Apigenin and naringenin regulate glucose and lipid metabolism, and ameliorate vascular dysfunction in type 2 diabetic rats

Effects of different natural products in patients with non-alcoholic fatty liver disease-A network meta-analysis of randomized controlled trials

Due to a scarcity of appropriate therapeutic approaches capable of ameliorating or eliminating non-alcoholic fatty liver disease (NAFLD), many researchers have come to focus on natural products based on traditional medicine that can be utilized to successfully treat NAFLD. In this study, we aimed to evaluate the effects exerted by seven natural products (curcumin, silymarin, resveratrol, artichoke leaf extract, berberine, catechins, and naringenin) on patients with NAFLD. For this purpose, PubMed, Embase, Cochrane Library, and Web of Science, were searched for randomized controlled trials (RCTs) exclusively. The selected studies were evaluated for methodological quality via the Cochrane bias risk assessment tool, and data analysis software was used to analyze the data accordingly. The RCTs from the earliest available date until September 2022 were collected. This process resulted in 37 RCTs with a total sample size of 2509 patients being included. The results of the network meta-analysis showed that artichoke leaf extract confers a relative advantage in reducing the aspartate aminotransferase (AST) levels (SUCRA: 99.1%), alanine aminotransferase (ALT) levels (SUCRA: 88.2%) and low-density lipoprotein cholesterol (LDL-C) levels (SUCRA: 88.9%). Naringenin conferred an advantage in reducing triglyceride (TG) levels (SUCRA: 97.3%), total cholesterol (TC) levels (SUCRA: 73.9%), and improving high-density lipoprotein cholesterol (HDL-C) levels (SUCRA: 74.9%). High-density catechins significantly reduced body mass index (BMI) levels (SUCRA: 98.5%) compared with the placebo. The Ranking Plot of the Network indicated that artichoke leaf extract and naringenin performed better than the other natural products in facilitating patient recovery. Therefore, we propose that artichoke leaf extract and naringenin may exert a better therapeutic effect on NAFLD. This study may help guide clinicians and lead to further detailed studies.

Naringenin: its chemistry and roles in neuroprotection

According to epidemiological research, as the population ages, neurological illnesses are becoming a bigger issue. Despite improvements in the treatment of these diseases, there are still widespread worries about how to find a long-lasting remedy. Several neurological diseases can be successfully treated with natural substances. As a result, current research has been concentrated on finding effective neuroprotective drugs with improved efficacy and fewer side effects. Naringenin is one potential treatment for neurodegenerative diseases. Many citrus fruits, tomatoes, bergamots, and other fruits are rich in naringenin, a flavonoid. This phytochemical is linked to a variety of biological functions. Naringenin has attracted a lot of interest for its ability to exhibit neuroprotection through several mechanisms. In the current article, we present evidence from the literature that naringenin reduces neurotoxicity and oxidative stress in brain tissues. Also, the literatures that are currently accessible shows that naringenin reduces neuroinflammation and other neurological anomalies. Additionally, we found several studies that touted naringenin as a promising anti-amyloidogenic, antidepressant, and neurotrophic treatment option. This review's major goal is to reflect on advancements in knowledge of the molecular processes that underlie naringenin's possible neuroprotective effects. Furthermore, this article also provides highlights of Naringenin with respect to its chemistry and pharmacokinetics.

Clinical applications and mechanism insights of natural flavonoids against type 2 diabetes mellitus

Diabetes is a complex disease that affects a large percentage of the world's population, and it is associated with several risk factors. Self-management poses a significant challenge, but natural sources have shown great potential in providing effective glucose reducing solutions. Flavonoids, a class of bioactive substances found in different natural sources including medicinal plants, have emerged as promising candidates in this regard. Indeed, several flavonoids, including apigenin, arbutin, catechins, and cyanidin, have demonstrated remarkable anti-diabetic properties. The clinical effectiveness of these flavonoids is linked to their potential to decrease blood glucose concentration and increase insulin concentration. Thus, the regulation of certain metabolic pathways such as glycolysis and neoglycogenesis has also been demonstrated. In vitro and in vivo investigations revealed different mechanisms of action related to flavonoid compounds at subcellular, cellular, and molecular levels. The main actions reside in the activation of glycolytic signaling pathways and the inhibition of signaling that promotes glucose synthesis and storage. In this review, we highlight the clinical efficiency of natural flavonoids as well as the molecular mechanisms underlying this effectiveness.

Dietary phenolic compounds as promising therapeutic agents for diabetes and its complications: A comprehensive review

In the middle of an ever-changing landscape of diabetes care, precision medicine, and lifestyle therapies are becoming increasingly important. Dietary polyphenols are like hidden allies found in our everyday meals. These biomolecules, found commonly in fruits, vegetables, and various plant-based sources, hold revolutionary potential within their molecular structure in the way we approach diabetes and its intimidating consequences. There are currently numerous types of diabetes medications, but they are not appropriate for all patients due to limitations in dosages, side effects, drug resistance, a lack of efficacy, and ethnicity. Currently, there has been increased interest in practicing herbal remedies to manage diabetes and its related complications. This article aims to summarize the potential of dietary polyphenols as a foundation in the treatment of diabetes and its associated consequences. We found that most polyphenols inhibit enzymes linked to diabetes. This review outlines the potential benefits of selected molecules, including kaempferol, catechins, rosmarinic acid, apigenin, chlorogenic acid, and caffeic acid, in managing diabetes mellitus as these compounds have exhibited promising results in in vitro, in vivo, in silico, and some preclinical trials study. This encompassing exploration reveals the multifaceted impact of polyphenols not only in mitigating diabetes but also in addressing associated conditions like inflammation, obesity, and even cancer. Their mechanisms involve antioxidant functions, immune modulation, and proinflammatory enzyme regulation. Furthermore, these molecules exhibit anti-tumor activities, influence cellular pathways, and activate AMPK pathways, offering a less toxic, cost-effective, and sustainable approach to addressing diabetes and its complications.

Transcriptomic and targeted metabolomic analyses provide insights into the flavonoids biosynthesis in the flowers of Lonicera macranthoides

BACKGROUND

Flavonoids are one of the bioactive ingredients of Lonicera macranthoides (L. macranthoides), however, their biosynthesis in the flower is still unclear. In this study, combined transcriptomic and targeted metabolomic analyses were performed to clarify the flavonoids biosynthesis during flowering of L. macranthoides.

RESULTS

In the three sample groups, GB_vs_WB, GB_vs_WF and GB_vs_GF, there were 25, 22 and 18 differentially expressed genes (DEGs) in flavonoids biosynthetic pathway respectively. A total of 339 flavonoids were detected and quantified at four developmental stages of flower in L. macranthoides. In the three sample groups, 113, 155 and 163 differentially accumulated flavonoids (DAFs) were detected respectively. Among the DAFs, most apigenin derivatives in flavones and most kaempferol derivatives in flavonols were up-regulated. Correlation analysis between DEGs and DAFs showed that the down-regulated expressions of the CHS, DFR, C4H, F3'H, CCoAOMT_32 and the up-regulated expressions of the two HCTs resulted in down-regulated levels of dihydroquercetin, epigallocatechin and up-regulated level of kaempferol-3-O-(6''-O-acetyl)-glucoside, cosmosiin and apigenin-4'-O-glucoside. The down-regulated expressions of F3H and FLS decreased the contents of 7 metabolites, including naringenin chalcone, proanthocyanidin B2, B3, B4, C1, limocitrin-3,7-di-O-glucoside and limocitrin-3-O-sophoroside.

CONCLUSION

The findings are helpful for genetic improvement of varieties in L.macranthoides.

Effect of apigenin on dynamin-related protein 1 in type 1 diabetic rats with cardiovascular complications

BACKGROUND AND OBJECTIVE

Cardiovascular complications cause increased mortality rates among diabetics. The molecular mechanisms of aberrant mitochondrial dynamics in diabetes mellitus (DM) are not fully understood. Dynamin-related protein 1 (Drp1) is thought to be a major regulator of mitochondrial fission. There is lack of studies that examined the relationship between apigenin and Drp1 expression in DM. Thus, the current study aimed to explore the expression of Drp1 in diabetic rats with cardiovascular complications, as well as to appraise the role of apigenin in modulating this expression.

METHODS

Twenty-eight adult male albino Wister rats were randomly and equally allocated into four groups: naive, streptozotocin-induced type 1 diabetic control and two apigenin-injected diabetic groups (early and late). Body weight, heart weight, blood pressure and ECG were recorded. Evaluation of blood glucose level, lipid profile and cardiac functions were measured. Determination of Drp1 mRNA expression, and histological examination of cardiac tissues from the four groups were performed.

RESULTS

Diabetic control rats developed decrease of body weight, increase of blood pressure, deterioration of the normal ECG pattern and upregulation of Drp1 mRNA expression in cardiac tissues. There was a significant correlation between the relative expression of Drp1 and all examined parameters. Apigenin-injection improved fasting blood glucose, lipid profile and cardiac function indicators (i.e., ECG parameters, CK-MB and troponin) as well as the cardiac histological structure. The decrease of Drp1 expression was more evident with early than with late apigenin-injection, however, without statistical significance.

CONCLUSIONS

Increased level of Drp1 expression in diabetic rats may be involved in the pathogenesis of diabetic cardiovascular complications. The changes that occurred in response to apigenin injection highlight its potential ameliorative effect on the diabetic cardiovascular complications and pave the route for further investigations.

Study on the action mechanism of the Polygonum perfoliatum L. on non-alcoholic fatty liver disease, based on network pharmacology and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese medicine (TCM) holds that non-alcoholic fatty liver disease (NAFLD) belong to the category of "thoracic fullness". Polygonum perfoliatum L. (PPL), a Chinese medicinal herb with the effect of treating thoracic fullness, was recorded in the ancient Chinese medicine book "Supplements to Compendium of Materia Medica". It has been used since ancient times to treat NAFLD. However, the underlying mechanism and active components of PPL against NAFLD remains unclear.

AIM OF STUDY

To identify the main active components and the anti-NAFLD mechanism of PPL.

MATERIALS AND METHODS

Network pharmacology, UPLC/QE-HFX analysis, and molecular docking were employed to determine the main bioactive compounds and key targets of PPL for the NAFLD treatment. This effect was further validated with administration of PPL (200 mg/kg and 400 mg/kg) to NAFLD model mice for 5 weeks. Systemic signs of obesity, biochemical parameters, and histological changes were characterized. Immunohistochemistry, western blot, and PCR analysis were conducted to elucidate the mechanistic pathways through which PPL exerts its effects.

RESULTS

Network pharmacology revealed 77 crossover genes between the PPL and NAFLD. The kyoto encyclopedia of genes and genomes (KEGG) analysis show that PPL treat NAFLD mainly regulating glucose-lipid metabolism mediated by PI3K/AKT signal pathway. The Gene Ontology (GO) enrichment analysis show that PPL treat NAFLD mainly regulating inflammation mediated by cytokine-mediated signaling pathway. In accordance with the anticipated outcomes, administration of PPL in a dose-dependent manner effectively mitigated insulin resistance induced by a high-fat diet (HFD) by activating the PI3K/AKT signaling pathway. Histopathological evaluation corroborated the hepatoprotective effects of PPL against HFD-induced hepatic steatosis, as evidenced by the inhibition of de novo fatty acid synthesis and promotion of fatty acid β-oxidation (FAO). Further research showed that PPL blocked cytokine production by inhibiting the NF-κB pathway, thereby reducing immune cell infiltration. Furthermore, five flavonoids from PPL, including quercetin, baicalein, galangin, apigenin, and genistein were identified as key compounds based on ingredient-target-pathway network analysis. Molecular docking show that these active compounds have favorable binding interactions with AKT1, PIK3R1, and MAPK1, further confirming the impact of PPL on the PI3K/AKT pathway.

CONCLUSIONS

Through the combination of network pharmacology prediction and experimental validation, this work determined that therapeutic effect of PPL on NAFLD, and such protective effect is mediated by activating PI3K/AKT-mediated glucolipid metabolism pathway and hepatic NF-κB-mediated cytokine signaling pathway.

Renal sympathetic denervation ameliorates the activated inflammatory response through JAK-STAT pathway in a chronic obstructive sleep apnea animal model

OBJECTIVES

Obstructive sleep apnea (OSA) is known to increase the risk of cardiovascular disease and inflammation plays a significant role in this process. Renal denervation (RDN) is a novel approach aimed at reducing sympathetic nervous system activity. The role of RDN in the inflammatory response to chronic OSA (COSA) is currently unclear. The main objective was to study inflammatory mechanisms in the rabbit heart with COSA and the effects of RDN.

METHODS

Eighteen rabbits were randomized into three groups: sham control, COSA, and COSA-RDN. COSA and COSA-RDN groups received liquid silicone injections, while the sham control group received normal saline. We performed combined surgical and chemical RDN through bilateral retroperitoneal flank incisions in the COSA-RDN group after silicone injections. The inflammatory mechanisms were assessed through immunoblotting, real-time PCR, and ELISA after the experiment.

RESULTS

H&E staining showed immune cell infiltration in COSA, which decreased after RDN treatment. The level of α7nAChR was significantly reduced in COSA compared to the sham control but was restored to a similar level in the COSA-RDN group. Furthermore, the expressions of p-JAK2 and p-STAT3 were significantly reduced in COSA but showed an up-regulation following RDN treatment. Similarly, levels of the inflammatory markers IL-6, IL-1β and TNF-α were markedly increased in COSA but decreased after RDN therapy. We observed NF-κB activation in the COSA rabbit model, which decreased after RDN treatment, as evidenced by decreased NF-κB expression.

CONCLUSIONS

Our study suggests that RDN treatment may prevent COSA-associated heart inflammation via the JAK2-STAT3 signaling pathway.

The Effects of Apigenin in the Treatment of Diabetic Nephropathy: A Systematic Review of Non-clinical Studies

PURPOSE

Diabetes is one of the important and growing diseases in the world. Among the most common diabetic complications are renal adverse effects. The use of apigenin may prevent the development and progression of diabetes-related injuries. The current study aims to review the effects of apigenin in the treatment of diabetic nephropathy.

METHODS

In this review, a systematic search was performed based on PRISMA guidelines for obtaining all relevant studies on "the effects of apigenin against diabetic nephropathy" in various electronic databases up to September 2022. Ninety-one articles were obtained and screened in accordance with the predefined inclusion and exclusion criteria. Seven eligible articles were finally included in this review.

RESULTS

The experimental findings revealed that hyperglycemia led to the decreased cell viability of kidney cells and body weight loss and an increased kidney weight of rats; however, apigenin administration had a reverse effect on these evaluated parameters. It was also found that hyperglycemia could induce alterations in the biochemical and renal function-related parameters as well as histopathological injuries in kidney cells or tissue; in contrast, the apigenin administration could ameliorate the hyperglycemia-induced renal adverse effects.

CONCLUSION

The results indicated that the use of apigenin could mitigate diabetes-induced renal adverse effects, mainly through its antioxidant, anti-apoptotic, and anti-inflammatory activities. Since the findings of this study are based on experimental studies, suggesting the use of apigenin (as a nephroprotective agent) against diabetic nephropathy requires further clinical studies.

Toxicological Assessment and Anti-diabetic Effects of Combined Extract of Chirata, Fenugreek and Sesame on Regulating TNF-α, TGF-β and Oxidative Stress in Streptozotocin Induced Diabetic Rats

BACKGROUND

Swertia chirayita, Trigonella foenum-gracum and Sesamum indicum are used as traditional medicines to treat diabetes mellitus. A collection of metabolic illnesses known as diabetes mellitus (DM) involves chronic hyperglycemia caused by flaws in insulin secretion, function, or both. Innate immunity and inflammation both play important roles in the etiology of diabetes- related microvascular problems.

OBJECTIVE

This study aims to examine the anti-diabetic effects and the acute toxicity of combined extract (1:1:1) of Swertia chirayita, Trigonella foenum-gracum and Sesamum indicum. To address the demand for higher effectiveness and safety, the current effort aims to construct anti-diabetic preparations containing methanolic extract from herbal medications.

METHODS

The OECD 423 method was used to investigate acute toxicity in rats. Rats were used as test subjects, and rats were given a 35 mg/kg BW injection of streptozotocin to develop diabetes. The diabetic control group was given Glibenclamide 0.25 mg/kg BW, while the experimental group's diabetic rats received 125 mg/kg BW and 250 mg/kg BW of a combined methanolic extract of all plants. Among the measurements looked at were acute oral toxicity, behavioral changes, body weight, serum glucose levels, lipid profiles, oxidative stress, renal function tests, and inflammatory mediators. All the rat groups' histopathologies of the kidney, liver, and stomach were compared. The data were evaluated using analysis of variance, and a post hoc test was then carried out.

RESULTS

The combined extracts' medium lethal doses (LD50) were higher than 2000 mg/kg, indicating that they are not poisonous under the conditions that can be observed. Streptozotocin-induced diabetic rats' elevated blood glucose was found to be considerably lower (p 0.01) in the treated group of rats. In the treated group of rats, it was discovered that the damage and disarray in the cells typical of Streptozotocin-induced DM had been repaired. The treated group of rats returned to normal levels of the lipid profile, hyperglycemia, decreased serum protein and liver glycogen, increased liver function, and kidney function markers seen in the rats of the DM control group.

CONCLUSION

The evaluated combined methanolic extract can be considered safe for use in rats. Combining methanolic extract from all selected medicinal plants (Swertia chirayita, Trigonella foenum-gracum and Sesamum indicum) has a potential anti-diabetic effect and can be safely developed as an alternative medicine.

Citrus flavonoids and adhesion molecules: Potential role in the management of atherosclerosis

Atherosclerosis as a chronic inflammatory disorder is accompanied with oxidative stress which causes a high morbidity and mortality. Adhesion molecules, including intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), P-selectin, and E-selectin, are amongst the most important contributors in atherosclerosis. In such cases, dietary interventions with functional foods containing natural antioxidant and anti-inflammatory constituents are of a great interest. Citrus fruits are rich sources of flavonoids as natural pigments with potent antioxidant and anti-inflammatory activities. This study aims to review current evidence regarding the role of citrus flavonoids in the management of atherosclerosis with a focus on their effect on adhesion molecules. Electronic databases including PubMed, Scopus, and Web of Science were searched with the names of adhesion molecules and flavonoids from inception until January 2023. The included articles highly support the beneficial effects of citrus flavonoids in preclinical models of atherosclerosis. Quercetin, naringin and naringenin, hesperidin and hesperetin, nobiletin, rutin, luteolin, apigenin, and kaempferol are the most common flavonoids in citrus fruits which could modulate adhesion molecules including ICAM-1, VCAM-1, E-selectin, and P-selectin. Additionally, markers of chronic inflammation such as interleukins, tumor necrosis factor-α, nuclear factor-κB, and nitric oxide signaling, as well as oxidative stress markers like superoxide dismutase and glutathione were all normalized upon administration of citrus flavonoids. Conclusively, this review confirms the modulatory role of flavonoids on adhesion molecules in atherosclerosis based on the preclinical evaluations. Thus, citrus fruits can be further studied in atherosclerotic patients regarding their activity in reducing adhesion molecules.

Biological activities of naringenin: A narrative review based on in vitro and in vivo studies

Naringenin (4',5,7-trihydroxyflavonone) is a phytochemical mainly found in citrus fruits. It is a promising phytochemical for human health because of its beneficial effects. This review aims to present comprehensive information on naringenin biological activities along with its action mechanisms and explain the pharmacokinetic properties of naringenin. This study involves a comprehensive literature review of in vitro and in vivo studies examining the effects of naringenin. Naringenin has antidiabetic, anticancer, antimicrobial, antiobesity, gastroprotective, immunomodulator, cardioprotective, nephroprotective, and neuroprotective properties. These properties are primarily attributed to its antioxidant and anti-inflammatory activities. The most important antioxidant activities of naringenin including free radical scavenging and preventing lipid peroxidation. Naringenin can increase the concentration of antioxidant enzymes and inhibit metal chelation and various pro-oxidant enzymes. Anti-inflammatory activities of naringenin are associated with decreased mitogen-activated protein kinase activities and nuclear factor kappa B by modulating the expression and release of proinflammatory cytokine and enzymes. In vitro and in vivo studies show that naringenin has promising biological activities for a variety of diseases. More research must be conducted on the bioactivities of naringenin, and to determine its optimum dose. In addition, the efficiency of naringenin must be examined with enhanced bioavailability methods to be able to increase its therapeutic effect.

Common mechanisms underlying diabetic vascular complications: focus on the interaction of metabolic disorders, immuno-inflammation, and endothelial dysfunction

Diabetic vascular complications (DVCs), including macro- and micro- angiopathy, account for a high percentage of mortality in patients with diabetes mellitus (DM). Endothelial dysfunction is the initial and role step for the pathogenesis of DVCs. Hyperglycemia and lipid metabolism disorders contribute to endothelial dysfunction via direct injury of metabolism products, crosstalk between immunity and inflammation, as well as related interaction network. Although physiological and phenotypic differences support their specified changes in different targeted organs, there are still several common mechanisms underlying DVCs. Also, inhibitors of these common mechanisms may decrease the incidence of DVCs effectively. Thus, this review may provide new insights into the possible measures for the secondary prevention of DM. And we discussed the current limitations of those present preventive measures in DVCs research. Video Abstract.

iPADD: A Computational Tool for Predicting Potential Antidiabetic Drugs Using Machine Learning Algorithms

Diabetes mellitus is a chronic metabolic disease, which causes an imbalance in blood glucose homeostasis and further leads to severe complications. With the increasing population of diabetes, there is an urgent need to develop drugs to treat diabetes. The development of artificial intelligence provides a powerful tool for accelerating the discovery of antidiabetic drugs. This work aims to establish a predictor called iPADD for discovering potential antidiabetic drugs. In the predictor, we used four kinds of molecular fingerprints and their combinations to encode the drugs and then adopted minimum-redundancy-maximum-relevance (mRMR) combined with an incremental feature selection strategy to screen optimal features. Based on the optimal feature subset, eight machine learning algorithms were applied to train models by using 5-fold cross-validation. The best model could produce an accuracy (Acc) of 0.983 with the area under the receiver operating characteristic curve (auROC) value of 0.989 on an independent test set. To further validate the performance of iPADD, we selected 65 natural products for case analysis, including 13 natural products in clinical trials as positive samples and 52 natural products as negative samples. Except for abscisic acid, our model can give correct prediction results. Molecular docking illustrated that quercetin and resveratrol stably bound with the diabetes target NR1I2. These results are consistent with the model prediction results of iPADD, indicating that the machine learning model has a strong generalization ability. The source code of iPADD is available at https://github.com/llllxw/iPADD.

High-Intensity Exercise Promotes Deleterious Cardiovascular Remodeling in a High-Cardiovascular-Risk Model: A Role for Oxidative Stress

Although the benefits of moderate exercise in patients at high cardiovascular risk are well established, the effects of strenuous exercise remain unknown. We aimed to study the impact of strenuous exercise in a very high cardiovascular risk model. Nephrectomized aged Zucker obese rats were trained at a moderate (MOD) or high (INT) intensity or were kept sedentary (SED) for 10 weeks. Subsequently, echocardiography and ex vivo vascular reactivity assays were performed, and blood, aortas, perivascular adipose tissue (PVAT), and left ventricles (LVs) were harvested. An improved risk profile consisting of decreased body weight and improved response to a glucose tolerance test was noted in the trained groups. Vascular reactivity experiments in the descending thoracic aorta demonstrated increased endothelial NO release in the MOD group but not in the INT group, compared with SED; the free radical scavenger TEMPOL improved endothelial function in INT rats to a similar level as MOD. An imbalance in the expression of oxidative stress-related genes toward a pro-oxidant environment was observed in the PVAT of INT rats. In the heart, INT training promoted eccentric hypertrophy and a mild reduction in ejection fraction. Obesity was associated with LV fibrosis and a transition toward β-myosin heavy chain and the N2Ba titin isoform. Exercise reverted the myosin imbalance, but only MOD reduced the predominance of the N2Ba titin isoform. In conclusion, moderate exercise yields the most intense cardiovascular benefits in a high-cardiovascular-risk animal model, while intense training partially reverts them.

Encapsulation of Hydrophobic Apigenin into Small Unilamellar Liposomes Coated with Chitosan Through Ethanol Injection and Spray Drying

Despite the multiple health benefits, natural flavonoid apigenin has poor aqueous solubility that restricts its delivery in foods. This study investigated the potential of spray-dried chitosan-coated liposomes prepared from scalable methods for the food industry as the delivery carriers for apigenin. Apigenin-loaded small unilamellar liposomes produced from ethanol injection had an encapsulation efficiency of 74.88 ± 5.31%. They were electrostatically stabilised via chitosan coating (0.25% w/v) and spray-dried. Spray-dried chitosan-coated apigenin liposomes (SCAL) exhibited the following powder characteristics: yield 66.62 ± 3.08%, moisture content 4.33 ± 0.56%, water activity 0.2242 ± 0.0548, particle size 10.97 ± 1.55 μm, nearly spherical morphology with wrinkles and dents under microscopic observation. Compared with the unencapsulated apigenin, SCAL demonstrated improved aqueous solubility (10.22 ± 0.18 mg/L), higher antioxidant capacity, and stability against simulated gastrointestinal digestion. The chitosan coating gave a slower in-vitro release of apigenin in SCAL (77.0 ± 6.2%) than that of uncoated apigenin liposomes (94.0 ± 5.3%) at 12 h. The apigenin release kinetics from SCAL could be represented by the Korsmeyer-Peppas model (R2 = 0.971). These findings suggest that SCAL could be a promising delivery system of apigenin for functional food applications.

The protective roles of citrus flavonoids, naringenin, and naringin on endothelial cell dysfunction in diseases

The endothelial cells (ECs) make up the inner lining of blood vessels, acting as a barrier separating the blood and the tissues in several organs. ECs maintain endothelium integrity by controlling the constriction and relaxation of the vasculature, blood fluidity, adhesion, and migration. These actions of ECs are efficiently coordinated via an intricate signaling network connecting receptors, and a wide range of cellular macromolecules. ECs are naturally quiescent i.e.; they are not stimulated and do not proliferate. Upon infection or disease, ECs become activated, and this alteration is pivotal in the pathogenesis of a spectrum of human neurological, cardiovascular, diabetic, cancerous, and viral diseases. Considering the central position that ECs play in disease pathogenesis, therapeutic options have been targeted at improving ECs integrity, assembly, functioning, and health. The dietary intake of flavonoids present in citrus fruits has been associated with a reduced risk of endothelium dysfunction. Naringenin (NGN) and Naringin (NAR), major flavonoids in grapefruit, tomatoes, and oranges possess anti-inflammatory, antioxidant properties, and cell survival potentials, which improve the health of the vascular endothelium. In this review, we provide a comprehensive summary and present the advances in understanding of the mechanisms through which NGN and NAR modulate the biomarkers of vascular dysfunction and protect the endothelium against unresolved inflammation, oxidative stress, atherosclerosis, and angiogenesis. We also provide perspectives and suggest further studies that will help assess the efficacy of citrus flavonoids in the therapeutics of human vascular diseases.

Hypoglycemic and Hypotensive Effects of Calycotome villosa Subsp. intermedia Seeds in Meriones shawi Rats: In Vivo, Ex Vivo, and In Vitro Investigations

Calycotome villosa subsp. intermedia is used in traditional medicine for the prevention and self-treatment of a variety of illnesses, including diabetes mellitus, obesity, and hypertension. The present study aims to investigate the in vivo, ex vivo, and in vitro hypoglycemic and hypotensive effects of the lyophilized aqueous extract of Calycotome villosa subsp. intermedia seeds (CV) on Meriones shawi submitted to hypercaloric diet and physical inactivity (HCD/PI) for 12 weeks. This diet induces a type 2 diabetes/metabolic syndrome phenotype with hypertension. Furthermore, HCD/PI decreased aorta contraction due to noradrenaline, enhanced L-arginine, and depressed insulin-evoked relaxation, while the relaxing effects of the NO donor SNAP and of diazoxide were unchanged. In vivo experiments showed that the oral administration of the CV extract (50 mg/kg b.wt) for 3 consecutive weeks significantly attenuated the development of type 2 diabetes, obesity, dyslipidemia, and hypertension. These effects may involve the improvement of lipid metabolism, insulin sensitivity, systolic arterial pressure, and urine output. Additionally, ex vivo and in vitro investigations revealed that CV treatment improved vascular contraction to noradrenaline, induced a slight aorta relaxation in response to carbachol, increased the vasorelaxation effect evoked by insulin, and depressed the L-arginine evoked relaxation. However, CV did not change the endothelium-independent vasorelaxation response evoked by SNAP or diazoxide. Hence, the present study provides useful information and supports the traditional use of CV in the prevention and self-treatment of numerous ailments. Overall, it can be concluded that Calycotome villosa subsp. intermedia seed extracts might be useful in the management of type 2 diabetes and hypertension.

Sarcopenic Obesity: Involvement of Oxidative Stress and Beneficial Role of Antioxidant Flavonoids

Sarcopenic obesity, which refers to concurrent sarcopenia and obesity, is characterized by decreased muscle mass, strength, and performance along with abnormally excessive fat mass. Sarcopenic obesity has received considerable attention as a major health threat in older people. However, it has recently become a health problem in the general population. Sarcopenic obesity is a major risk factor for metabolic syndrome and other complications such as osteoarthritis, osteoporosis, liver disease, lung disease, renal disease, mental disease and functional disability. The pathogenesis of sarcopenic obesity is multifactorial and complicated, and it is caused by insulin resistance, inflammation, hormonal changes, decreased physical activity, poor diet and aging. Oxidative stress is a core mechanism underlying sarcopenic obesity. Some evidence indicates a protective role of antioxidant flavonoids in sarcopenic obesity, although the precise mechanisms remain unclear. This review summarizes the general characteristics and pathophysiology of sarcopenic obesity and focuses on the role of oxidative stress in sarcopenic obesity. The potential benefits of flavonoids in sarcopenic obesity have also been discussed.

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.

Bio-Actives from Natural Products with Potential Cardioprotective Properties: Isolation, Identification, and Pharmacological Actions of Apigenin, Quercetin, and Silibinin

Cardiovascular diseases (CVDs) are the leading cause of morbidity and mortality worldwide. As a result, pharmaceutical and non-pharmaceutical interventions modifying risk factors for CVDs are a top priority of scientific research. Non-pharmaceutical therapeutical approaches, including herbal supplements, have gained growing interest from researchers as part of the therapeutic strategies for primary or secondary prevention of CVDs. Several experimental studies have supported the potential effects of apigenin, quercetin, and silibinin as beneficial supplements in cohorts at risk of CVDs. Accordingly, this comprehensive review focused critically on the cardioprotective effects/mechanisms of the abovementioned three bio-active compounds from natural products. For this purpose, we have included in vitro, preclinical, and clinical studies associated with atherosclerosis and a wide variety of cardiovascular risk factors (hypertension, diabetes, dyslipidemia, obesity, cardiac injury, and metabolic syndrome). In addition, we attempted to summarize and categorize the laboratory methods for their isolation and identification from plant extracts. This review unveiled many uncertainties which are still unexplored, such as the extrapolation of experimental results to clinical practice, mainly due to the small clinical studies, heterogeneous doses, divergent constituents, and the absence of pharmacodynamic/pharmacokinetic analyses.

Bee Pollen as Functional Food: Insights into Its Composition and Therapeutic Properties

Bee pollen is a hive product made up of flower pollen grains, nectar, and bee salivary secretions that beekeepers can collect without damaging the hive. Bee pollen, also called bee-collected pollen, contains a wide range of nutritious elements, including proteins, carbs, lipids, and dietary fibers, as well as bioactive micronutrients including vitamins, minerals, phenolic, and volatile compounds. Because of this composition of high quality, this product has been gaining prominence as a functional food, and studies have been conducted to show and establish its therapeutic potential for medical and food applications. In this context, this work aimed to provide a meticulous summary of the most relevant data about bee pollen, its composition—especially the phenolic compounds—and its biological and/or therapeutic properties as well as the involved molecular pathways.

TOTUM-63, a plant-based polyphenol-rich extract, improves glycaemic control in subjects with prediabetes or early stage newly-diagnosed type 2 diabetes in a randomized, double-blind, placebo-controlled trial

AIM

The plant-based polyphenol-rich extract TOTUM-63 improves glucose homeostasis in various preclinical models of obesity and type 2 diabetes (T2D). A pilot exploratory study showed that TOTUM-63 has good safety and tolerability profiles, and beneficial effects on postprandial glucose control in healthy individuals with overweight. The aim of this study was to assess the effects of TOTUM-63 on glycaemic control in individuals with prediabetes or early stage newly-diagnosed T2D (which does not require pharmacological treatment).

MATERIALS AND METHODS

This study was a multicentre, randomized, double-blind, placebo-controlled trial. Individuals with prediabetes or early stage newly-diagnosed T2D and with overweight/abdominal obesity received TOTUM-63 (5 g/day) or placebo for 6 months. The primary outcome was the change in fasting blood glucose.

RESULTS

Fifty-one participants (age: 57.1 ± 10 years; body mass index: 31.3 ± 5.7 kg.m² ; 35 women and 16 men) completed the study (n = 38 TOTUM-63, n = 13 placebo). After 6 months, blood glucose concentration after fasting and after the 2-h oral glucose tolerance test was reduced in the TOTUM-63-treated group compared with the placebo group (placebo-corrected difference between baseline and month 6: -0.71 mmol/L, p < .05, and -1.93 mmol/L, p < .05, respectively). TOTUM-63 was safe and well tolerated and significantly reduced body weight gain (-1.9 kg; p < .05), waist circumference (-4.5 cm; p < .001), circulating triglycerides (-0.54 mmol/L; p < .01) and low-density lipoprotein-cholesterol (-0.38 mmol/L; p < .05) compared with placebo.

CONCLUSIONS

TOTUM-63 lowered fasting blood glucose in participants with impaired fasting glycaemia and glucose intolerance. Moreover, TOTUM-63 showed a good safety and tolerability profile and improved several metabolic syndrome features. Therefore, TOTUM-63 is a promising candidate for T2D prevention.

Apigenin exerts protective effect and restores ovarian function in dehydroepiandrosterone induced polycystic ovary syndrome rats: a biochemical and histological analysis

BACKGROUND

Polycystic ovarian syndrome (PCOS) is one of the major causes encouraging the elevation of androgens, obesity along with menstrual complications. Here we study the effect of Apigenin in rat model of polycystic ovarian syndrome.

METHODS

Female Sprague Dawley (SD) rats were treated with Dehydroepiandrosterone (DHEA) (6 mg/100g) opting the post-pubertal approach for developing rat model of polycystic ovarian syndrome, Metformin was used as standard. The treatments were given for 21 days along with coloproctological analysis. After the treatment regimen, the biochemical analysis was carried in plasma samples, whereas the ovaries were submitted for histopathological analysis.

RESULTS

The treatment of DHEA resulted in disturbed lipid profile and anti-oxidant status along with increased weight, ovarian diameter and cysts in rats confirming the development of PCOS. However, treatment of Apigenin showed ameliorative effect by improving the lipid profile and anti-oxidant status, the treatment also normalised the body weight, reduced ovarian diameter, cysts and restored the healthy follicles compared to control rats. The treatment of Apigenin also suppressed the levels of oestradiol and testosterone compared to control group, also, levels of progesterone were increased in Apigenin treated group of rats. The treatment of Apigenin suppressed the levels of inflammatory cytokines TNF-α and IL-6. It was observed that the effect of Apigenin were to some extent parallel to standard drug Metformin.

CONCLUSION

The findings confirmed that Apigenin ameliorates the disturbed hormonal levels, lipid profile and antioxidant status in PCOS rats.

Luteolin loaded on zinc oxide nanoparticles ameliorates non-alcoholic fatty liver disease associated with insulin resistance in diabetic rats via regulation of PI3K/AKT/FoxO1 pathway

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is a worldwide health problem with high prevalence and morbidity associated with obesity, insulin resistance, type 2 diabetes mellitus (T2DM), and dyslipidemia. Nano-formulation of luteolin with Zn oxide in the form of Lut/ZnO NPs may improve the anti-diabetic property of each alone and ameliorate the insulin resistance thus management of NAFLD. This study aimed to measure the efficiency of Lut/ZnO NPs against insulin resistance coupled with NAFLD and T2DM.

METHODS

A diabetic rat model with NAFLD was induced by a high-fat diet and streptozotocin (30 mg/kg I.P). Serum diabetogenic markers levels, lipid profile, and activity of liver enzymes were measured beside liver oxidative stress markers. Moreover, the hepatic expressions of PI3K/AKT/FoxO1/SERBP1c as well as heme oxygenase-1 were measured beside the histopathological examination.

RESULTS

Lut/ZnO NPs treatment effectively reduced hyperglycemia, hyperinsulinemia, and ameliorated insulin resistance. Additionally, Lut/ZnO NPs improved the hepatic functions, the antioxidant system, and reduced the oxidative stress markers. Furthermore, the lipid load in the liver, as well as the circulating TG and TC, was minified via the suppression of lipogenesis and gluconeogenesis. Moreover, Lut/ZnO NPs activated the PI3K/AKT signaling pathway, hence inactivating FoxO1, therefore enhancing the hepatic cells' insulin sensitivity.

CONCLUSION

Lut/ZnO NPs have a hepatoprotective effect and may relieve the progression of NAFLD by alleviating insulin resistance, ameliorating the antioxidant status, and regulating the insulin signal pathway.

The Analytical Strategy of “Ion Induction and Deduction Based on Net-Hubs” for the Comprehensive Characterization of Naringenin Metabolites In Vivo and In Vitro Using a UHPLC-Q-Exactive Orbitrap Mass Spectrometer

Naringenin (5,7,4′-trihydroxyflavanone), belonging to the flavanone subclass, is associated with beneficial effects such as anti-oxidation, anticancer, anti-inflammatory, and anti-diabetic effects. Drug metabolism plays an essential role in drug discovery and clinical safety. However, due to the interference of numerous endogenous substances in metabolic samples, the identification and efficient characterization of drug metabolites are difficult. Here, ultra-high-performance liquid chromatography (UHPLC) coupled with high-resolution mass spectrometry was used to obtain mass spectral information of plasma (processed by three methods), urine, feces, liver tissue, and liver microsome samples. Moreover, a novel analytical strategy named “ion induction and deduction” was proposed to systematically screen and identify naringenin metabolites in vivo and in vitro. The analysis strategy was accomplished by the establishment of multiple “net-hubs” and the induction and deduction of fragmentation behavior. Finally, 78 naringenin metabolites were detected and identified from samples of rat plasma, urine, feces, liver tissue, and liver microsomes, of which 67 were detected in vivo and 13 were detected in vitro. Naringenin primarily underwent glucuronidation, sulfation, oxidation, methylation, ring fission, and conversion into phenolic acid and their composite reactions. The current study provides significant help in extracting target information from complex samples and sets the foundation for other pharmacology and toxicology research.

Carbon Nanotube and Its Derived Nanomaterials Based High Performance Biosensing Platform

After the COVID-19 pandemic, the development of an accurate diagnosis and monitoring of diseases became a more important issue. In order to fabricate high-performance and sensitive biosensors, many researchers and scientists have used many kinds of nanomaterials such as metal nanoparticles (NPs), metal oxide NPs, quantum dots (QDs), and carbon nanomaterials including graphene and carbon nanotubes (CNTs). Among them, CNTs have been considered important biosensing channel candidates due to their excellent physical properties such as high electrical conductivity, strong mechanical properties, plasmonic properties, and so on. Thus, in this review, CNT-based biosensing systems are introduced and various sensing approaches such as electrochemical, optical, and electrical methods are reported. Moreover, such biosensing platforms showed excellent sensitivity and high selectivity against not only viruses but also virus DNA structures. So, based on the amazing potential of CNTs-based biosensing systems, healthcare and public health can be significantly improved.

Ethanolic extract of Lippia graveolens stem reduce biochemical markers in a Murine Model with Metabolic Syndrome

Metabolic Syndrome (MetS) is a risk to develop metabolic-chronic degenerative disease, it is important to find natural alternatives to help decrease the risk. Mexican oregano has a traditional use in Mexican food, moreover, has pharmacologic effects that can help to reduce risk the metabolic syndrome. The aim of this work was to determine the effect of Mexican oregano ethanolic extract in metabolic syndrome in murine model.

Ethanolic extract of Mexican oregano (Lippia graveolens) stem (Ext) had a favorable effect on biochemical markers in a murine model of MetS, induced by injection of monosodium glutamate (MSG). From newborn female mice, two groups were formed: control and the MSG groups, which received a dosage of 2 mg/kg of MSG via subcutaneous injection at the second and fourth postnatal day (PD 2,4), and 4 mg/kg at the PD 6, 8, 10 to induce obesity. On week 13, a part of the MSG group received Ext (group MSG + Ext) at 300 mg/kg, administered orally daily from week 13 to week 18. The results indicated that ethanolic extract of Lippia graveolens stem decreases the percentage of body fat, waist circumference, and body weight gain as well as cholesterol, serum triglyceride concentrations and systolic and diastolic pressure. Insulin and leptin hormone values showed a significant effect with the Ext administration. However, hepatic lipoperoxidation levels of MSG and MSG + Ext groups did not show any statistically significant differences between them, both being higher than the control group. Taking in consideration the results obtained in this study, it is concluded that the administration of Ext had a beneficial effect in the murine model with MetS. This is the first study demonstrating the potential of the polar fraction Lippia graveolens stem in MetS.

Ameliorative role of Cyanus depressus (M.Bieb.) Soják plant extract against diabetes-associated oxidative-stress-induced liver, kidney, and pancreas damage in rats

In this original article, we aimed to assess the ameliorative role of Cyanus depressus (CD) plant ethanolic extract treatment of streptozotocin (STZ)-induced liver, kidney, and pancreas damage in rats. The rats were divided into five groups (n = 7): control, CD, Diabetes mellitus (DM), DM + CD, and DM + glibenclamide (Gly). The DM groups were injected with a single dose of 50 mg/kg STZ intraperitoneally (i.p.). While the CD and DM + CD groups received 400 mg/kg/day intragastrically for 21 days, the DM + Gly group received 3 mg/kg/day of Gly intragastrically throughout the experiment. Statistically significance was accepted as p < .05. According to our liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) data, quinic acid, cosmosiin, nicotiflorin, apigenin, and protocatechuic acid were the major compounds, in descending order. Weekly blood glucose, serum glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) and urea, malondialdehyde (MDA) (liver and pancreas), and blood glycosylated hemoglobin % (HbA1c %) were significantly decreased, whereas finally live body weights (LBWs), reduced glutathione (GSH), glutathione S-transferase (GST) and catalase (CAT) (pancreas), and pancreatic islet diameter and area were increased significantly in the CD-treated diabetic group. Moreover, CD administration was found to be effective in the protection of the histology of the liver, kidneys, and pancreatic islets in the STZ-induced rats. Consequently, we concluded that CD administration reduces hyperglycemia, oxidative stress, and histopathology in STZ-induced experimental rats by improving antioxidant defenses. PRACTICAL APPLICATIONS: Today, the prevalence of diabetes is increasing rapidly throughout the world and it causes complications such as kidney damage, blindness, amputations, and cardiovascular diseases. Despite medical technological advances, people's interest in medicinal herbal products is gradually increasing. Biochemical and histopathological findings showed that the use of the plant CD at the determined dose (400 mg/kg/day) in rats with DM by STZ had strong antioxidant and antidiabetic effects. CD may have a drug potential in preventing DM and its complications because of its phytochemical content including some phenolic acids such as quinic acid, cosmosiin, nicotiflorin, apigenin, and protocatechuic acid. Isolation of bioactive compounds from CD and investigation of their therapeutic effects could be planned as further studies.

Effect of Tecoma stans (L.) Juss. ex Kunth in a Murine Model of Metabolic Syndrome

Metabolic syndrome is a constellation of abnormalities related to insulin resistance with an unfortunately high prevalence worldwide. Tecoma stans (L.) Juss. Ex Kunth. is a well-known medicinal plant that has been studied in several biological models related to diabetes mellitus. The aim of this study was to evaluate the effects of T. stans on a hypercaloric diet-induced metabolic syndrome model. An organic fraction obtained using liquid–liquid separation from the hydroalcoholic extract of T. stans and four subfractions of this organic fraction were administered for ten weeks to C57BL6J male mice previously fed with a hypercaloric diet. The hypercaloric diet caused changes in glucose levels (from 65.3 to 221.5 mg/dL), body weight (31.3 to 42.2 g), triglycerides (91.4 to 177.7 mg/dL), systolic (89.9 to 110.3 mmHg) and diastolic (61.6 to 73.7 mg/dL) blood pressure, and insulin resistance (4.47 to 5.16). Treatment with T. stans resulted in improvements in triglycerides (83.4–125.0 mg/dL), systolic blood pressure (75.1–91.8 mmHg), and insulin resistance (4.72–4.93). However, the organic fraction and hydroalcoholic extract produced a better response in diastolic blood pressure (52.8–56.4 mmHg). Luteolin, apigenin, and chrysoeriol were the major constituents in the most active subfractions. Treatment with T. stans, particularly a luteolin-rich organic fraction, achieved an improvement in metabolic syndrome alterations.

Protective Effect of Butanolic Fraction of Delphinium brunonianum on Fructose-Mediated Metabolic Alterations in Rats

The present study was conducted with an intent to evaluate the protective effect of butanolic fraction of Delphinium brunonianum on fructose mediated metabolic abnormalities in rats. Rats in all groups except control group were fed on 10% fructose for 6 weeks; however, rats in the treated group also received butanolic fraction for the last 3 weeks, along with the fructose. Moreover, phytoconstituents present in butanolic fraction were analyzed using LC-MS. All doses of butanolic fraction profoundly reduce the fructose-induced blood pressure, sympathetic over-activity, and weight gain. Furthermore, butanolic fraction prominently reduces the glucose intolerance and hyperinsulinemia in fructose-fed rats. On treatment with butanolic fraction, oxidative enzymes and the functionality of the aorta was also restored. Phytochemical analysis revealed the presence of several active constituents including bergenin, scopolin, rutinoside, kaempferol, coumaric acid, apigenin, and gingerol. In conclusion, butanolic fraction of Delphinium brunonianum has the potential to prevent and recover the fructose-induced metabolic perturbations.

Antidiabetic Potential of Plants from the Caribbean Basin

Diabetes mellitus (DM) is a group of metabolic disorders characterized by hyperglycemia, insulin insufficiency or insulin resistance, and many issues, including vascular complications, glycative stress and lipid metabolism dysregulation. Natural products from plants with antihyperglycemic, hypolipidemic, pancreatic protective, antioxidative, and insulin-like properties complement conventional treatments. Throughout this review, we summarize the current status of knowledge of plants from the Caribbean basin traditionally used to manage DM and treat its sequelae. Seven plants were chosen due to their use in Caribbean folk medicine. We summarize the antidiabetic properties of each species, exploring the pharmacological mechanisms related to their antidiabetic effect reported in vitro and in vivo. We propose the Caribbean flora as a source of innovative bioactive phytocompounds to treat and prevent DM and DM-associated complications.

Protective Roles of Apigenin Against Cardiometabolic Diseases: A Systematic Review

Apigenin is a flavonoid with antioxidant, anti-inflammatory, and anti-apoptotic activity. In this study, the potential effects of apigenin on cardiometabolic diseases were investigated in vivo and in vitro. Potential signaling networks in different cell types induced by apigenin were identified, suggesting that the molecular mechanisms of apigenin in cardiometabolic diseases vary with cell types. Additionally, the mechanisms of apigenin-induced biological response in different cardiometabolic diseases were analyzed, including obesity, diabetes, hypertension and cardiovascular diseases. This review provides novel insights into the potential role of apigenin in cardiometabolic diseases.

Effects of naringenin supplementation on cardiovascular risk factors in overweight/obese patients with nonalcoholic fatty liver disease: a pilot double-blind, placebo-controlled, randomized clinical trial

OBJECTIVE

Although several experimental models have suggested promising pharmacological effects of naringenin in the management of obesity and its related disorders, the effects of naringenin supplementation on cardiovascular disorders as one of the main complications of nonalcoholic fatty liver disease (NAFLD) are yet to be examined in humans.

METHODS

In this double-blind, placebo-controlled, randomized clinical trial, 44 overweight/obese patients with NAFLD were equally allocated into either naringenin or placebo group for 4 weeks. Cardiovascular risk factors including atherogenic factors, hematological indices, obesity-related parameters, blood pressure, and heart rate were assessed pre- and postintervention.

RESULTS

The atherogenic index of plasma value, serum non-HDL-C levels as well as total cholesterol/high-density lipoprotein cholesterol (HDL-C), triglyceride/HDL-C, low-density lipoprotein cholesterol/HDL-C, and non-HDL-C/HDL-C ratios were significantly reduced in the intervention group, compared to the placebo group post intervention (P < 0.05). Moreover, there was a significant reduction in BMI and visceral fat level in the intervention group when compared with the placebo group (P = 0.001 and P = 0.039, respectively). Furthermore, naringenin supplementation could marginally reduce systolic blood pressure (P = 0.055). Mean corpuscular hemoglobin increased significantly in the naringenin group compared to the placebo group at the endpoint (P = 0.023). Supplementation with naringenin also resulted in a marginally significant increase in the mean corpuscular hemoglobin concentration when compared with the placebo group (P = 0.050). There were no significant between-group differences for other study outcomes post intervention.

CONCLUSION

In conclusion, these data indicate that naringenin supplementation may be a promising treatment strategy for cardiovascular complications among NAFLD patients. However, further trials are warranted.

Large-leaf yellow tea attenuates high glucose-induced vascular endothelial cells injury by up-regulating autophagy and down-regulating oxidative stress

Vascular endothelial cells injury induced by high glucose (HG) plays an important role in the occurrence and development of diabetic vascular complications. Yellow tea has a protective effect on vascular...

Naringenin prolongs lifespan and delays aging mediated by IIS and MAPK in Caenorhabditis elegans

Naringenin (NN) is one of the most abundant flavonoids in citrus and grapefruits and has been shown to have antioxidant properties in vitro. The purpose of the study is to examine the antioxidant and anti-aging activities of NN in C. elegans, and to further explore the molecular mechanism. The results showed that NN enhanced the lifespan under normal and oxidative stress induced by H₂O₂. After treatment with NN, locomotion capability was improved and aging pigment accumulation was suppressed. NN also delayed the paralysis and reversed the defective chemotaxis behavior induced by Aβ protein. Meanwhile, the treatment with NN enhanced the activities of antioxidant enzymes and reduced the accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA) content. The possible targets and pathways interacting with NN were predicted by network pharmacology. Real-time PCR analysis indicated that NN upregulated the expression levels of daf-16, sek-1 and skn-1, downregulated the expression levels of daf-2, age-1 and akt-1, and further activated sod-3, ctl-1, ctl-2, gst-4 and mtl-1. Moreover, the selected mutant strains were used and molecular docking was conducted to further suggest that IIS and MAPK pathways could be involved in the NN-mediated longevity-promoting effect.

Does naringenin supplementation improve lipid profile, severity of hepatic steatosis and probability of liver fibrosis in overweight/obese patients with NAFLD? A randomised, double-blind, placebo-controlled, clinical trial

BACKGROUND AND OBJECTIVES

Naringenin has been reported to have some promising pharmacological effects on the management of obesity and related metabolic complications including non-alcoholic fatty liver disease (NAFLD). Therefore, the present clinical trial study was done to assess the effects of naringenin supplementation on lipid profile, aminotransferase levels, severity of steatosis, as well as probability of fibrosis in overweight/obese patients with NAFLD.

MATERIALS AND METHODS

This placebo-controlled, parallel randomised, double-blind clinical trial study was conducted on 44 eligible overweight/obese patients with NAFLD (naringenin-treated group (n = 22), control group (n = 22)) referred to the national Iranian oil company (NIOC) Central Hospital, Tehran City, Tehran Province, Iran. Participants were randomly assigned to receive naringenin capsules (100 mg) and identical placebo capsules twice a day, before lunch and dinner, for 4 weeks. The primary outcomes were improvement of liver steatosis and NAFLD fibrosis score (NFS), and secondary outcomes included changes in levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lipid profile.

RESULTS

Naringenin consumption significantly reduced percentages of NAFLD grades (P < .001), as well as, serum levels of triglyceride (TG) (P < .001), total cholesterol (TC) (P = .01), and low-density lipoprotein (LDL) (P = .02) and increased serum level of high-density lipoprotein (HDL) (P = .02) compared with the control group. Even after adjusting for the confounders, the results were significant. However, there were no significant changes in AST, ALT and NFS.

CONCLUSION

Our findings revealed that daily intake of 200 mg of naringenin for 4 weeks had beneficial effects on lipid profile and percentages of NAFLD grades as an indicator for the severity of hepatic steatosis. Although, NFS values and serum levels of aminotransferase enzymes including AST and ALT did not remarkably change.

Citrus polyphenols and risk of type 2 diabetes: Evidence from mechanistic studies

Citrus fruits are a rich source of (poly)phenols, a group of dietary bioactive compounds that protect against developing type 2 diabetes. Our review critically evaluates how experimental in vitro and animal models have elucidated some of the underlying mechanisms on how citrus (poly)phenols affect the markers of type 2 diabetes. According to animal studies, the beneficial effects derived from consuming citrus compounds appear to be related to long-term effects, rather than acute. There are some notable effects from citrus (poly)phenol metabolites on post-absorptive processes, such as modulation of hepatic glucose metabolism and insulin sensitivity in target tissues, but with a more modest effect on digestion and sugar absorption within the gut. Experimental studies on cells and other systems in vitro have indicated some of the possible mechanisms involved, but ∼70% of the studies utilized unrealistically high concentrations and forms of the compounds, compromising physiological relevance. Future studies should discuss the relevance of concentration used in in vitro experiments, relative to the proposed site of action, and also examine the role of catabolites produced by the gut microbiota. Finally, it is important to examine the relationship between the gut microbiota and bioavailability on the action of citrus (poly)phenols.

Apigenin Improves Hypertension and Cardiac Hypertrophy Through Modulating NADPH Oxidase-Dependent ROS Generation and Cytokines in Hypothalamic Paraventricular Nucleus

Apigenin, identified as 4', 5, 7-trihydroxyflavone, is a natural flavonoid compound that has many interesting pharmacological activities and nutraceutical potential including anti-inflammatory and antioxidant functions. Chronic, low-grade inflammation and oxidative stress are involved in both the initiation and progression of hypertension and hypertension-induced cardiac hypertrophy. However, whether or not apigenin improves hypertension and cardiac hypertrophy through modulating NADPH oxidase-dependent reactive oxygen species (ROS) generation and inflammation in hypothalamic paraventricular nucleus (PVN) has not been reported. This study aimed to investigate the effects of apigenin on hypertension in spontaneously hypertensive rats (SHRs) and its possible central mechanism of action. SHRs and Wistar-Kyoto (WKY) rats were randomly assigned and treated with bilateral PVN infusion of apigenin or vehicle (artificial cerebrospinal fluid) via osmotic minipumps (20 μg/h) for 4 weeks. The results showed that after PVN infusion of apigenin, the mean arterial pressure (MAP), heart rate, plasma norepinephrine (NE), Beta 1 receptor in kidneys, level of phosphorylation of PKA in the ventricular tissue and cardiac hypertrophy, perivascular fibrosis, heart level of oxidative stress, PVN levels of oxidative stress, interleukin 1β (IL-1β), interleukin 6 (IL-6), iNOS, monocyte chemotactic protein 1 (MCP-1), tyrosine hydroxylase (TH), NOX2 and NOX4 were attenuated and PVN levels of interleukin 10 (IL-10), superoxide dismutase 1 (Cu/Zn-SOD) and the 67-kDa isoform of glutamate decarboxylase (GAD67) were increased. These results revealed that apigenin improves hypertension and cardiac hypertrophy in SHRs which are associated with the down-regulation of NADPH oxidase-dependent ROS generation and inflammation in the PVN.

Therapeutic Potential of Luteolin on Impaired Wound Healing in Streptozotocin-Induced Rats

Long-term hyperglycemia may lead to diabetic microvascular and macrovascular complications that can affect the peripheral vascular system, particularly in wound healing capacity. Impaired angiogenesis and delayed wound healing are significant clinically. Luteolin (3', 4', 5, 7-tetrahydroxyflavone) is a naturally occurring flavonoid that is ubiquitously found in plants. Recent evidence has shown that luteolin is an anti-inflammatory and anti-oxidative agent. However, the effect of systemic luteolin administration on diabetic wound restoration remains unclear. Herein, we explored the effectiveness of luteolin for improving delayed and impaired healing of skin wound and further clarified the underlying mechanisms. The results indicated that luteolin significantly attenuates blood glucose concentration, improves impaired healing and accelerates re-epithelization of skin wound in streptozotocin (STZ)-induced diabetic rats. Histopathological staining and immunoblotting revealed an inhibitory effect of luteolin on inflammatory cell and cytokine production. We also observed remarkable decreases in protein expressions of inflammatory factors including matrix metalloproteinase (MMP)-9, tumor necrosis factor (TNF)-α, interleukin (IL-6), and IL1-β and downregulation of nuclear factor (NF)-κB, as well as increases in anti-oxidative enzymes such as superoxide dismutase 1 (SOD1) and glutathione peroxidase (GSH-Px) induced by nuclear factor erythroid 2-related factor (Nrf)-2 following luteolin supplementation. Furthermore, luteolin decreased the expression of vascular endothelial growth factor (VEGF) and increased the expression of ubiquitin carboxy-terminal hydrolase (UCH)-L1, as evidenced by angiogenesis and neuronal regeneration in completely healed wound. In conclusion, systemic administration of luteolin promotes wound restoration by ameliorating inflammation and oxidative stress through the inactivation of NF-κB and upregulation of Nrf2 in STZ-induced diabetic rats.

Evidence for 5-HT1A receptor-mediated antiallodynic and antihyperalgesic effects of apigenin in mice suffering from mononeuropathy

BACKGROUND AND PURPOSE

Neuropathic pain places a devastating health burden, with very few effective therapies. We investigated the potential antiallodynic and antihyperalgesic effects of apigenin, a natural flavonoid with momoamine oxidase (MAO) inhibitory activity, against neuropathic pain and investigated the mechanism(s).

EXPERIMENTAL APPROACH

The neuropathic pain model was produced by chronic constriction injury of sciatic nerves in male C57BL/6J mice, with pain-related behaviours being assayed by von Frey test and Hargreaves test. In this model the role of 5-HT and 5-HT_1A receptor-related mechanisms were investigated in vivo/in vitro.

KEY RESULTS

Apigenin repeated treatment (p.o., once per day for 2 weeks), in a dose-related manner (3, 10 and 30 mg·kg^-1 ), ameliorated the allodynia and hyperalgesia in chronic nerve constriction injury in mice. These effects seem dependent on neuronal 5-hydroxytryptamine, because (i) the antihyperalgesia and antiallodynia were attenuated by depletion of 5-HT with p-chlorophenylalanine and potentiated by 5-hydroxytryptophan and (ii), apigenin-treated chronic constriction injury mice caused an increased level of spinal 5-HT, associated with diminished MAO activity. In vivo administration, spinally or systematically, of the 5-HT_1A antagonist WAY-100635 inhibited the apigenin-induced antiallodynia and antihyperalgesia. In vitro, apigenin acted as a positive allosteric modulator to increase the efficacy (stimulation of [³⁵ S]GTPγS binding) of the 5-HT_1A agonist 8-OH-DPAT. Apigenin attenuated neuronal changes caused by chronic constriction of the sciatic nerve in mice, without causing a hypertensive crisis.

CONCLUSION AND IMPLICATIONS

Apigenin antiallodynic and antihyperalgesic actions against neuropathic pain crucially involve spinal 5-HT_1A receptors and indicate it could be used to treat neuropathic pain.

Piper sarmentosum Roxb. Attenuates Vascular Endothelial Dysfunction in Nicotine-Induced Rats

Exposure to cigarette smoke is an important risk factor for cardiovascular diseases. Nicotine is an addictive compound in cigarette smoke that triggers oxidative stress, which leads to vascular dysfunction. Piper sarmentosum Roxb. is a herb with antioxidant and vascular protective effects. This study evaluated the potential protective effect of the aqueous extract of P. sarmentosum leaf (AEPS) on vascular dysfunction in rats induced with prolonged nicotine administration. A total of 22 male Sprague-Dawley rats were divided into control (normal saline, oral gavage [p.o.]), nicotine (0.8 mg/kg/day nicotine, intraperitoneally [i.p.]), and nicotine + AEPS groups (250 mg/kg/day AEPS, p.o. + 0.8 mg/kg/day nicotine, i.p.). Treatment was given for 21 days. Thoracic aortae were harvested from the rats for the measurement of vasorelaxation, vascular nitric oxide (NO) level, and antioxidant level and the assessment of vascular remodeling. Rats treated with AEPS had improved vasorelaxation to endothelium-dependent vasodilator, acetylcholine (ACh), compared with the nicotine-induced rats (p < 0.05). The presence of endothelium increased the maximum relaxation of aortic rings in response to ACh. Compared with the nicotine group, AEPS enhanced vascular NO level (p < 0.001) and increased antioxidant levels as measured by superoxide dismutase activity (p < 0.05), catalase activity (p < 0.01), and reduced glutathione level (p < 0.05). No remarkable changes in aortic histomorphometry were detected. In conclusion, P. sarmentosum attenuates vascular endothelial dysfunction in nicotine-induced rats by improving vasorelaxation and enhancing vascular NO and antioxidant levels.

Apigenin restores endothelial function by ameliorating oxidative stress, reverses aortic stiffening, and mitigates vascular inflammation with aging

We assessed the efficacy of oral supplementation with the flavanoid apigenin on arterial function during aging and identified critical mechanisms of action. Young (6 mo) and old (27 mo) C57BL/6N mice (model of arterial aging) consumed drinking water containing vehicle (0.2% carboxymethylcellulose; 10 young and 7 old) or apigenin (0.5 mg/mL in vehicle; 10 young and 9 old) for 6 wk. In vehicle-treated animals, isolated carotid artery endothelium-dependent dilation (EDD), bioassay of endothelial function, was impaired in old versus young (70% ± 9% vs. 92% ± 1%, P < 0.0001) due to reduced nitric oxide (NO) bioavailability. Old mice had greater arterial reactive oxygen species (ROS) production and oxidative stress (higher nitrotyrosine) associated with greater nicotinamide adenine dinucleotide phosphate oxidase (oxidant enzyme) and lower superoxide dismutase 1 and 2 (antioxidant enzymes); ex vivo administration of Tempol (antioxidant) restored EDD to young levels, indicating ROS-mediated suppression of EDD. Old animals also had greater aortic stiffness as indicated by higher aortic pulse wave velocity (PWV, 434 ± 9 vs. 346 ± 5 cm/s, P < 0.0001) due to greater intrinsic aortic wall stiffness associated with lower elastin levels and higher collagen, advanced glycation end products (AGEs), and proinflammatory cytokine abundance. In old mice, apigenin restored EDD (96% ± 2%) by increasing NO bioavailability, normalized arterial ROS, oxidative stress, and antioxidant expression, and abolished ROS inhibition of EDD. Moreover, apigenin prevented foam cell formation in vitro (initiating step in atherosclerosis) and mitigated age-associated aortic stiffening (PWV 373 ± 5 cm/s) by normalizing aortic intrinsic wall stiffness, collagen, elastin, AGEs, and inflammation. Thus, apigenin is a promising therapeutic for arterial aging.NEW & NOTEWORTHY Our study provides novel evidence that oral apigenin supplementation can reverse two clinically important indicators of arterial dysfunction with age, namely, vascular endothelial dysfunction and large elastic artery stiffening, and prevents foam cell formation in an established cell culture model of early atherosclerosis. Importantly, our results provide extensive insight into the biological mechanisms of apigenin action, including increased nitric oxide bioavailability, normalization of age-related increases in arterial ROS production and oxidative stress, reversal of age-associated aortic intrinsic mechanical wall stiffening and adverse remodeling of the extracellular matrix, and suppression of vascular inflammation. Given that apigenin is commercially available as a dietary supplement in humans, these preclinical findings provide the experimental basis for future translational studies assessing the potential of apigenin to treat arterial dysfunction and reduce cardiovascular disease risk with aging.