Role of medicinal plants in the management of diabetes mellitus: a review

Terpenoids as potential phytoconstituent in the treatment of diabetes: From preclinical to clinical advancement

BACKGROUND

Diabetes mellitus, a hyperglycemic condition associated with multitudinous organ dysfunction, is a hallmark of the metabolic disorder. This life-threatening condition affects millions of individuals globally, harming them financially, physically and psychologically in the course of therapy.

PURPOSES

The course therapy for illnesses has undergone ground-breaking transformations due to recent technical advances and insights. Alternatively, the administration of hyperglycemia-reducing agents results in several complications, including severe cardiovascular disease, kidney failure, hepatic problems, and several dermatological conditions. Consideration of alternate diabetic therapy having minimal side effects or no adverse reactions has been driven by such problems.

STUDY DESIGN

An extensive literature study was conducted in authoritative scientific databases such as PubMed, Scopus, and Web of Science to identify the studies elucidating the bioactivities of terpenoids in diabetic conditions.

METHODS

Keywords including 'terpenoids', 'monoterpenes', 'diterpenes', 'sesquiterpenes', 'diabetes', 'diabetes mellitus', 'clinical trials', 'preclinical studies', and 'increased blood glucose' were used to identify the relevant research articles. The exclusion criteria, such as English language, duplication, open access, abstract only, and studies not involving preclinical and clinical research, were set. Based on these criteria, 937 relevant articles were selected for further evaluation.

RESULTS

Triterpenes can serve as therapeutic agents for diabetic retinopathy, peripheral neuropathy, and kidney dysfunction by inhibiting several pathways linked to hyperglycemia and its complications. Therefore, it is essential to draw special attention to these compounds' therapeutic effectiveness and provide scientific professionals with novel data.

CONCLUSION

This study addressed recent progress in research focussing on mechanisms of terpenoid, its by-products, physiological actions, and therapeutic applications, particularly in diabetic and associated disorders.

Antidiabetic Properties of the Root Extracts of Dandelion (Taraxacum officinale) and Burdock (Arctium lappa)

Several preclinical studies suggest the potential of edible plants in controlling blood sugar levels and stabilizing diet. The goals of the study were to examine, analyze, and describe whether there are chemical compounds in dandelion and burdock roots that could have antidiabetic properties. The 70% ethyl alcohol and lyophilizate extracts (AE and LE, respectively), were used, and analyses were carried out on their total polysaccharide (TP), total phenolic content (TPC), tannin, and inulin. The antioxidant activity of extracts was determined using the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay, and hypoglycemic properties were based on α-amylase activity. Liquid chromatography-mass spectrometry was used for the tentative identification of the chemical components. Qualitative techniques confirmed the presence of inulin in both roots. Analysis of TPC, tannin content, DPPH assay, and α-amylase activity revealed higher values for burdock compared to dandelion. However, dandelion exhibited higher TP content. Burdock contained a small amount of tannin, whereas the tannin content in dandelion was insignificant. All LE consistently exhibited higher values in all analyses and assays for all roots compared to AE. Despite burdock root showing overall better results, it is uncertain whether these plants can be recommended as antidiabetic agents without in vivo studies.

Exploring the therapeutic potential of Derris elliptica (Wall.) Benth in Streptozotocin-Induced diabetic Rats: Phytochemical characterization and antidiabetic evaluation

Derris elliptica (Wall.) Benth, a native medicinal plant, has been used to treat diabetes for centuries; however, comprehensive documentation of its bioactive constituents and therapeutic effectiveness is lacking. In this study, we investigated the phytochemical profile and antidiabetic potential of D. elliptica methanolic leaf extract (DEME) in diabetic Sprague Dawley rats induced with streptozotocin (STZ). In normal rats, acute oral toxicity evaluations were conducted, and in STZ-induced rats, antidiabetic properties were investigated. 14 days of oral administration of standard glibenclamide and the extract at 200 and 400 mg/kg body weight to diabetic rodents. Assessed parameters included blood glucose levels, alterations in body weight, biochemical markers, and histological analysis of the pancreas, liver, and kidney. Numerous phytoconstituents were uncovered through qualitative phytochemical assays, 1H NMR, and 1H-13C HSQC screening. Quercetin was identified by 1H NMR characterization, and a ceramide analogue compound was isolated and partially characterized by 1H NMR. There were no indications of toxicity or mortality. The treatment with DEME significantly (p < 0.001) decreased body weight and had a remarkable hypoglycemic effect. Both 200 mg/kg and 400 mg/kg extract concentrations decreased total cholesterol levels significantly (p < 0.01 and p < 0.05, respectively). In addition, glibenclamide and the 400 mg/kg dose of extract increased serum insulin levels substantially (p < 0.05) and decreased total bilirubin, lactic acid dehydrogenase, aspartate aminotransferase, and alanine aminotransferase levels. In addition to glibenclamide, treatment with DEME has exhibited cytoprotective effects and increased insulin secretion, thereby exerting a potent antihyperglycemic effect. These results suggest that D. elliptica may have therapeutic potential for the treatment of diabetes mellitus.

In Vitro Hypoglycemic and Antioxidant Activities of Dichloromethane Extract of Xerophyta spekei

Diabetes mellitus is a chronic metabolic disorder which has greatly led to an increase in morbidity and mortality globally. Although Xerophyta spekei is widely used for the management of diabetes among the Embu and Mbeere communities in Kenya, it has never been empirically evaluated for its hypoglycemic activity. This study was carried out to verify the hypoglycemic activity of dichloromethane (DCM) extract of Xerophyta spekei as well as its antioxidant activity using various in vitro techniques. Phytochemicals associated with its antioxidant activity were identified through GC-MS. Data were subjected to descriptive statistics and expressed as mean ± standard error of the mean (X̄ ± SEM). Comparison between various variables was performed by using unpaired Student's t-test and one-way analysis of variance (ANOVA), followed by Tukey's post-hoc test. The confidence interval was set at 95%. The obtained results were presented in tables and graphs. Results showed that there was no difference in α-amylase inhibition activity between the plant extract and the standard (IC50 525.9 ± 12.34 and 475.1 ± 9.115, respectively; p  >  0.05). Besides, the glucose adsorption activity of the extract increased with an increase in glucose concentration (from 5.89 to 32.64 mg/dl at 5 mmol and 30 mmol of glucose, respectively; p  <  0.05). The extract also limited the diffusion of glucose more than the negative control (7.49 and 17.63 mg/dl, respectively; p  <  0.05). It also enhanced glucose uptake by yeast cells. In addition, the studied plant extract showed notable antioxidant activities. The therapeutic effects exhibited by this plant in managing diabetes mellitus and other ailments could be due to its antioxidant as well as its hypoglycemic activity. The study recommends the evaluation of X. spekei for in vivo hypoglycemic and antioxidant activities. Besides, the isolation of bioactive phytochemicals from the plant may lead to the development of new hypoglycaemic agents.

Chemical Composition and Insulin-Resistance Activity of Arginine-Loaded American Cranberry (Vaccinium macrocarpon Aiton, Ericaceae) Leaf Extracts

One of the key pathogenetic links in type 2 diabetes mellitus (T2DM) is the formation of insulin resistance (IR). Besides a wide selection of synthetic antidiabetic drugs, various plant-origin extracts are also available to support the treatment of T2DM. This study aimed to investigate and gain knowledge of the chemical composition and potential IR correction effect of American cranberry (Vaccinium macrocarpon Aiton) leaf extracts and formulate novel 3D-printed oral dosage forms for such extracts. The bioactivity and IR of L-arginine-loaded cranberry leaf extracts were studied in vivo in rats. The cranberry leaf extracts consisted of quinic, 3-caffeoylquinic (chlorogenic), p-coumaroylquinic acids, quercetin 3-O-galactoside, quercetin-3-O-glucoside, quercetin-3-xyloside, quercetin-3-O-arabino pyranoside, quercetin-3-O-arabinofuranoside, quercetin 3-O-rhamnoside, and quercetin-O-p-coumaroyl hexoside-2 identified by HPLC. In vivo studies with rats showed that the oral administration of the cranberry leaf extracts had a positive effect on insulin sensitivity coefficients under the insulin tolerance test and affected homeostasis model assessment IR levels and liver lipid content with experimental IR. A novel 3D-printed immediate-release dosage form was developed for the oral administration of cranberry leaf extracts using polyethylene oxide as a carrier gel in semi-solid extrusion 3D printing. In conclusion, American cranberry leaf extracts loaded with L-arginine could find uses in preventing health issues associated with IR.

Anti-Diabetic and Anti-Adipogenic Effect of Harmine in High-Fat-Diet-Induced Diabetes in Mice

One of the most important health issues facing the world today is obesity. It is an important independent risk factor for developing type 2 diabetes. Harmine offers various pharmacological effects, such as anti-inflammatory and anti-tumor effects. The current study aims to investigate Harmine's anti-diabetic and anti-adipogenic properties in albino mice after inducing low-grade inflammation with a high-fat diet (HFD). About forty-eight male albino mice were divided into four groups. Group 1: control mice were injected with daily saline and fed a normal chow diet of 21% protein for 5 months. Group 2: mice were treated daily with IP-injected Harmine (30 mg/kg body weight) and were fed a normal chow diet for 5 months. Group 3: mice were fed HFD to induce type 2 Diabetes Mellitus (T2DM) for 5 months. Group 4: mice were fed HFD for 14 weeks and treated with Harmine for the last 6 weeks. A figh-fat diet caused a significant increase in body and organ weight, lipid profiles, and destructive changes within the pancreas, kidney, and liver tissue. The administration of Harmine led to a remarkable improvement in the histological and ultrastructural changes induced by HFD. The findings indicate that mice cured using Harmine had lower oxidative stress, a higher total antioxidant capacity, and a reduced lipid profile compared to HFD mice. Harmine led to the hepatocytes partly restoring their ordinary configuration. Furthermore, it was noticed that the pathological incidence of damage in the structure of both the kidney and pancreas sections reduced in comparison with the diabetic group. Additional research will be required to fully understand Harmine and its preventive effects on the two forms of diabetes.

Potential use of the Asteraceae family as a cure for diabetes: A review of ethnopharmacology to modern day drug and nutraceuticals developments

The diabetes-associated mortality rate is increasing annually, along with the severity of its accompanying disorders that impair human health. Worldwide, several medicinal plants are frequently urged for the management of diabetes. Reports are available on the use of medicinal plants by traditional healers for their blood-sugar-lowering effects, along with scientific evidence to support such claims. The Asteraceae family is one of the most diverse flowering plants, with about 1,690 genera and 32,000 species. Since ancient times, people have consumed various herbs of the Asteraceae family as food and employed them as medicine. Despite the wide variety of members within the family, most of them are rich in naturally occurring polysaccharides that possess potent prebiotic effects, which trigger their use as potential nutraceuticals. This review provides detailed information on the reported Asteraceae plants traditionally used as antidiabetic agents, with a major focus on the plants of this family that are known to exert antioxidant, hepatoprotective, vasodilation, and wound healing effects, which further action for the prevention of major diseases like cardiovascular disease (CVD), liver cirrhosis, and diabetes mellitus (DM). Moreover, this review highlights the potential of Asteraceae plants to counteract diabetic conditions when used as food and nutraceuticals. The information documented in this review article can serve as a pioneer for developing research initiatives directed at the exploration of Asteraceae and, at the forefront, the development of a botanical drug for the treatment of DM.

The antidiabetic effect of methanolic extract of Holarrhena pubescens seeds is mediated through multiple mechanisms of action

Holarrhena pubescens is widely used in Indian and Chinese medicine in the treatment of diabetes. The current work determined the oral hypoglycemic and antidiabetic effects of seed extract in rats. The probable mechanism of action was evaluated in-vitro by α - glucosidase inhibition, glucose metabolism in insulinoma (INS-1) cells to reflect secretion of insulin, and protein glycation inhibition. Its potential for herb-drug interaction was evaluated in the cytochrome P450 3A4 (CYP3A4) inhibition assay. The seed extract increased serum insulin levels and reduced serum blood glucose levels in the oral glucose tolerance test. It also reduced the serum glucose levels in streptozocin-induced diabetes. The extract also inhibited α -glucosidase enzyme activity and demonstrated that it can increase the secretion of insulin from INS to 1-rat insulinoma cell line cells in-vitro in a concentration-dependent manner. However, it had a very weak inhibitory effect on protein glycation and it did not affect the activity of CYP3A4. The results of the study showed that H. pubescens seed extract increases insulin secretion and inhibits glucose absorption both in-vivo and in-vitro with a weak protein glycation inhibitory effect. The herb is devoid of CYP3A4 inhibitory effect indicating that it may not have pharmacokinetic interaction with the drug metabolized by this enzyme.

Anacardium occidentale leaves extract and riboceine mitigate hyperglycemia through anti-oxidative effects and modulation of some selected genes associated with diabetes

Background

Diabetes mellitus (DM) is one of the leading causes of death globally and complications of DM have become a major health concern. Anacardium occidentale is a plant widely recognized for its hypoglycemic properties and traditionally used in developing nations as remedy for DM treatment. Riboceine is a supplement that enhances production of glutathione and known for its vital role in supporting cellular function. This study was designed to evaluate the antidiabetic and antioxidant potential of riboceine and ethanolic extract of A. occidentale leaves in streptozotocin (STZ)-induced diabetic rats.

Method

Twenty-nine adult male Wistar rats were induced with DM intraperitoneally using a single dose of STZ (70 mg/kg). The STZ-induced rats were divided into groups and administered the same dose (100 mg/kg) of A. occidentale leaves extract and riboceine via gastric gavage at the dose (100 mg/kg) for seventeen days while metformin (40 mg/kg) was used as positive control. Fasting blood glucose and weight of the model rats were examined periodically. Activities of total protein, creatinine, urea, antioxidants (SOD, GSH and GPX), and level of serum insulin were determined. Expression of diabetes related genes including pancreas (Insulin, pdx-1, P16NK4A, and Mki-67), Liver (FAS, ACC, and GFAT) and KIM-1 genes were also determined.

Results

Data showed that treatment of STZ-induced diabetic rats with A. occidentale and riboceine at the same dose significantly (p < 0.05) ameliorated hyperglycemic effects by improving hepatic and renal functions and antioxidants, preventing hepatic fat accumulation by downregulation of ACC, FAS and GFAT expression, improving β-cell functions through up-regulation of pancreatic insulin, P16NK4A, Mki-67 and pdx-1 expression. Induction of diabetes upregulated mRNA expression of KIM-1, which was ameliorated after treatment of the rats with A. occidentale and riboceine.

Conclusion

The results obtained in this study demonstrate significant antidiabetic properties of ethanolic extract of A. occidentale and riboceine.

The Management of Diabetes Mellitus Using Medicinal Plants and Vitamins

Diabetes mellitus (DM) is a serious chronic metabolic disease that is associated with hyperglycemia and several complications including cardiovascular disease and chronic kidney disease. DM is caused by high levels of blood sugar in the body associated with the disruption of insulin metabolism and homeostasis. Over time, DM can induce life-threatening health problems such as blindness, heart disease, kidney damage, and stroke. Although the cure of DM has improved over the past decades, its morbidity and mortality rates remain high. Hence, new therapeutic strategies are needed to overcome the burden of this disease. One such prevention and treatment strategy that is easily accessible to diabetic patients at low cost is the use of medicinal plants, vitamins, and essential elements. The research objective of this review article is to study DM and explore its treatment modalities based on medicinal plants and vitamins. To achieve our objective, we searched scientific databases of ongoing trials in PubMed Central, Medline databases, and Google Scholar websites. We also searched databases on World Health Organization International Clinical Trials Registry Platform to collect relevant papers. Results of numerous scientific investigations revealed that phytochemicals present in medicinal plants (Allium sativum, Momordica charantia, Hibiscus sabdariffa L., and Zingiber officinale) possess anti-hypoglycemic activities and show promise for the prevention and/or control of DM. Results also revealed that intake of vitamins C, D, E, or their combination improves the health of diabetes patients by reducing blood glucose, inflammation, lipid peroxidation, and blood pressure levels. However, very limited studies have addressed the health benefits of medicinal plants and vitamins as chemo-therapeutic/preventive agents for the management of DM. This review paper aims at addressing this knowledge gap by studying DM and highlighting the biomedical significance of the most potent medicinal plants and vitamins with hypoglycemic properties that show a great potential to prevent and/or treat DM.

Luteolin and Vernodalol as Bioactive Compounds of Leaf and Root Vernonia amygdalina Extracts: Effects on α-Glucosidase, Glycation, ROS, Cell Viability, and In Silico ADMET Parameters

The aqueous decoctions of Vernonia amygdalina (VA) leaves and roots are widely used in traditional African medicine as an antidiabetic remedy. The amount of luteolin and vernodalol in leaf and root extracts was detected, and their role was studied regarding α-glucosidase activity, bovine serum albumin glycation (BSA), reactive oxygen species (ROS) formation, and cell viability, together with in silico absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties. Vernodalol did not affect α-glucosidase activity, whereas luteolin did. Furthermore, luteolin inhibited the formation of advanced glycation end products (AGEs) in a concentration-dependent manner, whereas vernodalol did not reduce it. Additionally, luteolin exhibited high antiradical activity, while vernodalol demonstrated a lower scavenger effect, although similar to that of ascorbic acid. Both luteolin and vernodalol inhibited HT-29 cell viability, showing a half-maximum inhibitory concentration (IC₅₀) of 22.2 µM (-Log IC₅₀ = 4.65 ± 0.05) and 5.7 µM (-Log IC₅₀ = 5.24 ± 0.16), respectively. Finally, an in silico ADMET study showed that both compounds are suitable candidates as drugs, with appropriate pharmacokinetics. This research underlines for the first time the greater presence of vernodalol in VA roots compared to leaves, while luteolin is prevalent in the latter, suggesting that the former could be used as a natural source of vernodalol. Consequently, root extracts could be proposed for vernodalol-dependent antiproliferative activity, while leaf extracts could be suggested for luteolin-dependent effects, such as antioxidant and antidiabetic effects.

Antidiabetic effects of Andrographis paniculata supplementation on biochemical parameters, inflammatory responses, and oxidative stress in canine diabetes

Introduction: Diabetes mellitus is a common endocrine disorder that causes hyperglycemia in dogs. Persistent hyperglycemia can induce inflammation and oxidative stress. This study aimed to investigate the effects of A. paniculata (Burm.f.) Nees (Acanthaceae) (A. paniculata) on blood glucose, inflammation, and oxidative stress in canine diabetes. A total of 41 client-owned dogs (23 diabetic and 18 clinically healthy) were included in this double-blind, placebo-controlled trial. Methods: The diabetic dogs were further divided into two treatments protocols: group 1 received A. paniculata extract capsules (50 mg/kg/day; n = 6) or received placebo for 90 days (n = 7); and group 2 received A. paniculata extract capsules (100 mg/kg/day; n = 6) or received a placebo for 180 days (n = 4). Blood and urine samples were collected every month. No significant differences in fasting blood glucose, fructosamine, interleukin-6, tumor necrosis factor-alpha, superoxide dismutase, and malondialdehyde levels were observed between the treatment and placebo groups (p > 0.05). Results and Discussion: The levels of alanine aminotransferase, alkaline phosphatase, blood urea nitrogen, and creatinine were stable in the treatment groups. The blood glucose levels and concentrations of inflammatory and oxidative stress markers in the client-owned diabetic dogs were not altered by A. paniculata supplementation. Furthermore, treatment with this extract did not have any adverse effects on the animals. Non-etheless, the effects of A. paniculata on canine diabetes must be appropriately evaluated using a proteomic approach and involving a wider variety of protein markers.

Chemical and Biological Review of Endophytic Fungi Associated with Morus sp. (Moraceae) and In Silico Study of Their Antidiabetic Potential

The chronic nature of diabetes mellitus motivates the quest for novel agents to improve its management. The scarcity and prior uncontrolled utilization of medicinal plants have encouraged researchers to seek new sources of promising compounds. Recently, endophytes have presented as eco-friendly leading sources for bioactive metabolites. This article reviewed the endophytic fungi associated with Morus species and their isolated compounds, in addition to the biological activities tested on their extracts and chemical constituents. The relevant literature was collected from the years 2008-2022 from PubMed and Web of Science databases. Notably, no antidiabetic activity was reported for any of the Morus-associated endophytic fungal extracts or their twenty-one previously isolated compounds. This encouraged us to perform an in silico study on the previously isolated compounds to explore their possible antidiabetic potential. Furthermore, pharmacokinetic and dynamic stability studies were performed on these compounds. Upon molecular docking, Colletotrichalactone A (14) showed a promising antidiabetic activity due to the inhibition of the α-amylase local target and the human sodium-glucose cotransporter 2 (hSGT2) systemic target with safe pharmacokinetic features. These results provide an in silico interpretation of the possible anti-diabetic potential of Morus endophytic metabolites, yet further study is required.

Zingiber officinale, Phyllanthus emblica, Cinnamomum verum, and Curcuma longa to Prevent Type 2 Diabetes: An Integrative Review

Diabetes mellitus has become a global pandemic progressively rising and affecting almost every household in all world regions. Diet is a significant root cause of type II diabetes; thus, the significance of dietary interventions in preventing and managing the disease cannot be neglected. Lowering the glycemic impact of diet is an alternative way of managing type II diabetes while improving insulin sensitivity. Medicinal plants are rich in therapeutic phytochemicals which possess hypoglycemic properties. Therefore, it could be speculated that the glycemic impact of diet can be reduced by adding hypoglycemic plant ingredients without altering the sensory properties of food. The main aim of this review is to discuss dietary interventions to manage diabetes and summarize available information on the hypoglycemic properties of four prime herbs of Asian origin. This article collected, tabulated, and summarized groundbreaking reveals from promising studies. This integrative review provides information on the hypoglycemic properties of ginger, Indian gooseberry, cinnamon, and turmeric and discusses the possibility of those herbs reducing the glycemic impact of a diet once incorporated. Further research should be done regarding the incorporation of these herbs successfully into a regular diet.

Ameliorative effect of selenium yeast in combination with pioglitazone on diabetes outcomes in streptozotocin-induced

Anti-diabetic therapies possess many side effects; thus, searching for alternative strategies with low cost, minimal side effects, and high therapeutic value is very important. The present study aimed to explore the combined use of selenium yeast (SY) and standard anti-diabetic drug pioglitazone (PGZ) for diabetes mellitus (DM) treatment in streptozotocin (STZ)-induced DM. STZ was injected daily intraperitoneally with a low dose (40 mg/kg) into Sprague-Dawley rats to induce DM. The synergistic effect of the SY (0.2 mg/kg) and PGZ (0.65 mg/kg) on DM complications was evaluated after 88 weeks of treatment. The impact of our medication on glucose levels, insulin sensitivity, lipid abnormalities, oxidative mediators, and inflammatory markers was assessed by biochemical techniques. STZ-induced diabetes has toxic effects, including toxic hepatic tissues, lipid disturbances, massive oxidative damage, and hyperinflammation. Experimental rats either treated with monotherapy alone or combined therapy resulted in a significant anti-diabetic effect. The PGZ+ SY combination has the best effect, as illustrated by significant (P < 0.05) decreases in fasting blood glucose, (FBG) insulin, HbA1c, and HOMA-IR levels. This combination attenuated (P < 0.05) lipid disturbances and their associated elevated atherogenicity biomarkers. At the same time, treatments with PGZ+ SY exhibited an anti-inflammatory effect as they ameliorated the increase in inflammatory parameters (CRP, TNF-α, IL-6). Also, it restored the total antioxidant capacity and peroxisome proliferator-activated receptor (PPARƔ) levels that were decreased by STZ-DM induction. In conclusion, this study finds PGZ+ SY as a promising DM therapeutic alternative. This synergistic combination alleviates most DM-related complications and insulin resistance.

Antidiabetic Activity of Hot Tea Infusion of Leaves of Moringa stenopetala in Streptozotocin-Induced Diabetic Rats

Background

Moringa stenopetala is a traditionally used medicinal plant that has been used for the management of different disorders including diabetes in Ethiopia. This study was aimed to assess the antidiabetic activity of hot tea infusion of leaves of Moringa stenopetala in streptozotocin-induced diabetic rats.

Methods

Experimental animals were Wistar male rats aged 4–6 weeks weighing 200–250 gram. The animals were maintained in equal light/dark series of laboratory conditions, and the average ambient temperature was 23±2 °C. The hot tea infusion of Moringa stenopetala leaves of different concentrations (as fine and coarse powder decoction), distilled water (10 mL/kg), and 150 mg/kg body weight of metformin were administered to diabetic rats as test, negative control, and positive standard drugs, respectively. Sucrose oral challenge test was also carried out to assess the effect of Moringa stenopetala hot tea infusion on postprandial glucose level. Blood glucose level was measured at 0, 30, 60, 90, and 180 minutes. Statistical analysis was conducted by SPSS package version 23, and the p-value less than 0.05 was declared as level of statistical significance.

Results

The phytoconstituents that tested positive in hot tea infusion of Moringa stenopetala leaves were alkaloids, tannins, flavonoids, saponins, and terpenoids. Different experimental groups treated with the hot tea infusion of Moringa stenopetala leaves showed significant reduction of blood glucose level after 30 minutes of hot tea infusion administration. In addition, the hot tea infusion at a different concentration for both fine and coarse powders reduced significantly raised blood glucose level. The present findings revealed that the hot tea infusion has blood glucose-lowering and antioxidant effects with wide safety margin.

Conclusion

The findings indicated that the hot tea infusion of the leaves of Moringa stenopetala shows a credible reduction in blood glucose level in rats.

Foods of the Mediterranean diet: garlic and Mediterranean legumes

The Mediterranean diet is a dietary regime derived from the one followed by the ancient civilizations of the Mediterranean region. It is characterized by many healthy constituents, among which are cereals, legumes, fruits, vegetables, olives, and white meat. Many studies suggest that this dietary regime is the key to obtaining a healthy and long life, like that of the Mediterranean peoples. Despite its popularity among health professionals, this diet is still confined to a certain geographical area of the world. Due to globalization and the modern busy lifestyle, this cultural diet is losing ground even in its home region, with more and more people embracing the so-called Western diet. An awareness of health benefits of the individual components of the Mediterranean diet will therefore draw attention from all over the world to this healthy and affordable dietary pattern, which can not only improve the overall health, but also reduce the risk of developing chronic and infectious diseases. In this regard, garlic and Mediterranean legumes present a huge repertoire of phytochemicals having both nutritive and nutraceutical properties, which therefore should be included in our daily dietary routines in moderate proportions. This narrative review aims at summarizing the principal components and health benefits of the Mediterranean diet, in particular of garlic and legumes.

An Overview of the Potential of Medicinal Plants Used in the Development of Nutraceuticals for the Management of Diabetes Mellitus: Proposed Biological Mechanisms

Diabetes mellitus (DM) is a chronic metabolic disorder in which the pancreas does not produce enough insulin or the body cannot effectively use it. The prevalence of diabetes is increasing steadily, making it a global public health problem. Several serious complications are associated with this disease. There are a number of different classes of antidiabetic medications. Interestingly, traditional medicine can also be used for the development of novel classes of hypoglycemic therapeutics. This article summarizes an update of the potential of various important medicinal plants used in the development of nutraceuticals for the management of diabetes mellitus, and a proposal of their biological mechanisms.

An Overview of Herbal-Based Antidiabetic Drug Delivery Systems: Focus on Lipid- and Inorganic-Based Nanoformulations

Diabetes is a metabolic pathology with chronic high blood glucose levels that occurs when the pancreas does not produce enough insulin or the body does not properly use the insulin it produces. Diabetes management is a puzzle and focuses on a healthy lifestyle, physical exercise, and medication. Thus far, the condition remains incurable; management just helps to control it. Its medical treatment is expensive and is to be followed for the long term, which is why people, especially from low-income countries, resort to herbal medicines. However, many active compounds isolated from plants (phytocompounds) are poorly bioavailable due to their low solubility, low permeability, or rapid elimination. To overcome these impediments and to alleviate the cost burden on disadvantaged populations, plant nanomedicines are being studied. Nanoparticulate formulations containing antidiabetic plant extracts or phytocompounds have shown promising results. We herein aimed to provide an overview of the use of lipid- and inorganic-based nanoparticulate delivery systems with plant extracts or phytocompounds for the treatment of diabetes while highlighting their advantages and limitations for clinical application. The findings from the reviewed works showed that these nanoparticulate formulations resulted in high antidiabetic activity at low doses compared to the corresponding plant extracts or phytocompounds alone. Moreover, it was shown that nanoparticulate systems address the poor bioavailability of herbal medicines, but the lack of enough preclinical and clinical pharmacokinetic and/or pharmacodynamic trials still delays their use in diabetic patients.

Antidiabetic and antioxidant potential of Gardenia latifolia in type-2 diabetic rats fed with high-fat diet plus low-dose streptozotocin

OBJECTIVES

To test the antidiabetic potential of Gardenia latifolia extract (GLE) in rats with type 2 diabetes mellitus (T2DM) induced by a high-fat diet (HFD) + streptozotocin (STZ).

METHODS

The study was carried out in June 2021. Gardenia latifolia powdered leaves were subjected to Soxhlet extraction using ethanol. Male rats were administered a low dose-40 mg/kg STZ by intraperitoneal route following 2 weeks of HFD to induce type-2 diabetic rats (T2DR). Rats were randomized into 5 groups (n=6). Group 1 (normal control; 10 ml/kg normal saline); Group 2 (diabetic control: DC); Group 3 (standard; DR + metformin, 100 mg/kg per oral); Group 4 (DR + GLE 250 mg/kg); Group 5 (DR + GLE 500 mg/kg). The treatment period extended for 2 weeks. Body weight and fasting blood glucose were determined on days 0, 7, and 14. Fasting serum insulin (FSI) levels, fasting blood glucose (FBG), HOMA-IR, antioxidant enzyme level, Insulin tolerance test (ITT), and intraperitoneal glucose tolerance test (IPGTT) tests were estimated.

RESULTS

Gardenia latifolia extract exhibited a marked decrease (p<0.001) in fasting blood glucose levels. T2DR receiving a higher dose of GLE showed a greater improvement in metabolic indices (FSI, FBG, Homeostatic Model Assessment of insulin resistance). The ITT and IPGTT results demonstrated that GLE could significantly enhance insulin tolerance, glucose tolerance, and antioxidant enzyme levels in T2DR.

CONCLUSION

Gardenia latifolia can be an ideal medicinal plant candidate for treating T2DM, and it should be investigated further for its therapeutic potential.

Herbal medications and natural products for patients with covid-19 and diabetes mellitus: Potentials and challenges

BACKGROUND

The presence of diabetes mellitus (DM) among COVID-19 patients is associated with increased hospitalization, morbidity, and mortality. Evidence has shown that hyperglycemia potentiates SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection and plays a central role in severe COVID-19 and diabetes comorbidity. In this review, we explore the therapeutic potentials of herbal medications and natural products in the management of COVID-19 and DM comorbidity and the challenges associated with the preexisting or concurrent use of these substances.

METHODS

Research papers that were published from January 2016 to December 2021 were retrieved from PubMed, ScienceDirect, and Google Scholar databases. Papers reporting clinical evidence of antidiabetic activities and any available evidence of the anti-COVID-19 potential of ten selected natural products were retrieved and analyzed for discussion in this review.

RESULTS

A total of 548 papers (73 clinical trials on the antidiabetic activities of the selected natural products and 475 research and review articles on their anti-COVID-19 potential) were retrieved from the literature search for further analysis. A total of 517 articles (reviews and less relevant research papers) were excluded. A cumulative sum of thirty-one (31) research papers (20 clinical trials and 10 others) met the criteria and have been discussed in this review.

CONCLUSION

The findings of this review suggest that phenolic compounds are the most promising phytochemicals in the management of COVID-19 and DM comorbidity. Curcumin and propolis have shown substantial evidence against COVID-19 and DM in humans and are thus, considered the best potential therapeutic options.

Methods of Isolation of Active Substances from Garlic (Allium sativum L.) and Its Impact on the Composition and Biological Properties of Garlic Extracts

Garlic (Allium sativum L.) is widely used in the human diet and in scientific research due to its biological properties. Various factors, e.g., temperature, pressure, extraction method, type of solvent, size, and territorial origin of garlic, affect the amount and type of bioactive compounds obtained from garlic extracts. In turn, the content of bioactive compounds correlates with the biological activity of the extracts. Therefore, the aim of this review was to summarize the current state of knowledge of the methods and effectiveness of isolation of active substances from garlic and their impact on the garlic extract composition and, consequently, biological properties. According to the literature, extracts obtained using water as a solvent are mainly responsible for antimicrobial properties, which is related to, inter alia, the high content of allicin. The use of alcohols, such as methanol or ethanol, is associated with the outstanding antioxidant power of extracts resulting from the presence of phenolic compounds. In turn, due to the presence of diallyl disulfide and disulfide trisulfide, garlic oil has anticancer potential. Acetone is the most effective organic solvent; however, it is not suitable for immediate consumption.

A Review of Anti-hyperglycemic Effects of Curry Leaf Tree (Murraya koenigii)

Diabetes mellitus is becoming a metabolic disease that is defined by the level of hyperglycemia. Nowadays, it has a serious threat to public healthiness in throughout the world. Constituents and extracts isolated from diverse natural resources, mainly plants, have constantly been a rich store for controlling and treating diabetes problems. Numerous researches are ongoing to identify the suitable traditional medical drugs, medicinal herbs, and resources for managing this condition. Murraya koenigii Spreng (family Rutaceae) is commonly known as a ‘curry leaf tree’ locally. It is widely scattered in India and Sri Lanka, and leaves are commonly used for cooking. And also mainly used for various health conditions such as diabetes, anemia, diarrhea, and others. The present review aimed to critically review the anti-hyperglycemic effect of the M. koenigii based on the review, in vitro, in vivo, and clinical studies. Based on this review, the M. koenigii possess flavonoids, phenols, saponins, alkaloids, tannins, and cardiac glycosides. It has shown a potential anti-hyperglycemic effect on induced diabetic rats. This review reported the potential of M. koenigii and its extract to be a high-value dietary product in terms of its anti-hyperglycemic effects and industrial profits. Therefore, the present review supports the researchers and readers/users to realize the importance of using M. koenigii in managing diabetes mellitus. Further, this review provides a valuable document for future scientific-related clinical trials in diabetic patients.

In Vitro Antioxidant and Alpha-Glucosidase Inhibition Activity of Polygonatum verticillatum of Karnali, Nepal

Background:

Diabetes mellitus is a metabolic disorder that has become a major health issue in modern era due to the long-term health consequences. α-amylase and α-glucosidase are the key enzymes involved in the digestion of starchy foods, and the inhibition of these enzymes is regarded as a postprandial hyperglycemia control strategy.

Objective:

The primary goal of this work is to examine the antioxidant activity as well as α-glucosidase inhibitory activity of Polygonatum verticillatum rhizomes via in vitro test.

Method:

The in vitro α-glucosidase inhibition activity was performed using p-nitrophenyl α-D¬-glucopyranoside (PNPG) substrate. 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay was performed to estimate the antioxidant activity.

Results:

The in vitro -glucosidase inhibitory activity of Polygonatum verticillatum was investigated for the very first time. Of the three fractions and a crude extract, the ethyl acetate (EA) fraction disclosed potent inhibition activity against α-glucosidase enzyme with an IC50 value of 22.3 ± 0.1 μg/mL. Likewise, the IC50 values for dichloromethane (DCM) fraction and the crude extract against α-glucosidase were reported 34 ± 0.1 μg/mL, and 402.2 ± 0.2 μg/mL, respectively. Similarly, the EA fraction, crude extract, and DCM fraction disclosed promising antioxidant activity with IC50 55 ± 0.3 μg/mL, 171.5 ± 0.6 μg/mL, and 164.1 ± 3.4 μg/mL, respectively.

Conclusion:

These findings concluded that among the crude extract and fractions of Polygonatum verticillatum of Nepalese origin, the EA fraction constituted a potent α-glucosidase inhibiting and antioxidant agent. Further research is required to expose the inhibiting compounds.

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.

Recent developments made in the assessment of the antidiabetic potential of gymnema species - From 2016 to 2020

BACKGROUND

In traditional herbal medicine, the Gymnema species has been well known for various therapeutic activities such as anti-diabetic, anti-inflammatory, anti-bacterial, anti-arthritic, anti-hyperlipidemic, cytotoxic, and immunostimulatory activities. This review is an effort to analyse all the recent studies done to explore the anti-diabetic potential of traditional Gymnema species. Gymnema sylvestre (Retz.) R.Br. ex Sm. is an important member of the Apocynaceae family that has been used to treat a variety of diseases, the most studied of which is diabetes. This action is mostly due to the pharmacologically active phytoconstituents present in its extract, which include gymnemic acids, triterpenoid saponin glycosides, and so on. Numerous other Gymnema species have also demonstrated a similar pharmacological action.

INTRODUCTION

The goal of this study is to give a critical overview of the available data on Gymnema species that are used to treat diabetes. The major goal of this study is to give up-to-date knowledge on ethnopharmacology, botany, pharmacology, and structure-activity relationships of Gymnemaspecies from 2016 to 2020, as well as potential future research. The potential of using medicinal plants for alleviating symptoms of diabetes is recently being recognized. This review aims to summarize the available data and highlight both the potential and shortcomings of using Gymnema therapeutically. This knowledge can further be used to develop more therapeutically effective drugs derived from Gymnema.

MATERIALS AND METHODS

Data for Gymnema species was obtained using a mix of several search terms from online databases such as PubMed, SCOPUS, and Europe PMC. Other literature surveys relevant to traditional knowledge, phytochemistry, pharmacology, or structure-activity relationship activity were also used as reference. Several methods by which Gymnema species extracts exert their effects have been investigated, and a summary of the newly discovered chemicals isolated from the plant in the previous five years has been provided.

RESULTS

SAR based evaluation has been carried out for a total of 27 pharmacologically active compounds belonging to three species of Gymnema genus (Gymnema sylvestre, Gymnema latifolium, and Gymnema inodorum).These compounds demonstrated the critical significance of plant medicines for diabetes management. Numerous heterocyclic compounds have anti-diabetic action and may serve as a starting point for the design and identification of new diabetes inhibitors.

CONCLUSIONS

This study aims to provide researchers with a better understanding of the antidiabetic potential Gymnema species, as well as an outline of prospective future developments. It was concluded after studying the evaluation done in the last 5 years that although extracts of Gymnema have shown good antidiabetic potential, further modifications in the structures could result in the development of more potent and safer compounds.

Flavonoids and proanthocyanidins-rich fractions from Eugenia dysenterica fruits and leaves inhibit the formation of advanced glycation end-products and the activities of α-amylase and α-glucosidase

ETHNOPHARMACOLOGICAL RELEVANCE

Different parts of Eugenia dysenterica have been popularly used in Brazil for treating diabetes mellitus and its complications. The present study aimed to screen extracts from E. dysenterica fruit pulp, peel, seed and leaf for carbohydrate digestive enzymes inhibitors with antioxidant and anti-glycation capacities.

MATERIALS AND METHODS

Ethanol extracts of E. dysenterica were subjected to a liquid-liquid fractionation and the fractions were used to evaluate their antioxidant properties and inhibitory potential against the formation of advanced glycation end-products (AGEs) and α-amylase and α-glucosidase.

RESULTS

The ethyl acetate fraction (EtOAcF) from seed and the dichloromethane fraction (CH₂Cl₂F) and EtOAcF from leaf had high antioxidant capacities (ORAC >5500 μmol trolox eq g^-1, FRAP >1500 μmol trolox eq g^-1 and DPPH IC₅₀ < 35 μg mL^-1) and showed exceptional inhibitory activities against AGEs formation (glycation inhibition above 80% at 10 μg mL^-1) and α-amylase and α-glucosidase (inhibition above 50% at 10 μg mL^-1). The gallated B-types proanthocyanidins were the most active ingredients found in the leaf of E. dysenterica (CH₂Cl₂ and EtOAcF), being responsible for the notorious inhibitory effects against glycation and glycoside hydrolases due to their ortho-hydroxyl groups, which play role in scavenge and quench free radicals and glycated products, and may occupy the enzymes' substrate binding pocket. Furthermore, gallic acid, quercetin and its glycoside derivatives were detected by the first time in the E. dysenterica fruit seed (EtOAcF).

CONCLUSIONS

The results strongly contribute to the understanding of the antidiabetic potential of seeds and leaves from E. dysenterica, a species from a global biodiversity hotspot, which appears to be linked to the prevention of oxidative stress, AGEs production and postprandial hyperglycemia.

Physiological, Biochemical, and Agronomic Trait Responses of Nigella sativa Genotypes to Water Stress

Water stress may affect the growth, physiology, morphology, biochemistry, and productivity of Nigella sativa (black cumin), a medicinal and aromatic plant. Measuring these parameters under various irrigation regimes could provide useful information for successful genotype selection and breeding. Therefore, these agronomically significant features were evaluated in ten black cumin genotypes (Afghanistan, Pakistan, Syria, India, Arak, Isfahan, Semirom, Shahreza, Shahrekord, and Mashhad) under three irrigation regimes (40% (I1), 60% (I2), and 80% (I3) of permissible moisture discharge) during the 2017 to 2018 growing seasons. Water stress was shown to increase the levels of carotenoids (Cars), proline, total soluble carbohydrates (TSC), malondialdehyde (MDA), hydrogen peroxide (H2O2), catalase (CAT), and ascorbate peroxidase (APX) activities but reduced the relative water content (RWC) and chlorophyll content. The highest increases in Cars, TSC, proline, CAT, and APX were noted in the Arak, Isfahan, Semirom, Shahreza, Shahrekord, and Mashhad genotypes under the I3 water regime, respectively. At the same time, the lowest decrease was observed in chlorophyll, H2O2, and relative water content (RWC) in Semirom. According to the stress susceptibility index, the most resistant genotypes were Shahrekord under I2 and Semirom under I3. These data demonstrate that the irrigation regimes affected the physiological, biochemical, and morphological features of black cumin both qualitatively and quantitatively, although the impact varied depending upon the genotype, irrigation regime, and traits. As such, the results presented represent valuable information with which to inform future selection and breeding programs for drought-tolerant black cumin. This is of particular significance considering global climate change.

The antihyperglycemic and hypolipidemic effects of Ribes khorassanicum hydro-ethanolic extract co-administration in type 2 diabetic patients: A randomized double blind placebo controlled trial

Objective

The present randomized clinical trial assessed the antihyperglycemic and hypolipidemic effects of hydro-ethanolic extract of Ribes khorassanicum.

Materials and Methods

Eighty type 2 diabetic patients were randomly allocated to placebo or intervention groups and respectively received placebo or extract capsules (700 mg, bid) beside their conventional medication for 3 months. Patients' blood pressure and blood levels of fasting blood glucose (FBS), glycosylated hemoglobin (HbA1c), 2 hr postprandial glucose (2hPPG), triglyceride, total cholesterol, low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were measured at the beginning of the study and after 3 months of treatment. For determination of plant safety, liver enzymes (SGOT and SGPT) and kidney function (in terms of urea, creatinine, and microalbumin levels) were assessed and patients were asked to report adverse effects.

Results

The R. khorasanicum hydro-ethanolic extract supplementation significantly decreased the levels of FBS, total cholesterol, triglyceride, and LDL-C in the extract group compared to the placebo group (p<0.05-p<0.01). However, 2hPPG, HbA1c, HDL-C, SGOT, SGPT, urea, creatinine, and urine microalbumin values were not significantly different between the placebo and the extract groups. No adverse effects were reported by the patients.

Conclusion

Co-supplementation of diabetic patients with R. khorasanicum extract ameliorated hyperglycemia and hyperlipidemia without causing any adverse effects; therefore, the plant extract may be recommended as a complementary therapy to improve diabetes-induced metabolic disturbances.

Medicinal Plants in the Treatment of Hypertension: A Review

Traditional medicine is a comprehensive term for ancient, culture-bound health care practices that existed before the use of science in health matters and has been used for centuries. Medicinal plants are used to treat patients with cardiovascular diseases, which may occur due to ailments of the heart and blood vessels and comprise heart attacks, cerebrovascular diseases, hypertension, and heart failure. Hypertension causes difficulty in the functioning of the heart and is involved in atherosclerosis, raising the risk of heart attack and stroke. Many drugs are available for managing these diseases, though common antihypertensive drugs are generally accompanied by many side effects. Medicinal herbs have several active substances with pharmacological and prophylactic properties that can be used in the treatment of hypertension. This review presents an overview of some medicinal plants that have been shown to have hypotensive or antihypertensive properties.

Washingtonia filifera seed extracts inhibit the islet amyloid polypeptide fibrils formations and α-amylase and α-glucosidase activity

Washingtonia filifera seeds have revealed to possess antioxidant properties, butyrylcholinesterase and xanthine oxidase inhibition activities. The literature has indicated a relationship between Alzheimer's disease (AD) and type-2 diabetes (T2D). Keeping this in mind, we have now evaluated the inhibitory properties of W. filifera seed extracts on α-amylase, α-glucosidase enzyme activity and the Islet Amyloid Polypeptide (IAPP) fibrils formation. Three extracts from seeds of W. filifera were evaluated for their enzyme inhibitory effect and IC50 values were calculated for all the extracts. The inhibition mode was investigated by Lineweaver-Burk plot analysis and the inhibition of IAPP aggregate formation was monitored. W. filifera methanol seed extract appears as the most potent inhibitor of α-amylase, α-glucosidase, and for the IAPP fibril formation. Current findings indicate new potential of this extract that could be used for the identification or development of novel potential agents for T2D and AD.

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.

Ameliorative potential of Operculina turpethum against streptozotocin-induced diabetes in rats: biochemical and histopathological studies

The study aimed to investigate the acute toxicity, antidiabetic potential (in-vitro and in-vivo) of the Operculina turpethum (L.) Silva Manso at fraction level. The plant was fractionated into different fractions, i.e., flavonoid fraction (OTFF), tannin fraction (OTTF), saponin fraction (OTSF). In-vitro alpha-amylase inhibition assay revealed that OTFF was found to be more potent than standard Acarbose. The plant fractions were evaluated by MTT assay at different concentrations ranging from 100 to 1000 µg/ml. All the fractions were further evaluated for their safety profile, and the biochemical, hematology and histopathology result exhibits that the OTFF fraction produces mild toxicity at organ level at a concentration of 2000 mg/kg in albino mice. The in-vivo antidiabetic study was carried out on Sprague-Dawley rats using high-fat diet (HFD) feeding streptozotocin (STZ) diabetic model, and the biochemical, histopathology research findings represent that OTFF at a concentration of 500 mg/kg, p.o. was found to be highly significant among all the fractions and found to be more potent than the standard Acarbose. LC-MS characterization of the bioactive fraction OTFF showed the presence of rutin with m/z 610.52 in 50.50% and Apigenin 7-O-6'' acetyl-glucoside with m/z 475.42 in 24.10%; from molecular docking study, it is predicted that the fraction primarily acts as an alpha-amylase inhibitor and PPAR gamma agonist. In conclusion, the plant's OTFF fraction acts as a potential therapeutic agent for Type II diabetes mellitus.

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.

Identification of Dipeptidyl Peptidase-4 and α-Amylase Inhibitors from Melicope glabra (Blume) T. G. Hartley (Rutaceae) Using Liquid Chromatography Tandem Mass Spectrometry, In Vitro and In Silico Methods

The present study investigated the antidiabetic properties of the extracts and fractions from leaves and stem bark of M. glabra based on dipeptidyl peptidase-4 (DPP-4) and α-Amylase inhibitory activity assays. The chloroform extract of the leaves was found to be most active towards inhibition of DPP-4 and α-Amylase with IC₅₀ of 169.40 μg/mL and 303.64 μg/mL, respectively. Bioassay-guided fractionation of the leaves' chloroform extract revealed fraction 4 (CF4) as the most active fraction (DPP-4 IC₅₀: 128.35 μg/mL; α-Amylase IC₅₀: 170.19 μg/mL). LC-MS/MS investigation of CF4 led to the identification of trans-decursidinol (1), swermirin (2), methyl 3,4,5-trimethoxycinnamate (3), renifolin (4), 4',5,6,7-tetramethoxy-flavone (5), isorhamnetin (6), quercetagetin-3,4'-dimethyl ether (7), 5,3',4'-trihydroxy-6,7-dimethoxy-flavone (8), and 2-methoxy-5-acetoxy-fruranogermacr-1(10)-en-6-one (9) as the major components. The computational study suggested that (8) and (7) were the most potent DPP-4 and α-Amylase inhibitors based on their lower binding affinities and extensive interactions with critical amino acid residues of the respective enzymes. The binding affinity of (8) with DPP-4 (-8.1 kcal/mol) was comparable to that of sitagliptin (-8.6 kcal/mol) while the binding affinity of (7) with α-Amylase (-8.6 kcal/mol) was better than acarbose (-6.9 kcal/mol). These findings highlight the phytochemical profile and potential antidiabetic compounds from M. glabra that may work as an alternative treatment for diabetes.

Antidiabetic effects of Syzygium cumini leaves: A non-hemolytic plant with potential against process of oxidation, glycation, inflammation and digestive enzymes catalysis

ETHNOPHARMACOLOGICAL RELEVANCE

Plant materials are commonly used in traditional medicine in order to treat various diseases such as Diabetes mellitus. Some plants, such as Syzygium cumini, have the capability to act controlling oxidative stress and protein glycation besides their potential to decrease hyperglycemia and hyperlipidemia by the inhibition of the catalysis of digestive enzymes. The aim of this study was to evaluate the antioxidant and antiglicant activity of S. cumini leaves fractions, their capacity to inhibit hydrolases and lipase enzymes, as well as the cytotoxicity effects against erythrocytes and comparate these results with isolate quercetin flavonoid.

MATERIAL AND METHODS

Ethnobotanical researches, carried out by academic studies at the Federal University of Uberlandia, led us to choose S. cumini as a potential plant for treatment of Diabetes mellitus. Fractions from ethanolic extract of S. cumini (hexane/Hex, dichloromethane/DCM, ethyl acetate/EtOAc, n-butanol/ButOH and water/H₂O) were used to evaluate their antioxidant (DPPH, ORAC and FRAP) and antiglycant (BSA/fructose, BSA/methylglyoxal and Arginine/Methylglyoxal) activity as well as the inhibitory potential against α-amylase, α-glucosidase and lipase. In addition, identification of the main bioactive compounds of S. cuimini leaves by HPLC-ESIMS/MS analysis was carried out.

RESULTS

Our results indicate that all fractions, for exception Hex, present noteworthy antioxidant activity, mainly in EtOAc and ButOH fractions (FRAP 1154.49 ± 67.37 and 1178.27 ± 21.26 μmol trolox eq g^-1, respectively; ORAC 1224.63 ± 58.16 and 1313.53 ± 85.23 μmol trolox eq g^-1, respectively; DPPH IC₅₀ 15.7 ± 2.4 and 23.5 ± 2.7 μg mL^-1, respectively). Regarding the antiglycant activity (BSA/fructose and Arginine/Methylglyoxal models), all fraction, for exception Hex, presented inhibition higher than 85%. All fractions were capable to inhibit 100% of α-amylase and the fractions DCM, EtOAc and ButOH inhibited α-glucosidase more than 50%. Regarding the lipase assay, DCM and Hex had the best activity (31.5 ± 14.3 and 44.3 ± 4.5 μg mL^-1, respectively). Various biomolecules known as potent antioxidants were identified in these fractions, such as quercetin, kaempferol, luteolin and (Epi)catechin.

CONCLUSION

S. cumini fractions and quercetin presented promising antioxidant and antiglycation properties as well as the ability to inhibit digestive enzymes. This study presents new biological activities not yet described for S. cumini which provide new possibilities for further studies in order to assess the antidiabetic potential of S. cumini fractions especially EtOAc and ButOH.

Flavanols and triterpenoids from Myrianthus arboreus ameliorate hyperglycaemia in streptozotocin-induced diabetic rats possibly via glucose uptake enhancement and α-amylase inhibition

Myrianthus arboreus is use traditionally as an antidiabetic agent in Ghana. We reported the in vivo antidiabetic activity of its 70 % ethanol stem bark extract (MAB) which we found to be strongly concentrated in its EtOAc fraction using glucose uptake and enzyme inhibitory assays. The present study sought to investigate the in vivo hypoglycaemic and anti-hyperlipidaemic activity of this ethyl acetate fraction of MAB (MAB-EtOAc, 50 and 100 mg/kg) in streptozotocin (STZ)-induced diabetic rats for 21 days, isolate and evaluate the bioactive constituents responsible for the antidiabetic activity. In silico pharmacokinetic and toxicity properties of the most active compound was also determined. MAB-EtOAc significantly (p < 0.001) reduced the blood glucose levels while normalizing considerably the altered serum lipid parameters of the diabetic rats which was comparable to glibenclamide (5 mg/kg). Chemical investigation of MAB-EtOAc led to the isolation of seven known compounds including three flavanols which are reported for the first time in the plant: epicatechin (1), epigallocatechin (2), dulcisflavan (3), euscaphic acid (4), tormentic acid (5), sitosterol-3-O-β-d-glucopyranoside (6) and arjunolic acid (7). The compounds markedly inhibited the action of α-amylase and, except for 4 and 6, which stimulated considerably glucose uptake in C2C12 cells. Compounds 2, 3, 5, 6 and 7 which were further evaluated in STZ-induced diabetic rats demonstrated hypoglycaemic and anti-hyperlipidaemic activities which, however, were not comparable with MAB-EtOAc. Compound 3, the most active compound was predicted to be non-toxic, non-mutagenic, has reasonable oral bioavailability and a decent substrate for further drug development. The findings of this study show that the isolated compounds may contribute to the antidiabetic activity of M. arboreus and could serve as marker compounds for the quality control of herbal medicines that would be made from the plant.

Assessment of the anti-diabetic potential of the Cratoxylum formosum subsp. formosum extracts via carbohydrate hydrolyzing enzymes inhibitory activities

Introduction: This research aims to evaluate the anti-diabetic activity of the extracts from different parts of Cratoxylum formosum subsp. formosum.Methods: The in vitro inhibitory activities of the hexane (HEX), dichloromethane (DCM) and ethyl acetate (EtOAc) extracts from the flowers, leaves, roots and stems on pancreatic α-amylase (pAA), Saccharomyces α-glucosidase (SAG), rat intestinal maltase (rIM), and sucrase (rIS) were investigated. Results: The DCM and EtOAc extracts from the flowers (IC50 5.4 ± 1.5 and 10.5 ± 0.6 µg/mL) displayed the similar inhibitory activities as acarbose (IC50 7.2 ± 0.4 µg/mL) in the pAA assay. The inhibitory activities of the DCM and EtOAc extracts from the flowers (IC50 56.7 ± 8.9 and 20.4 ± 0.4 µg/mL), EtOAc extract from leaves (IC50 45.0 ± 3.5 µg/mL), DCM and EtOAc extracts from roots (IC50 35.0 ± 6.7 and 16.7± 3.6 µg/mL), and EtOAc extract from stems (IC50 31.1 ± 7.3 µg/mL) were more potent than acarbose (IC50 431.4 ± 16.7 µg/mL) on SAG inhibitory assay (P<0.05). In the rIM assay, DCM and EtOAc extracts from the flowers (IC50 8.5 ± 0.2 and 12.4 ± 0.3 µg/mL) exhibited stronger inhibitory activity than acarbose (IC50 38.5 ± 7.2 µg/mL) (P<0.05). Moreover, the inhibitory activity of DCM extract from the flowers (IC50 16.9 ± 1.5 µg/ mL) was comparable to the acarbose (IC50 15.5 ± 1.2 µg/mL) on rIS assay. Conclusion: The DCM and EtOAc extracts from the flowers were more active than the leaves, roots and stems in the inhibition of our defined target enzymes.

Medicinal Plants Used in Traditional Management of Cancer in Uganda: A Review of Ethnobotanical Surveys, Phytochemistry, and Anticancer Studies

The burden of neoplastic diseases is a significant global health challenge accounting for thousands of deaths. In Uganda, about 32,617 cancer cases were reported in 2018, accompanied by 21,829 deaths. In a view to identify some potential anticancer plant candidates for possible drug development, the current study was designed to compile the inventory of plants with reported anticancer activity used in rural Uganda and the evidences supporting their use in cancer therapy. An electronic survey in multidisciplinary databases revealed that 29 plant species belonging to 28 genera distributed among 24 families have been reported to be used in the management of cancer in Uganda. Anticancer plants were majorly from the families Bignoniaceae (7%), Caricaceae (7%), Fabaceae (7%), Moraceae (7%), and Rutaceae (7%). Most species occur in the wild (52%), though some are cultivated (48%). The growth habit of the plants is as trees (55%) or herbs (45%). Anticancer extracts are usually prepared from leaves (29%), bark (24%), roots (21%), and fruits (13%) through decoctions (53%), as food spices (23%) or pounded to produce ointments that are applied topically (10%). Prunus africana (Hook.f.) Kalkman, Opuntia species, Albizia coriaria (Welw. ex Oliver), Daucus carota L., Cyperus alatus (Nees) F. Muell., Markhamia lutea (Benth.) K. Schum., and Oxalis corniculata L. were the most frequently encountered species. As per global reports, Allium sativum L., Annona muricata L., Carica papaya L., Moringa oleifera Lam., Opuntia species, Prunus africana (Hook.f.) Kalkman, and Catharanthus roseus (L.) G. Don. are the most studied species, with the latter having vincristine and vinblastine anticancer drugs developed from it. Prostate, cervical, breast, and skin cancers are the top traditionally treated malignancies. There is a need to isolate and evaluate the anticancer potential of the bioactive compounds in the unstudied claimed plants, such as Cyperus alatus (Nees) F. Muell., Ficus dawei Hutch., Ficus natalensis Hochst., and Lovoa trichilioides Harms, and elucidate their mechanism of anticancer activity.

Shorea roxburghii Leaf Extract Ameliorates Hyperglycemia Induced Abnormalities in High Fat/Fructose and Streptozotocin Induced Diabetic Rats

This study investigated the hypoglycemic effect of the methanol extract of Shorea roxburghii leaves (SRL) in high fat diet/high fructose solution (HFDHF) and streptozotocin (STZ) induced type 2 diabetes mellitus (T2DM) in rats as well as evaluating its ameliorative potentials in altered biochemical and hematological parameters in the treated rats. T2DM was induced in Sprague Dawley (SD) rats by feeding with HFDHF for 4 weeks and administering STZ (35 mg/kg, i. p.). Diabetic rats were given SRL extract at doses of 100 and 400 mg/kg for 30 days. The food and water intake were monitored on a daily basis, while the fasting blood glucose (FBG) levels and body weight were measured weekly. Biochemical and hematological parameters as well as histopathological studies of the pancreas were also evaluated. SRL significantly decreased FBG and improved the body weight, food and water intake of treated diabetic rats. Furthermore, biochemical and hematological parameters including liver and kidney function enzymes, lipid profiles, white blood and red blood cells parameters were markedly ameliorated by SRL. Histopathological analyses of the pancreas indicated reconstitution of β-cells architecture in SRL treated rats. The results of this study suggest that SRL has antidiabetic potential and can be considered for the treatment of T2DM.

Dietary Phytonutrients in the Prevention of Diabetes-related Complications

BACKGROUND

The increasing prevalence of reported cases of diabetes has evidently become a major global public health concern. Although diabetes management is possible by the administration of synthetic anti-diabetic agents, there are profound side-effects associated with their long-term usage. Hence there is a demand for safer alternatives which could be possibly formulated using specific yet common phytonutrients.

OBJECTIVES

The main objective of this review is to describe the cellular mechanisms of phytonutrients as an alternative to commercially available synthetic anti-diabetic agents in the management of diabetes and related complications. Furthermore, the clinical evidence that supports this view is also highlighted.

METHODOLOGY

An in-depth review of published literature was carried out to identify the most promising phytonutrients in the management of diabetes and related complications.

RESULTS

A number of phytonutrients are reported to be potential anti-diabetic agents. Few examples include biguanides, resveratrol, lycopene, thymoquinone and quercetin. However, suitable formulations using these phytonutrients and their clinical trials are still underway. Most of the reported findings focus on one aspect of several biochemical processes e.g. enhancement of glucose utilization, antioxidation, induction of insulin production, antiglycation, etc. An in-depth study of phytonutrients with respect to functional, immunological as well as biochemical factors suggesting their efficacy, as well as safety in the management of diabetes, is rarely reported.

CONCLUSION

Our study thus highlights the abundance of clinical evidence of the efficiency of phytonutrients, and at the same time, the scarcity of clinically approved and marketed phytonutrients, as drugs, for the management of diabetes and related complications.

Anti-adipogenic Effect of β-Carboline Alkaloids from Garlic (Allium sativum)

Garlic (Allium sativum L.) is utilized worldwide for culinary and medicinal use and has diverse health benefits. As part of our ongoing research to identify bioactive components from natural resources, phytochemical analysis of the methanolic extract of garlic led to the isolation and characterization of six compounds: Three eugenol diglycosides (1-3) and three β-carboline alkaloids (4-6). In particular, the absolute configurations of β-carboline alkaloids (5 and 6) were established by gauge-including atomic orbital nuclear magnetic resonance chemical shift calculations, followed by DP4+ analysis. Here, we evaluated the effects of compounds 1-6 on 3T3-L1 preadipocyte adipogenesis and lipid metabolism. 3T3-L1 adipocyte differentiation was evaluated using Oil Red O staining; the expression of adipogenic genes was detected using RT-qPCR. Among compounds 1-6, (1R,3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (6) inhibited 3T3-L1 preadipocyte adipogenesis and reduced the expression of adipogenic genes (Fabp4, PPARγ, C/EBPβ, Adipsin, and Adipoq). Moreover, it markedly decreased the actylation of α-tubulin, which is crucial for cytoskeletal remodeling during adipogenesis. Anti-adipogenic effects were observed upon treatment with compound 6, not only during the entire process, but also on the first two days of adipogenesis. Additionally, treatment with compound 6 regulated the expression of genes involved in adipocyte lipid metabolism, decreasing the lipogenic gene (SREBP1) and increasing lipolytic genes (ATGL and HSL). We provide experimental evidence of the health benefits of using (1R,3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid obtained from garlic to prevent excessive adipogenesis in obesity.

The effect of nettle (Urtica dioica) supplementation on the glycemic control of patients with type 2 diabetes mellitus: A systematic review and meta-analysis

Type 2 diabetes mellitus (T2DM) is a major health problem, worldwide, that is associated with increased morbidity and mortality. Several randomized controlled clinical trials (RCTs) have investigated the effect of nettle (Urtica dioica) supplementation on markers of glycemic status in patients with T2DM, with conflicting results. Therefore, the present study assessed the effect of nettle on some glycemic parameters in patients with T2DM. A comprehensive search was conducted in PubMed, Scopus, Cochrane Library, and Web of Science, from database inception up to June 2019, to identify RCTs investigating the effect of nettle supplementation on glycemic markers, including fasting blood sugar (FBS) concentrations, insulin levels, homeostasis model assessment-estimated insulin resistance index, and glycosylated hemoglobin percentage in adults with T2DM. The Cochrane Collaboration tool was used to assess the methodological quality of the included studies. Results of this meta-analysis were reported based on the random effects model. Eight RCTs, comprising 401 participants, were included in the present systematic review and meta-analysis. Based on the Cochrane Collaboration risk of bias tool, five studies were considered as good quality, one was fair, and two studies were poor, respectively. The results of the meta-analysis revealed a significant reduction in FBS concentrations (weighted mean difference [WMD]: -18.01 mg/dl, 95% confidence interval [CI]: -30.04 to -5.97, p < .001, I² = 94.6%) following nettle supplementation. However, no significant reduction was observed in insulin levels (WMD: 0.83 Hedges' g, 95% CI: -0.26 to 1.92, p = .13, I² = 89.4%), homeostasis model assessment-estimated insulin resistance index (WMD: -0.22, 95% CI: -0.83 to 0.40, p = .49, I² = 69.2%), or glycosylated hemoglobin percentage (WMD: -0.77%, 95% CI: -1.77 to 0.22, p = .12, I² = 83.0%). The findings of the present study suggest that nettle supplementation may be effective in controlling FBS for T2DM patients. However, further studies are needed to confirm the veracity of these results.

Anil Kumar N, Sharopov F, Ramírez-Alarcón K, Ruiz-Ortega A, Abdulmajid Ayatollahi S, Valere Tsouh Fokou P, Kobarfard F, Amiruddin Zakaria Z, Iriti M, Taheri Y, Martorell M, Sureda A, N. Setzer W, Durazzo A, Lucarini M, Santini A, Capasso R, Adrian Ostrander E, -ur-Rahman A, Iqbal Choudhary M, C. Cho W, Sharifi-Rad J. Antidiabetic Potential of Medicinal Plants and Their Active Components

Diabetes mellitus is one of the major health problems in the world, the incidence and associated mortality are increasing. Inadequate regulation of the blood sugar imposes serious consequences for health. Conventional antidiabetic drugs are effective, however, also with unavoidable side effects. On the other hand, medicinal plants may act as an alternative source of antidiabetic agents. Examples of medicinal plants with antidiabetic potential are described, with focuses on preclinical and clinical studies. The beneficial potential of each plant matrix is given by the combined and concerted action of their profile of biologically active compounds.

Bioactive Compounds and Biological Functions of Garlic (Allium sativum L.)

Garlic (Allium sativum L.) is a widely consumed spice in the world. Garlic contains diverse bioactive compounds, such as allicin, alliin, diallyl sulfide, diallyl disulfide, diallyl trisulfide, ajoene, and S-allyl-cysteine. Substantial studies have shown that garlic and its bioactive constituents exhibit antioxidant, anti-inflammatory, antibacterial, antifungal, immunomodulatory, cardiovascular protective, anticancer, hepatoprotective, digestive system protective, anti-diabetic, anti-obesity, neuroprotective, and renal protective properties. In this review, the main bioactive compounds and important biological functions of garlic are summarized, highlighting and discussing the relevant mechanisms of actions. Overall, garlic is an excellent natural source of bioactive sulfur-containing compounds and has promising applications in the development of functional foods or nutraceuticals for the prevention and management of certain diseases.