A Mechanistic Review on Medicinal Plants Used for Diabetes Mellitus in Traditional Persian Medicine

Plant-Based Diets and Phytochemicals in the Management of Diabetes Mellitus and Prevention of Its Complications: A Review

Diabetes mellitus (DM) is currently regarded as a global public health crisis for which lifelong treatment with conventional drugs presents limitations in terms of side effects, accessibility, and cost. Type 2 diabetes (T2DM), usually associated with obesity, is characterized by elevated blood glucose levels, hyperlipidemia, chronic inflammation, impaired β-cell function, and insulin resistance. If left untreated or when poorly controlled, DM increases the risk of vascular complications such as hypertension, nephropathy, neuropathy, and retinopathy, which can be severely debilitating or life-threatening. Plant-based foods represent a promising natural approach for the management of T2DM due to the vast array of phytochemicals they contain. Numerous epidemiological studies have highlighted the importance of a diet rich in plant-based foods (vegetables, fruits, spices, and condiments) in the prevention and management of DM. Unlike conventional medications, such natural products are widely accessible, affordable, and generally free from adverse effects. Integrating plant-derived foods into the daily diet not only helps control the hyperglycemia observed in DM but also supports weight management in obese individuals and has broad health benefits. In this review, we provide an overview of the pathogenesis and current therapeutic management of DM, with a particular focus on the promising potential of plant-based foods.

New insights into anti-diabetes effects and molecular mechanisms of dietary saponins

Diabetes mellitus (DM) is a long-term metabolic disorder that manifests as chronic hyperglycemia and impaired insulin, bringing a heavy load on the global health care system. Considering the inevitable side effects of conventional anti-diabetic drugs, saponins-rich natural products exert promising therapeutic properties to serve as safer and more cost-effective alternatives for DM management. Herein, this review systematically summarized the research progress on the anti-diabetic properties of dietary saponins and their underlying molecular mechanisms in the past 20 years. Dietary saponins possessed the multidirectional anti-diabetic capabilities by concurrent regulation of various signaling pathways, such as IRS-1/PI3K/Akt, AMPK, Nrf2/ARE, NF-κB-NLRP3, SREBP-1c, and PPARγ, in liver, pancreas, gut, and skeletal muscle. However, the industrialization and commercialization of dietary saponin-based drugs are confronted with a significant challenge due to the low bioavailability and lack of the standardization. Hence, in-depth evaluations in pharmacological profile, function-structure interaction, drug-signal pathway interrelation are essential for developing dietary saponins-based anti-diabetic treatments in the future.

Naturally-occurring carboxylic acids from traditional antidiabetic plants as potential pancreatic islet FABP3 inhibitors. A molecular docking-aided study

The antidiabetic action of traditional plants is mostly attributed to their antioxidant and anti-inflammatory properties. These plants are still having some secrets, making them an attractive source that allows for investigating new drugs or uncovering precise pharmacologic antidiabetic functions of their constituents. In diabetes, which is a lipid disease, long-term exposure of pancreatic islet beta cells to fatty acids (FAs) increases basal insulin release, reduces glucose-stimulated insulin secretion, causes islet beta cell inflammation, failure and apoptosis. Pancreatic islet beta cells express fatty acid binding protein 3 (FABP3) that receives long-chain FAs and traffics them throughout different cellular compartments to be metabolized and render their effects. Inhibition of this FABP3 may retard FA metabolism and protect islet beta cells. Since FAs interact with FABPs by their carboxylic group, some traditionally-known antidiabetic plants were reviewed in the present study, searching for their components that have common features of FABP ligands, namely carboxylic group and hydrophobic tail. Many of these carboxylic acids were computationally introduced into the ligand-binding pocket of FABP3 and some of them exhibited FABP3 ligand possibilities. Among others, the naturally occurring ferulic, cleomaldeic, caffeic, sinapic, hydroxycinnamic, 4-p-coumaroylquinic, quinoline-2-carboxylic, chlorogenic, 6-hydroxykynurenic, and rosmarinic acids in many plants are promising candidates for being FABP3-specific inhibitors. The study shed light on repurposing these phyto-carboxylic acids to function as FABP inhibitors. However, more in-depth biological and pharmacological studies to broaden the understanding of this function are needed.

A systematic analysis of anti-diabetic medicinal plants from cells to clinical trials

Background

Diabetes is one of the fastest-growing health emergencies of the 21st century, placing a severe economic burden on many countries. Current management approaches have improved diabetic care, but several limitations still exist, such as decreased efficacy, adverse effects, and the high cost of treatment, particularly for developing nations. There is, therefore, a need for more cost-effective therapies for diabetes management. The evidence-based application of phytochemicals from plants in the management of diseases is gaining traction.

Methodology

Various plants and plant parts have been investigated as antidiabetic agents. This review sought to collate and discuss published data on the cellular and molecular effects of medicinal plants and phytochemicals on insulin signaling pathways to better understand the current trend in using plant products in the management of diabetes. Furthermore, we explored available information on medicinal plants that consistently produced hypoglycemic effects from isolated cells to animal studies and clinical trials.

Results

There is substantial literature describing the effects of a range of plant extracts on insulin action and insulin signaling, revealing a depth in knowledge of molecular detail. Our exploration also reveals effective antidiabetic actions in animal studies, and clear translational potential evidenced by clinical trials.

Conclusion

We suggest that this area of research should be further exploited in the search for novel therapeutics for diabetes.

Endoplasmic reticulum as a therapeutic target in type 2 diabetes: Role of phytochemicals

Type 2 diabetes mellitus (T2DM) is a metabolic disorders characterized by insulin resistance and β-cell dysfunction with an increasing worldwide incidence. Several studies have revealed that long-term glucotoxicity results in β-cell failure and death through induction of endoplasmic reticulum (ER) stress. Owing to the chronic progression of T2DM and the low effectiveness of antidiabetic drugs in long-term use, medicinal plants and their secondary metabolites seem to be the promising alternatives. Here we have provided a comprehensive review regarding the role of phytochemicals to alleviate ER stress in T2DM. Ginsenoside compound K, baicalein, quercetin, isopulegol, kaempferol, liquiritigenin, aspalathin, and tyrosol have demonstrated remarkable improvement of T2DM via modulation of ER stress. Arctigenin and total glycosides of peony have been shown to be effective in the treatment of diabetic retinopathy through modulation of ER stress. The effectiveness of grape seed proanthocyanidins and wolfberry is also shown in the relief of diabetic neuropathy and retinopathy. Resveratrol is involved in the prevention of atherosclerosis via ER stress modulation. Taken together, the data described herein revealed the capability of herbal constituents to prevent different complications of T2DM via a decrease in ER stress which open new doors to the treatment of diabetes.

An assessment of the physicochemical characteristics and essential oil composition of Mentha longifolia (L.) Huds. exposed to different salt stress conditions

Salt stress adversely influences growth, development, and productivity in plants, resulting in a limitation on agriculture production worldwide. Therefore, this study aimed to investigate the effect of four different salts, i.e., NaCl, KCl, MgSO₄, and CaCl₂, applied at various concentrations of 0, 12.5, 25, 50, and 100 mM on the physico-chemical properties and essential oil composition of M. longifolia. After 45 days of transplantation, the plants were irrigated at different salinities at 4-day intervals for 60 days. The resulting data revealed a significant reduction in plant height, number of branches, biomass, chlorophyll content, and relative water content with rising concentrations of NaCl, KCl, and CaCl₂. However, MgSO₄ poses fewer toxic effects than other salts. Proline concentration, electrolyte leakage, and DPPH inhibition (%) increase with increasing salt concentrations. At lower-level salt conditions, we had a higher essential oil yield, and GC-MS analysis reported 36 compounds in which (-)-carvone and D-limonene covered the most area by 22%-50% and 45%-74%, respectively. The expression analyzed by qRT-PCR of synthetic Limonene (LS) and Carvone (ISPD) synthetic genes has synergistic and antagonistic relationships in response to salt treatments. To conclude, it can be said that lower levels of salt enhanced the production of essential oil in M. longifolia, which may provide future benefits commercially and medicinally. In addition to this, salt stress also resulted in the emergence of novel compounds in essential oils, for which future strategies are needed to identify the importance of these compounds in M. longifolia.

In Vitro Antidiabetic, Antioxidant, and Prebiotic Activities of the Chemical Compounds Isolated from Guizotia abyssinica

India and Ethiopia employ Guizotia abyssinica (niger plant) as a source of edible vegetable oil. Previous studies have documented the niger plant's antioxidant properties and dietary benefits. Here, G. abyssinica extract was obtained and ten known bioactive components (1-10) were isolated. The antioxidant, antidiabetic, and prebiotic properties of whole extract and isolated components of niger and the plant's ability to cooperate symbiotically with probiotic strains were examined. Compound 10, myricetin-3-O-L-rhamnoside, had the highest antioxidant capacity measured in the 2,2-diphenylpicrylhydrazyl (DPPH, 4629.76 ± 6.02 µmol Trolox equivalent/g compound) and ferric-reducing antioxidant power (FRAP, 2667.62 ± 7.5 mol Trolox equivalent/g compound) assays. The lowest α-amylase and glycogen phosphorylase activities and glucose diffusion were obtained with whole G. abyssinica extracts, whereas compounds 8-10 had moderate inhibitory effects. G. abyssinica extract also induced the highest glucose absorption by yeast cells in the presence of 5 mM of glucose. Moreover, Lactobacillus plantarum and L. rhamnosus incubated with β-sitosterol 3-O-D-glucoside (compound 7) showed the highest prebiotic activity score. The levels of L-(+)-lactic acid isomer in the probiotic strains were the highest in presence of the whole extract and decreased progressively in the presence of flavonoid glycosides (compounds 8-10) and β-sitosterol 3-O-D-glucoside. The enzymatic profile of the probiotic strains was unaffected by the niger extract and compounds 7-10. The findings revealed that the biological activities of G. abyssinica extract are mediated by the compounds 1-10, and it may be considered as a promising plant for the treatment of diabetes mellitus.

Evaluation of anti-inflammatory effects of leaf and seed extracts of Plantago major on acetic acid-induced ulcerative colitis in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Plantago major (P. major) has traditionally been used in Iranian Persian medicine to treat gastrointestinal ulcers and bleeding.

RESEARCH OBJECTIVES

This study aimed to investigate the anti-inflammatory effects of the leaf and seed extracts of P. major in rats with acetic acid-induced ulcerative colitis (UC).

MATERIALS AND METHODS

To this end, 49 rats were randomly divided into seven groups. UC was induced in all groups but the control (vehicle) group using a single intra-rectal administration of 2 ml of 4% acetic acid. Other groups received daily intraperitoneal (i.p.) injections of the seed extract of P. major (400 mg/kg and 700 mg/kg), the leaf extract of P. major (400 mg/kg and 700 mg/kg), and sulfasalazine (400 mg/kg) for seven consecutive days, respectively. The rats' rectum was surgically removed and evaluated for macroscopic and microscopic damage. The tissue levels of oxidative stress and inflammatory markers were measured using the ELISA method.

RESULTS

The high-dose leaf extract significantly decreased ulcer index and histopathologic damage as well as the tissue levels of IL-6, TNF-α, PGE2, IL-1β, MPO, and MDA compared to the damage group. The low-dose leaf extract also significantly reduced the levels of some markers. The seed extract in the two used doses caused a modest decrease in the histopathological damages and ulcer index.

CONCLUSIONS

P. major leaf extract effectively reduces inflammation and mucosal damage in rats with UC, especially when administered in high doses. P. major seed extract has minimal protective effects on UC.

Extraction of Bioactive Compounds for Antioxidant, Antimicrobial, and Antidiabetic Applications

This study was designed to check the potential of secondary metabolites of the selected plants; Citrullus colocynthis, Solanum nigrum, Solanum surattense, Calotropis procera, Agave americana, and Anagallis arvensis for antioxidant, antibacterial, antifungal, and antidiabetic agents. Plant material was soaked in ethanol/methanol to get the crude extract, which was further partitioned via solvent extraction technique. GCMS and FTIR analytical techniques were applied to check the compounds responsible for causing antioxidant, antimicrobial, and antidiabetic activities. It was concluded that about 80% of studied extracts/fractions were active against α-amylase, ranging from 43 to 96%. The highest activity (96.63%) was exhibited by butanol fractions of A. arvensis while the least response (43.65%) was shown by the aqueous fraction of C. colocynthis and the methanol fraction of fruit of S. surattense. The highest antioxidant activity was shown by the ethyl acetate fraction of Anagallis arvensis (78.1%), while aqueous as well as n-hexane fractions are the least active throughout the assay. Results showed that all tested plants can be an excellent source of natural products with potential antimicrobial, antioxidant, and antidiabetic potential. The biological response of these species is depicted as a good therapeutic agent, and, in the future, it can be encapsulated for drug discovery.

Promising influences of gingerols against metabolic syndrome: A mechanistic review

Metabolic syndrome is an inflammatory disorder characterized by diabetes, obesity, atherosclerosis, and hypertension. Globally, this disease is increasing, especially in developed countries. Supposedly, herbal treatments for this disease likely have fewer adverse effects than chemical medications. Thus, they can be suitable options among the available chemical treatments. Ginger has been used as a spice and medicinal plant in traditional medicine and cooking. This herbal compound and its derivatives, such as 6-gingerol, have shown promising effects on various molecular aspects of metabolic syndrome. In this study, we reviewed and discussed the significant impacts of gingerol, a derivative of ginger, on metabolic syndrome through various mechanisms. The benefits of 6-gingerol include its effects on AMP-activated protein kinase (AMPK), which prevent diabetes, lipid regulating effect (peroxisome proliferator-activated receptors, PPARs), as well as its effects on enzymes and proteins preventing hyperlipidemia caused by a high-fat diet. In addition, 6-gingerol has anti-atherosclerosis and anti-hypertension effects through several molecular mechanisms. The current review will discuss various effects of 6-gingerol on molecular pathways involved in diabetes, obesity, atherosclerosis, and hypertension as characterizing features of metabolic syndrome and suggests that 6-gingerol can be a potential treatment agent for metabolic syndrome and shed light on a higher requirement for more pre-clinical and clinical investigations.

Nutritional Profiling, Phytochemical Composition and Antidiabetic Potential of Taraxacum officinale, an Underutilized Herb

Taraxacum officinale (T. officinale), a wild vegetable with a number of health claims, has been mostly ignored and unexplored. The study aims to compare the nutritional, phytochemical as well as antidiabetic potential of fresh as well as shade-dried leaves of T. officinale, in order to recommend its best form as a dietary antidiabetic product. The results revealed that as compared to fresh leaves, the shade-dried leaves, in addition to possessing higher levels of carbohydrates, crude protein, crude fat, crude fiber, etc., also contain appreciable amounts of total phenols (5833.12 ± 4.222 mg/100), total flavonoids (188.84 ± 0.019 mg/100 g), ascorbic acid (34.70 ± 0.026 mg/100 g), β-carotene (3.88 ± 1.473 mg/100 g) and total chlorophyll (239.51 ± 0.015 mg/100 g) antioxidants. The study revealed the presence of medicinally important antidiabetic flavonoid quercetin present in T. officinale leaves. Among the three solvent systems used, the aqueous extract of shade-dried T. officinale leaves comparatively demonstrated potent antidiabetic activity under in vitro conditions in a dose-dependent manner via targeting α-amylase and α-glucosidase, the two potent enzymes of carbohydrate metabolism. Therefore, in addition to being a nutritious herb, the shade-dried leaves of T. officinale have great potential to suppress post-prandial glucose rise and can be better exploited through clinical trials to be used as a dietary intervention for better management of diabetes.

Medicinal Exploitation of <i>Coriandrum sativum</i> L

<i>Coriandrum sativum</i> L. is a potential herb that is commonly known as coriander or Chinese parsley is being possessed to have various medicinal properties. Almost all the parts of the herb have been examined for its effectiveness in various human diseases such as migraine, hypertension and diabetes specifically. The diseases considered for the current review are migraine, hypertension and diabetes, which are highly prevalent as well as major co-morbidity for other clinical conditions. The extracts of different parts of <i>C. sativum</i> have been identified to have roles in treating and managing migraine, hypertension and diabetes. The genetic inter-relationship of <i>C. sativum</i> with the diseases are also being discussed in this review. The literature surf was done in platforms for the journals life science and medicinal research using the keywords <i>C. sativum</i>, herbal medicine, anti-diabetic, anti-hypertensive, migraine, genetics etc. The results obtained through the clinical trials conducted by various researchers globally were satisfactorily acceptable in treating these diseases along with some other diseases to a certain extent, whereas the genetic studies were insignificant. Henceforth, the current literature review highlights the medicinal exploitation of <i>C. sativum</i> in accordance with the treatment and management of migraine, hypertension and diabetes.

Targeting the PI3K/Akt signaling pathway in pancreatic β-cells to enhance their survival and function: An emerging therapeutic strategy for type 1 diabetes

Type 1 diabetes (T1D) is an autoimmune disease caused by the destruction of the insulin-producing β-cells within the pancreas. Islet transplantation represents one cure; however, during islet preparation and post transplantation significant amounts of β-cell death occur. Therefore, prevention and cure of T1D is dependent upon the preservation of β-cell function and the prevention of β-cell death. Phosphoinositide 3-kinase (PI3K)/Akt signaling represents a promising therapeutic target for T1D due to its pronounced effects on cellular survival, proliferation, and metabolism. A growing amount of evidence indicates that PI3K/Akt signaling is a critical determinant of β-cell mass and function. Modulation of the PI3K/Akt pathway, directly (via the use of highly specific protein and peptide-based biologics, excretory/secretory products of parasitic worms, and complex constituents of plant extracts) or indirectly (through microRNA interactions) can regulate the β-cell processes to ultimately determine the fate of β-cell mass. An important consideration is the identification of the specific PI3K/Akt pathway modulators that enhance β-cell function and prevent β-cell death without inducing excessive β-cell proliferation, which may carry carcinogenic side effects. Among potential PI3K/Akt pathway agonists, we have identified a novel parasite-derived protein, termed FhHDM-1 (Fasciola hepatica helminth defense molecule 1), which efficiently stimulates the PI3K/Akt pathway in β-cells to enhance function and prevent death without concomitantly inducing proliferation unlike several other identified stimulators of PI3K/Akt signaling . As such, FhHDM-1 will inform the design of biologics aimed at targeting the PI3K/Akt pathway to prevent/ameliorate not only T1D but also T2D, which is now widely recognized as an inflammatory disease characterized by β-cell dysfunction and death. This review will explore the modulation of the PI3K/Akt signaling pathway as a novel strategy to enhance β-cell function and survival.

UHPLC-ESI-QTOF-MS2 analysis of Acacia pennata extract and its effects on glycemic indices, lipid profile, pancreatic and hepatorenal alterations in nicotinamide/streptozotocin-induced diabetic rats

Diabetes mellitus (DM) is a chronic disorder associated with severe metabolic derangement and comorbidities. The constant increase in the global population of diabetic patients coupled with some prevailing side effects associated with synthetic antidiabetic drugs has necessitated the urgent need for the search for alternative antidiabetic regimens. This study investigated the antidiabetic, antioxidant, and pancreatic protective effects of the Acacia pennata extract (APE) against nicotinamide/streptozotocin induced DM in rats. The antidiabetic activity of APE was evaluated and investigated at doses of 100 and 400 mg/kg body weight, while metformin (150 mg/kg bw) was used as a standard drug. APE markedly decreased blood glucose level, homeostatic model assessment for insulin resistance, serum total cholesterol, triglycerides, low‐density lipoprotein, blood urea nitrogen, creatinine, alanine transaminase, aspartate transaminase, and alanine phosphatase levels. Additionally, treatment with APE increased the body weight, serum insulin concentration, and high‐density lipoprotein. Moreover, activities of pancreatic superoxide dismutase, catalase, and glutathione peroxidase were increased, while the altered pancreatic architecture in the histopathological examination was notably restored in the treated rats. Ultra‐high performance liquid chromatography combined with electrospray ionization quadrupole time‐of‐flight mass spectrometry (UHPLC‐ESI‐QTOF‐MS) analysis of APE showcases the prevailing presence of polyphenolic compounds. Conclusively, this study showed the beneficial effects of the Acacia pennata in controlling metabolic derangement, pancreatic and hepatorenal dysfunction in diabetic rats.

The prevalence of using complementary and alternative medicine products among patients with pressure ulcer

Background

The use of complementary and alternative medicine (CAM) therapies has increased in recent years throughout the world and in Iran. Nonetheless, there are limited data about the prevalence of their use. This study aimed to assess the prevalence of using CAM therapies among patients with pressure ulcer (PU).

Methods

This cross-sectional study was conducted in 2019–2020. Participants were 299 patients with PU conveniently selected from wound clinics and healthcare settings in Shiraz, Iran. A demographic questionnaire and the International Questionnaire to Measure Use of CAM were used for data collection. The data were analyzed using the SPSS software (v. 22.0).

Results

All 299 participants completed the study. Their mean age was 59.56 ± 18.76 years. The most common CAM therapies used for PU management were herbal products (100%), vitamin supplementation therapy (45.2%), spiritual therapies (21.7%), wet cupping therapy (16.4%), leech therapy (9.4%), acupuncture (1.7%), dry cupping therapy (1.3%), and massage therapy (1.3%). The most common herbal product used for PU management was Pistacia atlantica gum either alone or in combination with other herbal products (15.5%). The use of CAM therapies had significant relationship with participants’ age, underlying conditions, and PU stage (P < 0.05) and the most significant predictor of using herbal products for PU was educational level (P < 0.05, OR = 5.098).

Conclusions

The use of CAM therapies, particularly herbal products, for PU management is high in Iran. Quality public education and close professional supervision are needed for the safe use of these products.

Metabolites of Prickly Rose: Chemodiversity and Digestive-Enzyme-Inhibiting Potential of Rosa acicularis and the Main Ellagitannin Rugosin D

Prickly rose (Rosaacicularis Lindl.) is the most distributed rose species in the Northern Hemisphere, used by indigenous people for various food purposes. The lack of detailed information about the chemical composition of R. acicularis has led us to study the phytochemical composition and metabolic profile of prickly rose extracts using chromatographic techniques. Many groups of phenolic and non-phenolic compounds were quantified in the leaves, flowers, roots and fruits of R. acicularis. Phenolic compounds were the dominant phytochemicals in the aerial parts and roots of R. acicularis. A precise study by high-performance liquid chromatography with photodiode array detection and electrospray ionization triple quadrupole mass spectrometric detection showed the presence of 123 compounds, among which ellagic acid derivatives, ellagitannins, gallotannins, catechins, catechin oligomers, hydroxycinnamates and flavonoid glycosides of kaempferol, quercetin and dihydroquercetin were all identified for the first time. The most abundant phenolic compounds were ellagitannins and flavonoid glycosides, with a maximal content of 70.04 mg/g in leaves and 66.72 mg/g in flowers, respectively, indicating the great ability of R. acicularis organs to accumulate phenolic compounds. By applying a standardized static, simulated gastrointestinal digestion method, we found the inhibitory potential of the leaf extract against digestive α-amylases. A pancreatic α-amylase activity-inhibiting assay coupled with HPLC microfractionation demonstrated high inhibition of enzyme activity by ellagitannin rugosin D, which was later confirmed by a microplate reaction with mammalian α-amylases and the simulated digestion method. This study clearly demonstrates that R. acicularis leaf extract and its main component, ellagitannin rugosin D, strongly inhibit digestive α-amylase, and may be a prospective antidiabetic agent.

Pleurotus tuber-regium inclusion in diet ameliorates dyslipidaemia in obese-type 2 diabetic rats

Background

Pleurotus tuber-regium (P.T) is an edible mushroom with abundant polysaccharides that has been used in traditional medicine to treat diabetes mellitus. This study investigated the hypoglycaemic potential and ameliorative activity of Pleurotus tuber-regium incorporated diet on diabetes induced dyslipidaemia.

Materials and methods

Thirty five (35) adult male wistar rats were randomly assigned to seven groups; Normal control, diabetic control, obese control, obese diabetic control, 10% PT, 20% PT, and Drug control. Type II DM was induced by placing the animals on high fat diet for a period of 10 weeks and a single intraperitoneal injection of streptozotocin (50 mg/kg/BW). P. T was incorporated into the feed and given to the animals for two weeks daily after the confirmation of diabetes.

Results

Treatment of the obese diabetic rats with P. T supplemented diet caused a decrease in the blood glucose level compared to the control groups. Increased organo-somatic ratio of the kidney and heart were markedly (p < 0.05) reduced following treatment (20% P.T). Furthermore, cholesterol, triglycerides, LDL-C and VLDL-C levels were reduced due to treatment accompanied by increased HDL-C in the liver. Histological evaluation of the liver, kidney, heart, and pancreas of the P. T treated groups were comparable to normal.

Conclusion

Incorporation of P. tuber-regium in diets could be effective in reversing dyslipidaemia in obese diabetic patients.

Antidiabetic effect of fucoxanthin extracted from Sargassum angustifolium on streptozotocin-nicotinamide-induced type 2 diabetic mice

This work aimed to study the antidiabetic effect of encapsulated fucoxanthin with porous starch (PS) in streptozotocin and nicotinamide-induced type 2 diabetic mice. Fucoxanthin was extracted and purified from Sargassum angustifolium and encapsulated in porous starch (PS). Diabetic mice groups were gavaged daily with fucoxanthin (400 mg/kg), either free or encapsulated into PS, and metformin (50 mg/kg) for three weeks. The results exhibited that the fucoxanthin and fucoxanthin-loaded PS markedly prevented the weight gain in treated groups (p < .05). Moreover, both free and encapsulated fucoxanthin could decrease the fasting blood glucose and increase the plasma insulin level similar to metformin (p < .05). In addition, total cholesterol, triglyceride, and low-density lipoprotein were lower in the treated groups. These results confirm antiobesity effect of fucoxanthin by regulating lipid profile parameters. Moreover, the histopathology evaluation of pancreatic tissue in diabetic mice exhibited that oral administration of metformin and fucoxanthin caused regeneration of pancreatic beta cells. This study revealed the healthy effect of seaweed pigment as a suitable bioactive compound which can be used in functional foods for natural diabetes therapy.

Untargeted Phytochemical Profile, Antioxidant Capacity and Enzyme Inhibitory Activity of Cultivated and Wild Lupin Seeds from Tunisia

Lupin seeds can represent a valuable source of phenolics and other antioxidant compounds. In this work, a comprehensive analysis of the phytochemical profile was performed on seeds from three Lupinus species, including one cultivar (Lupinus albus) and two wild accessions (Lupinus cossentinii and Lupinus luteus), collected from the northern region of Tunisia. Untargeted metabolomic profiling allowed to identify 249 compounds, with a great abundance of phenolics and alkaloids. In this regard, the species L. cossentinii showed the highest phenolic content, being 6.54 mg/g DW, followed by L. luteus (1.60 mg/g DW) and L. albus (1.14 mg/g DW). The in vitro antioxidant capacity measured by the ABTS assay on seed extracts ranged from 4.67 to 17.58 mg trolox equivalents (TE)/g, recording the highest values for L. albus and the lowest for L. luteus. The DPPH radical scavenging activity ranged from 0.39 to 3.50 mg TE/g. FRAP values varied between 4.11 and 5.75 mg TE/g. CUPRAC values for lupin seeds ranged from 7.20 to 8.95 mg TE/g, recording the highest for L. cossentinii. The results of phosphomolybdenum assay and metal chelation showed similarity between the three species of Lupinus. The acetylcholinesterase (AChE) inhibition activity was detected in each methanolic extract analyzed with similar results. Regarding the butyrylcholinesterase (BChE) enzyme, it was weakly inhibited by the Lupinus extracts; in particular, the highest activity values were recorded for L. albus (1.74 mg GALAE/g). Overall, our results showed that L. cossentinii was the most abundant source of polyphenols, consisting mainly in tyrosol equivalents (5.82 mg/g DW). Finally, significant correlations were outlined between the phenolic compounds and the in vitro biological activity measured, particularly when considering flavones, phenolic acids and lower-molecular-weight phenolics.

Cytotoxicity, Anti-diabetic, and hepato-protective potential of Ajuga bracteosa-conjugated silver nanoparticles in Balb/c mice

BACKGROUND

Ajuga bracteosa is a traditional herb used against various diseases.

OBJECTIVE

Current research aimed to investigate the anti-diabetic and hepato-protective effect of green synthesized silver nanoparticles (ABAgNPs) using Ajuga bracteosa aqueous extract (ABaqu).

METHODS

In vitro anti-diabetic and cytotoxic effects were carried out via α- glucosidase inhibition, brine shrimp lethality, and protein kinase inhibition assays. For in vivo screening of 200 mg/kg and 400 mg/kg of both ABAgNPs and ABaqu in alloxan-induced and CCl4-induced Swiss albino mice were used. Liver and kidney functional markers, hematology, and histopathological studies were carried out after 14 days of administration.

RESULTS

In vivo antidiabetic and anti-cancerous effects showed valuable anti-hyperglycemic and hepato-protective potential when mice were treated with ABaqu and ABAgNPs. A significant reduction in the blood glucose level was recorded when ABaqu and ABAgNPs were administrated orally compared to Glibenclamide treated group. Significant reduction in ALT, AST, ALP, urea, uric acid, and creatinine was recorded in ABaqu and ABAgNPs treated diabetic mice. The hepato-protective findings indicated that ALT, ALP, AST were elevated in CCl4-induced mice while declined in both ABAgNPs and ABaqu treated CCl4-induced mice. Histopathological examination revealed that ABAgNPs have hepato-protective activity.

CONCLUSION

It was concluded that ABAgNPs and ABaqu possessed strong anti-diabetic and hepato-protective phytoconstituents which could be used in the prevention of diseases.

In vitro and in vivo antidiabetic activity of Tamarix stricta Boiss.: Role of autophagy

ETHNOPHARMACOLOGICAL RELEVANCE

Type 2 diabetes mellitus (DM) is a complicated metabolic disorder with no definite treatment. Different species of the genus Tamarix (tamarisk) are used by local people to treat DM. Tamarix stricta Boiss. is an endemic species to Iran with several traditional therapeutic uses in Persian Medicine. This study aimed to assess the antidiabetic activity of T. stricta.

MATERIALS AND METHODS

Hydroethanolic extract of the plant was prepared and analyzed by High-performance liquid chromatography (HPLC). The protective effect of the extract was evaluated in streptozotocin (STZ)-induced toxicity and markers of autophagy in pancreatic RIN-5F cells. The effect of intragastric 10 or 20 mg/kg of the extract was compared with negative control (water) or positive control (metformin) treatment during four weeks of administration in high-fat diet + STZ-induced DM in Balb/c mice.

RESULTS

Results showed the presence of 8.436 mg of gallic acid in each gram of the extract. A significant cytoprotective effect was observed by T. stricta in STZ-induced toxicity in RIN-5F cells, partially due to the modulation of autophagy. Also, animals treated with the extract showed a significant improvement in glycemic and lipid profiles, liver function, and histopathologic features of pancreas and liver compared with the negative control.

CONCLUSION

T. stricta demonstrated beneficial effects in animal model of DM; though, further studies are recommended to confirm the clinical use of this plant in DM.

Anacardium humile St. Hil as a novel source of antioxidant, antiglycation and α-amylase inhibitors molecules with potential for management of oxidative stress and diabetes

ETHNOPHARMACOLOGICAL RELEVANCE

The substantial increase in diabetes cases worldwide has been a major public health problem, and the use of medicinal plants can be considered an interesting alternative to control the disease and its complications. Anacardium humile St. Hill. (Anacardiaceae) is a typical plant from the Brazilian savanna, popularly known for its antidiarrheal, expectorant, antidiabetic and anti-inflammatory properties, however, few studies have fully described its biological properties. This study aimed to investigate in vitro and ex vivo the antioxidant and antiglycation potential of A. humile ethanolic extract, its organic fractions and three isolated molecules (quercetin, catechin and gallic acid), their capacity to inhibit the glycolytic enzyme α-amylase, as well as their cytotoxic effects against RAW264.7 macrophages.

MATERIAL AND METHODS

The ethanolic extract of A. humile, its organic fractions and three isolated molecules (catechin, quercetin and gallic acid) were tested for their antioxidant (ORAC, FRAP and DPPH) and antiglycation (BSA/Fructose, BSA/Methylglyoxal, Arginine/Methylglyoxal and Lysine/Methylglyoxal) capacities, and also for its potential to inhibit the enzyme α-amylase. Additionally, bioactive compounds present in the A. humile leaves fractions were elucidated by an HPLC-ESIMS/MS analysis.

RESULTS

The analysis showed relevant antioxidant activity of DCM (1264.85 ± 76.90 μM Trolox eq/g ORAC; 216.71 ± 1.04 μM Trolox eq/g FRAP and 3.03 ± 0.08 IC₅₀ μg/mL IC₅₀ DPPH) and EtOAc (1300.11 ± 33.04 ORAC, 236.21 ± 23.86 FRAP and 3.03 ± 0.14 μg/mL IC₅₀ DPPH) fractions and also of the isolated molecules, mainly gallic acid (1291.19 ± 8.41 μM Trolox eq/g ORAC, 1103.52 ± 31.48 μM Trolox eq/g FRAP and 0.78 ± 0.11 μg/mL IC₅₀ DPPH). Concerning the antiglycation activity, all samples inhibited over 88% in the BSA-FRU method. In the BSA-MGO and ARG-MGO methods, the Hex, DCM, EtOAc fractions and the isolated molecule catechin stood out. However, in the LYS-MGO model, only the isolated molecules showed significant results. In α-amylase assay, all fractions, for exception Hex, presented notable inhibition capacity with low IC₅₀ values, especially DCM, EtOAc, ButOH and H₂O (IC₅₀ 0.56 ± 0.10, 0.84 ± 0.01, 0.74 ± 0.03 and 0.79 ± 0.06 μg/mL, respectively). Tests using hepatic tissue showed a notorious capacity of the DCM, AcOEt and ButOH fractions, as well as of the isolated molecules to inhibit lipid peroxidation and ROS production, and also to preserve thiol groups. Molecules of great antioxidant potential were found in our samples, such as kaempferol, quercetin, catechin, gallic acid and luteolin.

CONCLUSION

A. humile extract and its organic fractions showed promising antioxidant and antiglycation potential and a prominent capacity to inhibit the α-amylase enzyme. Hence, this study presents new results and stimulates further research to elucidate the biological properties of A. humile and its capacity to manage DM and its complications.

Exploring Phytotherapeutic Alternatives for Obesity, Insulin Resistance and Diabetes Mellitus

At present, the pathologic spectrum of obesity-insulin resistance (IR)-diabetes mellitus (DM) represents not only a pressing matter in public health but also a paramount object of study in biomedical research, as they constitute major risk factors for cardiovascular disease (CVD), and other chronic non-communicable diseases (NCD). Phytotherapy, the use of medicinal herbs (MH) with treatment purposes, offers a wide array of opportunities for innovation in the management of these disorders; mainly as pharmacological research on small molecules accumulates. Several MH has displayed varied mechanisms of action relevant to the pathogenesis of obesity, IR and DM, including immunological and endocrine modulation, reduction of inflammation and oxidative stress (OS), regulation of appetite, thermogenesis and energy homeostasis, sensitisation to insulin function and potentiation of insulin release, among many others. However, the clinical correlates of these molecular phenomena remain relatively uncertain, with only a handful of MH boasting convincing clinical evidence in this regard. This review comprises an exploration of currently available preclinical and clinical research on the role of MH in the management of obesity, IR, and DM.

Middle East Medicinal Plants in the Treatment of Diabetes: A Review

Diabetes is a global health problem, and the number of diabetic patients is in continuous rise. Conventional antidiabetic therapies are associated with high costs and limited efficiency. The use of traditional medicine and plant extracts to treat diabetes is gaining high popularity in many countries. Countries in the Middle East region have a long history of using herbal medicine to treat different diseases, including diabetes. In this review, we compiled and summarized all the in vivo and in vitro studies conducted for plants with potential antidiabetic activity in the Middle East region. Plants of the Asteraceae and Lamiaceae families are the most investigated. It is hoped that this review will contribute scientifically to evidence the ethnobotanical use of medicinal plants as antidiabetic agents. Work has to be done to define tagetes, mechanism of action and the compound responsible for activity. In addition, safety and pharmacokinetic parameters should be investigated.

Investigation of the Phytochemical Composition, Antioxidant Activity, and Methylglyoxal Trapping Effect of Galega officinalis L. Herb In Vitro

Galega officinalis L. has been known for centuries as an herbal medicine used to alleviate the symptoms of diabetes, but its comprehensive chemical composition and pharmacological activity are still insufficiently known. The current study involved the qualitative and quantitative phytochemical analysis and in vitro evaluation of the antioxidative and methylglyoxal (MGO) trapping properties of galega herb. Ultra high-performance liquid chromatography coupled with both the electrospray ionization mass spectrometer and diode-array detector (UHPLC-ESI-MS and UHPLC-DAD) were used to investigate the composition and evaluate the anti-MGO capability of extracts and their components. Hot water and aqueous methanol extracts, as well as individual compounds representing phytochemical groups, were also assessed for antioxidant activity using DPPH (2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl) and ABTS (2,2'-azino-bis(3-ethylbenz-thiazoline-6-sulfonic acid) assays. Quercetin and metformin were used as a positive control. We confirmed the presence of tricyclic quinazoline alkaloids, guanidines, flavonoids, and hydroxycinnamic acids (HCAs) in galega extracts. The polyphenolic fraction was dominated by mono-, di-, and triglycosylated flavonols, as well as monocaffeoylhexaric acids. The in vitro tests indicated which G. officinalis components exhibit beneficial antioxidative and MGO trapping effects. For galega extracts, flavonols, and HCAs, a potent antiradical activity was observed. The ability to trap MGO was noted for guanidines and flavonoids, whereas HCA esters and quinazoline alkaloids were ineffective. The formation of mono-MGO adducts of galegine, hydroxygalegine, and rutin in the examined water infusion was observed.

Secondary Metabolites in the Treatment of Diabetes Mellitus: A Paradigm Shift

Diabetes mellitus (DM) is a chronic, polygenic and non-infectious group of diseases that occurs due to insulin resistance or its low production by the pancreas and is also associated with lifelong damage, dysfunction and collapse of various organs. Management of diabetes is quite complex having many bodily and emotional complications and warrants efficient measures for prevention and control of the same. As per the estimates of the current and future diabetes prevalence, around 425 million people were diabetic in 2017 which is anticipated to rise up to 629 million by 2045. Various studies have vaguely proven the fact that several vitamins, minerals, botanicals and secondary metabolites demonstrate hypoglycemic activity in vivo as well as in vitro. Flavonoids, anthocyanin, catechin, lipoic acid, coumarin metabolites, etc. derived from herbs were found to elicit a significant influence on diabetes. However, the prescription of herbal compounds depend on various factors, including the degree of diabetes progression, comorbidities, feasibility, economics as well as their ADR profile. For instance, cinnamon could be a more favorable choice for diabetic hypertensive patients. Diabecon®, Glyoherb® and Diabeta Plus® are some of the herbal products that had been launched in the market for the favorable or adjuvant therapy of diabetes. Moreover, Aloe vera leaf gel extract demonstrates significant activity in diabetes. The goal of this review was to inscribe various classes of secondary metabolites, in particular those obtained from plants, and their role in the treatment of DM. Recent advancements in recognizing the markers which can be employed for identifying altered metabolic pathways, biomarker discovery, limitations, metabolic markers of drug potency and off-label effects are also reviewed.

Glucose lowering and pancreato-protective effects of Abrus Precatorius (L.) leaf extract in normoglycemic and STZ/Nicotinamide - Induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Abrus precatorius (L.) leaves are used as folk medicine by the local communities in the western region of Ghana to treat diabetes mellitus; however, this health claim remains unverified scientifically.

OBJECTIVE

The study investigated glucose lowering and pancreato-protective effects of Abrus precatorius leaf extract (APLE) in normoglycemic and STZ/nicotinamide (NIC)-induced diabetic rats.

METHOD

after preparation of APLE, it was subjected to phytochemical screening, proximate composition and elemental assessments by using standard methods. Oral glucose tolerance test (OGTT) and maltose, lactose and sucrose oral challenge were assessed in normoglycemic rats post-APLE. Morphological characteristics of glucose response curve (time of glucose peak and shape of glucose response curve) were determined. Subsequently, diabetes mellitus was experimentally established in normoglycaemic adult Sprague-Dawley rats (weighing 150-250 g) of both sexes by sequential injection of Streptozotocin (STZ, 60 mg/kg ip)-reconstituted in sodium citrate buffer and NIC (110 mg/kg ip)-reconstituted in normal saline (1:1 v/v) for 16 weeks. Except control rats (normal saline 5 ml/kg ip; baseline fasting blood glucose [FBG] of 6.48 mmol/L), rats having FBG (stable at 11.1 mmol/L or ≥ 250 mg/dL) 3 days post-STZ/NIC injection were randomly re-assigned to one of the following groups: model (STZ/NIC-induced diabetic rats), APLE (100, 200 and 400 mg/kg respectively po) and metformin (300 mg/kg po) and treated daily for 28 days. Bodyweight and FBG were measured on weekly basis. FBG was measured by using standard glucometers. On day 28, rats were sacrificed under chloroform anesthesia, blood collected via cardiac puncture; kidney, liver and pancreas surgically harvested. While the pancreas was processed, sectioned and H&E-stained for histological examination, fresh kidney and liver were homogenized for assessment of total anti-oxidant capacity. Median cross-sectional area of pancreatic islets of Langerhans was determined for each group by using Amscope.

RESULTS

Cumulatively, APLE (100, 200 and 400 mg/kg respectively) dose-dependently decreased the initial FBG by 55.22, 76.15 and 77.77% respectively compared to model (-1.04%) and metformin (72.29%) groups. APLE treatment recovered damaged pancreatic β-cells and also increased median cross-sectional area (x10⁶ μm²) of pancreatic islets compared to that of model group. APLE significantly (P < 0.05) increased total anti-oxidant capacity (5.21 ± 0.02 AscAE μg/mL) of plasma, kidney and liver compared to model (4.06 ± 0.04 AscAE μg/mL) and metformin (4.87 ± 0.03 AscAE μg/mL) groups.

CONCLUSION

APLE has demonstrated glucose lowering and pancreato-protective effects in rats and arrested the characteristic loss in bodyweight associated with diabetes mellitus. This finding preliminarily confirms folk use of APLE as an anti-diabetic herbal medicine, whiles providing a rationale for further translational studies on APLE.

Evaluation of the in vitro ⍺-amylase inhibitory, antiglycation, and antioxidant properties of Punica granatum L. (pomegranate) fruit peel acetone extract and its effect on glucose uptake and oxidative stress in hepatocytes

Punica granatum L. (pomegranate) is a widely eaten fruit. The antidiabetic, antioxidative, and antilipidemic properties of the hydroalcoholic extracts of the different plant's parts have been extensively studied, with scarce information on the acetone extract (ACE). This study investigated antidiabetic, antioxidative, and antiobesogenic properties of ACE of the fruit peel. Preliminary data showed that ACE showed stronger antioxidant (radical-scavenging IC₅₀  = 1.56 μg/ml) and ⍺-amylase inhibitory (IC₅₀  = 10.6 μg/ml) properties than the hydroalcoholic extracts and Acarbose. The ACE inhibited protein glycation and lipase activity. In hepatocytes, ACE impaired oxidative stress-induced lipid peroxidation and reduced glutathione depletion but increased glucose uptake without decreasing the cell viability. HPLC analysis showed predominant presence of bioactive phenolic acids (ferulic, caffeic, and gallic acids) in this extract. This study suggests that ACE of P. granatum fruit peel may be an understudied extract that contains potent antidiabetic and antioxidative bioactive principles with minimal toxicity. PRACTICAL APPLICATIONS: Plant derived medicines have been an affordable and effective alternative therapy for many metabolic diseases, including diabetes. The fruit juice and fruits of pomegranate is widely consumed for the palatable taste and cardiovascular benefits. This study provides preliminary experimental evidences confirming that of the acetone extracts of pomegranate fruit peel, which has been sparsely studied, may possess more potent antidiabetic and antioxidative property than to the routinely studied hydroalcoholic counterparts. Additionally, the acetone extract is rich in bioactive phenolic acids, suggesting that the acetone extract of pomegranate fruit peel may be a promising candidate for further antidiabetic study and a source of bioactive principles for the management of diabetes and oxidative complications.

Study on the Chemical Composition, Enzyme Inhibition and Antioxidant Activity of Ziziphora taurica subsp. cleonioides

Ziziphora is a plant used in Turkish and Iran traditional medicine for its antibacterial activity, sedative and stomach soothing properties. Although the chemical profile of the essential oil of different Ziziphora species is well documented, data regarding plant extracts are incomplete. In this study extracts from Ziziphora taurica subsp. cleonioides were obtained using ethyl acetate, methanol and water and the chemical profile of the aerial part of the plant was elucidated. Among the compounds identified, rosmarinic acid was the most abundant (3375.67 ± 38.02 μg/mL), at the extract of methanol, followed by chlorogenic acid (3225.10 ± 16.44). Enzyme inhibition activity against α-amylase and tyrosinase was also estimated. The ethyl acetate extract showed the highest α-amylase activity (1.95 ± 0.04 mg/mL), while the best anti-tyrosinase activity was calculated for the methanolic extract (1.25 ± 0.01 mg/mL). In addition, total phenolic, flavonoid content and antioxidant activity were evaluated. According to our results, bioactivity of the plant is of great interest, nonetheless, at the same time, it is strongly depended on the solvent used during the extraction process. Our data suggest that the plant under study may be an important source to consider against metabolic, skin pigmentation and oxidative stress related disorders.

Medicinal plants with concomitant anti-diabetic and anti-hypertensive effects as potential sources of dual acting therapies against diabetes and hypertension: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetes and hypertension are pathophysiologically related diseases that co-exist with a wider complex of metabolic diseases having similar set of risk factors. There are numerous ethnopharmacological evidences on the anti-diabetic and/or anti-hypertensive properties of medicinal plants from various parts of the world, which are used as therapies to concomitantly manage diabetes and hypertension.

AIM OF THE REVIEW

This article reviewed findings on medicinal plants with both anti-diabetic and anti-hypertensive effects reported in same experimental study to facilitate the development of dual-acting therapies against diabetes and hypertension.

MATERIALS AND METHODS

A literature search was carried out on different scientific search engines including, but not limited to "PubMed", "Google Scholar", "Scopus" and ScienceDirect to identify published data in which plants in same experimental studies were reported to possess both anti-hyperglycemic and anti-hypertensive effects. Subsequently, the anti-diabetic/anti-hypertensive potency ratio (ψ) of the medicinal plants was computed.

RESULTS

Sixty-four studies with 102 plant species matched the selection criteria. Members of the Fabaceae family were the most investigated plants, while the ψ greatly varied across the plants, with only 11 plants having a ψ ≃ 1. Withania somnifera Dunal was the only plant reported to show blood glucose-lowering and diuretic effects in humans, comparable to daonil. Caffeic acid, chlorogenic acid, caftaric acid, cichoric acid, verbascoside, leucosceptoside A, isoacteoside, fucoxanthin and nicotinamide were the reported dual acting anti-diabetic and anti-hypertensive compounds identified and/or isolated in the plants.

CONCLUSIONS

This review suggests that medicinal plants possess varied therapeutic dynamics against hypertension and diabetes that could be exploited for the discovery of therapeutic preparation(s) or agent(s) for treating the two diseases.

Astragalin augments basal calcium influx and insulin secretion in rat pancreatic islets

Astragalin is a flavonol glycoside with several biological activities, including antidiabetic properties. The objective of this study was to investigate the effects of astragalin on glycaemia and insulin secretion, in vivo, and on calcium influx and insulin secretion in isolated rat pancreatic islets, ex vivo. Astragalin (1 and 10 mg / kg) was administered by oral gavage to fasted Wistar rats and serum glucose and plasma insulin were measured. Isolated pancreatic islets were used to measure basal insulin secretion and calcium influx. Astragalin (10 mg/ kg) decreased glycaemia and increased insulin secretion significantly at 15-180 min, respectively, in the glucose tolerance test. In isolated pancreatic cells, astragalin (100 μM) stimulated calcium influx through a mechanism involving ATP-dependent potassium channels, L-type voltage-dependent calcium channels, the sarcoendoplasmic reticulum calcium transport ATPase (SERCA), PKC and PKA. These findings highlight the dietary coadjuvant, astragalin, as a potential insulin secretagogue that may contribute to glucose homeostasis.

In vivo antihyperglycemic, antihyperlipidemic, antioxidative stress and antioxidant potential activities of Syzygium paniculatum Gaertn. in Streptozotocin-induced diabetic rats

Abnormal glucose metabolism causes various complications in many metabolic diseases such as obesity, hypertension, cardiovascular diseases and mainly diabetes. But commonly used oral hypoglycemic drugs cause severe side effects. Hence, there is a need to find the medicine without side effects. Compounds of medicinal plants were nontoxic, inexpensive and less or no side effects. Syzygium paniculatum Gaertn. (Magenta Cherry) is one of the important medicinal plants in the genus Syzygium. The fruit of S. paniculatum is sour apple-like flavor which tribes using for diabetes without scientific evidence. The purpose of study was to investigate the phytochemical analysis, antihyperglycemic, antihyperlipidemic, antioxidative stress and antioxidant activities of the daily oral administration of the fruit aqueous extract of S. paniculatum at a dose of 100 mg/kg bw over a period of 120 days in Streptozotocin-induced diabetic rats.

The plant material collected, shade dried and the extracts prepared in increasing order of polarity and screened for different phytoconstituents by Harborne method. The extract with significant antihyperglycemic activity evaluated for antihyperlipidemic, antioxidative stress, antioxidant activity and also for insulin resistance by OGTT. The levels of insulin, HbA1c, lipid profile, glycogen, total proteins, liver and kidney functional markers were measured. The changes in antioxidant defense system were evaluated by TBARS assay. Histopathological examination of pancreas sections carried by hematoxylin and eosin stain. The findings confirm that S. paniculatum possesses potential antihyperglycemic, antihyperlipidemic, antioxidative stress and antioxidant activity. The histological changes also coincide with its potential on insulin secretion, glycemic control, lipid metabolisms, oxidative stress and antioxidant enzyme activities. This investigation confirms the traditional use of this plant in the folk medicine.

Anthocyanins in the Management of Metabolic Syndrome: A Pharmacological and Biopharmaceutical Review

The term "metabolic syndrome" (MetS) refers to a combination of diabetes, high blood pressure, and obesity. The origin of MetS includes a combination of multiple factors, such as sedentary lifestyle, unhealthy diet choice, and genetic factors. MetS is highly prevalent and adversely affects the general population by elevating risk of cardiovascular complications, organ failure, and much other pathology associated with late-stage diabetes. Anthocyanins (ANTs) are health-promoting bioactive compounds belonging to the flavonoids subclass of polyphenols. Numerous studies have reported the potential therapeutic benefits on MetS syndrome and diabetes from fruits rich in ANTs. This review summarizes the role of several dietary ANTs on preventing and managing MetS as well as the pharmacological mechanisms and biopharmaceutical features of their action. We also discuss potential nanoformulation and encapsulation approaches that may enhance the bioefficacy of ANTs in MetS. Experiments have demonstrated that ANTs may attenuate the symptoms of MetS via improving insulin resistance, impaired glucose tolerance, dyslipidaemia, cholesterol levels, hypertension, blood glucose, protecting β cells, and preventing free radical production. In brief, the intake of ANT-rich supplements should be considered due to their plausible ability for prevention and management of MetS. Additionally, randomized double-blind clinical trials are obligatory for evaluating the bioefficacy and pharmacological mechanisms of ANTs and their pharmaceutical formulations in patients with MetS.

Clerodendrum volubile inhibits key enzymes linked to type 2 diabetes but induces cytotoxicity in human embryonic kidney (HEK293) cells via exacerbated oxidative stress and proinflammation

The toxicity and safety associated with the use of medicinal plants remains a major concern. In this study, the antidiabetic properties of the dichloromethane (DCM) fraction of C. volubile leaves were investigated in vitro. Its cytotoxic effect and mechanism of toxicity were also investigated in Human Embryonic Kidney (HEK293) cells. The fraction was subjected to in vitro antioxidant assays using the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) scavenging and Ferric reducing antioxidant power (FRAP) protocols. Its enzyme-inhibitory properties were investigated on α-glucosidase and α-amylase activities. Gas Chromatography Mass Spectroscopy (GCMS) and Fourier Transform Infrared (FTIR) spectroscopic analysis were used to identify its phytoconstituents. Cytotoxicity was determined via MTT assay. The treated cells were assayed for reduced glutathione (GSH), non-protein thiol, nitric oxide and malondialdehyde (MDA) levels, as well as Superoxide Dismutase (SOD), catalase, myeloperoxidase and ATPase activities. Cell apoptosis and/or morphological changes were determined using the acridine orange and ethidium bromide (AO/EB) dual staining method. The fraction showed significant (p < 0.05) antioxidant and enzyme-inhibitory activity. It showed significant (p < 0.05) cytotoxic effect against HEK293 cells with concomitant depletion of antioxidative and elevation of proinflammatory biomarkers. Morphological changes were examined in the cells with an apoptotic index of 0.84. 1,1-Dodecanediol, diacetate was identified as the most predominant compound, while aromatics and amines as the most functional groups present in the fraction. These results suggest the antidiabetic and cytotoxic effects of C. volubile leaves. The toxicity can be attributed to induced oxidative stress and proinflammation with concomitant depletion of ATP leading to apoptosis of the cells.

Effects of a hydroalcoholic extract of Juglans regia (walnut) leaves on blood glucose and major cardiovascular risk factors in type 2 diabetic patients: a double-blind, placebo-controlled clinical trial

Background

We aimed to evaluate the effects of a hydroalcoholic extract of Juglans regia L. leaves on blood glucose level and cardiovascular risk factors in type 2 diabetic patients.

Methods

In this randomized, double-blind, placebo-controlled, parallel-group (2 arms) clinical trial, 50 diabetic patients were divided into two groups: treatment group (receive the capsules containing 100 mg J. regia leaf extract) and control group (receive the capsules containing placebo, microcrystallin cellulose). Baseline participant data were matched between the two arms of the study. We administered the prepared capsules to the patients twice daily for 8 weeks. Blood glucose level, glycosylated hemoglobin (HbA1c) level, body weight, body mass index, blood pressure, lipid profile, serum insulin, and insulin resistance were compared between the two groups before and after the intervention. P < 0.05 was considered significant.

Results

After excluding eleven patients, 20 received J. regia leaf extract and 20 patients received placebo. The J. regia leaf extract did not significantly change the blood glucose and insulin resistance condition. However, in this group, body weight, body mass index, and systolic blood pressure significantly decreased compared with the baseline measurements (P = 0.028, P = 0.030, and P = 0.005, respectively). The lipid profile did not change significantly compared with the baseline measurements. In the control group, postprandial glucose and HbA1c levels significantly decreased after the intervention (P = 0.030 and P = 0.028, respectively). The other variables were not significantly different in this group. At the end of the study, the variables were not significantly different between the two groups.

Conclusion

In this double-blind study, 200 mg/d of J. regia leaf extract had no significant effect on blood glucose level and HOMA-IR score in patients with type 2 diabetes. However, the J. regia leaf extract was effective in reducing body weight and blood pressure. An accidental finding of our study was that microcrystalline cellulose, a widely used placebo in clinical trials, led to a reduction in blood glucose level.

Trial registration

Iranian Registry of Clinical Trials (IRCT: 138901203180 N2, 2010/6/6); retrospectively registered.

Phytotherapy in the Management of Diabetes: A Review

Phytotherapy has long been a source of medicinal products and over the years there have been many attempts to use herbal medicines for the treatment of diabetes. Several medicinal plants and their preparations have been demonstrated to act at key points of glucidic metabolism. The most common mechanisms of action found include the inhibition of α-glucosidase and of AGE formation, the increase of GLUT-4 and PPARs expression and antioxidant activity. Despite the large amount of literature available, the actual clinical effectiveness of medicinal plants in controlling diabetes-related symptoms remains controversial and there is a crucial need for stronger evidence-based data. In this review, an overview of the medicinal plants, which use in the management of diabetes is supported by authoritative monographs, is provided. References to some species which are currently under increasing clinical investigation are also reported.

Mechanistic In vitro Evaluation of Prosopis farcta Roots Potential as an Antidiabetic Folk Medicinal Plant

OBJECTIVE

Prosopis farcta has been used as a traditional herbal medicine for treating Diabetes mellitus. The aim of this study is to investigate the antidiabetic mechanisms of infusion (INF) extract of P. farcta and discovering the active extract for the first time.

MATERIALS AND METHODS

Six different extracts of P. farcta were prepared using five different solvents (ethanol, n-hexane, acetone, ethanol:water (1:1 v/v), and water). Cytotoxicity and cell proliferation assays were performed on mouse pancreatic β-cells (β-TC3) using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium method. The effects of P. farcta on glucose metabolism (in a hepatocellular carcinoma cell line [HepG2]) and glucose diffusion across a dialysis membrane (as a model of cellular glucose absorption) were evaluated. The protective effect of various P. farcta extracts on cytotoxicity, mitochondrial membrane potential (MMP), and streptozotocin (STZ)-induced apoptosis in β-TC3 cells was investigated.

RESULTS

Cytotoxicity study indicated that extracts were safe on β-TC3 and HepG2 (≤0.5 mg/ml). INF protected β-TC3 cells from apoptosis induced by STZ and improved cell viability for 20% and significantly decrease depolarization of MMP (P < 0.005). The results showed that INF inhabited breaking/streaking the DNA. Proliferation study showed no significant increase in the number of cells either at single or multiple doses. In moderate hyperglycemia (11.1 mmol/l), a significant glucose-lowering effect was observed but glucose diffusion was not the probable mechanism of extracts antidiabetic effect. In conclusion, only INF, the traditionally used extract, has an antidiabetic potential by attenuating the death and apoptosis induced by STZ in β-TC3 cells and increase glucose consumption.

CONCLUSION

The present study demonstrates that only INF extract have an antidiabetic potential by attenuating the death and apoptosis induced by STZ in β-TC3 cells and increase glucose consumption.

SUMMARY

Six different extracts from P. farcta were prepared using five different solvents [ethanol, n-hexane, acetone, ethanol: water (1:1 v/v), and water]The protective effect of various P. farcta extracts on cytotoxicity, mitochondrial membrane potential (MMP), and Streptozotocin-induced apoptosis in β-TC3 cells were investigated.Infusion has an antidiabetic potential by attenuating the death and apoptosis induced by STZ in β-TC3 cells and increase glucose consumptionThe effect of infusion extract on glucose consumption in hepatocellular carcinoma cell line cells (a) and effect of infusion extract on glucose consumption in hepatocellular carcinoma cell line cells adjusted by optical density MTT (b). Significance was calculated by analysis of variance (*P ≤ 0.05). MTT: 3 (4,5 dimethylthiazol 2 yl) 2,5 diphenyltetrazolium. Abbreviations used: AC: Acetone extract; ANOVA: Analysis of variance; BSA: Bovine serum albumin; β-TC3: Mouse pancreatic β-cells; DMEM: Dulbecco modified Eagle medium; DMSO: Dimethyl sulfoxide; ETH: Ethyl acetate extract; FBS: Fetal bovine serum; HDETH: Hydroethanolic extract; HepG2: Hepatocellular carcinoma cell line; HEX: Hexane extract; INF: Infusion; KUMS: Kermanshah University of Medical Sciences; MMP: Mitochondrial membrane potential; MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium; NaCl: Natrium chloride; OD: Optical density; spp: Species; STZ: Streptozotocin; Tag: T-antigen; USA: United States of America.

An Overview of Herbal Products and Secondary Metabolites Used for Management of Type Two Diabetes

Diabetes mellitus is a common effect of uncontrolled high blood sugar and it is associated with long-term damage, dysfunction, and failure of various organs. In the adult population, the global prevalence of diabetes has nearly doubled since 1980. Without effective prevention and management programs, the continuing significant rise in diabetes will have grave consequences on the health and lifespan of the world population, and also on the world economy. Supplements can be used to correct nutritional deficiencies or to maintain an adequate intake of certain nutrients. These are often used as treatments for diabetes, sometimes because they have lower costs, or are more accessible or "natural" compared to prescribed medications. Several vitamins, minerals, botanicals, and secondary metabolites have been reported to elicit beneficial effects in hypoglycemic actions in vivo and in vitro; however, the data remain conflicting. Many pharmaceuticals commonly used today are structurally derived from natural compounds from traditional medicinal plants. Botanicals that are most frequently used to help manage blood glucose include: bitter melon (Momordica charantia), fenugreek (Trigonella foenum graecum), gurmar (Gymnema sylvestre), ivy gourd (Coccinia indica), nopal (Opuntia spp.), ginseng, Russian tarragon (Artemisia dracunculus), cinnamon (Cinnamomum cassia), psyllium (Plantago ovata), and garlic (Allium sativum). In majority of the herbal products and secondary metabolites used in treating diabetes, the mechanisms of action involve regulation of insulin signaling pathways, translocation of GLUT-4 receptor and/or activation the PPARγ. Several flavonoids inhibit glucose absorption by inhibiting intestinal α-amylase and α-glucosidase. In-depth studies to validate the efficacies and safeties of extracts of these traditional medicinal plants are needed, and large, well designed, clinical studies need to be carried out before the use of such preparations can be recommended for treatment and/or prevention of diabetes. The main focus of this review is to describe what we know to date of the active compounds in these, along with their glucose-lowering mechanisms, which are either through insulin-mimicking activity or enhanced glucose uptake.