Tocotrienol-rich fraction supplementation reduces hyperglycemia-induced skeletal muscle damage through regulation of insulin signaling and oxidative stress in type 2 diabetic mice

1,25(OH)2D3 inhibits pancreatic stellate cells activation and promotes insulin secretion in T2DM

PURPOSE

To evaluate the effect and mechanism of 1,25(OH)2D3 on pancreatic stellate cells (PSCs) in type 2 diabetes mellitus (T2DM).

METHODS

A mouse model of T2DM was successfully established by high-fat diet (HFD) /streptozotocin (STZ) and administered 1,25(OH)2D3 for 3 weeks. Fasting blood glucose (FBG), glycated hemoglobin A1c (GHbA1c), insulin (INS) and glucose tolerance were measured. Histopathology changes and fibrosis of pancreas were examined by hematoxylin and eosin staining and Masson staining. Mouse PSCs were extracted, co-cultured with mouse insulinoma β cells (MIN6 cells) and treated with 1,25(OH)2D3. ELISA detection of inflammatory factor expression. Tissue reactive oxygen species (ROS) levels were also measured. Immunofluorescence or Western blotting were used to measure fibrosis and inflammation-related protein expression.

RESULTS

PSCs activation and islets fibrosis in T2DM mice. Elevated blood glucose was accompanied by significant increases in serum inflammatory cytokines and tissue ROS levels. 1,25(OH)2D3 attenuated islet fibrosis by reducing hyperglycemia, ROS levels, and inflammatory factors expression. Additionally, the co-culture system confirmed that 1,25(OH)2D3 inhibited PSCs activation, reduced the secretion of pro-inflammatory cytokines, down-regulated the expression of fibrosis and inflammation-related proteins, and promoted insulin secretion.

CONCLUSION

Our findings identify that PSCs activation contributes to islet fibrosis and β-cell dysfunction. 1,25(OH)2D3 exerts beneficial effects on T2DM potentially by inhibiting PSCs activation and inflammatory response, highlighting promising control strategies of T2DM by vitamin D.

Attenuation of PI3K/AKT signaling pathway by Ocimum gratissimum leaf flavonoid-rich extracts in streptozotocin-induced diabetic male rats

Diabetes is a group of medical conditions characterized by the body's inability to effectively control blood glucose levels, due to either insufficient insulin synthesis in type 1 diabetes or inadequate insulin sensitivity in type 2 diabetes. According to this research, the PI3K/AKT pathway of Ocimum gratissimum leaf flavonoid-rich extracts in streptozotocin-induced diabetic rats was studied. We purchased and used a total of forty (40) male Wistar rats for the study. We divided the animals into five (5) different groups: normal control (Group A), diabetic control (Group B), low dose (150 mg/kg body weight) of Ocimum gratissimum flavonoid-rich leaf extract (LDOGFL) (Group C), high dose (300 mg/kg body weight) of Ocimum gratissimum flavonoid-rich leaf extract (HDOGFL) (Group D), and 200 mg/kg of metformin (MET) (Group E). Streptozotocin induced all groups except Group A, which serves as the normal control group. The experiment lasted for 21 days, following which we sacrificed the animals and harvested their brains for biochemical analysis on the 22nd day. We carried out an analysis that included reduced glutathione (GSH), glutathione transferases (GST), catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD), along with GLUT4, MDA, pro-inflammatory cytokines, NO, neurotransmitters, cholinergic enzyme activities, cardiolipin, and the gene expression of PI3K/AKT. The obtained result indicates that the flavonoid-rich extracts of O. gratissimum significantly enhanced the levels of GSH, GST, CAT, GPx, and SOD, as well as GLUT4 and cardiolipin. The levels of GSH, GST, CAT, GPx, and SOD, as well as GLUT4 and cardiolipin, were significantly increased by gratissimum. Moreover, the extracts decrease the levels of MDA, pro-inflammatory cytokines, NO, neurotransmitters, and cholinergic enzyme activities. Additionally, the flavonoid-rich extracts of O. gratissimum significantly improved the AKT and PI3K gene expressions in diabetic rats. gratissimum had their AKT and PI3K gene expressions significantly (p < 0.05) improved. The findings indicate that O. gratissimum leaf flavonoids have the potential to treat diabetes mellitus. gratissimum leaf flavonoids possess therapeutic potential in themselves and can be applied in the management of diabetes mellitus. Although further analysis can be carried out in terms of isolating, profiling, or purifying the active compounds present in the plant's extract.

Health Benefits of Palm Tocotrienol-Rich Fraction: A Systematic Review of Randomized Controlled Trials

CONTEXT

Vitamin E, a well-known antioxidant with numerous positive effects on human health, encompasses tocotrienol-rich fraction (TRF), a natural variant abundant in palm oil.

OBJECTIVE

This systematic review analyzed findings from randomized controlled trials published until 2022 to evaluate the health impacts of palm TRF.

DATA SOURCES

A literature search was performed in Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, OVID Medline, SCOPUS, and Web of Science from inception until December 2022. Thirty studies involving 2646 patients, including both healthy individuals and those with underlying conditions, were identified.

RESULTS

This review shows palm TRF to be a promising natural supplement against inflammation and lipid peroxidation and that can significantly enhance overall health. Additionally, the study underscores the necessity for further research to ascertain the optimal dosage, formulation, and duration of supplementation, maximizing the potential health advantages.

CONCLUSION

This systematic review provides evidence supporting the health benefits associated with palm TRF.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42020204070.

Vitamin E and conflicting understandings in noncommunicable diseases: Is it worth supplementing?

Vitamin E is a lipid-soluble nutrient found mainly in vegetable oils and oilseeds. It is divided into eight homologous compounds; however, only α-tocopherol exhibits vitamin activity. Many advantages are related to these compounds, including cellular protection through antioxidant and anti-inflammatory activity, and improving lipid metabolism. Physiopathology of many diseases incepts with reduced antioxidant defense, characterized by an increased reactive oxygen species production and activation of transcription factors involved in inflammation, such as nuclear factor-kappa B (NF-κB), that can be linked to oxidative stress. Moreover, disorders of lipid metabolism can increase the risk of cardiovascular diseases. In addition, intestinal dysbiosis plays a vital role in developing chronic non-communicable diseases. In this regard, vitamin E can be considered to mitigate those disorders, but data still needs to be more conclusive. This narrative review aims to elucidate the mechanisms of action of vitamin E and if supplementation can be beneficial in a disease scenario regarding non-communicable diseases.

Solanum melongena extract supplementation protected skeletal muscle and brain damage by regulation of BDNF/PGC1α/irisin pathway via brain function-related myokines in high-fat diet induced obese mice

In this study, we investigated the protective effects of SM on skeletal muscle and brain damage by regulation of BDNF/PGC1α/irisin pathway via brain function related myokines in high-fat diet-induced OB mice. OB was induced by high-fat diet for 6 weeks. SM extract (SME) was administered with 200 mg/kg BW (LSM) and 500 mg/kg BW (HSM) by oral gavage every day for 12 weeks. Behavior tests such as grip strength, Y-maze, and passive avoidance test were conducted to analyze muscle and cognitive function. Histopathological changes in skeletal muscle and brain were examined by hematoxylin and eosin staining and the protein levels of biomarkers related to oxidative stress, inflammation, protein degradation, neuro-plasticity, and cell cycling were measured by western blot. SME regulated morphological changes (muscle cross-sectional area: 1.23%, 1.40%; density of neurons in hippocampus:1.74%, 1.73%) in T2DM mice. Importantly, SME supplementation significantly increased several muscle-derived myokines which might influence the expression of neuronal markers in OB mice (FGF21: 1.27%, 1.34%; PGC1α: 1.0%, 1.32%; IRISIN: 1.9%, 1.08%; BDNF: 1.35%, 1.23%). Accordingly, SME activated hippocampal neurotrophic factors including BDNF (1.0%, 1.2%) and its associated PGC1α/irisin pathway (PGC1α :1.1%, 1.1%; IRISIN:1.1%, 0.9%) significantly. This study demonstrated the possibliy that protective myokines increased by SME supplementation may contribute to neuro-protection in OB mice. Taken together, the current study suggests that SME can be used to prevent skeletal muscle and brain damage in OB by protecting against oxidative stress and inflammatin via modulation of the BDNF/PGC1α/irisin pathway in the therapeutic approach of obese patients.

Tocotrienol isoforms: The molecular mechanisms underlying their effects in cancer therapy and their implementation in clinical trials

Tocotrienols are found in a variety of natural sources, like rice bran, annatto seeds and palm oil, and have been shown to have several health-promoting properties, particularly against chronic diseases such as cancer. The incidence of cancer is rapidly increasing around the world, not only a result of continued aging and population growth, but also due to the adoption of aspects of the Western lifestyle, such as high-fat diets and low-physical activity. The literature provides strong evidence that tocotrienols are able to inhibit the growth of various cancers, including breast, lung, ovarian, prostate, liver, brain, colon, myeloma and pancreatic cancers. These findings, along with the reported safety profile of tocotrienols in healthy human volunteers, encourage further research into these compounds' potential use in cancer prevention and treatment. The current review provided detailed information about the molecular mechanisms of action of different tocotrienol isoforms in various cancer models and evaluated the potential therapeutic effects of different vitamin E analogues on important cancer hallmarks, such as cellular proliferation, apoptosis, angiogenesis and metastasis. MEDLINE/PubMed and Scopus databases were used to identify recently published articles that investigated the anticancer effects of vitamin E derivatives in various types of cancer in vitro and in vivo along with clinical evidence of adjuvant chemopreventive benefits. Following an overview of pre-clinical studies, we describe several completed and ongoing clinical trials that are paving the way for the successful implementation of tocotrienols in cancer chemotherapy.

Heme oxygenase-1: A potential therapeutic target for improving skeletal muscle atrophy

Skeletal muscle atrophy is a common muscle disease that is directly caused by an imbalance in protein synthesis and degradation. At the histological level, it is mainly characterized by a reduction in muscle mass and fiber cross-sectional area (CSA). Patients with skeletal muscle atrophy present with reduced motor ability, easy fatigue, and poor life quality. Heme oxygenase-1 (HO-1) is an inducible enzyme that catalyzes the degradation of heme and has attracted much attention for its anti-oxidation effects. In addition, there is growing evidence that HO-1 plays an important role in anti-inflammatory, anti-apoptosis, pro-angiogenesis, and maintaining skeletal muscle homeostasis, making it a potential therapeutic target for improving skeletal muscle atrophy. Here, we review the pathogenesis of skeletal muscle atrophy, the biology of HO-1 and its regulation, and the biological function of HO-1 in skeletal muscle homeostasis, with a specific focus on the role of HO-1 in skeletal muscle atrophy, aiming to observe the therapeutic potential of HO-1 for skeletal muscle atrophy.

Tocotrienol-rich fraction reduces retinal inflammation and angiogenesis in rats with streptozotocin-induced diabetes

BACKGROUND

Diabetic retinopathy (DR) is the second commonest microvascular complication of diabetes mellitus. It is characterized by chronic inflammation and angiogenesis. Palm oil-derived tocotrienol-rich fraction (TRF), a substance with anti-inflammatory and anti-angiogenic properties, may provide protection against DR development. Therefore, in this study, we investigated the effect of TRF on retinal vascular and morphological changes in diabetic rats. The effects of TRF on the retinal expression of inflammatory and angiogenic markers were also studied in the streptozotocin (STZ)-induced diabetic rats.

METHODS

Male Sprague Dawley rats weighing 200-250 g were grouped into normal rats (N) and diabetic rats. Diabetes was induced by intraperitoneal injection of streptozotocin (55 mg/kg body weight) whereas N similarly received citrate buffer. STZ-injected rats with blood glucose of more than 20 mmol/L were considered diabetic and were divided into vehicle-treated (DV) and TRF-treated (DT) groups. N and DV received vehicle, whereas DT received TRF (100 mg/kg body weight) via oral gavage once daily for 12 weeks. Fundus images were captured at week 0 (baseline), week 6 and week 12 post-STZ induction to estimate vascular diameters. At the end of experimental period, rats were euthanized, and retinal tissues were collected for morphometric analysis and measurement of NFκB, phospho-NFκB (Ser536), HIF-1α using immunohistochemistry (IHC) and enzyme-linked immunosorbent assay (ELISA). Retinal inflammatory and angiogenic cytokines expression were measured by ELISA and real-time quantitative PCR.

RESULTS

TRF preserved the retinal layer thickness (GCL, IPL, INL and OR; p < 0.05) and retinal venous diameter (p < 0.001). TRF also lowered the retinal NFκB activation (p < 0.05) as well as expressions of IL-1β, IL-6, TNF-α, IFN-γ, iNOS and MCP-1 (p < 0.05) compared to vehicle-treated diabetic rats. Moreover, TRF also reduced retinal expression of VEGF (p < 0.001), IGF-1 (p < 0.001) and HIF-1α (p < 0.05) compared to vehicle-treated rats with diabetes.

CONCLUSION

Oral TRF provided protection against retinal inflammation and angiogenesis in rats with STZ-induced diabetes by suppressing the expression of the markers of retinal inflammation and angiogenesis.

Tocotrienol-Rich Fraction Ameliorates the Aluminium Chloride-Induced Neurovascular Dysfunction-Associated Vascular Dementia in Rats

Neurovascular dysfunction leads to the second most common type of dementia, i.e., vascular dementia (VaD). Toxic metals, such as aluminium, increase the risk of neurovascular dysfunction-associated VaD. Hence, we hypothesized that a natural antioxidant derived from palm oil, i.e., tocotrienol-rich fraction (TRF), can attenuate the aluminium chloride (AlCl₃)-induced VaD in rats. Rats were induced with AlCl₃ (150 mg/kg) intraperitoneally for seven days followed by TRF treatment for twenty-one days. The elevated plus maze test was performed for memory assessment. Serum nitrite and plasma myeloperoxidase (MPO) levels were measured as biomarkers for endothelial dysfunction and small vessel disease determination. Thiobarbituric acid reactive substance (TBARS) was determined as brain oxidative stress marker. Platelet-derived growth factor-C (PDGF-C) expression in the hippocampus was identified using immunohistochemistry for detecting the neovascularisation process. AlCl₃ showed a significant decrease in memory and serum nitrite levels, while MPO and TBARS levels were increased; moreover, PDGF-C was not expressed in the hippocampus. However, TRF treatment significantly improved memory, increased serum nitrite, decreased MPO and TBARS, and expressed PDGF-C in hippocampus. Thus, the results imply that TRF reduces brain oxidative stress, improves endothelial function, facilitates hippocampus PDGF-C expression for neovascularisation process, protects neurons, and improves memory in neurovascular dysfunction-associated VaD rats.

Anti-inflammatory and antioxidant properties of rice bran oil extract in copper sulfate-induced inflammation in zebrafish (Danio rerio)

Tocotrienols have strong antioxidant properties; however, tocotrienol has not been investigated in detail in aquatic products. In this study, the anti-inflammatory and antioxidant activities of the tocotrienol-rich fraction from rice bran oil and its potential mechanism were verified in a zebrafish CuSO₄ inflammation model. The in vitro antioxidant activity was evaluated using the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) stable radical method. The copper chelating activity was determined using the pyrocatechol violet method. Intracellular reactive oxygen species in zebrafish were detected using a fluorescent ROS probe. Transgenic Tg (lyz: DsRed2) zebrafish were used for neutrophil transmigration assays. The mRNA expression levels of antioxidant and pro-inflammatory factor genes were measured using quantitative real-time reverse transcription PCR. In the concentration range tested, 100 μg/mL TRF had the highest copper chelating activity (10%). TRF showed DPPH-free radical scavenging ability, which was 53% at 100 μg/mL TRF. TRF effectively repressed ROS generation and inhibited neutrophil migration to the inflamed site. Moreover, TRF upregulated the expression of antioxidant genes sod and gpx4b, inhibited the expression of pro-inflammatory factors tnfa and il8, and suppressed CuSO₄-induced inflammation. In conclusion, TRF has significant anti-inflammatory and antioxidant properties, which supports the use of TRF as an aquatic feed additive to improve the anti-inflammatory and antioxidant capacity of aquatic products.

Current progress in the hypoglycemic mechanisms of natural polysaccharides

Unhealthy dietary pattern-induced type 2 diabetes mellitus poses a great threat to human health all over the world. Accumulating evidence has revealed that the pathophysiology of type 2 diabetes mellitus is closely associated with the dysregulation of glucose metabolism and energy metabolism, serious oxidative stress, prolonged endoplasmic reticulum stress, metabolic inflammation and intestinal microbial dysbiosis. Most important of all, insulin resistance and insulin deficiency are two key factors inducing type 2 diabetes mellitus. Nowadays, natural polysaccharides have gained increasing attention owing to their numerous health-promoting functions, such as hypoglycemic, energy-regulating, antioxidant, anti-inflammatory and prebiotic activities. Therefore, natural polysaccharides have been used to alleviate diet-induced type 2 diabetes mellitus. Specifically, this review comprehensively summarizes the underlying hypoglycemic mechanisms of natural polysaccharides and provides a theoretical basis for the development of functional foods. For the first time, this review elucidates hypoglycemic mechanisms of natural polysaccharides from the perspectives of their regulatory effects on glucose metabolism, insulin resistance and mitochondrial dysfunction.

Chemical Constituents and Hypoglycemic Mechanisms of Dendrobium nobile in Treatment of Type 2 Diabetic Rats by UPLC-ESI-Q-Orbitrap, Network Pharmacology and In Vivo Experimental Verification

This study aimed to systematically explore the chemical constituents of D. nobile and its hypoglycemic effect by UPLC-ESI-Q-Orbitrap, network pharmacology and in vivo experiment. The chemical constituents of D. nobile were qualitatively analyzed, and the hypoglycemic compounds were quickly identified. Network pharmacological analysis and molecular docking technique were applied to assist in the elucidation of the hypoglycemic mechanisms of D. nobile. A type 2 diabetic mellitus (T2DM) rat model was established using the HFD and STZ method for in vivo experimental verification, and these T2DM rats were treated with D. nobile extract and D. nobile polysaccharide for two months by gavage. The results showed that a total of 39 chemical constituents of D. nobile, including alkaloids, bibenzyls, phenanthrenes and other types of compounds, were identified. D. nobile extract and D. nobile polysaccharide could significantly ameliorate the body weight, hyperglycemia, insulin resistance, dyslipidemia and morphological impairment of the liver and pancreas in the T2DM rats. α-Linolenic acid, dihydroconiferyl dihydro-p-coumarate, naringenin, trans-N-feruloyltyramine, gigantol, moscatilin, 4-O-methylpinosylvic acid, venlafaxine, nordendrobin and tristin were regarded as the key hypoglycemic compounds of D. nobile, along with the hypoglycemic effect on the PI3K-AKT signaling pathway, the insulin signaling pathway, the FOXO signaling pathway, the improvement of insulin resistance and the AGE-RAGE signaling pathway. The Western blotting experiment results confirmed that D. nobile activated the PI3K/AKT pathway and insulin signaling pathway, promoted glycogen synthesis via regulating the expression of glycogen synthase kinase 3 beta (GSK-3β) and glucose transporter 4 (GLUT4), and inhibited liver gluconeogenesis by regulating the expression of phosphoenolpyruvate carboxykinase (PEPCK) and glucose 6 phosphatase (G6pase) in the liver. The results suggested that the hypoglycemic mechanism of D. nobile might be associated with liver glycogen synthesis and gluconeogenesis, contributing to improving insulin resistance and abnormal glucose metabolism in the T2DM rats.

Whole grains-derived functional ingredients against hyperglycemia: targeting hepatic glucose metabolism

Type 2 diabetes mellitus (T2DM) is characterized by the dysregulation of glucose homeostasis, resulting in hyperglycemia. However, concerns have been raised about the safety and efficacy of current hypoglycemic drugs due to undesirable side effects. Increasing studies have shown that whole grains (WG) consumption is inversely associated with the risk of T2DM and its subsequent complications. Thus, dietary strategies involving functional components from the WG provide an intriguing approach to restoring and maintaining glucose homeostasis. This review provides a comprehensive understanding of the major functional components derived from WG and their positive effects on glucose homeostasis, demonstrates the underlying molecular mechanisms targeting hepatic glucose metabolism, and discusses the unclear aspects according to the latest viewpoints and current research. Improved glycemic response and insulin resistance were observed after consumption of WG-derived bioactive ingredients, which are involved in the integrated, multi-factorial, multi-targeted regulation of hepatic glucose metabolism. Promotion of glucose uptake, glycolysis, and glycogen synthesis pathways, while inhibition of gluconeogenesis, contributes to amelioration of abnormal hepatic glucose metabolism and insulin resistance by bioactive components. Hence, the development of WG-based functional food ingredients with potent hypoglycemic properties is necessary to manage insulin resistance and T2DM.

Tocotrienol in the Management of Nonalcoholic Fatty Liver Disease: A Systematic Review

The increasing burden of nonalcoholic fatty liver disease (NAFLD) requires innovative management strategies, but an effective pharmacological agent has yet to be found. Apart from weight loss and lifestyle adjustments, one isomer of the vitamin E family-alpha-tocopherol-is currently recommended for nondiabetic steatohepatitis patients. Another member of the vitamin E family, tocotrienol (T3), has anti-inflammatory and antioxidant properties that reach beyond those of alpha-tocopherol, making it a potential agent for use in NAFLD management. This systematic review aimed to provide an overview of the effects of T3 supplementation on NAFLD from both clinical and preclinical perspectives. A literature search was performed in October 2022 using PubMed, Scopus and Web of Science. Original research articles reporting NAFLD outcomes were included in this review. The search located 12 articles (8 animal studies and 4 human studies). The literature reports state that T3 isomers or natural mixtures (derived from palm or annatto) improved NAFLD outcomes (liver histology, ultrasound or liver profile). However, the improvement depended on the severity of NAFLD, study period and type of intervention (isomers/mixture of different compositions). Mechanistically, T3 improved lipid metabolism and prevented liver steatosis, and reduced mitochondrial and endoplasmic reticulum stress, inflammation and ultimately liver fibrosis. In summary, T3 could be a potential agent for use in managing NAFLD, pending more comprehensive preclinical and human studies.

Lespedeza bicolor extract supplementation reduced hyperglycemia-induced skeletal muscle damage by regulation of AMPK/SIRT/PGC1α-related energy metabolism in type 2 diabetic mice

Lespedeza bicolor (LB) is known to have antidiabetic activities; however, the underlying molecular mechanisms of LB in hyperglycemia-induced skeletal muscle damage is unclear. Inflammation and oxidative stress caused by type 2 diabetes mellitus (T2DM) not only contributes to insulin resistance, but also promotes muscle atrophy via decreased muscle protein synthesis and increased protein degradation, leading to frailty and sarcopenia. In this study, we hypothesized that LB extract (LBE) supplementatin has an ameliorative effect on hyperglycemia-induced skeletal muscle damage by activation of 5' adenosine monophosphate-activated protein kinase (AMPK)/sirtuin (SIRT)/proliferator-activated receptor γ coactivator 1α (PGC1α)-associated energy metabolism in mice with T2DM. Diabetes was induced by a high-fat diet with a 2-time streptozotoxin injection (30 mg/kg body weight) in male C57BL/6J mice. After diabetes was induced (fasting blood glucose level ≥140 mg/dL), the mice were administered with LBE at a low dose (100 mg/kg/d) or high dose (250 mg/kg/d) by gavage for 12 weeks. LBE supplementation ameliorated glucose tolerance and hemoglobin A1c (%) in mice with T2DM. Moreover, LBE supplementation upregulated protein levels of insulin receptor subunit-1 and Akt accompanied by increased translocation of glucose transporter 4 in mice with T2DM. Furthermore, LBE increased mitochondrial biogenesis by activating SIRT1, SIRT3, SIRT4, and peroxisome PGC1α in diabetic skeletal muscle. Meanwhile, LBE supplementation reduced oxidative stress and inflammation in mice with T2DM. Taken together, the current study suggested that LBE could be a potential therapeutic to prevent skeletal muscle damage by regulation AMPK/SIRT/PGC1α-related energy metabolism in T2DM.

Palm Oil Derived Tocotrienol-Rich Fraction Attenuates Vascular Dementia in Type 2 Diabetic Rats

Vascular dementia (VaD) is a serious global health issue and type 2 diabetes mellitus (T2DM) patients are at higher risk. Palm oil tocotrienol-rich fraction (TRF) exhibits neuroprotective properties; however, its effect on VaD is not reported. Hence, we evaluated TRF effectiveness in T2DM-induced VaD rats. Rats were given a single dose of streptozotocin (STZ) and nicotinamide (NA) to develop T2DM. Seven days later, diabetic rats were given TRF doses of 30, 60, and 120 mg/kg orally for 21 days. The Morris water maze (MWM) test was performed for memory assessment. Biochemical parameters such as blood glucose, plasma homocysteine (HCY) level, acetylcholinesterase (AChE) activity, reduced glutathione (GSH), superoxide dismutase (SOD) level, and histopathological changes in brain hippocampus and immunohistochemistry for platelet-derived growth factor-C (PDGF-C) expression were evaluated. VaD rats had significantly reduced memory, higher plasma HCY, increased AChE activity, and decreased GSH and SOD levels. However, treatment with TRF significantly attenuated the biochemical parameters and prevented memory loss. Moreover, histopathological changes were attenuated and there was increased PDGF-C expression in the hippocampus of VaD rats treated with TRF, indicating neuroprotective action. In conclusion, this research paves the way for future studies and benefits in understanding the potential effects of TRF in VaD rats.

Peroxisome proliferator-activated receptor gamma and its natural agonists in the treatment of kidney diseases

Kidney disease is one of the leading non-communicable diseases related to tremendous health and economic burden globally. Diabetes, hypertension, obesity and cardiovascular conditions are the major risk factors for kidney disease, followed by infections, toxicity and autoimmune causes. The peroxisome proliferator-activated receptor gamma (PPAR-γ) is a ligand-activated nuclear receptor that plays an essential role in kidney physiology and disease. The synthetic agonists of PPAR-γ shows a therapeutic effect in various kidney conditions; however, the associated side effect restricts their use. Therefore, there is an increasing interest in exploring natural products with PPARγ-activating potential, which can be a promising solution to developing effective and safe treatment of kidney diseases. In this review, we have discussed the role of PPAR-γ in the pathophysiology of kidney disease and the potential of natural PPAR-γ agonists in treating various kidney diseases, including acute kidney injury, diabetic kidney disease, obesity-induced nephropathy, hypertension nephropathy and IgA nephropathy. PPAR-γ is a potential target for the natural PPAR-γ agonists against kidney disease; however, more studies are required in this direction.

Effects of Whey Peptide Supplementation on Sarcopenic Obesity in High-Fat Diet-Fed Mice

The incidence of sarcopenic obesity gradually increased in parallel with the aged population. This research examined the effects of whey peptide (WP) supplementation with/without resistant exercise (RE) on sarcopenic obesity. Male 8-month-old C57BL/6J mice were fed a control diet (10 kcal% fat) or a high-fat diet (60 kcal% fat) for 8 weeks. High-fat diet-fed mice were randomly divided into four groups: obesity control group (OB), RE (RE only), WP (WP only), and WPE (RE and WP). WP supplementation (1500 mg/day/kg B.W.) gavage and RE (ladder climbing, five times weekly, 8−10 repetitions, 10−20% B.W. load) were conducted for an additional 8 weeks. Protein and mRNA levels of markers related to energy, protein, and lipid metabolism were analyzed in skeletal muscle and adipose tissue by one-way analysis of variance (ANOVA). WP supplementation regardless of RE significantly suppressed the increasing fat mass (p = 0.016) and decreasing lean mass (p = 0.014) and alleviated abnormal morphological changes in skeletal muscle and adipose tissue (p < 0.001). In adipose tissue, WP supplementation regardless of RE ameliorated dysregulated energy metabolism and contributed to the reduction in adipocyte differentiation (PPAR-γ (p = 0.017), C/EBPα (p = 0.034)). In skeletal muscle, WP supplementation regardless of RE alleviated energy metabolism dysregulation and resulted in down-regulated protein degradation (Atrogin-1 (p = 0.003), MuRF1 (p = 0.006)) and apoptosis (Bax) (p = 0.004). Taken together, the current study elucidated that WP supplementation regardless of RE has potential anti-obesity and anti-sarcopenic effects in sarcopenic obesity.

Bioactive Components in Whole Grains for the Regulation of Skeletal Muscle Function

Skeletal muscle plays a primary role in metabolic health and physical performance. Conversely, skeletal muscle dysfunctions such as muscular dystrophy, atrophy and aging-related sarcopenia could lead to frailty, decreased independence and increased risk of hospitalization. Dietary intervention has become an effective approach to improving muscle health and function. Evidence shows that whole grains possess multiple health benefits compared with refined grains. Importantly, there is growing evidence demonstrating that bioactive substances derived from whole grains such as polyphenols, γ-oryzanol, β-sitosterol, betaine, octacosanol, alkylresorcinols and β-glucan could contribute to enhancing myogenesis, muscle mass and metabolic function. In this review, we discuss the potential role of whole-grain-derived bioactive components in the regulation of muscle function, emphasizing the underlying mechanisms by which these compounds regulate muscle biology. This work will contribute toward increasing awareness of nutraceutical supplementation of whole grain functional ingredients for the prevention and treatment of muscle dysfunctions.

Revisiting the therapeutic potential of tocotrienol

The therapeutic potential of the tocotrienol group stems from its nutraceutical properties as a dietary supplement. It is largely considered to be safe when consumed at low doses for attenuating pathophysiology as shown by animal models, in vitro assays, and ongoing human trials. Medical researchers and the allied sciences have experimented with tocotrienols for many decades, but its therapeutic potential was limited to adjuvant or concurrent treatment regimens. Recent studies have focused on targeted drug delivery by enhancing the bioavailability through carriers, self-sustained emulsions, nanoparticles, and ethosomes. Epigenetic modulation and computer remodeling are other means that will help increase chemosensitivity. This review will focus on the systemic intracellular anti-cancer, antioxidant, and anti-inflammatory mechanisms that are stimulated and/or regulated by tocotrienols while highlighting its potent therapeutic properties in a diverse group of clinical diseases.

The Potential Role of Myokines/Hepatokines in the Progression of Neuronal Damage in Streptozotocin and High-Fat Diet-Induced Type 2 Diabetes Mellitus Mice

Background: Diabetes is highly prevalent, and the number of patients with diabetic sarcopenia and cognitive impairment has grown, leading to decreased quality of life. Although the exact mechanisms between sarcopenia and cognitive impairment have not been elucidated, it is speculated that muscle and liver-derived mediators might contribute to brain function. This study examined the molecular mechanisms associated with muscle-brain interaction accompanied by insulin resistance (IR) caused by aberrant energy metabolism via myokines/hepatokines in type 2 diabetes mellitus (T2DM) mice. Methods: T2DM was induced by a high-fat diet and streptozotocin injection. Behavior tests were conducted to analyze grip strength and cognitive function. Histopathological changes in skeletal muscle and brain tissue were examined by hematoxylin and eosin staining and the protein levels of biomarkers related to energy metabolism via myokines/hepatokines were measured by western blot. Results: T2DM caused peripheral and central IR. Furthermore, T2DM led to aberrant energy metabolism through the reduced fibroblast growth factor 21 dependent AMP-activated kinase (AMPK)/surtuin1/proliferator-activated receptor γ coactivator-1α pathway in T2DM. Subsequently, reduced circulating myokines/hepatokines were in accordance with their levels with hippocampal neuronal markers in T2DM mice. Accordingly, skeletal muscle (muscle strength: 2.83 ± 0.39 vs. 2.187 ± 0.51, p = 0.004) and brain function (PAT: 38.5 ± 57.91 vs. 11.556 ± 12.03, p = 0.02) impairment and morphological changes (muscle cross-sectional area: 872.43 ± 242.87 vs. 743.68 ± 169.31, p = 0.01; density of neurons in hippocampus: 145 ± 15.13 vs. 77 ± 35.51, p = 0.05; density of neurons in cortex: 138.333 ± 6.66 vs. 78 ± 17.35, p = 0.05) were shown in T2DM mice. In addition, the working ability demonstrated by Y-maze was positively correlated with % lean mass (p = 0.046, R = 0.3426). Conclusions: T2DM led to aberrant energy in skeletal muscle and brain via myokines/hepatokines. This study suggested that myokines and hepatokines might have potential roles in skeletal muscle and central metabolic functions which can mediate cognitive function in T2DM mice.

Potential Health Benefits of Whole Grains: Modulation of Mitochondrial Biogenesis and Energy Metabolism

Mitochondria play an essential role in maintaining cellular metabolic homeostasis. However, its dysfunction will cause different pathophysiological consequences. A specific mechanism of action has been developed by cells to adapt to changes in physiological conditions or in response to different stimuli, by meditating mitochondrial number, structure, and energy metabolism. Whole grains are considered healthier than refined grains for their higher amounts of bioactive components, with proven multiple health benefits. The modulation of an appropriate mitochondrial function contributes to the bioactive-component-based health improvements. Thus, this review aims to represent current studies that identify the impact of natural bioactive components in whole grains against metabolic disorders by modulating mitochondrial biogenesis and energy metabolism. It seems most attractive to aim nutritional intervention at the prevention or treatment of metabolic abnormalities and hence to target dietary management at improvement of mitochondrial function.

Nutrient weight against sarcopenia: regulation of the IGF-1/PI3K/Akt/FOXO pathway in quinoa metabolites

Sarcopenia is characterized by the loss of muscle mass and strength, and one of its major molecular mechanisms is muscle protein turnover. Quinoa, the grain-like food crop, is a health nutrient used to treat diseases that predispose individuals to muscle wasting, including cardiovascular disorders, diabetes mellitus, and cancer. Quinoa secondary metabolites have recently been demonstrated to regulate protein turnover (including protein synthesis and degradation), a main biological process within muscle cells, through diverse signals (such as the p38 MAPK, TNF-α, and IGF-1/PI3K/Akt/FOXO pathways). Here, we describe how quinoa functions in the main pathway of protein synthesis and degradation, screen promising pharmacological components in nutritional applications, and provide guidance for the effects of quinoa products in sarcopenia.

Vanillin modulates activities linked to dysmetabolism in psoas muscle of diabetic rats

Skeletal muscles are important in glucose metabolism and are affected in type 2 diabetes (T2D) and its complications. This study investigated the effect of vanillin on redox imbalance, cholinergic and purinergic dysfunction, and glucose-lipid dysmetabolism in muscles of rats with T2D. Male albino rats (Sprague-Dawley strain) were fed 10% fructose ad libitum for 2 weeks before intraperitoneally injecting them with 40 mg/kg streptozotocin to induce T2D. Low (150 mg/kg bodyweight (BW)) and high (300 mg/kg BW) doses of vanillin were orally administered to diabetic rats. Untreated diabetic rats and normal rats made up the diabetic control (DC) and normal control (NC) groups, respectively. The standard antidiabetic drug was metformin. The rats were humanely put to sleep after 5 weeks of treatment and their psoas muscles were harvested. There was suppression in the levels of glutathione, activities of SOD, catalase, ENTPDase, 5'Nucleotidase and glycogen levels on T2D induction. This was accompanied by concomitantly elevated levels of malondialdehyde, serum creatine kinase-MB, nitric oxide, acetylcholinesterase, ATPase, amylase, lipase, glucose-6-phosphatase (G6Pase), fructose-1,6-biphophastase (FBPase) and glycogen phosphorylase activities. T2D induction further resulted in the inactivation of fatty acid biosynthesis, glycerolipid metabolism, fatty acid elongation in mitochondria and fatty acid metabolism pathways. There were close to normal and significant reversals in these activities and levels, with concomitant reactivation of the deactivated pathways following treatment with vanillin, which compared favorably with the standard drug (metformin). Vanillin also significantly increased muscle glucose uptake ex vivo. The results suggest the therapeutic effect of vanillin against muscle dysmetabolism in T2D as portrayed by its ability to mitigate redox imbalance, inflammation, cholinergic and purinergic dysfunctions, while modulating glucose-lipid metabolic switch and maintaining muscle histology.

Moisture and caking resistant Tremella fuciformis polysaccharides microcapsules with hypoglycemic activity

Tremella fuciformis polysaccharides (TPs) have attracted extensive attention as functional food constituents due to their bioactivity. However, β-D-glucan obtained from TPs is readily degraded by oxidation and easy to absorb water and agglomerate. The purpose of this study was to reduce moisture adsorption and caking strength through spray drying by using maltodextrin as wall materials and explore the hypoglycemic effect and molecular mechanism of TPs microcapsules. It was observed that dextrose equivalent (DE) value and concentration of maltodextrin (MD) affect the morphology, encapsulation efficiency, loading capacity, water adsorption and caking strength of TPs microcapsules powder. The administration of TPs microcapsules powder prevented body weight and serum insulin loss, and significantly decreased the blood glucose level, serum triglycerides, as well as total cholesterol levels, which seemed to be related to increasing the glycogen synthesis and facilitating the glucose transportation by regulating the PI3K/Akt pathway.

Effects of delta-tocotrienol supplementation on Glycemic Control, oxidative stress, inflammatory biomarkers and miRNA expression in type 2 diabetes mellitus: A randomized control trial

The study aimed to ascertain the effects of delta-tocotrienol (δT3) supplementation on glycemic control, oxidative stress, inflammation and related micro-ribonucleic acid (miRNA) expression in patients with type 2 diabetes mellitus (T2DM). Total 110 patients of T2DM on oral hypoglycemic agents, were randomly divided into tocotrienol and placebo groups and given 250 mg δT3 or cellulose soft gel capsule once daily respectively for 24 weeks. Glycemic control, oxidative stress, inflammatory biomarkers, and miRNAs expression were measured in serum at baseline and end of the intervention by using standard laboratory methods. Compared to the placebo, δT3 supplementation resulted in a significant (p ≤ .05) reduction [mean difference (95% confidence interval)] in plasma glucose [-0.48 (-0.65, -0.30)], insulin [-1.19 (-1.51, -0.87)], homeostatic model assessment of insulin resistance [-0.67 (-0.86, -0.49)], glycosylated hemoglobin [-0.53 (-0.79, -0.28)], malondialdehyde [-0.34 (-0.45, -0.22)], high sensitive-C-reactive protein[-0.35 (-0.54, -0.16)], tumor necrosis factor-alpha [-1.22 (-1.62, -0.83)], and interleukin-6[-2.30 (-2.91, -1.68)]. More than twofold downregulation in miRNA-375, miRNA-34a, miRNA-21, and upregulation in miRNA-126, miRNA-132 expression was observed in the δT3 group compared to the placebo. The study demonstrated that δT3 supplementation in addition to oral hypoglycemic agents, improved glycemic control, inflammation, oxidative stress, and miRNA expression in T2DM without any adverse effect. Thus, δT3 might be considered as an effective dietary supplement to prevent long-term diabetic complications.

Vitamin E beyond Its Antioxidant Label

Vitamin E, comprising tocopherols and tocotrienols, is mainly known as an antioxidant. The aim of this review is to summarize the molecular mechanisms and signaling pathways linked to inflammation and malignancy modulated by its vitamers. Preclinical reports highlighted a myriad of cellular effects like modulating the synthesis of pro-inflammatory molecules and oxidative stress response, inhibiting the NF-κB pathway, regulating cell cycle, and apoptosis. Furthermore, animal-based models have shown that these molecules affect the activity of various enzymes and signaling pathways, such as MAPK, PI3K/Akt/mTOR, JAK/STAT, and NF-κB, acting as the underlying mechanisms of their reported anti-inflammatory, neuroprotective, and anti-cancer effects. In clinical settings, not all of these were proven, with reports varying considerably. Nonetheless, vitamin E was shown to improve redox and inflammatory status in healthy, diabetic, and metabolic syndrome subjects. The anti-cancer effects were inconsistent, with both pro- and anti-malignant being reported. Regarding its neuroprotective properties, several studies have shown protective effects suggesting vitamin E as a potential prevention and therapeutic (as adjuvant) tool. However, source and dosage greatly influence the observed effects, with bioavailability seemingly a key factor in obtaining the preferred outcome. We conclude that this group of molecules presents exciting potential for the prevention and treatment of diseases with an inflammatory, redox, or malignant component.

Hawthorn polyphenols reduce high glucose-induced inflammation and apoptosis in ARPE-19 cells by regulating miR-34a/SIRT1 to reduce acetylation

Diabetic retinopathy is a major complication in patients with diabetes. Herein, we investigate how hawthorn polyphenol extract (HPE) affects high glucose-induced oxidation, inflammation, and apoptosis in ARPE-19 cells. HPLC-MS/MS was used to determine HPE content and composition. Reactive oxygen species (ROS) production was assessed using fluorescence microscopy, while glucose-induced gene and protein expressions were analyzed using real-time PCR and western blotting in cells transfected with miR-34a mimics. We found that treating cells with 10 μg/ml of HPE, 30 μM procyanidin B2, chlorogenic acid, epicatechin, or resveratrol (positive control) significantly reduced ROS production and decreased apoptosis and inflammation-related factors (p < .01). Moreover, the expression level of SIRT1 was increased, while that of acetylated NF-κB p65 and p53 proteins was decreased. These data suggest that HPE can inhibit oxidative damage, inflammation, and apoptosis through the AMPK/SIRT1/NF-κB pathway, and decrease miR-34a/SIRT1/p53 pathway activation in ARPE-19 cells, thereby demonstrating a potential use as a food additive to mitigate hyperglycemia-induced retinal damage. PRACTICAL APPLICATIONS: Hawthorn polyphenol extract (HPE) significantly reduced ROS levels, apoptosis, and the expression of inflammation-related factors in ARPE-19 cells. HPE also inhibited the AMPK/SIRT1/NF-κB and miR-34a/SIRT1/p53 pathways, which are involved in hyperglycemia-induced inflammation and apoptosis of ARPE-19 cells by regulating acetylation. Thus, HPE, as a potential food additive, may mitigate hyperglycemia-induced retinal damage.

Impacts of Selected Dietary Nutrient Intakes on Skeletal Muscle Insulin Sensitivity and Applications to Early Prevention of Type 2 Diabetes

As the largest tissue in the body, skeletal muscle not only plays key roles in movement and glucose uptake and utilization but also mediates insulin sensitivity in the body by myokines. Insulin resistance in the skeletal muscle is a major feature of type 2 diabetes (T2D). A weakened response to insulin could lead to muscle mass loss and dysfunction. Increasing evidence in skeletal muscle cells, rodents, nonhuman primates, and humans has shown that restriction of caloric or protein intake positively mediates insulin sensitivity. Restriction of essential or nonessential amino acids was reported to facilitate glucose utilization and regulate protein turnover in skeletal muscle under certain conditions. Furthermore, some minerals, such as zinc, chromium, vitamins, and some natural phytochemicals such as curcumin, resveratrol, berberine, astragalus polysaccharide, emodin, and genistein, have been shown recently to protect skeletal muscle cells, mice, or humans with or without diabetes from insulin resistance. In this review, we discuss the roles of nutritional interventions in the regulation of skeletal muscle insulin sensitivity. A comprehensive understanding of the nutritional regulation of insulin signaling would contribute to the development of tools and treatment programs for improving skeletal muscle health and for preventing T2D.

Tocotrienol Rich Fraction Supplementation Modulate Brain Hippocampal Gene Expression in APPswe/PS1dE9 Alzheimer's Disease Mouse Model

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder characterized by loss of memory and other cognitive abilities. AD is associated with aggregation of amyloid-β (Aβ) deposited in the hippocampal brain region. Our previous work has shown that tocotrienol rich fraction (TRF) supplementation was able to attenuate the blood oxidative status, improve behavior, and reduce fibrillary-type Aβ deposition in the hippocampus of an AD mouse model. In the present study, we investigate the effect of 6 months of TRF supplementation on transcriptome profile in the hippocampus of APPswe/PS1dE9 double transgenic mice. TRF supplementation can alleviate AD conditions by modulating several important genes in AD. Moreover, TRF supplementation attenuated the affected biological process and pathways that were upregulated in the AD mouse model. Our findings indicate that TRF supplementation can modulate hippocampal gene expression as well as biological processes that can potentially delay the progression of AD.

The effects of royal jelly and tocotrienol-rich fraction on impaired glycemic control and inflammation through irisin in obese rats

The effects of royal jelly (RJ) and tocotrienol-rich fraction (TRF) on obesity-induced glucose intolerance and inflammation were assessed in the current study. Regarding irisin as an important adipomyokine that attenuates obesity-induced disorders, we evaluated whether RJ and TRF could exert their metabolism regulatory effects through irisin. Obese rats were fed a high-fat diet (HFD) with or without supplementation of RJ, TRF, or both, for 8 weeks. At the end of the intervention, weight, irisin, glycemic, and inflammatory indices were measured. The weight of the rats did not remarkably reduce in any of the groups. Glucose homeostasis and inflammation were improved when we added RJ and TRF to HFD. RJ elevated irisin concentration, but the effect of TRF on irisin was not noticeable. Our results indicated that, despite the lack of significant weight loss, RJ and TRF promoted healthy obesity. This improvement was mediated by irisin in RJ consuming rats. PRACTICAL APPLICATIONS: Obesity is a public health concern associated with several chronic disorders. The beneficial effects of irisin on obesity-related disorders are well-established. It is the first study assessing the effect of RJ and TRF as functional foods, with pharmacological and nutritional activities on obesity complications, through irisin mediation. Our study demonstrated that RJ exerts its metabolic regulatory effects by irisin as a mediator. Our investigation makes a remarkable contribution to the literature, because it suggests a new mechanism for the anti-obesity properties of RJ and TRF.

Physicochemical Characterization of Hizikia fusiforme Polysaccharide and Its Hypoglycemic Activity via Mediating Insulin-Stimulated Blood Glucose Utilization of Skeletal Muscle in Type 2 Diabetic Rats

In the current study, a functional polysaccharide fraction (HFP) was obtained from Hizikia fusiforme by ultrasound-assisted enzymatic extraction, and its structural characterization and hypoglycemic activity and potential molecular mechanism were investigated. The results indicated that HFP with high uronic acid was a heterogeneous polysaccharide composed of six monosaccharides. Congo red test explained that HFP had no triple helix conformation. AFM analysis revealed that HFP was spherical particle with flame-like aggregates and multiple strands closely arranged. Rheological analysis showed that HFP exhibited shear-thinning flow behavior. HFP significantly ameliorated diabetes-related symptoms and serum profiles and increased muscle glycogen storage in rats. HFP administration at 400 mg/kg body weight/day displayed greater advantages than metformin in controlling the levels of fasting blood glucose, triglyceride (TG), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bile acid (TBA) of diabetic rats. Intervention of HFP up-regulated markedly the expression of AMPK-α, GLUT4, PI3K and Akt in skeletal muscle of diabetic rats at the mRNA and protein levels, revealing hypoglycemic effects of HFP may be related closely to improving insulin resistance and mitochondrial function of skeletal muscle.

Potential mechanisms of uremic muscle wasting and the protective role of the mitochondria-targeted antioxidant Mito-TEMPO

BACKGROUND

Muscle wasting is common in patients with chronic kidney disease (CKD). Many studies report that mitochondrial dysfunction and endoplasmic reticulum (ER) stress are involved in the development of muscle wasting. However, treatment approaches to protect against muscle wasting are limited. In this study, we investigated the benefits and potential mechanism of Mito-TEMPO, a mitochondria-targeted antioxidant on uremic-induced muscle wasting.

METHODS

Mice were randomly divided into four groups as follows: control group, CKD group, CKD + Mito-TEMPO group, and Mito-TEMPO group. Renal injury was assessed by measurement of serum creatinine and BUN along with PAS and Masson's staining. Bodyweight, gastrocnemius muscle mass, grip strength, and myofiber cross-sectional areas were investigated to evaluate muscle atrophy. Muscle protein synthesis and proteolysis were evaluated by Western blot and real-time PCR. Inflammatory cytokines including TNF-α, IL-6, IL-1β, and MCP-1 were measured by ELISA kits. Oxidative stress markers such as SOD2 activity and MDA level in gastrocnemius muscle tissue were measured by colorimetric assay. Mitochondrial dysfunction was evaluated by transmission electron microscopy and real-time PCR. ER stress was evaluated by Western blot.

RESULTS

Impaired renal function was significantly restored by Mito-TEMPO treatment. Severe muscle atrophy was observed in muscle tissues of CKD mice along with increased inflammatory factors, oxidative stress markers, mitochondrial dysfunction, and ER stress. However, these effects were significantly attenuated with Mito-TEMPO treatment.

CONCLUSIONS

Mito-TEMPO improved muscle wasting in CKD mice possibly through alleviating mitochondrial dysfunction and endoplasmic reticulum stress, providing a potential new therapeutic approach for preventing muscle wasting in chronic kidney disease.

Inflammatory Diseases and Vitamin E-What Do We Know and Where Do We Go?

Inflammation-driven diseases and related comorbidities, such as the metabolic syndrome, obesity, fatty liver disease, and cardiovascular diseases cause significant global burden. There is a growing body of evidence that nutrients alter inflammatory responses and can therefore make a decisive contribution to the treatment of these diseases. Recently, the inflammasome, a cytosolic multiprotein complex, has been identified as a key player in inflammation and the development of various inflammation-mediated disorders, with nucleotide-binding domain and leucine-rich repeat pyrin domain (NLRP) 3 being the inflammasome of interest. Here an overview about the cellular signaling pathways underlying nuclear factor "kappa-light-chain-enhancer" of activated B-cells (NF-κB)- and NLRP3-mediated inflammatory processes, and the pathogenesis of the inflammatory diseases atherosclerosis and non-alcoholic fatty liver disease (NAFLD) is provided; next, the current state of knowledge for drug-based and dietary-based interventions for treating cardiovascular diseases and NAFLD is discussed. To date, one of the most important antioxidants in the human diet is vitamin E. Various in vitro and in vivo studies suggest that the different forms of vitamin E and also their derivatives have anti-inflammatory activity. Recent publications suggest that vitamin E-and possibly metabolites of vitamin E-are a promising therapeutic approach for treating inflammatory diseases such as NAFLD.

Is inflammatory signaling involved in disease-related muscle wasting? Evidence from osteoarthritis, chronic obstructive pulmonary disease and type II diabetes

Muscle loss is an important feature that occurs in multiple pathologies including osteoarthritis (OA), chronic obstructive pulmonary disease (COPD) and type II diabetes (T2D). Despite differences in pathogenesis and disease-related complications, there are reasons to believe that some fundamental underlying mechanisms are inherent to the muscle wasting process, irrespective of the pathology. Recent evidence shows that inflammation, either local or systemic, contributes to the modulation of muscle mass and/or muscle strength, via an altered molecular profile in muscle tissue. However, it remains ambiguous to which extent and via which mechanisms inflammatory signaling affects muscle mass in disease. Therefore, the objective of the present review is to discuss the role of inflammation on skeletal muscle anabolism, catabolism and functionality in three pathologies that are characterized by an eventual loss in muscle mass (and muscle strength), i.e. OA, COPD and T2D. In OA and COPD, most rodent models confirmed that systemic (COPD) or muscle (OA) inflammation directly induces muscle loss or muscle dysfunctionality. However, in a patient population, the association between inflammation and muscular maladaptations are more ambiguous. For example, in T2D patients, systemic inflammation is associated with muscle loss whereas in OA patients this link has not consistently been established. T2D rodent models revealed that increased levels of advanced glycation end-products (AGEs) and a decreased mTORC1 activation play a key role in muscle atrophy, but it remains to be elucidated whether AGEs and mTORC1 are interconnected and contribute to muscle loss in T2D patients. Generally, if any, associations between inflammation and muscle are mainly based on observational and cross-sectional data. There is definitely a need for longitudinal evidence through well-powered randomized control trials that take into account confounders such as age, disease-phenotypes, comorbidities, physical (in) activity etc. This will allow to improve our understanding of the complex interaction between inflammatory signaling and muscle mass loss and hence contribute to the development of therapeutic strategies to combat muscle wasting in these diseases.

Protective Effect of Palm Oil-Derived Tocotrienol-Rich Fraction Against Retinal Neurodegenerative Changes in Rats with Streptozotocin-Induced Diabetic Retinopathy

Oxidative stress plays an important role in retinal neurodegeneration and angiogenesis associated with diabetes. In this study, we investigated the effect of the tocotrienol-rich fraction (TRF), a potent antioxidant, against diabetes-induced changes in retinal layer thickness (RLT), retinal cell count (RCC), retinal cell apoptosis, and retinal expression of vascular endothelial growth factor (VEGF) in rats. Additionally, the efficacy of TRF after administration by two different routes was compared. The diabetes was induced in Sprague-Dawley rats by intraperitoneal injection of streptozotocin. Subsequently, diabetic rats received either oral or topical treatment with vehicle or TRF. Additionally, a group of non-diabetic rats was included with either oral or topical treatment with a vehicle. After 12 weeks of the treatment period, rats were euthanized, and retinas were collected for measurement of RLT, RCC, retinal cell apoptosis, and VEGF expression. RLT and RCC in the ganglion cell layer were reduced in all diabetic groups compared to control groups (p < 0.01). However, at the end of the experimental period, oral TRF-treated rats showed a significantly greater RLT compared to topical TRF-treated rats. A similar observation was made for retinal cell apoptosis and VEGF expression. In conclusion, oral TRF supplementation protects against retinal degenerative changes and an increase in VEGF expression in rats with streptozotocin-induced diabetic retinopathy. Similar effects were not observed after topical administration of TRF.

Physicochemical properties of polysaccharide fractions from Sargassum fusiforme and their hypoglycemic and hypolipidemic activities in type 2 diabetic rats

Two polysaccharide fractions (SFPs, designated as respectively SFP-1 and SFP-2) were acquired from Sargassum fusiforme by ultrasound-assisted enzymatic extraction, and their physicochemical properties and hypoglycemic and hypolipidemic effects were investigated. Structural analysis indicated that SFPs were obvious different in the zeta potential, molecular weight distribution, characteristic organic group, microstructure and the contents of total sugar, uronic acid, sulfate and moisture. SFPs consisted of fucose, mannose, rhamnose, glucose, galactose and glucuronic acid with different molar ratios. Congo red test explained that SFPs had no triple-helix structure. SFP-1 exhibited lower viscosity due to its lower molecular weight. Regarding to hypoglycemic and hypolipidemic effects, oral administration of SFPs prominently restrained loss of body weight and increase of water intake, and also significantly controlled the increase of levels of fasting blood glucose, triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), uric acid (UA), urea nitrogen (BUN), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) of diabetic rats, and SFP-2 showed better effects in controlling fasting blood glucose, ALT, UA and BUN levels. Intervention of SFP-2 reduced the levels of insulin, FFA and TBA of diabetic rats. Histomorphological observation further demonstrated that SFPs could attenuate liver and kidney damage caused by hyperglycemia and hyperlipidemia. Data indicated that SFPs, especially SFP-2, significantly improved hyperglycemia, hyperlipidemia and liver and kidney function of diabetic rats.

Potential Role of Tocotrienols on Non-Communicable Diseases: A Review of Current Evidence

Tocotrienol (T3) is a subfamily of vitamin E known for its wide array of medicinal properties. This review aimed to summarize the health benefits of T3, particularly in prevention or treatment of non-communicable diseases (NCDs), including cardiovascular, musculoskeletal, metabolic, gastric, and skin disorders, as well as cancers. Studies showed that T3 could prevent various NCDs, by suppressing 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) in the mevalonate pathway, inflammatory response, oxidative stress, and alternating hormones. The efficacy of T3 in preventing/treating these NCDs is similar or greater compared to tocopherol (TF). TF may lower the efficacy of T3 because the efficacy of the combination of TF and T3 was lower than T3 alone in some studies. Data investigating the effects of T3 on osteoporosis, arthritis, and peptic ulcers in human are limited. The positive outcomes of T3 treatment obtained from the preclinical studies warrant further validation from clinical trials.

Can Medicinal Plants and Bioactive Compounds Combat Lipid Peroxidation Product 4-HNE-Induced Deleterious Effects?

The toxic reactive aldehyde 4-hydroxynonenal (4-HNE) belongs to the advanced lipid peroxidation end products. Accumulation of 4-HNE and formation of 4-HNE adducts induced by redox imbalance participate in several cytotoxic processes, which contribute to the pathogenesis and progression of oxidative stress-related human disorders. Medicinal plants and bioactive natural compounds are suggested to be attractive sources of potential agents to mitigate oxidative stress, but little is known about the therapeutic potentials especially on combating 4-HNE-induced deleterious effects. Of note, some investigations clarify the attenuation of medicinal plants and bioactive compounds on 4-HNE-induced disturbances, but strong evidence is needed that these plants and compounds serve as potent agents in the prevention and treatment of disorders driven by 4-HNE. Therefore, this review highlights the pharmacological basis of these medicinal plants and bioactive compounds to combat 4-HNE-induced deleterious effects in oxidative stress-related disorders, such as neurotoxicity and neurological disorder, eye damage, cardiovascular injury, liver injury, and energy metabolism disorder. In addition, this review briefly discusses with special attention to the strategies for developing potential therapies by future applications of these medicinal plants and bioactive compounds, which will help biological and pharmacological scientists to explore the new vistas of medicinal plants in combating 4-HNE-induced deleterious effects.

Antidiabetic Effect of Casein Glycomacropeptide Hydrolysates on High-Fat Diet and STZ-Induced Diabetic Mice via Regulating Insulin Signaling in Skeletal Muscle and Modulating Gut Microbiota

This study evaluated the effects and the underlying mechanisms of casein glycomacropeptide hydrolysate (GHP) on high-fat diet-fed and streptozotocin-induced type 2 diabetes (T2D) in C57BL/6J mice. Results showed that 8-week GHP supplementation significantly decreased fasting blood glucose levels, restored insulin production, improved glucose tolerance and insulin tolerance, and alleviated dyslipidemia in T2D mice. In addition, GHP supplementation reduced the concentration of lipopolysaccharides (LPSs) and pro-inflammatory cytokines in serum, which led to reduced systematic inflammation. Furthermore, GHP supplementation increased muscle glycogen content in diabetic mice, which was probably due to the regulation of glycogen synthase kinase 3 beta and glycogen synthase. GHP regulated the insulin receptor substrate-1/phosphatidylinositol 3-kinase/protein kinase B pathway in skeletal muscle, which promoted glucose transporter 4 (GLUT4) translocation. Moreover, GHP modulated the overall structure and diversity of gut microbiota in T2D mice. GHP increased the Bacteroidetes/Firmicutes ratio and the abundance of S24-7, Ruminiclostridium, Blautia and Allobaculum, which might contribute to its antidiabetic effect. Taken together, our findings demonstrate that the antidiabetic effect of GHP may be associated with the recovery of skeletal muscle insulin sensitivity and the regulation of gut microbiota.

Hypoglycemic effect of glycyrrhizic acid, a natural non-carbohydrate sweetener, on streptozotocin-induced diabetic mice

Glycyrrhizic acid (GZA) was extracted from the stem of licorice by enzymatic hydrolysis, separated and purified by silica gel column chromatography, its purity was determined by HPLC, and the structure was identified by FT-IR and NMR methods.

Berberis aristata, Elaeis guineensis and Coffea canephora Extracts Modulate the Insulin Receptor Expression and Improve Hepatic Steatosis in NAFLD Patients: A Pilot Clinical Trial

Non-alcoholic fatty liver disease (NAFLD) is associated with insulin resistance and diabetes. A reduction in insulin receptor (IR) expression has been reported in these patients. The aims of this study were to evaluate the effects of a mixture of plant extracts consisting of Berberis aristata, Elaeis guineensis and decaffeinated green coffee by Coffea canephora on the improvement of glycaemic profile, through the modulation of IR levels, and of hepatic steatosis in NAFLD patients. Forty-nine patients with a grade of steatosis S1-S2 were randomly allocated to the treatment with plant extracts or placebo for six months. Hepatic steatosis was evaluated using transient elastography with CAP (controlled attenuation parameter). Glucose, insulin, and IR levels were measured in serum samples. At the end of the study, patients treated with plant extracts displayed a significant reduction of serum glucose (p < 0.001), insulin levels (p < 0.01), homeostatic model assessment for insulin resistance (HOMA-IR) index (p < 0.001), and CAP value (p < 0.01) compared to placebo. Moreover, the IR expression was increased significantly in the plant extracts group compared to the placebo group (p < 0.05). The combination of plant extracts increases serum IR levels, determining amelioration of glycemic profile and improvement of hepatic steatosis in NAFLD patients.

Plin5/p-Plin5 Guards Diabetic CMECs by Regulating FFAs Metabolism Bidirectionally

Background

Hyper-free fatty acidemia (HFFA) impairs cardiac capillaries, as well as type 2 diabetes mellitus (T2DM). Perilipin 5 (Plin5) maintains metabolic balance of free fatty acids (FFAs) in high oxidative tissues via the states of nonphosphorylation and phosphorylation. However, when facing to T2DM-HFFA, Plin5's role in cardiac microvascular endothelial cells (CMECs) is not defined.

Methods

In mice of WT or Plin5^−/−, T2DM models were rendered by high-fat diet combined with intraperitoneal injection of streptozocin. CMECs isolated from left ventricles were incubated with high glucose (HG) and high FFAs (HFFAs). Plin5 phosphorylation was stimulated by isoproterenol. Plin5 expression was knocked down by small interfering RNA (siRNA). We determined cardiac function by small animal ultrasound, apoptotic rate by flow cytometry, microvessel quantity by immunohistochemistry, microvascular integrity by scanning electron microscopy, intracellular FFAs by spectrophotometry, lipid droplets (LDs) by Nile red staining, mRNAs by quantitative real-time polymerase chain reaction, proteins by western blots, nitric oxide (NO) and reactive oxygen species (ROS) by fluorescent dye staining and enzyme-linked immunosorbent assay kits.

Results

In CMECs, HFFAs aggravated cell injury induced by HG and activated Plin5 expression. In mice with T2DM-HFFA, Plin5 deficiency reduced number of cardiac capillaries, worsened structural incompleteness, and enhanced diastolic dysfunction. Moreover, in CMECs treated with HG-HFFAs, both ablation and phosphorylation of Plin5 reduced LDs content, increased intracellular FFAs, stimulated mitochondrial β-oxidation, added ROS generation, and reduced the expression and activity of endothelial nitric oxide synthase (eNOS), eventually leading to increased apoptotic rate and decreased NO content, all of which were reversed by N-acetyl-L-cysteine.

Conclusion

Plin5 preserves lipid balance and cell survival in diabetic CMECs by regulating FFAs metabolism bidirectionally via the states of nonphosphorylation and phosphorylation.