide dismutase (SOD) and glutathione (GSH) concentration in the hippocampus and the cerebral cortex were estimated. RESULTS While LPS administered animals showed significantly decreased memory retention in both MWM and Y maze, a significant reversal in all the parameters were observed following treatment with phloridzin. LPS-treated animals showed significantly decreased level of antioxidants (SOD and GSH), neurotropic factor (BDNF) and cholinergic transmission (increased AChE) and increased levels of inflammatory/oxidative markers (TNF-α, IL-6 and MDA) in hippocampus and cortex. These changes were alleviated after the treatment with phloridzin. CONCLUSIONS Phloridzin may have neuroprotective role against LPS-induced neuroinflammation and memory impairment by virtue of its antioxidant, anti-inflammatory, and enhanced cholinergic signalling activity in the hippocampus and cerebral cortex.
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Affiliation(s)
- Sandesh P Kamdi
- Faculty of Pharmacy, Pacific Academy of Higher Education and Research University, Udaipur, Rajasthan, India.
| | - Amit Raval
- Faculty of Pharmacy, Pacific Academy of Higher Education and Research University, Udaipur, Rajasthan, India
| | - Kartik T Nakhate
- National Institute of Pharmaceutical Education and Research (NIPER), Export Promotions Industrial Park, Industrial Area, Hajipur, Dist: Vaishali 844102, Bihar, India
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Glucose transporters in brain in health and disease. Pflugers Arch 2020; 472:1299-1343. [PMID: 32789766 PMCID: PMC7462931 DOI: 10.1007/s00424-020-02441-x] [Citation(s) in RCA: 216] [Impact Index Per Article: 54.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 07/20/2020] [Accepted: 07/24/2020] [Indexed: 12/15/2022]
Abstract
Energy demand of neurons in brain that is covered by glucose supply from the blood is ensured by glucose transporters in capillaries and brain cells. In brain, the facilitative diffusion glucose transporters GLUT1-6 and GLUT8, and the Na+-d-glucose cotransporters SGLT1 are expressed. The glucose transporters mediate uptake of d-glucose across the blood-brain barrier and delivery of d-glucose to astrocytes and neurons. They are critically involved in regulatory adaptations to varying energy demands in response to differing neuronal activities and glucose supply. In this review, a comprehensive overview about verified and proposed roles of cerebral glucose transporters during health and diseases is presented. Our current knowledge is mainly based on experiments performed in rodents. First, the functional properties of human glucose transporters expressed in brain and their cerebral locations are described. Thereafter, proposed physiological functions of GLUT1, GLUT2, GLUT3, GLUT4, and SGLT1 for energy supply to neurons, glucose sensing, central regulation of glucohomeostasis, and feeding behavior are compiled, and their roles in learning and memory formation are discussed. In addition, diseases are described in which functional changes of cerebral glucose transporters are relevant. These are GLUT1 deficiency syndrome (GLUT1-SD), diabetes mellitus, Alzheimer’s disease (AD), stroke, and traumatic brain injury (TBI). GLUT1-SD is caused by defect mutations in GLUT1. Diabetes and AD are associated with changed expression of glucose transporters in brain, and transporter-related energy deficiency of neurons may contribute to pathogenesis of AD. Stroke and TBI are associated with changes of glucose transporter expression that influence clinical outcome.
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Yang JY, Zhong YT, Hao WN, Liu XX, Shen Q, Li YF, Ren S, Wang Z, Li W, Zhao LC. The PI3K/Akt and NF-κB signaling pathways are involved in the protective effects of Lithocarpus polystachyus (sweet tea) on APAP-induced oxidative stress injury in mice. RSC Adv 2020; 10:18044-18053. [PMID: 35517205 PMCID: PMC9053632 DOI: 10.1039/d0ra00020e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 04/25/2020] [Indexed: 12/17/2022] Open
Abstract
Acetaminophen (APAP)-induced acute liver injury (ALI) is a health issue that has gradually attracted attention, and is often regarded as a model of drug-induced hepatotoxicity. The leaves of Lithocarpus polystachyus Rehd. (named as “sweet tea”, ST) usually serve as tea drink and folk medicine for healthcare in the southwest part of China. In previous reports, it has been proven to protect various animal models, except for APAP-induced liver injury model. Therefore, this study initially explored the protective effect of ST leaf extract (STL-E) on hepatotoxicity induced by APAP in ICR mice. STL-E of 50 and 100 mg kg−1 were given to each group for 7 days. ALI was intraperitoneally induced by APAP treatment (i.p. 250 mg per kg body weight). Biochemical markers, levels of inflammatory factors, histopathological staining and western blotting were used to analyze the inflammation and apoptosis of liver tissues. Interestingly, the treatment with STL-E significantly attenuated APAP-induced liver injury (p < 0.05). Moreover, STL-E partially mitigated APAP-induced liver injury by effectively activating the PI3K/Akt pathway and inhibiting the NF-κB pathway. In a word, STL-E protected liver against APAP-induced hepatotoxicity by inhibiting the PI3K/Akt-mediated apoptosis signal pathway and inhibiting the NF-κB-mediated signaling pathway. Acetaminophen (APAP)-induced acute liver injury (ALI) is a health issue that has gradually attracted attention, and is often regarded as a model of drug-induced hepatotoxicity.![]()
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Affiliation(s)
- Jia-Yu Yang
- College of Chinese Medicinal Materials, Jilin Agricultural University Changchun 130118 China +86-431-84533304 +86-431-84533304
| | - Yu-Te Zhong
- College of Pharmacy, Guangxi University of Chinese Medicine Nanning 530200 China
| | - Wei-Nan Hao
- College of Chinese Medicinal Materials, Jilin Agricultural University Changchun 130118 China +86-431-84533304 +86-431-84533304
| | - Xiang-Xiang Liu
- College of Chinese Medicinal Materials, Jilin Agricultural University Changchun 130118 China +86-431-84533304 +86-431-84533304
| | - Qiong Shen
- College of Chinese Medicinal Materials, Jilin Agricultural University Changchun 130118 China +86-431-84533304 +86-431-84533304
| | - Yan-Fei Li
- College of Chinese Medicinal Materials, Jilin Agricultural University Changchun 130118 China +86-431-84533304 +86-431-84533304
| | - Shen Ren
- College of Chinese Medicinal Materials, Jilin Agricultural University Changchun 130118 China +86-431-84533304 +86-431-84533304
| | - Zi Wang
- College of Chinese Medicinal Materials, Jilin Agricultural University Changchun 130118 China +86-431-84533304 +86-431-84533304
| | - Wei Li
- College of Chinese Medicinal Materials, Jilin Agricultural University Changchun 130118 China +86-431-84533304 +86-431-84533304
| | - Li-Chun Zhao
- College of Pharmacy, Guangxi University of Chinese Medicine Nanning 530200 China
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Yu C, Ai D, Lin R, Cheng S. Effects of toxic β-glucosides on carbohydrate metabolism in cotton bollworm, Helicoverpa armigera (Hübner). ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2019; 100:e21526. [PMID: 30653757 DOI: 10.1002/arch.21526] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 11/22/2018] [Accepted: 11/22/2018] [Indexed: 06/09/2023]
Abstract
The purpose of this study was to evaluate the effects of three toxic β-glucosides, phlorizin, santonin, and amygdalin, on carbohydrate metabolism in the cotton bollworm, Helicoverpa armigera (Hübner), when diets mixed with β-glucosides were fed to third-instar larvae. The growth of the larvae was significantly inhibited by exposure to santonin after 96 hr but not obviously affected by phlorizin and amygdalin. The midgut trehalase activities were only 51.7%, 32%, and 42.5% of that of the control after treatment with phlorizin, santonin and amygdalin at 2 mg/ml, respectively. In the hemolymph and fat body, the amount of trehalose decreased in all cases. However, the effects of santonin on the alteration of the glycogen and glucose levels as well as the activities of glycogen phosphorylase, were different than those of the other two β-glucosides. It appears that the three β-glucosides have different influences on the carbohydrate metabolism of cotton bollworm.
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Affiliation(s)
- Caihong Yu
- School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing, China
| | - Dong Ai
- School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing, China
| | - Ronghua Lin
- Institute for the Control of Agrochemicals, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Shenhang Cheng
- School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing, China
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Tian Y, Lu W, Deng H, Yang F, Guo Y, Gao L, Xu Y. Phlorizin administration ameliorates cognitive deficits by reducing oxidative stress, tau hyper‐phosphorylation, and neuroinflammation in a rat model of Alzheimer’s disease. J Food Biochem 2018. [DOI: 10.1111/jfbc.12644] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Yuan Tian
- Department of Endocrinology Zhongnan Hospital of Wuhan University Wuhan China
- Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science Xiangyang China
| | - Weibing Lu
- Qingdao Women and Children’s Hospital Qingdao China
- The Institute of Human Nutrition, Qingdao University of Medicine Qingdao China
| | - Haohua Deng
- Department of Endocrinology Zhongnan Hospital of Wuhan University Wuhan China
| | - Fan Yang
- Department of Endocrinology, The Central Hospital of Wuhan, Tongji MedicalCollege Huazhong University of Science and Technology Wuhan China
| | - Yan Guo
- Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science Xiangyang China
| | - Ling Gao
- Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science Xiangyang China
| | - Yancheng Xu
- Department of Endocrinology Zhongnan Hospital of Wuhan University Wuhan China
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Chen Y, Yin LZ, Zhao L, Shu G, Yuan ZX, Fu HL, Lv C, Lin JC. Optimization of the ultrasound-assisted extraction of antioxidant phloridzin from Lithocarpus polystachyus Rehd. using response surface methodology. J Sep Sci 2017; 40:4329-4337. [PMID: 28898533 DOI: 10.1002/jssc.201700686] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 09/04/2017] [Accepted: 09/05/2017] [Indexed: 11/09/2022]
Abstract
The purpose of this study was to optimize the extraction process of phloridzin from Lithocarpus polystachyus Rehd. leaves using response surface methodology and to determine the antioxidant capacity of the extract. A Box-Behnken design was used to analyze the effects of ethanol concentration, liquid-solid ratio, soak time and extraction time on the extraction yield of phloridzin. The content of phloridzin was determined by high-performance liquid chromatography. To assess the antioxidant capacity of the extract, three in vitro test systems were used (1,1-,diphenyl-2-picrylhydrazyl, hydroxyl radical scavenging test and reduction force). The optimal parameters obtained by response surface methodology were a volume fraction of ethanol of 64%, a liquid-solid ratio of 37:1, a soaking time of 35 h and a sonication time of 38 min. The proportion of the extraction of phloridzin from L. polystachyus under these industrial process conditions was 3.83%. According to the obtained results, response surface methodology could be suggested as an adequate model for optimizing the extraction process of phloridzin from L. polystachyus. Ultrasound extraction significantly increased the extraction rate of phloridzin, which could be used as an antioxidant in pharmaceutical and food products.
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Affiliation(s)
- Yang Chen
- Sichuan Agricultural University, College of Veterinary Medicine, Department of Pharmacy, Chengdu, China
| | - Li-Zi Yin
- Sichuan Agricultural University, College of Veterinary Medicine, Department of Pharmacy, Chengdu, China
| | - Ling Zhao
- Sichuan Agricultural University, College of Veterinary Medicine, Department of Pharmacy, Chengdu, China
| | - Gang Shu
- Sichuan Agricultural University, College of Veterinary Medicine, Department of Pharmacy, Chengdu, China
| | - Zhi-Xiang Yuan
- Sichuan Agricultural University, College of Veterinary Medicine, Department of Pharmacy, Chengdu, China
| | - Hua-Lin Fu
- Sichuan Agricultural University, College of Veterinary Medicine, Department of Pharmacy, Chengdu, China
| | - Cheng Lv
- Sichuan Agricultural University, College of Veterinary Medicine, Department of Pharmacy, Chengdu, China
| | - Ju-Chun Lin
- Sichuan Agricultural University, College of Veterinary Medicine, Department of Pharmacy, Chengdu, China
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Novel Roles for the Insulin-Regulated Glucose Transporter-4 in Hippocampally Dependent Memory. J Neurosci 2017; 36:11851-11864. [PMID: 27881773 DOI: 10.1523/jneurosci.1700-16.2016] [Citation(s) in RCA: 97] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 09/15/2016] [Accepted: 09/20/2016] [Indexed: 11/21/2022] Open
Abstract
The insulin-regulated glucose transporter-4 (GluT4) is critical for insulin- and contractile-mediated glucose uptake in skeletal muscle. GluT4 is also expressed in some hippocampal neurons, but its functional role in the brain is unclear. Several established molecular modulators of memory processing regulate hippocampal GluT4 trafficking and hippocampal memory formation is limited by both glucose metabolism and insulin signaling. Therefore, we hypothesized that hippocampal GluT4 might be involved in memory processes. Here, we show that, in male rats, hippocampal GluT4 translocates to the plasma membrane after memory training and that acute, selective intrahippocampal inhibition of GluT4-mediated glucose transport impaired memory acquisition, but not memory retrieval. Other studies have shown that prolonged systemic GluT4 blockade causes insulin resistance. Unexpectedly, we found that prolonged hippocampal blockade of glucose transport through GluT4-upregulated markers of hippocampal insulin signaling prevented task-associated depletion of hippocampal glucose and enhanced both working and short-term memory while also impairing long-term memory. These effects were accompanied by increased expression of hippocampal AMPA GluR1 subunits and the neuronal GluT3, but decreased expression of hippocampal brain-derived neurotrophic factor, consistent with impaired ability to form long-term memories. Our findings are the first to show the cognitive impact of brain GluT4 modulation. They identify GluT4 as a key regulator of hippocampal memory processing and also suggest differential regulation of GluT4 in the hippocampus from that in peripheral tissues. SIGNIFICANCE STATEMENT The role of insulin-regulated glucose transporter-4 (GluT4) in the brain is unclear. In the current study, we demonstrate that GluT4 is a critical component of hippocampal memory processes. Memory training increased hippocampal GluT4 translocation and memory acquisition was impaired by GluT4 blockade. Unexpectedly, whereas long-term inhibition of GluT4 impaired long-term memory, short-term memory was enhanced. These data further our understanding of the molecular mechanisms of memory and have particular significance for type 2 diabetes (in which GluT4 activity in the periphery is impaired) and Alzheimer's disease (which is linked to impaired brain insulin signaling and for which type 2 diabetes is a key risk factor). Both diseases cause marked impairment of hippocampal memory linked to hippocampal hypometabolism, suggesting the possibility that brain GluT4 dysregulation may be one cause of cognitive impairment in these disease states.
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Analysis of Chemical Constituents Changing in Physical Process and Nutritional Components of Malus halliana Koehne Tea. J FOOD QUALITY 2017. [DOI: 10.1155/2017/7950137] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
This study aimed to establish a HPLC method for simultaneous determination of the changing of quercitrin, 3-hydroxyphloridzin, and phloridzin in physical process of M. halliana tea. Meanwhile, the nutritional compositions were determined, using anthrone-sulfuric acid colorimetry and direct titration determination of total sugar and reducing sugar, respectively, in order to provide theoretical basis for quality control and tea production. The results showed that the regression equations for quercitrin, 3-hydroxyphloridzin, and phloridzin were linear in the range of 0.0972–12.15 μg (r=0.999 8), 0.0932~11.65 μg (r=0.999 1), and 0.9~112.5 μg (r=0.999 6), respectively. The average recoveries ranged from 98.19% to 99.35%. The contents of crude protein and the crude fat were measured by spectrophotometric detection and soxhlet extraction detection, respectively. The contents of total sugar, reducing sugar, the fat, and protein were 6.8 g/100 g, 8.5 mg/100 g, 2.399 g/100 g, and 4.362 g/100 g, respectively, in M. halliana tea.
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Zhou CJ, Huang S, Liu JQ, Qiu SQ, Xie FY, Song HP, Li YS, Hou SZ, Lai XP. Sweet tea leaves extract improves leptin resistance in diet-induced obese rats. JOURNAL OF ETHNOPHARMACOLOGY 2013; 145:386-392. [PMID: 23147498 DOI: 10.1016/j.jep.2012.09.057] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Revised: 09/04/2012] [Accepted: 09/16/2012] [Indexed: 06/01/2023]
Abstract
AIM OF THE STUDY Dietary obesity is usually characterized by leptin resistance and abnormal lipid metabolism. Lithocarpus polystachyus Rehd.(Sweet Tea) leaf is a kind of Chinese folkloric medicine, and it has been widely used for obesity, diabetes, and hypertension in South China. The present study is aimed at investigating the pharmacological mechanism of the anti-hyperleptinaemia effects of Sweet Tea leaves extract in high fat diet-induced obese rats. MATERIALS AND METHODS We induced high fat diet obesity for 14 weeks to test the corrective effects of three ST doses (75, 150 and 300 mg/kg per day) for 8 weeks. At the end of the experiment, body weight, fasting blood glucose and serum lipids, superoxide dismutase (SOD), malondialdehyde (MDA), fasting serum insulin and leptin, C-reactive protein, adiponectin and resistin levels were measured, Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) was also calculated. mRNA gene expression of PPARγ (peroxisome proliferator-activated receptor γ) and C/EBPα(CCAAT/enhancer-binding protein α) in epididymal adipose tissue of DIO control and experimental groups were evaluated. RESULTS Sweet Tea leaves extract could significantly decrease the levels of serum lipids, attenuate body weight gain and lower circulating leptin and insulin levels, ameliorate the state of oxidative stress, raise serum adiponectin, reduce circulating CRP and resistin levels, and depress the expression of PPARγ and C/EBPα in epididymal adipose tissue of obese rats. CONCLUSION The present findings suggest that ST can effectively attenuate the leptin resistance at least through anti-hyperlipidemic activity and thus has the therapeutic potential in treating hyperlipidemia and hyperleptinaemia related to dietary obesity.
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Abstract
The sodium-glucose co-transporter-2 (SGLT2) is a low-affinity transport system that is specifically expressed in the kidney and plays an important role in renal glucose reabsorption in the proximal tubule. Competitive inhibition of SGLT2 therefore represents an innovative therapeutic strategy for the treatment of hyperglycaemia and/or obesity in patients with type 1 or type 2 diabetes by enhancing glucose and energy loss through the urine. The observation that individuals with familial renal glycosuria maintain normal long-term kidney function provides some reassurance that this mode of action will not adversely affect renal function. Intense research in this therapeutic area has led to the discovery of novel SGLT2 inhibitors, each with different chemical, pharmacodynamic and pharmacokinetic profiles. This review outlines the biology, expression and pleotropic activity of the SGLT system and the pharmacological profile of SGLT2 inhibitors and provides a summary of preclinical and limited clinical data available to characterize the efficacy, safety and potential clinical utility of SGLT2 inhibitors in the management of diabetes.
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Affiliation(s)
- Iskandar Idris
- Department of Diabetes and Endocrinology, Sherwood Forest Hospitals Foundation Trust, Nottinghamshire, UK.
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14
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Stone WS, Seidman LJ. Toward a model of memory enhancement in schizophrenia: glucose administration and hippocampal function. Schizophr Bull 2008; 34:93-108. [PMID: 17504777 PMCID: PMC2632374 DOI: 10.1093/schbul/sbm041] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Recognition of the need to treat cognitive deficits in schizophrenia is compelling and well established, with empirical findings and conceptual arguments related to cognitive enhancement appearing regularly in the literature. Cognitive enhancement itself, however, remains at an early stage. Biological approaches have centered on the development of antipsychotic medications that also improve cognition, but the results have so far remained modest. As a way to facilitate the development of cognitive enhancers in schizophrenia, this article focuses on adjunctive pharmacological approaches to antipsychotic medications and highlights the need for systematic explorations of relevant brain mechanisms. While numerous conceptual criteria might be employed to guide the search, we will focus on 4 points that are especially likely to be useful and which have not yet been considered together. First, the discussion will focus on deficits in a particular cognitive domain, verbal declarative memory. Second, we will review the current status of preclinical and clinical efforts to improve declarative memory using antipsychotic medications, which is the main, existing mode of treatment. Third, we will examine an example of an adjunctive intervention-glucose administration-that improves memory in animals and humans, modulates function in brain regions related to verbal declarative memory, and is highly amenable to translational research. Finally, a heuristic model will be outlined to explore how the intervention maps on to the underlying neurobiology of schizophrenia. More generally, the discussion underlines the promise of cognitive improvement in schizophrenia and the need to approach the issue in a programmatic manner.
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Affiliation(s)
- William S Stone
- Department of Psychiatry, Harvard Medical School, Boston, MA 02114, USA.
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15
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Dong H, Ning Z, Yu L, Li L, Lin L, Huang J. Preparative separation and identification of the flavonoid phlorhizin from the crude extract of Lithocarpus polystachyus Rehd. Molecules 2007; 12:552-62. [PMID: 17851410 PMCID: PMC6149386 DOI: 10.3390/12030552] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2007] [Revised: 03/13/2007] [Accepted: 03/13/2007] [Indexed: 01/04/2023] Open
Abstract
The flavonoid phlorhizin is abundant in the leaves of Sweet Tea (ST, Lithocarpus Polystachyus Rehd). Phlorhizin was preparatively separated and purified from a crude ST extract containing 40% total flavonoids by static adsorption and dynamic desorption on ADS-7 macroporous resin and neutral alumina column chromatography. Only water and ethanol were used as solvents and eluants throughout the whole separation and purification process. Using a phlorhizin standard as the reference compound, the target compound separated from the crude ST extracts was analyzed by thin layer chromatography (TLC), high performance liquid chromatography (HPLC) and electrospray ionization mass spectrometry (EIS-MS) and identified as 99.87% pure (by HPLC-UV) phlorhizin. The results showed that 10 g of the target compound could be obtained from 40 g of the crude extracts in a single operation, indicating a 40% recovery. Therefore, this represents an efficient and environmentally-friendly technology for separating and purifying phlorhizin from ST leaves.
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Affiliation(s)
- Huaqiang Dong
- College of Light Industry and Food Technology, South China University of Technology, Guangzhou, 510641, P.R. China; E-mails: ; ;
- Department of Food Science, Foshan University, Nanhai Dali, Guangdong 528231, P.R. China; E-mails: ;
- Author to whom correspondence should be addressed; E.mail: ; Tel: (+86)-757-85505064
| | - Zhengxiang Ning
- College of Light Industry and Food Technology, South China University of Technology, Guangzhou, 510641, P.R. China; E-mails: ; ;
| | - Lijing Yu
- College of Light Industry and Food Technology, South China University of Technology, Guangzhou, 510641, P.R. China; E-mails: ; ;
| | - Lin Li
- College of Light Industry and Food Technology, South China University of Technology, Guangzhou, 510641, P.R. China; E-mails: ; ;
| | - Lichao Lin
- Department of Food Science, Foshan University, Nanhai Dali, Guangdong 528231, P.R. China; E-mails: ;
| | - Jianbo Huang
- Department of Food Science, Foshan University, Nanhai Dali, Guangdong 528231, P.R. China; E-mails: ;
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16
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Abstract
The dihydrochalcone phlorizin is a natural product and dietary constituent found in a number of fruit trees. It has been used as a pharmaceutical and tool for physiology research for over 150 years. Phlorizin's principal pharmacological action is to produce renal glycosuria and block intestinal glucose absorption through inhibition of the sodium-glucose symporters located in the proximal renal tubule and mucosa of the small intestine. This review covers the role phlorizin has played in the history of diabetes mellitus and its use as an agent to understand fundamental concepts in renal physiology as well as summarizes the physiology of cellular glucose transport and the pathophysiology of renal glycosuria. It reviews the biology and pathobiology of glucose transporters and discusses the medical botany of phlorizin and the potential effects of plant flavonoids, such as phlorizin, on human metabolism. Lastly, it describes the clinical pharmacology and toxicology of phlorizin, including investigational uses of phlorizin and phlorizin analogs in the treatment of diabetes, obesity, and stress hyperglycemia.
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Affiliation(s)
- Joel R L Ehrenkranz
- Department of Medicine, University of Colorado Health Sciences Center, Denver, Colorado, USA.
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17
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Abstract
The memory-improving action of glucose has now been studied for almost 20 years and the study of this phenomenon has led to a number of important developments in the understanding of memory, brain physiology and pathological consequences of impaired glucose tolerance. Glucose improvement of memory appears to involve two optimal doses in animals (100 mg/kg and 2 g/kg) that may correspond to two physiological mechanisms underlying glucose effects on memory. In humans, there have been few dose-response studies so the existence of more than one effective dose in humans is uncertain. Many tasks are facilitated by glucose in humans but tasks that are difficult to master or involve divided attention are improved more readily that easier tasks. There are a number of hypotheses about the physiological bases of the memory-improving action of glucose. Peripheral glucose injections could alleviate localized deficits in extracellular glucose in the hippocampus. These localized deficits may be due to changes in glucose transporters in that structure. Because certain neurotransmitters such as acetylcholine are directly dependent on the glucose supply for their synthesis, glucose is thought to facilitate neurotransmitter synthesis under certain circumstances. However, these hypotheses cannot account for the specificity of the dose-response effect of glucose. A number of peripheral mechanisms have been proposed, including the possibility that glucose-sensitive neurons in the brain or in the periphery may serve as glucose sensors and eventually produce neural changes that would facilitate memory processing. These latter results could be of importance because the mechanisms they suggest appear to be dose-dependent, a crucial characteristic to explain the dose-dependent effects of glucose. There may be an advantage to develop hypotheses that include both peripheral and central actions of glucose. There is evidence that impaired glucose regulation is associated with impaired cognition, particularly episodic memory. This impairment is minimal in young people but increases in older people (65 years and over) where it may compound other aging processes leading to reduced brain function. A small number of studies showed that glucose improvement of memory is associated with poor glucose regulation although this may not be the case for diabetic patients. Results of a few studies also suggest that drug treatments that improve glucose regulation also produce cognitive improvement in diabetic patients.
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Affiliation(s)
- Claude Messier
- School of Psychology, University of Ottawa, 145 Jean-Jacques Lussier Room 352, Ottawa, Ontario, Canada K1N 6N5.
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18
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Boccia MM, Kopf SR, Baratti CM. Phlorizin, a competitive inhibitor of glucose transport, facilitates memory storage in mice. Neurobiol Learn Mem 1999; 71:104-12. [PMID: 9889076 DOI: 10.1006/nlme.1998.3856] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Posttraining intraperitoneal administration of phlorizin (3.0-300.0 microg/kg), a competitive inhibitor of glucose transport from blood to brain, facilitated 48-h retention, in male Swiss mice, of a one-trial step-through inhibitory avoidance task. The dose-response curve was an inverted-U shape. Phlorizin did not increase the retention latencies of mice that had not received a foot shock during training. The effects of phlorizin (30.0 microg/kg) on retention were time dependent, and the administration of phlorizin (30.0 microg/kg) 5 or 10 min prior to the retention test did not affect the retention performance of mice given posttraining injections of saline or phlorizin (30.0 microg/kg). These findings indicate that phlorizin influenced memory storage, but not memory retrieval. Finally, the simultaneous administration of phlorizin (3. 0-300.0 microg/kg, ip) antagonized, in a dose-related manner, the memory impairment induced by insulin (8 IU/kg, ip). Taken together, the results show that phlorizin enhance retention acting as a "glucose-like substance" although the mechanism(s) of this enhancement is unknown.
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Affiliation(s)
- M M Boccia
- Cátedra de Farmacología-Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Junín 956-5 degrees Piso, 1113-, Argentina
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Messier C, Gagnon M. Glucose regulation and cognitive functions: relation to Alzheimer's disease and diabetes. Behav Brain Res 1996; 75:1-11. [PMID: 8800646 DOI: 10.1016/0166-4328(95)00153-0] [Citation(s) in RCA: 164] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Glucose has been found to improve memory in animals and humans. Animal research has revealed that glucose may improve memory through a facilitation of acetylcholine (ACh) synthesis and release in the brain. This glucose-related memory improvement has prompted research in elderly humans. These studies have shown that the memory-improving action of glucose depends on each individuals' blood glucose regulation. Based on these data, researchers have evaluated the effect of glucose on memory in patients with Alzheimer's disease (AD). Results demonstrated that glucose could improve memory in a subset of patients that had abnormalities in their blood glucose regulation. Interestingly, these alterations in blood glucose regulation were believed to depend on the severity of the disease process. Another line of investigation has focused on alterations in brain glucose metabolism. Both animal models and studies with Type II diabetic elderly patients have shown that altered glucose regulation impairs learning and memory processes. It is possible that in AD patients, hyperglycemia exerts a deleterious effect by potentiating the neuronal death produced by other pathological processes taking place such as amyloid deposition. Based on these data, it appears important to find the prevalence of altered glucoregulation at various stages of AD. Secondly, it may be of interest to determine prospectively whether altered glucoregulation is linked to a faster progression of the disease. Finally, if such a relationship is observed, the next logical step would be to determine whether AD patients could benefit from treatments aimed at normalizing blood glucose regulation and improving insulin sensitivity.
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Affiliation(s)
- C Messier
- School of Psychology, University of Ottawa, Ontario, Canada.
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