Medicinal Plants with Multiple Effects on Diabetes Mellitus and Its Complications: a Systematic Review

Antioxidant, Cytotoxicity, Antimicrobial Activity, and In Silico Analysis of the Methanolic Leaf and Flower Extracts of Clitoria ternatea

Infectious diseases pose a significant threat to human health worldwide. To address this challenge, we conducted a comprehensive study on the leaf and flower extracts of Clitoria ternatea plants. Our research encompassed in vitro assessments of their antibacterial, antibiofilm, antioxidant, and cytotoxic properties. Additionally, we employed in silico screening to identify promising compounds with potential applications in developing novel anti-Escherichia coli medications. Notably, our investigation revealed a remarkable inhibition zone of 13.00 ± 1 mm when applying the leaf extract (200 μg/ml) against E. coli, showcasing its potent antibacterial properties. Furthermore, both the leaf and flower extracts exhibited substantial biofilm inhibition efficacy against S. aureus, with inhibition percentages of 54% and 58%, respectively. In the realm of antioxidant activity, the leaf and flower extracts of C. ternatea displayed noteworthy DPPH free radical scavenging capabilities. Specifically, the leaf extract exhibited a substantial activity of 62.39% at a concentration of 150 μg/ml, while the flower extract achieved 44.08% at the same concentration. Our study also evaluated the impact on brine shrimp, where the floral extract displayed a significantly higher mortality rate of 93.33% at a dosage of 200 μg/ml compared to the leaf extract. To elucidate potential therapeutic targets, we utilized molecular docking techniques, focusing on the acbR protein (5ENR) associated with antibiotic resistance in E. coli. In this analysis, compounds isolated from the C. ternatea leaf extract, namely D1 (CID-14478556), D2 (CID-6423376), and D3 (CID-20393), exhibited binding energies of -8.2 kcal/mol, -6.5 kcal/mol, and -6.3 kcal/mol, respectively. Additionally, compounds from the flower extract, E1 (CID-5282761), E2 (CID-538757), and E3 (CID-536762), displayed binding energies of -5.4 kcal/mol, -5.3 kcal/mol, and -5.1 kcal/mol, respectively. In conclusion, the leaf and flower extracts derived from C. ternatea represent a promising natural resource with potential therapeutic applications in combating antibiotic-resistant pathogens.

The Emerging Importance of Cirsimaritin in Type 2 Diabetes Treatment

Cirsimaritin is a dimethoxy flavon that has different biological activities such as antiproliferative, antimicrobial, and antioxidant activities. This study aims to investigate the anti-diabetic effects of cirsimaritin in a high-fat diet and streptozotocin-(HFD/STZ)-induced rat model of type 2 diabetes mellitus (T2D). Rats were fed HFD, followed by a single low dose of STZ (40 mg/kg). HFD/STZ diabetic rats were treated orally with cirsimaritin (50 mg/kg) or metformin (200 mg/kg) for 10 days before terminating the experiment and collecting plasma, soleus muscle, adipose tissue, and liver for further downstream analysis. Cirsimaritin reduced the elevated levels of serum glucose in diabetic rats compared to the vehicle control group (p < 0.001). Cirsimaritin abrogated the increase in serum insulin in the treated diabetic group compared to the vehicle control rats (p < 0.01). The homeostasis model assessment of insulin resistance (HOMA-IR) was decreased in the diabetic rats treated with cirsimaritin compared to the vehicle controls. The skeletal muscle and adipose tissue protein contents of GLUT4 (p < 0.01 and p < 0.05, respectively) and pAMPK-α1 (p < 0.05) were upregulated following treatment with cirsimaritin. Cirsimaritin was able to upregulate GLUT2 and AMPK protein expression in the liver (p < 0.01, <0.05, respectively). LDL, triglyceride, and cholesterol were reduced in diabetic rats treated with cirsimaritin compared to the vehicle controls (p < 0.001). Cirsimaritin reduced MDA, and IL-6 levels (p < 0.001), increased GSH levels (p < 0.001), and reduced GSSG levels (p < 0.001) in diabetic rats compared to the vehicle control. Cirsimaritin could represent a promising therapeutic agent to treat T2D.

Kaempferol 3-O-rutinoside from Antidesma acidum Retz. Stimulates glucose uptake through SIRT1 induction followed by GLUT4 translocation in skeletal muscle L6 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Antidesma acidum Retz, a perennial herb is known for its anti-diabetic potential among the traditional health care providers of the tribal communities of Manipur, India. Scientific validation of the ancient knowledge on traditional use of this plant with the help of modern tools and techniques can promote further research and its use in health care.

AIM OF THE STUDY

Type 2 Diabetes (T2D) is a complex metabolic disorder and linked with hyperglycemia occurring from insufficiency in insulin secretion, action, or both. The aim of this study was to scientifically validate the traditional myth behind the uses of this plant material against diabetes. More specifically, it was aimed to determine the effect of methanolic extract of A. acidum leaves and/or any of its bioactive phytochemical(s), in enhancing insulin sensitization and subsequently stimulating the insulin signaling cascade of glucose metabolism.

MATERIALS AND METHODS

Methanol was used for extraction from the leaf powder of A. acidum followed by bioactivity guided fractionation and isolation of most active component. Biological evaluation was performed to determine the glucose uptake ability against insulin resistance in skeletal muscle (L6) cells. To understand the detailed mechanism of actions of the purified compound, several molecular biology and structural biology experiments such as Western blot, siRNA transfection assay and molecular docking study were performed.

RESULTS AND DISCUSSION

Bioactivity guided isolation of pure compound and spectral data analysis led us to identify the active component as Kaempferol 3-O-rutinoside (KOR) for the first time from the leaf of A. acidum. Over expression of NAD-dependent histone deacetylase, Sirtuin 1 (SIRT1) was observed following KOR treatment. SIRT1 plays an important role in the metabolic pathway and over expression of SIRT implies that it involves in insulin signaling directly or indirectly. Molecular docking and simulation study showed the strong involvement between KOR and SIRT1.Treatment with KOR resulted in significant over expression of SIRT1followed by upregulation of insulin-dependent p-IRS, AKT and AMPK signaling molecules, and stimulation of the GLUT4 translocation, which ultimately enhanced the glucose uptake in sodium palmitate-treated insulin resistant L6 myotubes. Further, the effect of KOR on IRS1, AKT and AMPK phosphorylation, GLUT4 translocation, and glucose uptake was attenuated in SIRT1-knockdown myotubes.

CONCLUSION

Overall, the results of this study suggest that Kaempferol 3-O-rutinoside is the active component presents in the leaf of A. acidum which increases glucose consumption by inducing SIRT1 activation and consequently improves insulin sensitization. These results may find future applications in drug discovery research against T2DM.

Tissue engineering approaches and generation of insulin-producing cells to treat type 1 diabetes

Tissue engineering (TE) has become a new effective solution to a variety of medical problems, including diabetes. Mesenchymal stem cells (MSCs), which have the ability to differentiate into endodermal and mesodermal cells, appear to be appropriate for this function. The purpose of this review was to evaluate the outcomes of various researches on the insulin-producing cells (IPCs) generation from MSCs with TE approaches to increase efficacy of type 1 diabetes treatments. The search was performed in PubMed/Medline, Scopus and Embase databases until 2021. Studies revealed that MSCs could also differentiate into IPCs under certain conditions. Therefore, a wide range of protocols have been used for this differentiation, but their effectiveness is very different. Scaffolds can provide a microenvironment that enhances the MSCs to IPCs differentiation, improves their metabolic activity and up-regulate pancreatic-specific transcription factors. They also preserve IPCs architecture and enhance insulin production as well as protect against cell death. This systematic review offers a framework for prospective research based on data. In vitro and in vivo evidence suggests that scaffold-based TE can improve the viability and function of IPCs.

Loquat (Eriobotrya japonica (Thunb) Lindl.): Evaluation of nutritional value, polyphenol composition, antidiabetic effect, and toxicity of leaf aqueous extract

ETHNOPHARMACOLOGICAL RELEVANCE

Loquat (Eriobotrya japonica (Thunb.) Lindl.) is an evergreen tree native to China, which is introduced in many Mediterranean countries. As in many ancient medical systems, loquat leaves have been used in Moroccan traditional medicine to treat diabetes and its complications.

AIM OF THE STUDY

This study aims to determine the nutritional and polyphenol composition and to evaluate the in vivo antidiabetic, and antihyperlipidemic properties and oral toxicity of a leaf aqueous extract (LLE) derived from loquat grown in Morocco.

MATERIALS AND METHODS

Energy value and fiber, fatty acids, minerals, vitamins, total carbohydrate, sugar, lipid, and protein contents were determined according to international methods committee guidelines. Polyphenol profiling was carried out using the HPLC-DAD method. Mice fed a high-fat and high-glucose (HFG) diet for 10 weeks were used as a model to assess the antidiabetic and antihyperlipidemic effects of a daily administration of LLE at three different doses (150, 200, 250 mg/kg body weight (BW)/day), in comparison with metformin (50 mg/kg BW/day) and pravastatin (20 mg/kg BW/day). The oral toxicity was determined following OECD 425 Guideline.

RESULTS

Loquat leaves were found to be rich in fiber, minerals (potassium, calcium, magnesium, iron, and sodium), and vitamins (B2, B6, and B12) and lower in energy, sugar, and fat. Ten different phenolic compounds were characterized. Naringenin, procyanidin C1, epicatechin, and rutin were the more abundant compounds in LLE. The administration of the LLE dose-dependently ameliorated hyperglycemia, insulin resistance, oxidative stress, and hyperlipidemia in HFG diet-fed mice. The median lethal dose of LLE was higher than 5000 mg/kg BW.

CONCLUSIONS

Loquat leaves are a potential source of micronutrients and polyphenols with beneficial effects on diabetes and its complications.

Exploring the plant-derived bioactive substances as antidiabetic agent: An extensive review

Diabetes mellitus (DM) is a metabolic syndrome. Diabetes has become more common in recent years. Chemically generated drugs are used to lessen the effects of DM and its following repercussions due to unpleasant side effects such as weight gain, gastrointestinal issues, and heart failure. On the other hand, medicinal plants could be a good source of anti-diabetic medications. This article aims to determine any plant matrix's positive potential. Food restriction, physical activity, and the use of antidiabetic plant-derived chemicals are all being promoted as effective ways to manage diabetes because they are less expensive and have fewer or no side effects. This review focuses on antidiabetic plants, along with their bioactive constituent, chemically characterization, and plant-based diets for diabetes management. There is minimal scientific data about the mechanism of action of the plant-based product has been found. The purpose of this article is to highlight anti-diabetic plants and plant-derived bioactive compounds that have anti-diabetic properties. It also provides researchers with data that may be used to build future strategies, such as identifying promising bioactive molecules to make diabetes management easier.

Ceratonia siliqua leaves ethanol extracts exert anti-nociceptive and anti-inflammatory effects

Background

Ceratonia siliqua L. (Leguminosae) has neuroprotective, mutagenic, hypotensive, anti-bacterial, hypoglycaemic, and anti-inflammatory effects through extracts from its leaves. Therefore, the aim of this study is to assess the anti-nociceptive activity of ethanol extracts of Ceratonia siliqua leaves.

Methods

Ethanol extract of Ceratonia siliqua leaves were studied using well-established animal models of inflammation and pain. A hot plate latency assay (55 °C) was used to assess the analgesic effect of 10, 31.6, 100, and 316 mg/kg doses of ethanol extracts in addition to paw licking time in early and late phase using a formalin-induced paw licking assay test. Paw oedema induction using carrageenan and cotton pellet granuloma assays were used to assess the anti-inflammatory effect of 10, 31.6, 100, and 316 mg/kg doses of ethanol extract.

Results

The ethanol extract of Ceratonia siliqua leaves reduces paw licking time in early and late phase after formalin injection. The same effect was also observed when the hotplate test was performed. Ethanol extract of Ceratonia siliqua leaves caused dose dependent inhibition in paw oedema after the injection of carrageenan and cotton pellet granuloma in mice. These effects were not antagonized when opioid receptors were blocked by naloxone (5 mg/kg). The preliminary phytochemical analysis of the ethanol extract of Ceratonia siliqua leaves showed the presence of tannins, alkaloids, flavonoids and terpenoids.

Conclusion

The present data indicate that ethanol extract of Ceratonia siliqua leaves might possess anti-inflammatory and anti-nociception properties and should be considered for further therapeutic research.

The Role of Polyphenol in Modulating Associated Genes in Diabetes-Induced Vascular Disorders

Diabetes-induced vascular disorder is considered one of the deadly risk factors among diabetic patients that are caused by persistent hyperglycemia that eventually leads to cardiovascular diseases. Elevated reactive oxygen species (ROS) due to high blood glucose levels activate signaling pathways such as AGE/RAGE, PKC, polyol, and hexosamine pathways. The activated signaling pathway triggers oxidative stress, inflammation, and apoptosis which later lead to vascular dysfunction induced by diabetes. Polyphenol is a bioactive compound that can be found abundantly in plants such as vegetables, fruits, whole grains, and nuts. This compound exerts therapeutic effects in alleviating diabetes-induced vascular disorder, mainly due to its potential as an anti-oxidative, anti-inflammatory, and anti-apoptotic agent. In this review, we sought to summarize the recent discovery of polyphenol treatments in modulating associated genes involved in the progression of diabetes-induced vascular disorder.

Oakmoss Exhibits Antihyperglycemic Activity in Streptozotocin-Induced Diabetic Rats

AIMS

The study aimed to assess the antidiabetic effect of Oakmoss.

BACKGROUND

Lichens species are dual organisms consisting of a mycobiont (Fungi) and a photoautotrophic partner (Algae). They are widely used in traditional medicine as a treatment against diabetes.

OBJECTIVE

This study was designed to assess the antihyperglycemic activity as well as the antihyperlipidemic capacity of Oakmoss (Evernia prunastri (L.)) in normal and streptozotocin(STZ)-induced diabetic rats.

METHODS

This study has evaluated the effects of aqueous extract of Oakmoss at a dose of 60 mg/kg on blood glucose levels and lipid profile in normal and STZ-induced diabetic rats. Histopathological examination of liver, determination of glycogen content in liver and skeletal muscles (EDL and soleus), antioxidant activity, and phytochemical investigation were also performed.

RESULTS

Both single and repeated oral doses of Oakmoss (60 mg/kg) produced a significant reduction of blood glucose, triglycerides and very low-density lipoprotein (VLDL) levels in diabetic rats. Furthermore, repeated oral administration of Oakmoss during 7 days ameliorated the liver function by increasing its glycogen content and improving its histological architecture in treated diabetic rats. In addition, the aqueous extract of Oakmoss exhibited an antioxidant activity and showed richness in certain phytochemicals especially in phenolic acids and flavonoids.

CONCLUSION

Oakmoss, a lichen species, exhibits a potential effect on improving hyperglycemia and hypertriglyceridemia in diabetic rats.

Bridelia ferruginea Benth. (Euphorbiaceae) mitigates oxidative imbalance and lipotoxicity, with concomitant modulation of insulin signaling pathways via GLUT4 upregulation in hepatic tissues of diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Bridelia ferruginea Benth. (Euphorbiaceae) is among the medicinal plants commonly used for the management of type 2 diabetes (T2D) and its complications.

AIM OF THE STUDY

The hepato-therapeutic effect of the butanol fraction of Bridelia ferruginea leaves was investigated in diabetic rats.

METHODS

The butanol fraction of B. ferruginea was given to type 2 diabetic rats at both low and high doses (150 and 300 mg/kg bodyweight, respectively), while metformin and glibenclamide served as the standard anti-diabetic drugs. A normal toxicological group was administered a high dose of the fraction. At the end of the experimental period, the rats were sacrificed, and their livers and psoas muscle collected. The liver was assayed for oxidative stress markers, liver glycogen content, lipid metabolite profile (using GC-MS) and their metabolic pathways were analyzed using the MetaboAnalyst 5.0 online server. The expression of GLUT4 was also assayed in the liver and muscle as well as the identification of signaling pathways associated with GLUT4 expression using the Enrichr online server. In silico molecular docking was used to investigate the molecular interactions of some postulated compound found in B. ferruginea with GLUT4. The ability of the fraction to stimulate muscle glucose uptake was determined in isolated rat psoas muscle ex vivo.

RESULTS

Treatment with the high dose of fraction caused an inhibition of lipid peroxidation as well as the elevation of catalase, SOD, glutathione reductase and glutathione peroxidase activities in the rat liver. There was an increased expression of GLUT4 in livers and muscles of diabetic rats following treatment with B. ferruginea. Treatment with the fraction also caused inactivation of diabetes-activated pathways and changes in the distribution of the hepatic lipid metabolites. Molecular docking analysis revealed strong molecular interactions of pyrogallol and sitosterol with GLUT4.

CONCLUSIONS

These data illustrate the hepato-protective effect of B. ferruginea in diabetic rats which compare favorably with the tested anti-diabetic drugs (metformin and glibenclamide).

Protective effect of vanillic acid against diabetes and diabetic nephropathy by attenuating oxidative stress and upregulation of NF-κB, TNF-α and COX-2 proteins in rats

Diabetes is the most prevalent disorder in the world characterized by uncontrolled high blood glucose levels and nephropathy is one of the chief complications allied with hyperglycemia. Vanillic acid; the main bioactive compound derived from natural sources such as vegetables, fruits and plants possesses various pharmacological activities such as antioxidant, anti-inflammatory and anti-proliferative. The current study was designed to investigate the antidiabetic and renoprotective effects of vanillic acid by its various pharmacological activities. Streptozotocin (50 mg/kg)/nicotinamide (110 mg/kg) was used to induce diabetes in rats. Oral administration of vanillic acid once daily for 6 weeks (25, 50 and 100 mg/kg) significantly reduced the hyperglycemia, increased liver enzymes and normalized lipid profile that was altered in diabetic rats. Moreover, vanillic acid attenuated the impaired renal function as evidenced by a reduction in serum creatinine, urea, uric acid and urinary microproteinuria levels with a concomitant increase in urinary creatinine clearance in the nephropathic rats. Diabetic rats showed a marked increase in thiobarbituric acid reactive substances (TBARS) and superoxide anion generation (SAG) along with decreased reduced glutathione (GSH) in the renal tissue which was ameliorated in the vanillic acid-treated rats. Histopathologically, vanillic acid treatment was associated with reduced damage with normalized structural changes in renal tissue. Furthermore, treatment groups showed the suppression of upregulation of nuclear factor (NF)-κB, tumor necrosis factor (TNF)-α, cyclo-oxygenase (COX)-2 and up-regulation of Nuclear factor-erythroid 2-related factor 2 (Nrf-2) in the renal tissue. In conclusion, vanillic acid's ameliorative impact on diabetic nephropathic rats may be attributed to its powerful free radical scavenging property, down-regulation of NF-κB, TNF-α, COX-2 and up-regulation of Nrf-2 proteins in renal tissue.

Neuroinflammation and Oxidative Stress in Alzheimer's Disease; Can Nutraceuticals and Functional Foods Come to the Rescue?

Alzheimer's disease (AD), the most prevalent form of age-related dementia, is typified by progressive memory loss and spatial awareness with personality changes. The increasing socioeconomic burden associated with AD has made it a focus of extensive research. Ample scientific evidence supports the role of neuroinflammation and oxidative stress in AD pathophysiology, and there is increasing research into the possible role of anti-inflammatory and antioxidative agents as disease modifying therapies. While, the result of numerous preclinical studies has demonstrated the benefits of anti-inflammatory agents, these benefits however have not been replicated in clinical trials, necessitating a further search for more promising anti-inflammatory agents. Current understanding highlights the role of diet in the development of neuroinflammation and oxidative stress, as well as the importance of dietary interventions and lifestyle modifications in mitigating them. The current narrative review examines scientific literature for evidence of the roles (if any) of dietary components, nutraceuticals and functional foods in the prevention or management of AD. It also examines how diet/ dietary components could modulate oxidative stress/inflammatory mediators and pathways that are crucial to the pathogenesis and/or progression of AD.

The Mechanisms and Management of Age-Related Oxidative Stress in Male Hypogonadism Associated with Non-communicable Chronic Disease

Androgens have diverse functions in muscle physiology, lean body mass, the regulation of adipose tissue, bone density, neurocognitive regulation, and spermatogenesis, the male reproductive and sexual function. Male hypogonadism, characterized by reduced testosterone, is commonly seen in ageing males, and has a complex relationship as a risk factor and a comorbidity in age-related noncommunicable chronic diseases (NCDs), such as obesity, metabolic syndrome, type 2 diabetes, and malignancy. Oxidative stress, as a significant contributor to the ageing process, is a common feature between ageing and NCDs, and the related comorbidities, including hypertension, dyslipidemia, hyperglycemia, hyperinsulinemia, and chronic inflammation. Oxidative stress may also be a mediator of hypogonadism in males. Consequently, the management of oxidative stress may represent a novel therapeutic approach in this context. Therefore, this narrative review aims to discuss the mechanisms of age-related oxidative stress in male hypogonadism associated with NCDs and discusses current and potential approaches for the clinical management of these patients, which may include conventional hormone replacement therapy, nutrition and lifestyle changes, adherence to the optimal body mass index, and dietary antioxidant supplementation and/or phytomedicines.

Function of selected natural antidiabetic compounds with potential against cancer via modulation of the PI3K/AKT/mTOR cascade

Diabetes mellitus (DM) is a metabolic disorder with growing global incidence, as 387 million people were diagnosed in 2014 with an expected projection of 642 million in 2040. Several complications are associated with DM including heart attack, stroke, kidney failure, blindness, and cancer. The latter is the second leading cause of death worldwide accounting for one in every six deaths, with liver, pancreas, and endometrium cancers are the most abundant among patients with diabetes. Phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway plays a vital role in developing a wide array of pathological disorders, among them diabetes and cancer. Natural secondary metabolites that counteract the deleterious effects of reactive oxygen species (ROS) and modulate PI3K/Akt/mTOR pathway could be a promising approach in cancer therapy. Here, 717 medicinal plants with antidiabetic activities were highlighted along with 357 bioactive compounds responsible for the antidiabetic activity. Also, 43 individual plant compounds with potential antidiabetic activities against cancer via the modulation of PI3K/Akt/mTOR cascade were identified. Taken together, the available data give an insight of the potential of repurposing medicinal plants and/or the individual secondary metabolites with antidiabetic activities for cancer therapy.

Environmental cadmium exposure during pregnancy causes diabetes-like phenotypes in mouse offspring: Association with oxidative stress in the fetal liver

Cadmium (Cd), a noxious heavy metal, is widespread in the living environment. Gestational exposure to Cd at environmental dose has been shown to cause fetal growth restriction (FGR). However, the long-term effects and the mechanisms underlying environmental Cd exposure on glucose metabolism in offspring remain unclear. Here, we established a murine model to study the impacts of gestational exposure to environmental Cd on glucose metabolism at different life stages of offspring. Results demonstrated that the offspring mice developed hyperglycemia in puberty and impaired glucose tolerance in adulthood following maternal Cd exposure during gestation. Further mechanistic investigation showed that Cd exposure upregulated the expression of key proteins in hepatic gluconeogenesis, including p-CREB, PGC-1α and G6PC, in pubertal and adult offspring. In addition, we demonstrated that Cd exposure during pregnancy markedly elevated the level of oxidative stress-related proteins, including NOX2, NOX4 and HO-1, in the fetal liver. The effects of gestational exposure to N-acetylcysteine (NAC), a free-radical scavenging antioxidant, presented that NAC supplementation alleviated hepatic oxidative stress in fetuses, and thereby reversed hyperglycemia and glucose intolerance in mouse offspring. Collectively, our data suggested that gestational exposure to environmental Cd caused diabetes-like phenotypes via enhancing hepatic gluconeogenesis, which is associated with oxidative stress in fetal livers. This work provides new insights into the protective effects of antioxidants on fetal-originated diabetes triggered by environmental toxicants.

Antihyperglycemic Potential of Matricaria pubescens (Desf.) Schultz. in Streptozotocin-induced Diabetic Rats

AIMS

The study aimed to investigate the antihyperglycemic activity of Matricaria pubescens.

BACKGROUND

Matricaria pubescens (Def). Shultz (Asteraceae) is commonly used traditionally for the treatment of diabetes in Morocco.

OBJECTIVE

The present investigation aimed to assess the antihyperglycemic and antioxidant effects of the aqueous extract of the aerial part of Matricaria pubescens (M. pubescens).

METHODS

The effect of a single and repeated oral administration of the aqueous extract of aerial part of M. pubescens (AEAPMP) at a dose of 40 mg/kg on glucose was examined in normal and streptozotocin-induced diabetic rats. Additionally, histopathological examination of the pancreas and liver was carried out according to the Hematoxylin-Eosin method. The antioxidant activity was performed using the DPPH assay.

RESULTS

The results showed that the aqueous extract of M. pubescens (AEAPMP) exhibited a significant lowering activity on blood glucose levels in STZ-induced diabetic rats. In addition, AEAPMP ameliorated the histopathological tissues of the liver and pancreas. Furthermore, in vitro antioxidant activity of AEAPMP has been shown.

CONCLUSION

In conclusion, this study demonstrates that M. pubescens possesses a beneficial effect against hyperglycemia associated with diabetes.

Novel advances in inhibiting advanced glycation end product formation using natural compounds

Advanced glycation end products (AGEs) are a group of complex compounds generated by nonenzymatic interactions between proteins and reducing sugars or lipids. AGEs accumulate in vivo and activate various signaling pathways closely related to the occurrence of various chronic metabolic diseases. In this paper, we describe the process through which AGEs are formed, the classification of AGEs, and biological effects of AGEs on human health. Most importantly, we review recent progress in natural compound-based AGE formation inhibitors. Major classes of natural inhibitors, including polyphenols, polysaccharides, terpenoids, vitamins and alkaloids, have been described. Their mechanisms of action have been summarized as scavenging free radicals, chelating metal ions, capturing active carbonyl compounds, protecting protein glycation sites, and lowering blood glucose levels. Although these natural compounds have good antiglycation activity, to date, they are not widely used in the clinic, likely because of their low content levels. However, these natural compounds and their molecular frameworks will play a valuable role in inspiring drug discovery.

Activation of Insulin Signaling by Botanical Products

Type 2 diabetes (T2D) is a worldwide health problem, ranked as one of the leading causes for severe morbidity and premature mortality in modern society. Management of blood glucose is of major importance in order to limit the severe outcomes of the disease. However, despite the impressive success in the development of new antidiabetic drugs, almost no progress has been achieved with regard to the development of novel insulin-sensitizing agents. As insulin resistance is the most eminent factor in the patho-etiology of T2D, it is not surprising that an alarming number of patients still fail to meet glycemic goals. Owing to its wealth of chemical structures, the plant kingdom is considered as an inventory of compounds exerting various bioactivities, which might be used as a basis for the development of novel medications for various pathologies. Antidiabetic activity is found in over 400 plant species, and is attributable to varying mechanisms of action. Nevertheless, relatively limited evidence exists regarding phytochemicals directly activating insulin signaling, which is the focus of this review. Here, we will list plants and phytochemicals that have been found to improve insulin sensitivity by activation of the insulin signaling cascade, and will describe the active constituents and their mechanism of action.

Efficient Separation of Phytochemicals from Muehlenbeckia volcanica (Benth.) Endl. by Polarity-Stepwise Elution Counter-Current Chromatography and Their Antioxidant, Antiglycation, and Aldose Reductase Inhibition Potentials

Muehlenbeckia volcanica (Benth.) Endl. (M. volcanica), native to South America, is a traditional Peruvian medicinal plant that has multi-therapeutic properties; however, no phytochemicals have been identified from it yet. In this study, a five-step polarity-stepwise elution counter-current chromatography (CCC) was developed using methanol/water (1:5, v/v) as the stationary phase and different ratios of n-hexane, ethyl acetate, and n-butanol as mobile phases to separate the compounds from the 70% methanol extract of M. volcanica, by which six compounds with a wide range of polarities were separated in a single run of CCC and were identified as gallic acid, protocatechuic acid, 4,4'-dihydroxy-3,3'-imino-di-benzoic acid, rutin, quercitrin, and quercetin. Then, two compounds from the fractions of stepwise elution CCC were separated using conventional high-speed CCC, pH-zone-refining CCC, and preparative high-performance liquid chromatography, and identified as shikimic acid and miquelianin. These compounds are reported from M. volcanica for the first time. Notably, except for shikimic acid, all other compounds showed anti-diabetic potentials via antioxidant, antiglycation, and aldose reductase inhibition. The results suggest that the polarity-stepwise elution CCC can be used to efficiently separate or fractionate compounds with a wide range of polarities from natural products. Moreover, M. volcanica and its bioactive compounds are potent anti-diabetic agents.

Potent Antihyperglycemic Effect of an Endemic Plant from Morocco (Matthiola Maroccana Coss.) on Normal and Streptozotocin-Induced Diabetic Rats

BACKGROUND

Matthiola maroccana (Coss.) belongs to the Brassicaceae family and it is an endemic plant from Morocco.

OBJECTIVE

The objective of the study was to evaluate the effect of aqueous extract of Matthiola maroccana (Coss.) on blood glucose levels in normal and diabetic rats.

METHODS

The effect of single dose (6 hours) and daily oral administration for seven days of the Aerial Part Aqueous Extract (A.P.A.E) of Matthiola maroccana (Coss.) (M. maroccana) at a dose of 20 mg/kg body weight on blood glucose levels in normal and streptozotocin(STZ)-induced diabetic rats was observed. Furthermore, body weight, oral glucose tolerance test, liver histopathological examination, phytochemical screening, and in vitro antioxidant activity of A.P.A.E were evaluated in this study.

RESULTS

The results showed that M. maroccana A.P.A.E exerts potent hypoglycemic and antihyperglycemic effects on normal and STZ-induced diabetic rats (p<0.0001). Also, it was able to restore body weight in diabetic rats (p<0.05). Furthermore, the aqueous extract has been shown to regenerate hepatic tissues in diabetic rats. Besides, A.P.A.E revealed the presence of several phytochemical constituents (polyphenols, flavonoids, tannins, saponins, alkaloids, sterols and terpenoids), and possessed antioxidant activity.

CONCLUSION

In conclusion, our findings showed that A.P.A.E of M. maroccana (A.P.A.E MM) possesses significant antihyperglycemic and hypoglycemic activities.

Comprehensive chemical analysis of Zhenshu Tiaozhi formula and its effect on ameliorating glucolipid metabolic disorders in diabetic rats

The present study aims to reveal the compositions of Zhenshu TiaoZhi formula (FTZ) comprehensively, and investigate whether FTZ ameliorate glucolipid metabolism disorders in diabetic rats with the involvement of glucocorticoids in peripheral insulin-sensitive tissues. The fingerprint was established based on 11 batches of FTZ samples and chemical compostions of FTZ were identified by ultra performance liquid chromatography-time of flight/mass spectrometry (UPLC-TOF/MS). High-fat diet (HFD) and streptozotocin (STZ) induced diabetic rats were orally administrated with 3 and 6 g/kg body weight of FTZ for 8 weeks. Indices of glucolipid metabolism, including fasting blood glucose (FBG), fasting insulin, insulin resistance index (IRI) and blood lipids were evaluated after treatment of FTZ. The levels of HPA axis hormones were examined. Reverse transcription-polymerase chain reaction (RT-PCR) was adopted to investigate the relative mRNA expressions of 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) and glucolipid metabolic indicators. A reference fingerprint was established and 93 compounds of FTZ were tentatively identified. In vivo, FTZ treatment exerted antidiabetic and antidyslipidemic effects while decreased the level of corticotropin releasing hormone (CRH). 11β-HSD1 mRNA showed similar trajectory in both liver, adipose and skeletal muscle tissues, which was up-regulated in diabetic group and ameliorated in FTZ groups. Furthermore, the expressions of glucose-6-phosphatase (G6Pase), phosphoenolpyruvate carboxykinase (PEPCK) and adipose triglyceride lipase (ATGL) were down-regulated in liver and skeletal muscle. These results elucidated the compositions of FTZ comprehensively and indicated its effect on ameliorating glucolipid metabolism of diabetic rats involved hypothalamus-pituitary-adrenal (HPA) axis homeostasis. Down-regulating 11β-HSD1 in insulin-sensitive tissues might be a potential mechanism of FTZ in treating type 2 diabetes mellitus (T2DM).

Jaceosidin Ameliorates Insulin Resistance and Kidney Dysfunction by Enhancing Insulin Receptor Signaling and the Antioxidant Defense System in Type 2 Diabetic Mice

Emerging evidence has shown that flavonoids extracted from Artemisia have beneficial effects on metabolic disorders. However, whether and how jaceosidin ameliorates insulin resistance and diabetic nephropathy in type 2 diabetes mellitus is largely unknown. For 8 weeks, db/db diabetic mice were fed with or without jaceosidin. Oral jaceosidin supplementation reduced fasting blood glucose levels and insulin resistance through the upregulation of insulin receptor downstream pathways in the liver and skeletal muscles. While jaceosidin did not noticeably alter kidney filtration function, this dietary intervention contributed to attenuating the accumulation of advanced glycation end products in diabetic kidneys. The levels of VEGF-a (vascular endothelial growth factor-a) proteins in the diabetic kidneys were markedly diminished by jaceosidin treatments, which increased the expression and activity of Cu (copper) and Zn-SOD (zinc-superoxide dismutase). Therefore, it is suggested that jaceosidin supplementation elicits antidiabetic effects and treats diabetic nephropathy by augmenting insulin signaling, suppressing fibrosis, and enhancing antioxidant activity.

Puerarin ameliorates hyperglycemia in HFD diabetic mice by promoting β-cell neogenesis via GLP-1R signaling activation

BACKGROUND

Diabetes is characterized by β-cell loss and dysfunction. A strategy for diabetes treatment is to promote new β-cell formation. Puerarin is an isoflavone from the root of Pueraria lobata (Willd.) Ohwi. Our previous study demonstrated puerarin could ameliorate hyperglycemia in diabetic mice. However, related mechanisms and potential roles of puerarin in β-cell neogenesis have not been elucidated.

PURPOSE

The present study aims to investigate whether anti-diabetic effect of puerarin is dependent on promoting β-cell neogenesis via GLP-1R signaling activation.

METHODS

A high-fat diet (HFD) induced diabetic mouse model was applied to investigate effects of puerarin in vivo, exendin-4 (GLP-1R agonist) and metformin were used as positive controls. Moreover, related mechanisms and GLP-1R downstream signal transduction were explored in isolated cultured mouse pancreatic ductal cells.

RESULTS

Puerarin improved glucose homeostasis in HFD diabetic mice significantly. Markers of new β-cell formation (insulin, PDX1 and Ngn3) were observed in pancreatic ducts of HFD mice treated by puerarin. Of note, efficacy of puerarin in vivo was suppressed by GLP-1R antagonist exendin9-39, but enhanced by exendin-4 respectively. In cultured mouse pancreatic ductal cells, puerarin induced expressions of insulin and PDX1, upregulated GLP-1R expression and activated β-catenin and STAT3 subsequently. Expressions of insulin and PDX1 in ductal cells could be blocked by exendin9-39, or β-catenin inhibitor ICG001, or JAK2 inhibitor AG490.

CONCLUSION

These data clarified puerarin ameliorated hyperglycemia of HFD mice via a novel mechanism involved promoting β-cell neogenesis. Our finding highlights the potential value of puerarin developing as an anti-diabetic agent.

Ethnopharmacological review of medicinal plants used to manage diabetes in Morocco

Diabetes is a chronic metabolic disorder which affects millions of people every year. If diabetes is not controlled, it can cause serious damage and a number of health complications. The aim of this paper was to review published ethnobotanical and ethnopharmacological evidences of Moroccan plants with antidiabetic potentials. Publications describing the medicinal plants used for the treatment of diabetes in Morocco were searched from the databases, including Google Scholar, Elsevier, Medline, Web of Science, SCOPUS and Pubmed. Other literature source was also used including books and theses available in library. About 750 literature references were studied, and only 240 research publications based on data from different Moroccan provinces published until June 2019 were included in this review. In total, 255 plants species belonging to 70 families were reported. Compositae and Lamiaceae were mentioned as the most represented families. The frequently used plant species in the dwellers of most regions of Morocco are Trigonella foenum-graecum, Artemesia herba-alba, Nigella sativa, Olea europaea, Allium cepa and Marrubium vulgare. This review provides useful information and current scientific knowledge on the medicinal plants used to manage diabetes in Morocco. Medicinal plants reported should be submitted to chemical, pharmacological and clinical studies to identify pharmacologically active metabolites and to confirm their antidiabetic activity.

Pharmacological potential of the combination of Salvia miltiorrhiza (Danshen) and Carthamus tinctorius (Honghua) for diabetes mellitus and its cardiovascular complications

Metabolic syndrome, such as diabetes mellitus, obesity, atherosclerosis, and high blood pressure (HBP), are closely linked pathophysiologically. However, current monotherapies for metabolic syndrome fail to target the multifactorial pathology via multiple mechanisms, as well as resolving the dysfunctionality of the cells and organs of the body. We aimed to provide a comprehensive and up-to-date review of the pharmacological advances, therapeutic potential, and phytochemistry of Salvia miltiorrhiza, Carthamus tinctorius, and Danhong injection (DHI). We discussed the molecular mechanisms of the bioactive constituents relating to diabetes mellitus and metabolic disease for further research and drug development. Interestingly, Salvia miltiorrhiza, Carthamus tinctorius, and DHI have anti-inflammatory, anti-glycemic, anti-thrombotic, and anti-cancer properties; and they mainly act by targeting the dysfunctional vasculatures including the inflammatory components of the disease to provide vascular repair as well as resolving oxidative stress. The major bioactive chemical constituents of these plants include polyphenolic acids, diterpene compounds, carthamin, and hydroxysafflor yellow A. Treatment of diabetes mellitus and its associated cardiovascular complication requires a comprehensive approach involving the use of appropriate traditional Chinese medicine formula. Danshen, Honghua, and DHI target the multiple risk factors regulating the physiologic function of the body and restore normalcy, apart from the traditional advice on exercise and diet control as treatment options in a metabolic syndrome patient.

Effect of a polyherbal formulation in streptozotocin-induced diabetic nephropathy in wistar rats

OBJECTIVES:

Chronic kidney failure among people with diabetes mellitus (DM) is a burgeoning health problem that affects up to 25% of patients with type 2 DM. Current pharmacological treatment for diabetic nephropathy (DN) does not stop the attainment of renal complications. The intention of the current study was to explore the role of a polyherbal formulation (PHF) in diabetic-induced nephropathy in experimental animals.

MATERIALS AND METHODS:

Diabetic rats were grouped as follows and underwent the following treatment for about 16 weeks: Group I – normal rats – no treatment, Group II – DN rats – only vehicle (p.o), and Group III and IV – DN rats – PHF orally at 250 and 500 mg/kg, respectively. After the treatment, the animals were sacrificed, and lipid, renal function, and inflammatory markers were estimated. The observed microscopic changes in kidney were analyzed.

RESULTS:

Animals administered with PHF exhibited noteworthy decrease in triglycerides, total cholesterol, very low-density lipoprotein (LDL), LDL, serum creatinine, urinary protein, urinary albumin excretion rate, advanced glycation end products, type IV collagen excretion, interleukin-6, transforming growth factor-ß, and tumor necrosis factor-alpha and showed significant increase in high-density lipoprotein, urine volume, urinary urea, and urine creatinine. Histopathological examination established that administration of PHF prohibited kidney damage.

CONCLUSION:

Treatment with PHF showed beneficial effect on DN which may be due to the improvement of renal function parameters and hyperlipidemic and inflammatory mediators.

Analgesic Medicinal Plants in Shahrekord, Southwest of Iran: An Ethnobotanical Study

Background:

Identification of indigenous medicinal plants, including the gathering of information regarding the uses of these plants can help find out their traditional pharmacological activities and their benefits for the community’s healthcare system. In this study, an ethnobotanical investigation was conducted in Shahrekord city, southwest of Iran to indicate the ethnobotanical knowledge about analgesic medicinal plants in the region and the methods of using them.

Materials and Methods:

To this end, plant antioxidants and analgesic medicinal plants were identified. For this purpose, a questionnaire was used to obtain indigenous knowledge from traditional therapists in Shahrekord regarding pain relief using medicinal plants. This ethnobotanical study was conducted in 2018 with the participation of 29 traditional therapists of the region under purpose. Finally, the data drawn from the questionnaires were analyzed using the Excel software. The frequency of plants use was also calculated.

Results:

Our study showed that in Shahrekord, 23 species of medicinal plants are used to relieve pain. The highest frequency of use was obtained for Eugenia caryophylata (44%), followed by Alhagi maurorum (31%), Tribulus terrestris (27%), and angustifolia (24%). The Laminaceae family (7 species) was the most frequently used plant family for pain relief. The most frequently used plant organ to relieve the pain was flower (25%), followed by the stem (22%) and leaves (19%).

Conclusion:

Given the high importance of medicinal plants in Shahrekord, the results of this study and additional scientific investigations can help produce more effective and less harmful drugs from medicinal plants.

Effect of pomegranate seed oil supplementation on the GLUT-4 gene expression and glycemic control in obese people with type 2 diabetes: A randomized controlled clinical trial

Abnormality in glucose transporter type 4 (GLUT-4) function and insulin secretion are the main causes of type 2 diabetes mellitus (T2DM). Due to adverse effects of antidiabetic drugs, nowadays, nutraceuticals have been of much interest to investigators. The aim of the present study was to determine the effect of pomegranate seed oil (PSO) on the GLUT-4 gene expression and glycemic control in obese people with T2DM. This randomized clinical trial was conducted on 52 obese type 2 diabetic patients for 8 weeks in Tabriz, Iran, in 2018. Patients were divided into the intervention group (n = 26; who consumed daily three capsules containing 1 g PSO) and the placebo group (n = 26; the same amounts paraffin). GLUT-4 gene expression and glycemic indices were evaluated by standard methods. GLUT-4 gene expression was increased significantly in the PSO group. Within-group changes in fasting blood sugar (FBS) and quantitative insulin sensitivity check index were significant in the PSO group. After adjusting the age, gender, and baseline values, FBS was significantly decreased. Insulin concentration, HbA1C, HOMA-IR, and HOMA-β did not manifest significant changes. PSO increased the GLUT-4 gene expression in diabetic patients without any side effects. However, future clinical studies are needed to confirm the obtained results.

A review of the most important medicinal herbs affecting giardiasis

Infection due to the protozoa giardia is one of the most common parasitic infections in the world. Millions of people across the world acquire this infection each year. The most common clinical symptoms of giardiasis include abdominal pain, bloating and diarrhea, indigestion, epigastric pain, nausea, vomiting, and oily feces with bad smell. Drugs used for giardiasis lead to certain side effects, such as unpleasant taste in the mouth, gastrointestinal discomfort, nausea, headache and leukopenia. Considering the importance of giardiasis infection, it is essential to identify anti-parasitic herbal drugs to eliminate cystic and trophozoite types of this disease. Hence, this article is aimed to report the medicinal plants that are used in Iranian traditional medicine against giardiasis. The information in this review study was obtained from scientific articles indexed in databases such as ISI, PubMed, Scopus, SID, Magiran and Google Scholar that were retrieved using the search terms giardia, protozoa, herbs, extracts and essential oils. Medicinal plants such as Lavandula stoechas, Ferula assa-foetida, Tanacetum parthenium, Allium paradoxum, Chenopodium botrys, Carum copticum, Allium sativum, Artemisia annua, Allium ascalonicum, ZizIphora clinopodioides, Zataria multiflorahad, Eucalyptus globulus, Lippia beriandievi, Punica granatum are among the most important herbs used in Iranian herbal medicine as anti-giardiasis agents. These herbs are good candidates to produce natural and effective drugs for giardia.

Chia Seed (Salvia hispanica L.) as a Source of Proteins and Bioactive Peptides with Health Benefits: A Review

The consumption of chia seed (Salvia hispanica L.) has increased in recent years due its high content of omega-3 fatty acids and dietary fiber. This seed also has a high concentration of proteins and essential amino acids, becoming a promising source of bioactive peptides. The objective of this review was to identify the composition and the beneficial effects of chia seeds (S. hispanica L.), their proteins, peptides, and their potential impact on human health. The UniProt database was used to identify the chia proteins and their amino acid sequences. The BIOPEP database was used to analyze the peptides's bioactive potential. A total of 20 proteins were cataloged in chia seed, 12 of those were involved in the regular metabolic processes of the plant cells. However, eight proteins were specifically related to production and storage of plant lipids, thus explaining the high concentration of lipids in chia seeds (around 30%), especially omega-3 fatty acids (around 20%). The analyses of amino acid sequences showed peptides with bioactive potential, including dipeptidyl peptidase-IV inhibitors, angiotensin-converting enzyme inhibitors, and antioxidant capacity. These results correlated with the main health benefits of whole chia seed in humans such as antioxidant capacity, and hypotensive, hypoglycemic, and anticholesterolemic effects. Such relation can be associated with chia protein and peptide compositions and therefore needs further investigation in vitro and in vivo.

Phytochemical Profiles and Antibacterial Activities of Hydroalcoholic Extracts of Origanum vulgare and Hypericum perforatum and Carvacrol and Hypericin as a Promising Anti-Staphylococcus aureus

OBJECTIVES

Staphylococcus aureus, a Gram-positive bacteria, is ranked second among the causes of hospital infections and is one of the three main causes of food poisoning. In recent times, the spread of antibiotic resistance in S. aureus has become very worrisome. Therefore, research for new effective drugs is important. The present study aims to investigate the phytochemical profiles and antibacterial effects of hydroalcoholic extracts of Origanum vulgare (Lamiaceae family) and Hypericum perforatum (Clusiaceae family) and their active compounds on S. aureus (ATCC 12600) in vitro.

METHODS

The identification of phytochemical compounds in both plants was performed by Highperformance liquid chromatography (HPLC), headspace-solid-phase microextraction (HS-SPME) and Fourier-transform infrared spectroscopy (FTIR). To investigate microbial susceptibility, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and disc diffusion method (DAD) were used. Finally, the results of the study were compared with methicillin.

RESULTS

Of the 42 combinations of O. vulgare, carvacrol (48%) and of the 38 combinations of H. perforatum, hypericin (46.2%) were the most abundant. The MIC, MBC and DAD of O. vulgare and H. perforatum, carvacrol, hypericin and methicillin were 625, 625, 312.5, 78.12 and 384 µg/mL, 10000, 10000, 2500, 2500 and 384 µg/mL, and 15.66 ± 4.49, 12.66 ± 0.47 and 22 ± 0.81 mm, respectively.

CONCLUSION

Due to the significant effects of O. vulgare and H. perforatum and their active components against S. aureus, it is expected that in the future, hypericin, carvacrol and their derivatives can be used as effective antibacterial agents against S. aureus.