Syzygium cumini ameliorates insulin resistance and β-cell dysfunction via modulation of PPAR, dyslipidemia, oxidative stress, and TNF-α in type 2 diabetic rats

Syzygium cumini ameliorates high fat diet induced glucose intolerance, insulin resistance, weight gain, hepatic injury and nephrotoxicity through modulation of PTP1B and PPARγ signaling

Metabolic disorders are majorly associated with insulin resistance and an impaired glucose tolerance. Since, many of the currently available drugs exhibit adverse effects and are resistant to therapies, natural products are a promising alternate in the alleviation of complex metabolic disorders. In the current study, Syzygium cumini methanolic extract (SCE) was investigated for its anti-diabetic and anti-adipogenic potential using C57BL/6 mice fed on high fat diet (HFD). The HFD fed obese mice were treated with 200 mg/kg SCE and compared with positive controls Metformin, Pioglitazone and Sodium Orthovanadate. The biometabolites in SCE were characterized using Fourier transform infrared and gas chromatography and mass spectroscopy. A reduction in blood glucose levels with improved insulin sensitivity and glucose tolerance was observed in SCE-treated HFD obese mice. Histopathological and biochemical investigations showed a reduction in hepatic injury and nephrotoxicity in SCE-administered HFD mice. Results showed inhibition of PTP1B and an upregulation of IRS1 and PKB-mediated signaling in skeletal muscle. A significant decrease in lipid markers such as TC, TG, LDL-c and VLDL-c levels were observed with increased HDL-c in SCE-treated HFD mice. A significant decrease in weight and adiposity was observed in SCE-administered HFD mice in comparison to controls. This decrease could be due to the partial agonism of PPARγ and an increased expression of adiponectin, an insulin sensitizer. Hence, the dual-modulatory effect of SCE, partly due to the presence of 26% Pyrogallol, could be useful in the management of diabetes and its associated maladies.

Beneficial effect of honokiol and magnolol on polyol pathway and oxidative stress parameters in the testes of diabetic rats

In diabetes hyperglycemia, excessive production of free radicals and present oxidative stress lead to many complications in the body, including male reproductive system disorders. To prevent the development of diabetic complications in the testes resulting from them, it seems beneficial to include compounds considered as natural antioxidants. Honokiol and magnolol are neolignans obtained from magnolia bark, which possess proven antioxidant properties. The aim of this study was to evaluate the effect of honokiol and magnolol on the parameters of oxidative stress, polyol pathway and glycation products in the testes as well as on selected biochemical parameters in the blood serum of rats with type 2 diabetes. The study was conducted on mature male Wistar rats with high fat diet and streptozotocin-induced type 2 diabetes. Neolignans-treated rats received honokiol or magnolol orally at the doses of 5 or 25 mg/kg, respectively, for 4 weeks. Parameters related to glucose and lipid homeostasis, basic serological parameters and sex hormones level in the serum as well as polyol pathway parameters, antioxidant enzyme activity, endogenous antioxidants level, sumaric parameters for oxidative stress and oxidative damage in the testes were estimated. Oral administration of honokiol and magnolol turned out to be beneficial in combating the effects of oxidative stess in the testes, but showed no favorable effects on serum biochemical parameters. Additionally, magnolol compared to honokiol revealed more advantageous impact indicating the reversal of the effects of diabetic complications in the male reproductive system and counteracted oxidative stress damages and polyol pathway disorders in the testes.

A Critical Review on Role of Available Synthetic Drugs and Phytochemicals in Insulin Resistance Treatment by Targeting PTP1B

Insulin resistance (IR) is a condition of impaired response of cells towards insulin. It is marked by excessive blood glucose, dysregulated insulin signalling, altered pathways, damaged pancreatic β-cells, metabolic disorders, etc. Chronic hyperglycemic conditions leads to type 2 diabetes mellitus (T2DM) which causes excess generation of highly reactive free radicals, causing oxidative stress, further leading to development and progression of complications like vascular dysfunction, damaged cellular proteins, and DNA. One of the causes for IR is dysregulation of protein tyrosine phosphatase 1B (PTP1B). Advancements in drug therapeutics have helped people manage IR by regulating PTP1B, however have been reported to cause side effects. Therefore, there is a growing interest on usage of phytochemical constituents having IR therapeutic properties and aiding to minimize these complications. Medicinal plants have not been utilized to their full potential as a therapeutic drug due to lack of knowledge of their active and effective chemical constituents, mode of action, regulation of IR parameters, and dosage of administration. This review highlights phytochemical constituents present in medicinal plants or spices, their potential effectiveness on proteins (PTP1B) regulating IR, and reported possible mechanism of action studied on in vitro models. The study gives current knowledge and future recommendations on the above aspects and is expected to be beneficial in developing herbal drug using these phytochemical constituents, either alone or in combination, for medication of IR and diabetes.

Roles of Syzygium in Anti-Cholinesterase, Anti-Diabetic, Anti-Inflammatory, and Antioxidant: From Alzheimer's Perspective

Alzheimer's disease (AD) causes progressive memory loss and cognitive dysfunction. It is triggered by multifaceted burdens such as cholinergic toxicity, insulin resistance, neuroinflammation, and oxidative stress. Syzygium plants are ethnomedicinally used in treating inflammation, diabetes, as well as memory impairment. They are rich in antioxidant phenolic compounds, which can be multi-target neuroprotective agents against AD. This review attempts to review the pharmacological importance of the Syzygium genus in neuroprotection, focusing on anti-cholinesterase, anti-diabetic, anti-inflammatory, and antioxidant properties. Articles published in bibliographic databases within recent years relevant to neuroprotection were reviewed. About 10 species were examined for their anti-cholinesterase capacity. Most studies were conducted in the form of extracts rather than compounds. Syzygium aromaticum (particularly its essential oil and eugenol component) represents the most studied species owing to its economic significance in food and therapy. The molecular mechanisms of Syzygium species in neuroprotection include the inhibition of AChE to correct cholinergic transmission, suppression of pro-inflammatory mediators, oxidative stress markers, RIS production, enhancement of antioxidant enzymes, the restoration of brain ions homeostasis, the inhibition of microglial invasion, the modulation of ß-cell insulin release, the enhancement of lipid accumulation, glucose uptake, and adiponectin secretion via the activation of the insulin signaling pathway. Additional efforts are warranted to explore less studied species, including the Australian and Western Syzygium species. The effectiveness of the Syzygium genus in neuroprotective responses is markedly established, but further compound isolation, in silico, and clinical studies are demanded.

Role of Plant Derived Products Through Exhilarating Peroxisome Proliferator Activated Receptor-γ (ppar-γ) in the Amelioration of Obesity Induced Insulin Resistance

Abstract:

Insulin resistance is an elemental facet of the etiology of diabetes mellitus and the principal relating factor between obesity and diabetes. Oxidative stress, lipotoxicity, inflammation and receptor dysfunction are the underlying determinants of insulin resistance commencement in metabolic illnesses. ppar-γ is a nuclear transcription factor whose activation or inhibition directly influences insulin resistance and controls glucose and lipid homeostasis by modulating gene expression. Synthetic ligands of ppar-γ are therapeutically employed to counter the hyper-glycaemia associated with obesity and type 2 diabetes, but they possess severe side effects. In the modern era, bioactive phytochemicals have been employed in the drug development process and a considerable investigation has recently been initiated to analyze the ppar-γ activating ability of diverse phytochemicals. In this review, we outlined the role of phytochemicals in insulin resistance treatment through ppar-γ activation.

Phytochemical Profile, Biological Properties, and Food Applications of the Medicinal Plant Syzygium cumini

Syzygium cumini, locally known as Jamun in Asia, is a fruit-bearing crop belonging to the Myrtaceae family. This study aims to summarize the most recent literature related to botany, traditional applications, phytochemical ingredients, pharmacological activities, nutrition, and potential food applications of S. cumini. Traditionally, S. cumini has been utilized to combat diabetes and dysentery, and it is given to females with a history of abortions. Anatomical parts of S. cumini exhibit therapeutic potentials including antioxidant, anti-inflammatory, analgesic, antipyretic, antimalarial, anticancer, and antidiabetic activities attributed to the presence of various primary and secondary metabolites such as carbohydrates, proteins, amino acids, alkaloids, flavonoids (i.e., quercetin, myricetin, kaempferol), phenolic acids (gallic acid, caffeic acid, ellagic acid) and anthocyanins (delphinidin-3,5-O-diglucoside, petunidin-3,5-O-diglucoside, malvidin-3,5-O-diglucoside). Different fruit parts of S. cumini have been employed to enhance the nutritional and overall quality of jams, jellies, wines, and fermented products. Today, S. cumini is also used in edible films. So, we believe that S. cumini’s anatomical parts, extracts, and isolated compounds can be used in the food industry with applications in food packaging and as food additives. Future research should focus on the isolation and purification of compounds from S. cumini to treat various disorders. More importantly, clinical trials are required to develop low-cost medications with a low therapeutic index.

The self-nanoemulsifying drug delivery system of Petiveria alliacea extract reduced the homeostatic model assessment-insulin resistance value, interleukin-6, and tumor necrosis factor-α level in diabetic rat models

Background and Aim:

Metaflammation plays a significant role in the pathogenesis, development, and complication of diabetes mellitus (DM). This inflammation is associated with insulin resistance. Therefore, the inflammatory pathways have been targeted for pharmacological treatment. Petiveria alliacea can decrease blood glucose levels and has anti-inflammatory and antioxidant activities; however, there are still insufficient data regarding its efficacy for the treatment of DM. This study aimed to investigate the effect of the self-nanoemulsifying drug delivery system (SNEDDS) of P. alliacea leaf extract on the homeostatic model assessment (HOMA)-insulin resistance (IR) value and interleukin (IL)-6 and tumor necrosis factor-α (TNF-α) levels in a streptozotocin (STZ)-induced diabetic rat model.

Materials and Methods:

Thirty-five diabetic rat models were randomly divided into five groups. The first group received the SNEDDS of P. alliacea leaf extract at a dose of 50 mg/kg body weight (BW), the second group received it at a dose of 100 mg/kg BW, the third group received it at a dose of 200 mg/kg BW, the fourth group received 18 mg of metformin, and the fifth group only received the SNEDDS formula. The treatment was administered once a day, orally, for 14 days. On the 15^th day after treatment, the rats were sacrificed to obtain blood samples for cardiac examination. The IL-6, TNF-α, and insulin levels in the serum were measured using the enzyme-linked immunosorbent assay method. The HOMA-IR value was calculated using a formula.

Results:

The mean IL-6 and TNF-α levels were low in the group that received the SNEDDS of P. alliacea leaf extract. There was no significant difference in the insulin level in all treatment and control groups. However, a significant difference in the HOMA-IR value was noted between the group that received the SNEDDS of P. alliacea leaf extract and metformin and the group that did not receive treatment (p<0.05).

Conclusion:

The SNEDDS of P. alliacea leaf extract reduced the HOMA-IR value and suppressed the TNF-α and IL-6 levels in the STZ-induced diabetic rat model.

Antidiabetic Medicinal Plants Used in Democratic Republic of Congo: A Critical Review of Ethnopharmacology and Bioactivity Data

Several studies have been conducted and published on medicinal plants used to manage Diabetes Mellitus worldwide. It is of great interest to review available studies from a country or a region to resort to similarities/discrepancies and data quality. Here, we examined data related to ethnopharmacology and bioactivity of antidiabetic plants used in the Democratic Republic of Congo. Data were extracted from Google Scholar, Medline/PubMed, Scopus, ScienceDirect, the Wiley Online Library, Web of Science, and other documents focusing on ethnopharmacology, pharmacology, and phytochemistry antidiabetic plants used in the Democratic Republic of Congo from 2005 to September 2021. The Kew Botanic Royal Garden and Plants of the World Online web databases were consulted to verify the taxonomic information. CAMARADES checklist was used to assess the quality of animal studies and Jadad scores for clinical trials. In total, 213 plant species belonging to 72 botanical families were reported. Only one plant, Droogmansia munamensis, is typically native to the DRC flora; 117 species are growing in the DRC and neighboring countries; 31 species are either introduced from other regions, and 64 are not specified. Alongside the treatment of Diabetes, about 78.13% of plants have multiple therapeutic uses, depending on the study sites. Experimental studies explored the antidiabetic activity of 133 plants, mainly in mice, rats, guinea pigs, and rabbits. Several chemical classes of antidiabetic compounds isolated from 67 plant species have been documented. Rare phase II clinical trials have been conducted. Critical issues included poor quality methodological protocols, author name incorrectly written (16.16%) or absent (14.25%) or confused with a synonym (4.69%), family name revised (17.26%) or missing (1.10%), voucher number not available 336(92.05%), ecological information not reported (49.59%). Most plant species have been identified and authenticated (89.32%). Hundreds of plants are used to treat Diabetes by traditional healers in DRC. However, most plants are not exclusively native to the local flora and have multiple therapeutic uses. The analysis showed the scarcity or absence of high-quality, in-depth pharmacological studies. There is a need to conduct further studies of locally specific species to fill the gap before their introduction into the national pharmacopeia.

Establishment of long-term high-fat diet and low dose streptozotocin-induced experimental type-2 diabetes mellitus model of insulin resistance and evaluation of seed extracts of Syzygium cumini

Introduction: The principal mechanism responsible for reducing blood glucose is through insulin-stimulated glucose transport into skeletal muscle. The transporter protein that mediates this uptake is GLUT-4. A defect in this step is associated with reduced glucose utilization in muscle and adipose tissue, as observed in insulin-resistant type-2 diabetes mellitus (T2DM) patients. This study aimed to develop an experimental T2DM model and evaluate altered glucose transporter type 4 (GLUT-4) levels as a biomarker of insulin resistance. Antidiabetic activities of Syzygium cumini hydro-ethanolic seed extracts (SCE) were also evaluated. Methods: Adult male Wistar albino rats were fed a high-fat diet for 12 weeks and dosed intraperitoneally with streptozotocin (35 mg/kg). After treatment for 21 days, all investigations were done. The homeostasis model of assessment (HOMA) was used for the calculation of insulin resistance (HOMA-IR) and beta-cell function (HOMA-B) index. Diaphragm muscle and retroperitoneal fat were collected for real-time polymerase chain reaction (RT-PCR) studies. Results: A significant increase in fasting blood glucose, HOMA-IR, and serum lipids, and a decrease in serum insulin and HOMA-B were observed in the diabetic group, effects that reversed following pioglitazone and SCE treatment. The diabetic group showed a downregulation of GLUT-4 expression in skeletal muscle while an increase was observed in adipose tissue. Conclusion: A high-fat diet and low dose streptozotocin-induced experimental T2DM model of insulin resistance was developed to screen novel insulin sensitizers. Data generated demonstrated that altered GLUT-4 levels could be used as a biomarker of insulin resistance. Antidiabetic activity of S. cumini hydro-ethanolic seed extract was also confirmed in this study.

Risperidone Exacerbates Glucose Intolerance, Nonalcoholic Fatty Liver Disease, and Renal Impairment in Obese Mice

Risperidone, a second-generation antipsychotic drug used for schizophrenia treatment with less-severe side effects, has recently been applied in major depressive disorder treatment. The mechanism underlying risperidone-associated metabolic disturbances and liver and renal adverse effects warrants further exploration. This research explores how risperidone influences weight, glucose homeostasis, fatty liver scores, liver damage, and renal impairment in high-fat diet (HFD)-administered C57BL6/J mice. Compared with HFD control mice, risperidone-treated obese mice exhibited increases in body, liver, kidney, and retroperitoneal and epididymal fat pad weights, daily food efficiency, serum triglyceride, blood urea nitrogen, creatinine, hepatic triglyceride, and aspartate aminotransferase, and alanine aminotransferase levels, and hepatic fatty acid regulation marker expression. They also exhibited increased insulin resistance and glucose intolerance but decreased serum insulin levels, Akt phosphorylation, and glucose transporter 4 expression. Moreover, their fatty liver score and liver damage demonstrated considerable increases, corresponding to increases in sterol regulatory element-binding protein 1 mRNA, fatty acid-binding protein 4 mRNA, and patatin-like phospholipid domain containing protein 3 expression. Finally, these mice demonstrated renal impairment, associated with decreases in glutathione peroxidase, superoxide dismutase, and catalase levels. In conclusion, long-term administration of risperidone may exacerbate diabetes syndrome, nonalcoholic fatty liver disease, and kidney injury.

Antihyperlipidemic Activities and Hematological Properties of Ethanol Extract of Blighia Sapida Koenig Bark in Alloxan-Induced Diabetic Rats

Blighia sapida (BS) has been shown to be rich sources of antioxidant, thus, we evaluated effects of B. sapida Koenig stem bark ethanol extract (BSE) on lipid metabolism and hematological indices in diabetes rats.

Thirty male rats were divided into six groups of five rats each. Diabetes was elicited by intraperitoneal injection of alloxan (65 mg/kg body weight) once and orally administered with glibenclamide (5 mg/kg), B. sapida extract (50, 100 and 150 mg/kg body weight (bw) once daily for 21 days. Serum lipid profile, markers of hepato-renal toxicity and hemato-logical indices were examined using automated analyzer. Data were analyzed using one-way ANOVA and p < 0.05 was considered to be statistically different.

Diabetic untreated animals showed considerably elevated total cholesterol p < 0.05, also, significant increase in AST, ALT, ALP, urea and creatinine compared to control. Triglycerides, LDL-c, VLDL-c, AI and CRI decreased with extract administration and HDL-c increased considerable compared to untreated diabetic rats. Furthermore, significant lower hemoglobin (Hb) levels, packed cell volume (PCV), red blood cells (RBCs) levels, white blood cells (WBCs) compared to normal animals was recorded in the untreated group. These changes were returned to normal after the administration of extract 50, 100 and 150 mg/ kg body weight. Hence, these effects were most prominent in the animals treated with 150 mg/kg body weight of B. sapida bark.

This indicates that B. sapida stem bark possess anti-hyperlipidemic activity and improved the biochemical parameters within the hematological profile of diabetic rats.

Therapeutic effects of different doses of prebiotic (isolated from Saccharomyces cerevisiae) in comparison to n-3 supplement on glycemic control, lipid profiles and immunological response in diabetic rats

BACKGROUND

The regular intake of fiber generates numerous health benefits. However, the efficacy depends on the duration of consumption and the ingested dose. Studies investigating the optimal dose are of interest to enable the inclusion of fiber in the routine treatment of diabetic patients.

OBJECTIVE

We aimed to evaluate the effects of different doses of β-glucan (BG-isolated from Saccharomyces cerevisiae), in comparison to n-3 supplement, on the inflammatory and metabolic parameters of Wistar rats induced to diabetes by streptozotocin.

METHODS

Forty animals were randomly divided into six groups receiving 0 mg/kg, 10 mg/kg, 20 mg/kg, or 40 mg/kg BG daily for 4 weeks or fish oil derivative [1000 mg/kg of omega-3 fatty acids (n-3)] for the same period. One additional group was composed of healthy controls. Serum metabolic and immunological parameters were evaluated by colorimetric and ELISA assays respectively. Histopathological analysis of the liver, small intestine and pancreas were also conducted. Significant changes due to BG intake were set into regression models with second-degree fit in order to estimate the optimal BG dose to achieve health benefits.

RESULTS

The animals that ingested BG had lower food and water intake (p < 0.05) than the negative control group (0 mg/kg). However, consumption was still elevated in comparison to healthy controls. Blood glucose and serum levels of total cholesterol, LDL-c, and TG (p < 0.05) reduced in comparison to diabetic animals without treatment (better or similar to n-3 group depending on dose), but did not reach normal levels (in comparison to healthy controls). HDL-c was not different (p > 0.05) among all groups. These reductions were already seen with the lowest dose of 10 mg/kg. On average, the serum levels of the hepatic enzymes ALT and AST were 40% and 60% lower in the BG groups in comparison to diabetic animals without treatment (better results than n-3 group). The group receiving 40 mg/kg reached similar values of healthy controls for ALT; whereas the same result occurred from the dose of 10 mg/kg for AST. The ideal dose, estimated from the mean of all metabolic parameters was approximately 30 mg/kg/day. Regarding the immunological profile, TNF-α significantly decreased in the BG groups compared to controls (p < 0.05), reaching better values than n-3 group and similar to healthy controls. No significant differences were found between the groups in IL-1β or IL-10 (p > 0.05). No histological changes were found in the pancreas, liver, or intestine due to treatment among diabetic animals.

CONCLUSIONS

BG significantly reduced blood glucose as well as serum total cholesterol, LDL-c and TG. There was a hepatoprotective effect due to the reduction in ALT and AST and a reduction in TNF-α, indicating a modulation of the immune response. In general, BG effects were better than n-3 supplement (or at least comparable) depending on the dose.

Suppression of NLRP3 inflammasome improves alveolar bone defect healing in diabetic rats

Background

Excessive inflammatory response under hyperglycemia can impair alveolar bone defect healing under diabetic conditions. NLRP3 (NACHT [nucleotide-binding oligomerization], LRR [leucine-rich repeat], and PYD [pyrin domain] domains-containing protein 3) inflammasome has been considered to play a crucial role in the inflammatory response, but its correlation with the impaired alveolar bone repair in diabetes still remains unclarified. The objective of the current study is to investigate the effect of NLRP3 inflammasome inhibition by a lentiviral short hairpin RNA (shRNA) targeting NLRP3 on alveolar bone defect healing in diabetic rats.

Methods

Diabetes was induced in rats by high-fat diet and streptozotocin injection, and alveolar bone defects in both maxillae were created by surgery. Then, the lentiviral shRNA targeting NLRP3 was applied in the defect. Eight weeks after surgery, the alveolar bone regeneration was examined using hematoxylin and eosin (H&E) staining, and the gene expression in the bone healing site was detected using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) analysis and western blot analysis.

Results

H&E staining showed that treatment with lentiviral shRNA targeting NLRP3 could increase the bone regeneration score in the alveolar bone defect of diabetic rats. Additionally, qRT-PCR analysis and western blot analysis of the bone defect demonstrated that this shRNA inhibited the expression of NLRP3, apoptosis-associated speck-like protein containing a CARD, caspase-1, and proinflammatory cytokine interleukin-1β and increased the expression of osteogenic markers Runt-related transcription factor 2 and osteocalcin.

Conclusions

Our findings suggested that inhibition of NLRP3 inflammasome could improve alveolar bone defect healing in diabetic rats. The beneficial effect may correlate with reduced proinflammatory cytokine production and increased osteogenic gene expression in hyperglycemia.

Electronic supplementary material

The online version of this article (10.1186/s13018-019-1215-9) contains supplementary material, which is available to authorized users.

Syzygium cumini Leaf Extract Reverts Hypertriglyceridemia via Downregulation of the Hepatic XBP-1s/PDI/MTP Axis in Monosodium L-Glutamate-Induced Obese Rats

Syzygium cumini is used worldwide for the treatment of metabolic syndrome-associated outcomes. Previously, we described the antihypertriglyceridemic effect of the hydroethanolic extract of S. cumini leaf (HESc) in monosodium L-glutamate- (MSG-) induced obese rats. This study sought to investigate the molecular mechanisms underlying the antihypertriglyceridemic effect of HESc in MSG-obese rats. Newborn male Wistar rats were injected subcutaneously with MSG (4.0 g/kg/day, obese group) or saline 1.25% (1.0 mL/kg/day, lean group), from 2nd through 10th postnatal day. At 8 weeks old, obese rats started to be orally treated with HESc (0.5 or 1.0 g/kg/day, n = 7) or saline 0.9% (1 mL/kg/day, n = 7). Lean rats received saline solution (1 mL/kg/day, n = 7). Upon 8-week treatment, animals were euthanized for blood and tissue collection. Another set of adult nonobese Wistar rats was used for the assessment of HESc acute effects on Triton WR1339-induced hypertriglyceridemia. HESc reduced weight gain, as well as adipose tissue fat pads, without altering food intake of obese rats. HESc restored fasting serum glucose, triglycerides, total cholesterol, and free fatty acids, as well as insulin sensitivity, to levels similar to lean rats. Additionally, HESc halved the triglyceride content into very low-density lipoprotein particles, as well as healed liver steatosis, in obese rats. Hepatic protein expression of the endoplasmic reticulum chaperone GRP94 was decreased by HESc, which also downregulated the hepatic triglyceride secretion pathway by reducing the splicing of X-box binding protein 1 (XBP-1s), as well as protein disulfide isomerase (PDI) and microsomal triglyceride transfer protein (MTP) translational levels. This action was further corroborated by the acute inhibitory effect of HESc on triglyceride accumulation on Triton WR1339-treated rats. Our data support the downregulation of the XBP-1s/PDI/MTP axis in the liver of MSG-obese rats as a novel feasible mechanism for the antihypertriglyceridemic effect promoted by the polyphenolic phytocomplex present in S. cumini leaf.

Evaluation of the Anti-Diabetic Activity of Polysaccharide from Cordyceps cicadae in Experimental Diabetic Rats

Cordyceps cicadae is a medicinal fungus used in treating night sweat, childhood convulsions, vision improvement and pain. This study was designed to evaluate the anti-diabetic activity of the crude polysaccharide (SHF) from the mycelium and body portion of C. cicadae. Diabetes mellitus was induced in the rat with a single intravenous injection of alloxan monohydrate (150 mg/kg). In other to evaluate the anti-diabetic effects of C. cicadae polysaccharide in alloxan-induced diabetic rats, the crude polysaccharide (SHF at 100, 200 and 400 mg/kg body weight) and glibenclamide were administered orally to diabetic rats for 30 days. Blood glucose level, total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), high density lipoprotein (HDL), alanine transaminase (ALT), aspartate aminotransferase (AST), alkaline phosphate (ALP), creatinine (CREA), urea, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH) were determined. SHF showed significant reduction in blood glucose in diabetic rats. Treatment of diabetic rats also resulted an improvement in body weights, increased HDL, SOD and GSH, as well as decreased TC, TG, LDL, MDA, urea, CREA, ALT, AST and ALP. These results suggested that C. cicadae polysaccharide displayed anti-hyperglycemic, anti-hyperlipidemic and antioxidant activities and could be a promising therapeutic source in managing diabetes mellitus and its associated complications.

Evaluation of 4-methyl-2-[(2-methylbenzyl) amino]-1,3-thiazole-5-carboxylic acid against hyperglycemia, insulin sensitivity, and oxidative stress-induced inflammatory responses and β-cell damage in the pancreas of streptozotocin-induced diabetic rats

4-Methyl-2-[(2-methylbenzyl) amino]-1,3-thiazole-5-carboxylic acid (bioactive compound (BAC)), a novel thiazole derivative, is a xanthine oxidase inhibitor and free radical scavenging agent. Effects of BAC on hyperglycemia, insulin sensitivity, oxidative stress, and inflammatory mediators were evaluated in streptozotocin (STZ)-induced neonatal models of non-insulin-dependent diabetes mellitus (NIDDM) rats where NIDDM was induced in neonatal pups with single intraperitoneal injection of STZ (100 mg/kg). The effect of BAC (10 and 20 mg/kg, p.o.) for 3 weeks was evaluated by the determination of blood glucose, oral glucose tolerance test (OGTT), HbA1c level, insulin level, insulin sensitivity, and insulin resistance (IR). Furthermore, inflammatory mediators (tumor necrosis factor-alpha and interleukin-6) and oxidative stress were estimated in serum and pancreatic tissue, respectively. Significant alteration in the level of blood glucose, OGTT, HbA1c, insulin level, insulin sensitivity, in addition variation in the antioxidant status and inflammatory mediators, and alteration in histoarchitecture of pancreatic tissue confirmed the potential of BAC in STZ-induced neonatal models of NIDDM rats. Pretreatment with BAC restored the level of glucose by decreasing the IR and increasing the insulin sensitivity. Furthermore, BAC balanced the antioxidant status and preserved the inflammatory mediators. Histological studies of pancreatic tissues showed normal architecture after BAC administration to diabetic rats. Altogether, our results suggest that BAC successfully reduces the blood glucose level and possesses antioxidant as well as anti-inflammatory activities. This leads to decreased histological damage in diabetic pancreatic tissues, suggesting the possibility of future diabetes treatments.

Chinese Olive (Canarium album L.) Fruit Extract Attenuates Metabolic Dysfunction in Diabetic Rats

Hyperglycemia and dysregulation of lipid metabolism play a crucial role in metabolic dysfunction. The aims of present study were to evaluate the ameliorative effect of the ethyl acetate fraction of Chinese olive fruit extract (CO-EtOAc) on high-fat diet (HFD) and streptozotocin (STZ)-induced diabetic rats. CO-EtOAc, rich in gallic acid and ellagic acid, could markedly decreased the body weight and epididymal adipose mass. In addition, CO-EtOAc increased serum HDL-C levels, hepatic GSH levels, and antioxidant enzyme activities; lowered blood glucose, serum levels of total cholesterol (TC), triglycerides (TG), bile acid, and tumor necrosis factor alpha (TNFα); and reduced TC and TG in liver. We further demonstrated that CO-EtOAc mildly suppressed hepatic levels of phosphorylated IRS-1, TNF-α, and IL-6, but enhanced Akt phosphorylation. The possible mechanisms of cholesterol metabolism were assessed by determining the expression of genes involved in cholesterol transportation, biosynthesis, and degradation. It was found that CO-EtOAc not only inhibited mRNA levels of SREBP-2, HMG-CoAR, SR-B1, and CYP7A1 but also increased the expression of genes, such as ABCA1 and LDLR that governed cholesterol efflux and cholesterol uptake. Moreover, the protein expressions of ABCA1 and LDLR were also significantly increased in the liver of rats supplemented with CO-EtOAc. We suggest that Chinese olive fruit may ameliorate metabolic dysfunction in diabetic rats under HFD challenge.

Supplementation of Syzygium cumini seed powder prevented obesity, glucose intolerance, hyperlipidemia and oxidative stress in high carbohydrate high fat diet induced obese rats

Background

Obesity and related complications have now became epidemic both in developed and developing countries. Cafeteria type diet mainly composed of high fat high carbohydrate components which plays a significant role in the development of obesity and metabolic syndrome.

This study investigated the effect of Syzygium cumini seed powder on fat accumulation and dyslipidemia in high carbohydrate high fat diet (HCHF) induced obese rats.

Method

Male Wistar rats were fed with HCHF diet ad libitum, and the rats on HCHF diet were supplemented with Syzygium cumini seed powder for 56 days (2.5% w/w of diet). Oral glucose tolerance test, lipid parameters, liver marker enzymes (AST, ALT and ALP) and lipid peroxidation products were analyzed at the end of 56 days. Moreover, antioxidant enzyme activities were also measured in all groups of rats.

Results

Supplementation with Syzygium cumini seed powder significantly reduced body weight gain, white adipose tissue (WAT) weights, blood glucose, serum insulin, and plasma lipids such as total cholesterol, triglyceride, LDL and HDL concentration. Syzygium cumini seed powder supplementation in HCHF rats improved serum aspartate amino transferase (AST), alanine amino transferase (ALT), and alkaline phosphatase (ALP) activities. Syzygium cumini seed powder supplementation also reduced the hepatic thiobarbituric acid reactive substances (TBARS) and elevated the antioxidant enzyme superoxide dismutase (SOD) and catalase (CAT) activities as well as increased glutathione (GSH) concentration. In addition, histological assessment showed that Syzygium cumini seed powder supplementation prevented inflammatory cell infiltration; fatty droplet deposition and fibrosis in liver of HCHFD fed rats.

Conclusion

Our investigation suggests that Syzygium cumini seed powder supplementation prevents oxidative stress and showed anti-inflammatory and antifibrotic activity in liver of HCHF diet fed rats. In addition, Syzygium cumini seed powder may be beneficial in ameliorating insulin resistance and dyslipidemia probably by increasing lipid metabolism in liver of HCHF diet fed rats.

ANTI-DIABETIC EFFECTS OF ZHUODUQING FORMULA, A CHINESE HERBAL DECOCTION, ON A RAT MODEL OF TYPE 2 DIABETES

Background:

Zhuoduqing formula (ZDQ) is a Chinese herbal decoction and used to treat type 2 diabetes in clinical practice, but the potential evidence needs to be provided.

Materials and Methods:

Type 2 diabetic model rats were induced by feeding high fat diet (HFD) and intraperitoneal injection of streptozotocin (STZ). The model rats were given ZDQ for 4 weeks. Insulin sensitivity was evaluated by homeostasis model assessment of basal insulin resistance (HOMA-IR) and intraperitoneal glucose tolerance test (IPGTT). Blood insulin and tumour necrosis factor-α (TNF-α) levels as well as SOCS-3 levels in skeletal muscles were analyzed by ELISA.

Results:

ZDQ significantly decreased fasting blood glucose, ameliorated HOMA-IR and IPGTT, and reduced triglyceride and total cholesterol in type 2 diabetic rats. Moreover, ZDQ remarkably lowered blood TNF-α levels and inhibited SOCS-3 levels in skeletal muscles.

Conclusion:

The results display that ZDQ performs anti-diabetic functions in type 2 diabetic rats induced by feeding HFD and intraperitoneal injection of STZ.

Abbreviations: ZDQ, zhuoduqing formula; ROS, rosiglitazone; HOMA-IR, homeostasis model assessment of basal insulin resistance; IPGTT, intraperitoneal glucose tolerance test; HFD, high fat diet; SOCS-3, suppressor of cytokine signaling-3; TNF-α, tumour necrosis factor-α.

Preparation and Evaluations of Mangiferin-Loaded PLGA Scaffolds for Alveolar Bone Repair Treatment Under the Diabetic Condition

The aim of the present study was to prepare and evaluate a sustained-release mangiferin scaffold for improving alveolar bone defect repair in diabetes. Mangiferin-loaded poly(D,L-lactide-co-glycolide) (PLGA) scaffolds were prepared using a freeze-drying technique with ice particles as the porogen material. The produced scaffolds were examined using a scanning electron microscope (SEM). Drug content and drug release were detected using a spectrophotometer. Degradation behaviors were monitored as a measure of weight loss and examined using SEM. Then, the scaffolds were incubated with rat bone marrow stromal cells under the diabetic condition in vitro, and cell viability was assessed using an 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Afterward, the scaffolds were implanted into alveolar bone defects of diabetic rats, and bone repair was examined using hematoxylin and eosin staining. The fabricated scaffolds showed porous structures, with average pore size range from 111.35 to 169.45 μm. A higher PLGA concentration led to decreased average pore size. A lower PLGA concentration or a higher mangiferin concentration resulted in increased drug content. The prepared scaffolds released mangiferin in a sustained manner with relatively low initial burst during 10 weeks. Their degradation ratios gradually increased as degradation proceeded. The mangiferin-loaded scaffolds attenuated cell viability decrease under the diabetic condition in vitro. Moreover, they increased histological scorings of bone regeneration and improved delayed alveolar bone defect healing in diabetic rats. These results suggest that the produced mangiferin-loaded scaffolds may provide a potential approach in the treatment of impaired alveolar bone healing in diabetes.

Arachidonic acid causes hidden blood loss-like red blood cell damage through oxidative stress reactions

BACKGROUND

Hidden blood loss (HBL) often occurs in the prosthetic replacement for joint, but the mechanism is still not clear.

MATERIALS AND METHODS

This study tried to establish an animal model of HBL by injecting arachidonic acid (AA) into the Sprague-Dawley rats. Different concentrations of AA were injected into the tail veins of the rats, and blood samples were collected before and after administration at 24, 48, and 72 h. A complete blood count was obtained by to find the hemoglobin (Hb) and red blood cell (RBC) count changes. The glutathione peroxidase (GSH-PX) and total superoxide dismutase (T-SOD) activities and hydrogen peroxide (H₂O₂) levels were detected. The morphological changes of erythrocyte were observed under a polarizing microscope. The absorbance values of the blood samples were tested to determine the presence of ferryl Hb.

RESULTS

HBL occurred in the experimental groups when the concentration of AA reached 10 mmol/L; Hb and RBC values decreased sharply at 24- and 48-h postinjection. This was followed by reduced activities of GSH-PX and T-SOD and decreased levels of H₂O₂. Moreover, the pathologic changes of red cell morphology mainly presented as pleomorphic RBC morphology, including cell rupture. The absorbance values of the blood samples were in accordance with ferryl Hb features. RBC and Hb values were relatively stable at 72 h. The GSH-PX and T-SOD activities and H₂O₂ levels gradually increased up to a balanced state.

CONCLUSIONS

The study concluded that high concentrations of AA can induce oxidative stress reactions in the body, causing acute injury of RBCs, which is closely related to HBL.

Syzygium cumini seed extract ameliorates adenosine deaminase activity and biochemical parameters but does not alter insulin sensitivity and pancreas architecture in a short-term model of diabetes

BACKGROUND

The effects of the aqueous seed extract of Syzygium cumini (ASc) in a short-term model of diabetes in rats are little explored. The present study was designed to evaluate the effect of the ASc on adenosine deaminase (ADA) activity and on biochemical and histopathological parameters in diabetic rats.

METHODS

ASc (100 mg/kg) was administered for 21 days in control and streptozotocin (STZ)-induced (60 mg/kg) diabetic rats. ADA activity, lipoperoxidation (cerebral cortex, kidney, liver and pancreas) and biochemical (serum) and histopathological (pancreas) parameters were evaluated.

RESULTS

The main findings in this short-term model of Diabetes mellitus (DM) were that the ASc (i) significantly reverted the increase of ADA activity in serum and kidney; (ii) ameliorated the lipoperoxidation in the cerebral cortex and pancreas of the diabetic group; (iii) demonstrated hypolipidemic and hypoglycemic properties and recovered the liver glycogen; and iv) prevented the HOMA-IR index increase in the diabetic group. Therefore, the ASc can be a positive factor for increasing the availability of substrates with significant protective actions, such as adenosine. Moreover, by maintaining glycogen and HOMA-IR levels, the extract could modulate the hyperglycemic state through the direct peripheral glucose uptake.

CONCLUSIONS

Our data revealed that the short-term treatment with ASc has an important protective role under pathophysiological conditions caused by the early stage of DM. These results enhance our understanding of the effect of the ASc on the purinergic system in DM.

Trigonella foenum-graecum water extract improves insulin sensitivity and stimulates PPAR and γ gene expression in high fructose-fed insulin-resistant rats

BACKGROUND

Insulin resistance is the main defect associated with the metabolic syndrome. In obesity, the decreased adiponectin levels and elevation of plasma-free fatty acids are the main factors associated with insulin resistance. In this study, we evaluated the effect of trigonella foenum-graecum (TFG) extract on insulin sensitivity in high fructose-fed insulin-resistant rats.

MATERIALS AND METHODS

Experimental rats were fed with a high fructose diet for eight weeks. After the first six weeks, the animals were treated with trigonella foenum-graecum extract or pioglitazone for two weeks. Serum glucose, triglycerides, cholesterol, and HDL-c were measured. The insulin and adiponectin levels were assayed by the enzyme-linked immunosorbent assay (ELISA), and Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) was calculated. The plasma-free fatty acid profile was obtained by gas chromatography. PPARγ and GLUT4 gene expression were assessed by real-time polymerase chain reaction (PCR) and western blotting.

RESULTS

In the trigonella foenum-graecum- extract treated group the following results were obtained: Insulin (49.02 ± 6.93 pmol/L), adiponectin (7.1 ± 0.64 μg/ml), and triglycerides (110.3 ± 16.7 mg/dl), which were significantly different and improved compared to the control group (insulin (137 ± 34 pmol/l), adiponectin (3.9 ± 0.15 μg/ml), glucose (187 ± 15 mg/dl), and triglycerides (217 ± 18 mg/dl). Also the PPARγ gene expression was significantly increased compared to the control group.

CONCLUSION

This study demonstrates the beneficial effects of trigonella foenum-graecum extract on insulin resistance in rats fed on a high-fructose diet. At least three mechanisms are involved, including direct insulin-like effect, increase in adiponectin levels, and PPARγ protein expression.

Polyphenol-Rich Extract of Syzygium cumini Leaf Dually Improves Peripheral Insulin Sensitivity and Pancreatic Islet Function in Monosodium L-Glutamate-Induced Obese Rats

Syzygium cumini (L.) Skeels (Myrtaceae) has been traditionally used to treat a number of illnesses. Ethnopharmacological studies have particularly addressed antidiabetic and metabolic-related effects of extracts prepared from its different parts, especially seed, and pulp-fruit, however. there is a lack of studies on phytochemical profile and biological properties of its leaf. As there is considerable interest in bioactive compounds to treat metabolic syndrome and its clustered risk factors, we sought to characterize the metabolic effects of hydroethanolic extract of S. cumini leaf (HESc) on lean and monosodium L-glutamate (MSG)-induced obese rats. HPLC-MS/MS characterization of the HESc polyphenolic profile, at 254 nm, identified 15 compounds pertaining to hydrolysable tannin and flavanol subclasses. At 60 days of age, both groups were randomly assigned to receive HESc (500 mg/kg) or vehicle for 30 days. At the end of treatment, obese+HESc exhibited significantly lower body weight gain, body mass index, and white adipose tissue mass, compared to obese rats receiving vehicle. Obese rats treated with HESc showed a twofold increase in lipolytic activity in the periepididymal fat pad, as well as, brought triglyceride levels in serum, liver and skeletal muscle back to levels close those found in lean animals. Furthermore, HESc also improved hyperinsulinemia and insulin resistance in obese+HESc rats, which resulted in partial reversal of glucose intolerance, as compared to obese rats. HESc had no effect in lean rats. Assessment of ex vivo glucose-stimulated insulin secretion showed HESc potentiated pancreatic function in islets isolated from both lean and obese rats treated with HESc. In addition, HESc (10–1000 μg/mL) increased glucose stimulated insulin secretion from both isolated rat islets and INS-1E β-cells. These data demonstrate that S. cumini leaf improved peripheral insulin sensitivity via stimulating/modulating β-cell insulin release, which was associated with improvements in metabolic outcomes in MSG-induced obese rats.

Ethyl acetate fraction of Aframomum melegueta fruit ameliorates pancreatic β-cell dysfunction and major diabetes-related parameters in a type 2 diabetes model of rats

ETHNOPHARMACOLOGICAL RELEVANCE

In West Africa, various preparations of the fruit, seed and leaf of Aframomum melegueta K. Schum. are reputably used for the management of diabetes mellitus (DM) and other metabolic disorders. The present study evaluated the anti-diabetic effects of A. melegueta ethyl acetate fraction (AMEF) from fruit ethanolic extract in a type 2 diabetes (T2D) model of rats.

MATERIALS AND METHODS

T2D was induced in rats by feeding a 10% fructose solution ad libitum for two weeks followed by a single intraperitoneal injection of streptozotocin (40 mg/kg body weight) and the animals were orally treated with 150 or 300 mg/kg body weight (bw) of the AMEF once daily for four weeks.

RESULTS

At the end of the intervention, diabetic untreated animals showed significantly higher serum glucose, serum fructosamine, LDH, CK-MB, serum lipids, liver glycogen, insulin resistance (HOMA-IR), AI, CRI and lower serum insulin, pancreatic β-cell function (HOMA- β) and glucose tolerance ability compared to the normal animals. Histopathological examination of their pancreas revealed corresponding pathological changes in the islets and β-cells. These alterations were reverted to near-normal after the treatment of AMEF at 150 and 300 mg/kg bw when, the effects were more pronounced at 300 mg/kg bw compared to the 150 mg/kg bw.

CONCLUSION

The results of our study suggest that AMEF treatment at 300 mg/kg bw showed potent anti-diabetic effect in a T2D model of rats.

Traditional management of diabetes in Pakistan: Ethnobotanical investigation from Traditional Health Practitioners

ETHNOPHARMACOLOGICAL RELEVANCE

The uses of anti-diabetic plants are well anchored in the traditional health care system of Pakistan. To the best of our knowledge, this is the first ethno-botanical study about the uses of plants for the treatment of diabetes. The aim of the study is to record indigenous knowledge on anti-diabetic plants from Traditional Health Practitioners (THPs) and diabetic patients. In addition, it is aimed to ascertain and validate the traditional uses of anti-diabetic plants by citing pharmacological activities and phytochemical constitutes from previously published literature.

MATERIALS AND METHODS

The ethno-medicinal data was documented during 14 field surveys, each comprising of 10 days, from 3 regions of Pakistan (Islamabad, Khyber Pukhtoonkhwa and Deserts of Sindh). In total, 113 THPs and 44 diabetic patients were interviewed using open-ended and semi-structured questionnaires. Quantitative indices, including Relative Frequency of Citation percentage (RFC %) and Disease Consensus Index (DCI) were calculated. The documented data is authenticated by comparing with 28 published articles on ethno-botanical aspects and many pharmacological studies.

RESULTS

In total, 120 plant species belonging to 50 families were reported. The ethno-botanical results indicated that Moraceae (11 species); herb (56 reports) is dominant life form; the leaves (56 reports) are the most used plant part and decoction (24%) is the preferred mode of preparation. The quantitative analysis shows that RFC% ranges from 14 to 42 and DCI varies from 0.15 to 0.74. By comparing to previous studies, 64 species are reported new in traditional treatment of DM; 40 species are new to pharmacological evidence and 3 species are new to phytochemical studies.

CONCLUSIONS

This study recoded the significant indigenous knowledge about anti-diabetic plants among the THPs and diabetic patients in Pakistan. This type of ethno-botanical knowledge on traditional use of anti-diabetic plants is an important step in designing detailed pharmacological and clinical trials for Diabetes Miletus treatment. It is recommended that further pharmacological and phytochemical analysis should be conducted on those species which lack previous references in literature and have highest Frequency of Citation (FC), Disease Consensus Index (DCI) and Relative Frequency of Citation percentage (RFC%).

Syzygium cumini (L.) skeels: a prominent source of bioactive molecules against cardiometabolic diseases

Syzygium cumini (Myrtaceae) is a worldwide medicinal plant traditionally used in herbal medicines due to its vaunted properties against cardiometabolic disorders, which include: antihyperglycemic, hypolipemiant, antiinflammatory, cardioprotective, and antioxidant activities. These properties have been attributed to the presence of bioactive compounds such as phenols, flavonoids, and tannins in different parts of the plant, albeit the knowledge on their mechanisms of action is scarce. This mini-review highlights the cardiometabolic properties of S. cumini by correlating its already identified phytochemicals with their described mechanisms of action. Data herein compiled show that some compounds target multiple metabolic pathways; thereby, becoming potential pharmacological tools. Moreover, the lack of clinical trials on S. cumini usage makes it a fruitful field of interest for both scientific community and pharmaceutical industry.

Immunohistochemistry, histopathology, and biomarker studies of swertiamarin, a secoiridoid glycoside, prevents and protects streptozotocin-induced β-cell damage in Wistar rat pancreas

BACKGROUND

Diabetes mellitus is globally the major cause for metabolic syndrome in STZ-induced diabetic rats, leading to mortality. Treatment of diabetes by oral hypoglycemic agents causes adverse side effects and thus treatment with natural herbal drugs like swertiamarin is promising. Swertiamarin, an active compound isolated from Enicostemma littorale possesses antidiabetic activity and enhances β cell regeneration which causes reversal of diabetes.

OBJECTIVES

The present study aims at the following: (1) to evaluate antidiabetic, anti-hyperlipidaemic, activity of swertiamarin in Streptozotocin- induced diabetic rats using biomarkers. (2) To assess histopathological alterations in Pancreas, Liver, Kidney, and Heart of swertiamarin-treated STZ-induced diabetic rats and confirm cytoprotective activity of swertiamarin by Immunohistochemistry and morphometric investigations.

METHODS

Diabetes was induced intraperitoneally in male Wistar rats by Streptozotocin (STZ 50 mg/kg). After STZ-induction, hyperglycemic rats were treated with doses of swertiamarin orally (15, 25, 50 mg/kg) each for 28 days. Glibenclamide (2.5 mg/kg), a sulphonyl urea, was used as a standard drug. The glycemic control was measured by the biochemical parameter assays. Histopathology analysis of organs and immunohistochemistry of islets were carried out.

RESULTS

Our study results showed that oral administration of swertiamarin at a dosage of 15, 25, 50 mg/kg bw for 28 days resulted in a significant (p < 0.01) decrease in fasting blood glucose, HbA1c, TC, TG, LDL, and increased the levels of hemoglobin, plasma insulin, TP, body weight, and HDL levels significantly (p < 0.01) when compared to STZ-induced diabetic rats, as confirmed by immunohistochemical studies. The effect of swertiamarin on Carbohydrate-metabolizing enzymes was investigated and found to have normal therapeutic activity. Histopathological studies of Pancreas of swertiamarin-treated diabetic rats showed regeneration of islets when compared to STZ-induced diabetic rats, as confirmed by immunohistochemical studies.

CONCLUSION

Our research results clearly substantiate that swertiamarin possesses antihyperglycemic, antihyperlipidemic, cytoprotective, and immune reactivity and also a broad spectrum potential of treating diabetes and other complications related to diabetes and hence can be developed into a potent oral antidiabetic drug.

Antidiabetic potential of some less commonly used plants in traditional medicinal systems of India and Nigeria

The incidence of diabetes mellitus continue to rise annually all over the world with India and Nigeria having recorded cases of 65.1 and 3.9 million respectively in 2013 and expected to increase by a large amount in 2035. Hyperglycemia is a pre-condition for the development of diabetic complications and is accompanied by an increase in the production of free radicals. The present available treatment option for diabetes like sulfonylurea, metformin and alpha-glucosidase are restricted by their limited actions, secondary failure rates, and side-effects; and unaffordable to the majority of the population. Hence, the need to screen for more medicinal plants with antidiabetic ability due to the fact that plants are; biodegradable, safe and cheap with fewer side-effects. In this review article, we have presented the current status of diabetes in India and Nigeria and the role of some less commonly used medicinal plants from both countries that have antidiabetic potential.

Antioxidant activity of Syzygium cumini leaf gall extracts

INTRODUCTION

Free radicals are implicated in several metabolic diseases and the medicinal properties of plants have been explored for their potent antioxidant activities to counteract metabolic disorders. This research highlights the chemical composition and antioxidant potential of leaf gall extracts (aqueous and methanol) of Syzygium cumini (S. cumini), which have been extensively used in traditional medications to treat various metabolic diseases.

METHODS

The antioxidant activities of leaf gall extracts were examined using diphenylpicrylhydrazyl (DPPH), nitric oxide scavenging, hydroxyl scavenging and ferric reducing power (FRAP) methods.

RESULTS

In all the methods, the methanolic extract showed higher antioxidant potential than the standard ascorbic acid. The presence of phenolics, flavonoids, phytosterols, terpenoids, and reducing sugars was identified in both the extracts. When compared, the methanol extract had the highest total phenolic and flavonoid contents at 474±2.2 mg of GAE/g d.w and 668±1.4 mg of QUE/g d.w, respectively. The significant high antioxidant activity can be positively correlated to the high content of total polyphenols/flavonoids of the methanol extract.

CONCLUSION

The present study confirms the folklore use of S. cumini leaves gall extracts as a natural antioxidant and justifies its ethnobotanical use. Further, the result of antioxidant properties encourages the use of S. cumini leaf gall extracts for medicinal health, functional food and nutraceuticals applications.

Anti-hyperglycemic effect, inhibition of inflammatory cytokines expression, and histopathology profile in streptozotocin-induced diabetic rats treated with Arracacia tolucensis aerial-parts extracts

ETHNOPHARMACOLOGICAL RELEVANCE

Arracacia tolucensis is a medicinal plant used in northeast of Mexico as a remedy to treat people with Diabetes mellitus (DM); however, there are no scientific studies that support this information. Thus, we evaluated the anti-hyperglycemic effect of the hexane, ethyl acetate and ethanol extracts from aerial parts in streptozotocin-induced diabetic rats.

MATERIALS AND METHODS

DM was induced in Wistar male rats by single intraperitoneal injection of streptozotocin (STZ 50mg/kg). After STZ-induction, hyperglycemic rats were treated with all three extracts orally at a single dose (250 mg/kg) each 48 h for 21 days. Glibenclamide (1mg/kg) was used as a reference drug. The fasting blood glucose levels, the hematic biometry and biochemical profiles, and the inhibition of inflammatory cytokines expression were estimated. Histopathology analysis of pancreas, liver, spleen, and kidney tissue was carried out.

RESULTS

Ours results showed that ethyl acetate extract decreased blood glucose levels significantly (75%, p< 0.05) when compared to diabetic rats and controlled the body weight loss; the lipids level did not change, but the enzyme levels of aspartate aminotransferase and alanine aminotransferase decreased significantly (60.83% and 66.16%, respectively, p< 0.05) and inhibited the expression of inflammatory cytokines,with respect to diabetic rats. Histopathology injury was not observed; by contrast repair of islet of Langerhans was exhibited.

CONCLUSION

These results validate the use of Arracacia tolucensis as a treatment against DM and suggests it is suitable to continue studies for its safe therapeutic use.

Traditional medicinal plants used for the treatment of diabetes in rural and urban areas of Dhaka, Bangladesh--an ethnobotanical survey

BACKGROUND

The usage of medicinal plants is traditionally rooted in Bangladesh and still an essential part of public healthcare. Recently, a dramatically increasing prevalence brought diabetes mellitus and its therapy to the focus of public health interests in Bangladesh. We conducted an ethnobotanical survey to identify the traditional medicinal plants being used to treat diabetes in Bangladesh and to critically assess their anti-diabetic potentials with focus on evidence-based criteria.

METHODS

In an ethnobotanical survey in defined rural and urban areas 63 randomly chosen individuals (health professionals, diabetic patients), identified to use traditional medicinal plants to treat diabetes, were interviewed in a structured manner about their administration or use of plants for treating diabetes.

RESULTS

In total 37 medicinal plants belonging to 25 families were reported as being used for the treatment of diabetes in Bangladesh. The most frequently mentioned plants were Coccinia indica, Azadirachta indica, Trigonella foenum-graecum, Syzygium cumini, Terminalia chebula, Ficus racemosa, Momordica charantia, Swietenia mahagoni.

CONCLUSION

Traditional medicinal plants are commonly used in Bangladesh to treat diabetes. The available data regarding the anti-diabetic activity of the detected plants is not sufficient to adequately evaluate or recommend their use. Clinical intervention studies are required to provide evidence for a safe and effective use of the identified plants in the treatment of diabetes.

25-Hydroxyvitamin D(3)-loaded PLA microspheres: in vitro characterization and application in diabetic periodontitis models

This study aimed at the preparation of a sustained-release 25-hydroxyvitamin D(3) (25OHD) treatment for diabetic periodontitis, a known complication of diabetes. 25OHD-loaded polylactic acid (PLA) microspheres were prepared using oil-in-water emulsion-solvent evaporation method. The prepared microspheres exhibited intact surfaces, with average sizes ranging from 42.3 to 119.4 μm. The encapsulation efficiency ranged from 79.2% (w/w) to 88.5% (w/w), and the drug content was between 15.8% (w/w) and 17.8% (w/w). Drug release from the produced microspheres followed a near-to-zero-order release pattern and lasted over 10 weeks. In an in vitro model of diabetic periodontitis, the abnormal morphological changes and the decrease in the cell viability of bone marrow stromal cells could be effectively attenuated after the 25OHD-loaded microsphere application. Additionally, in a rat model of diabetic periodontitis, alveolar bone loss was inhibited and osteoid formation in the periodontium was promoted upon 25OHD-loaded microsphere treatment. In conclusion, 25OHD-loaded PLA microspheres may provide an effective approach for the treatment of this disease.

Protective effect of boschniakia rossica ethanol extract on nonalcoholic fatty liver disease in rats and mechanisms involved

AIM: To assess the protective effect of boschniakia rossica ethanol extract (BREE) on non-alcoholic fatty liver disease (NAFLD) in rats and explore the possible mechanisms involved.

METHODS: Fifty SD rats were randomly and equally divided into five groups: normal group, model group, and three BREE groups. The normal group was fed a normal diet, and the model group and BREE groups were fed a diet with choline-deficient amino acid-defined (CDAA) for 8 wk to induce NAFLD. From the second week, the three BREE groups were intragastrically administered with high- (500 mg/kg), medium- (250 mg/kg) and low-dose (125 mg/kg) BREE daily. At the end of the 8th week, portal vein blood and liver tissue samples were taken from all the rats. Serum biological parameters were determined routinely, and tumor necrosis factor-α (TNF-α) was determined by ELISA. Expression of CYP 2E1, α-smooth muscle actin (α-SMA), transforming growth factor-β1 (TGF-β1), and tissue inhibitor of metalloproteinase-1 (TIMP-1) in liver tissue were determined by immunohistochemistry, and pathological changes in liver tissues were detected by HE staining.

RESULTS: The levels of alanine aminotransferase, aspartate transaminase, total bile acids, TNF-α in serum and CYP 2E1 expression in liver tissue were lower significantly in the high-dose BREE group than in the model group (41.31 ± 12.32 vs 67.92 ± 1.28, 42.12 ± 6.32 vs 74.12 ± 5.20, 68.20 ± 32.62 vs 129.56 ± 23.12, all P < 0.01; 31.20 ± 2.44 vs 70.04 ± 12.62, P < 0.05; 1.20 ± 0.44 vs 5.30 ± 2.62, P < 0.01), and in the high-dose BREE group than in the low-dose BREE group (all P < 0.05). Expression of α-SMA, TGF-β1 and TIMP-1 was detectable in liver tissue in the model group, but not in the three BREE groups and normal group. Rats of the model group showed severe fatty liver degeneration and necrosis, infiltration of a large number of inflammatory cells in portal area, and varying degrees of improvement of these hepatic pathologic lesions were observed in the BREE groups.

CONCLUSION: BREE has a significant protective effect on CDAA-induced NAFLD in rats possibly via mechanisms related to decreasing expression of liver CYP-2E1 and serum TNF-α levels. The observation that BREE inhibited the expression of α-SMA, TGF-β1 and TIMP-1 in liver tissue in rats with NAFLD suggests that BREE may have anti-non alcoholic liver fibrosis effect.