Antidiabetic activity of alcoholic leaves extract of Alangium lamarckii Thwaites on streptozotocin-nicotinamide induced type 2 diabetic rats

Synergistic Effect of Naringin and Glimepiride in Streptozotocin-induced Diabetic Rats

OBJECTIVE

Evaluation of the synergistic effect of Naringin and Glimepiride in streptozotocin (STZ)-induced diabetic rats.

METHODS

Wistar rats were chosen and divided into five groups (n=6). STZ was used for the induction of diabetes. The combination of naringin and glimepiride was administered to diabetic rats. The changes in fasting blood sugar, body weight, Hb, HbA1c, and creatinine were evaluated, and urine was collected and the volume was observed. The lipid profiles like TC, HDL, LDL, and TG were measured. The biochemical parameters SGOT, SGPT, and ALP were analysed. Besides, endogenous antioxidant parameters like SOD, GSH, and catalase were also assessed. Lastly, the histopathological study of the beta cells in islets of the pancreas, glomerulus, and tubules of kidney and liver cells was conducted in all groups.

RESULTS

The result shows significant reduction (p<0.001) of blood sugar in the naringin and glimepiride-treated group when compared with the control group (diabetes). Additionally, the combination of Naringin (100 mg/kg) and Glimepiride (0.1 mg/kg) significantly restores the creatinine levels and urine volumes, SGOT, SGPT, and ALP when compared to a single dose of administration. Further, the abnormal lipid profile levels (TC, LDL, TG, and HDL), and endogenous antioxidant enzymes (SOD, GSH, catalase) in diabetic control rats were restored to normal levels in a significant manner. The histopathological result reveals significant alterations, including hypertrophy of islets and mild degeneration, renal necrosis, and inflammation of hepatocytes.

CONCLUSION

A synergistic effect of Naringin and glimepiride was observed during the estimation of various biochemical parameters like body weight, fasting blood sugar, creatinine, urine level, TG, total cholesterol, SGOT, SGPT, ALP, Insulin, HbA1c, antioxidant parameters like SOD, GSH, and catalase in STZ-induced diabetic rats. Further, the combination of therapy improves the protective effect of the pancreas, kidney, and liver, suggesting a potential antidiabetic effect.

Exogenous glutamine ameliorates diabetic nephropathy in a rat model of type 2 diabetes mellitus through its antioxidant and anti-inflammatory activities

This study aimed to evaluate the effects of glutamine (Gln) on diabetic nephropathy and other complications in a rat model of type 2 diabetes mellitus. Streptozotocin/nicotinamide induced diabetic rats were enrolled as an animal model of type 2 diabetes mellitus. Animals were divided into control, diabetic, and Gln (1000 mg/l in drinking water, eight weeks) treated diabetic groups. Gln alleviated renal inflammatory and oxidative stress biomarkers (tumour necrosis factor-alpha, interleukin 6, glutathione peroxidase, total superoxide dismutase, and glutathione), decreased serum uric acid and creatinine, and restored renal histopathological changes (glomerular volume, sclerosis, and leukocyte infiltration). Additionally, Gln ameliorated other complications, including systemic oxidative stress (serum malondialdehyde and nitric oxide, serum and liver glutathione, glutathione peroxidase, and total superoxide dismutase, and liver catalase), insulin resistance, hyperglycaemia, and hyperlipidaemia. Collectively, Gln attenuates diabetic nephropathy and other complications in type 2 diabetes mellitus in rats through its antioxidant and anti-inflammatory activities.

Effects of preharvest factors on antidiabetic potential of some foods and herbal plants

Diabetes is a metabolic disorder with no definite treatment, but it can be controlled by changing lifestyle and diet. Consumption of high-fiber and nutrient-rich foods including vegetables have been shown to reduce risks of obesity and Type II Diabetes Mellitus (T2DM). Also, many herbal plants have been associated with reduced risks of T2DM because of their composition of secondary metabolites. Antioxidant activities of some secondary metabolites have potent inhibitory effects against inflammation linked with insulin resistance and oxidative stress. More than 800 known medicinal plants are used to control diabetes and its relevant complications. However, variations in preharvest factors including plant genotype, growing medium properties, climatic factors, and management practices can influence plant growth and their accumulation of phytochemicals with health-promoting properties. However, the effects of these preharvest factors on the antidiabetic properties of plant secondary metabolites are neither explicit nor easily accessible in the literature. Therefore, this review aims to document recent studies that reported on under-exploited medicinal plants with antidiabetic properties. We reviewed several important preharvest factors that can potentially affect the synthesis of phytoconstituents which possess antidiabetic properties. This review will help identify gaps for future research in phytomedicine and functional foods.

Natural aldose reductase inhibitors for treatment and prevention of diabetic cataract: A review

Introduction: Aldose reductase (AR) is an enzyme that catalyzes the reduction of glucose to sorbitol responsible for the development of diabetic complications like cataracts. Medicinal plants contain several phytocompounds that can inhibit this enzyme.

Objective: The purpose of this review is to cite medicinal plants that have been tested for their ability to inhibit aldose reductase and consequently prevent cataracts and classify the major isolated compounds that have this activity.

Methods: We reviewed 154 articles published between 1954 and 2020 in English via three databases: ScienceDirect, Web of Science, and PubMed. We have classified the plants that showed a significant anti-cataract effect, in the form of a list including the scientific and family names of each plant. Also, we have cited the IC50 values and the active constituents of each plant that showed inhibitory activity towards AR.

Results: We have described 38 herbs belonging to 29 families. Besides, 47 isolated compounds obtained from the cited herbs have shown an AR inhibitory effect: luteolin, luteolin-7-O-β-D-glucopyranoside, apigenin, 3,5-di-O-caffeoyl-epi-quinic acid, delphinidin 3-O-β-galactopyranoside-3’-O-β-glucopyranoside, 3,5-di-O-caffeoylquinic acid methyl ester, andrographolide, 1,2,3,6-tetra-O-galloyl-β-D-glucose, 1,2,4,6-tetra-O-galloyl-β-D-glucose, 7-(3-hydroxypropyl)-3-methyl-8-β-O-D-glucoside-2H-chromen-2-one, E-4-(60-hydroxyhex-30-en-1-yl)phenyl propionate, delphinidin 3-O-β-galactopyranoside-3’,5’-di-O-β-glucopyranoside, 1,2,3-tri-O-galloyl-β-D-glucose, 1,2,3,4,6-penta-O-galloyl-β-D-glucose, 1,2,6-tri-O-galloyl-β-D-glucose, 2-(4-hydroxy-3-methoxyphenyl)ethanol, (4-hydroxy-3-methoxyphenyl)methanol, trans-anethole, gallic acid 4-O-β-D-(6’-O-galloyl)-glucoside, β-glucogallin, puerariafuran, quercetin, gallic acid 4-O-β-D-glucoside, 2,5-dihydroxybenzoic acid, 4-(4-hydroxy-3-methoxyphenyl)-2-butanone, protocatechuic acid, trans-cinnamic acid, gallic acid, p-coumaric acid and syringic acid.

Conclusion: natural therapy becomes an interesting alternative in the treatment and prevention of cataract by using medicinal plants rich in active compounds considered as AR inhibitors.

Hypoglycemic, hypolipidemic and hepatoprotective effects of Alpinia officinarum on nicotinamide/streptozotocin induced type II diabetic rats

OBJECTIVES

Alpinia officinarum Hance, commonly known as lesser galangal, is a member of the ginger family (Zingiberaceae) traditionally used for many decades to treat inflammation, pain, stomach ache and cold. In the present study, the antidiabetic and hypolipidemic potentials of the hydroalcoholic extract of A. officinarum (AO) were investigated in the nicotinamide/streptozotocin induced type II diabetic rats.

METHODS

Male Wistar rats were divided into following six groups: Group I was normal control rats. Group II: normal diabetic control, Group III: Diabetic rats treated with glibenclamide (0.25 mg/kg), IV, V and VI: Diabetic rats treated with 100, 200 and 500 mg/kg AO hydroalcoholic extract by daily gavage for 28 days, respectively. At the end of treatment, biochemical analysis, histological study, phytochemical analysis and acute toxicity tests were carried out.

RESULTS

The results show significant reduction in blood glucose, serum lipid profiles, and liver enzyme levels in diabetic rats compared with diabetic control in AO treated group.

CONCLUSIONS

In conclusion, the present study demonstrated that AO extract had significant (p<0.05) antidiabetic and anti-hyperlipidemia effects in addition to hepatoprotective effect in type II diabetic rats.

A Review on Antidiabetic Activity of Centaurea spp.: A New Approach for Developing Herbal Remedies

Objective

Diabetes mellitus (DM) is a long-life metabolic disorder, characterized by high blood glucose levels. The hyperglycemic condition generally leads to irreversible nerve injury and vascular damage. Among different types of diabetes, type 2 is more common and has spread all over the world. Although various therapeutic approaches have been developed to control type 2 DM, regulating blood glucose levels has still remained a controversial challenge for patients. Also, most prescription drugs cause different side effects, such as gastrointestinal disorders. Thus, developing novel and efficient antidiabetic agents possessing fewer adverse effects is in high demand.

Method

The literature was comprehensively surveyed via search engines such as Google Scholar, PubMed, and Scopus using appropriate keywords.

Results

Medicinal plants, both extracts and isolated active components, have played a significant role in controlling the blood glucose levels. Good-to-excellent results documented in the literature have made them a precious origin for developing and designing drugs and supplements against DM. Centaurea spp. have been traditionally used for controlling high blood glucose levels. Also, the antidiabetic properties of different species of Centaurea have been confirmed in recent studies through in vitro assays as well as in vivo experiments.

Conclusion

Potent results encouraged us to review their efficacy to open a new horizon for development of herbal antidiabetic agents.

Effect of Alpinia officinarum extract on reproductive damages in streptozotocin induced diabetic male rats

PURPOSE

Infertility is one of the systemic problems in diabetic men. The purpose of the present study is investigation of the effects of the Alpinia officinarum (AO) hydro-alcoholic extract on the reproductive system damages in diabetic male rats.

METHODS

Twenty four male rats were randomly assigned into 4 groups (n = 6); i.e., control, diabetic control, and diabetic rats treated orally with AO extract (200 and 500 mg kg-1). A single dose (60 mg kg-1) of streptozotocin (STZ) was injected intraperitoneally (IP) to induce diabetes. After 8 weeks of treatment, blood samples, testis, and cauda epididymis were excised to evaluate specific hormonal changes, sperm parameters, and testis morphology.

RESULTS

Diabetic control rats showed remarkably lower body and testicular weights, testicular volumes, and sperm parameters compared with the control group (p <0.05). Diabetic control rats also exhibited significantly decreased serum testosterone and follicle stimulating hormone (FSH). Sperm parameters were considerably enhanced in diabetic animals gavaged with AO extract. Testosterone levels were significantly elevated by administrating 500 mg kg-1 AO extract to the diabetic control rats (p <0.05). The morphological assessment of testis of treatment group (500 mg kg-1) indicated remarkable differences (p <0.05) by increasing the seminiferous tubules diameter (STD) and thickness of the seminiferous epithelium (TSE) compared with diabetic control rats.

CONCLUSION

As demonstrated by the results, AO extract ameliorated sperm damage and improved sperm morphology besides improving histological damage in the testis in diabetic rats. In addition, the dose of 500 mg kg-1 worked more efficiently than 200 mg kg-1.

Genus Alangium - A review on its traditional uses, phytochemistry and pharmacological activities

The species from Alangium have been used as folk medicine to treat rheumatism, skin diseases, diabetes by the people of Southeast Asia. Previous phytochemical studies have shown this genus are rich sources of alkaloids, glycosides, and terpenoids, which have attracted considerable attention of many researchers due to their markedly diverse and complex architecture. The crude extracts as well as the monomeric compounds from the title genus possess anti-tumor, anti-inflammatory, antibacterial, anti-oxidant pharmacological activities. Besides, some isolates from Alangium exhibited the effects on skeletal, smooth muscle and the nervous system. As a large genus of medicinal plants, the medicinal value of Alangium has been widely reported, but there is no review that provide a systematic summary towards its chemical constituents and pharmacological activities, to our knowledge. This work aims to present a comprehensive overview on the traditional uses, phytochemistry, and pharmacological activities of medicinal plants in the genus Alangium, and to explore the evidence supporting its ethnopharmacological effectiveness.

Hypoglycemic and Antihyperglycemic Activities of 80% Methanol Root Extract of Acanthus polystachyus Delile (Acanthaceae) in Type 2 Diabetic Rats

Background

The morbidity and mortality rate from diabetic mellitus are increasing in the world especially in low- and middle-income countries; hence, it is necessary to evaluate the efficacy and safety of medicinal plants to support existing drugs in treating diabetes mellitus. Therefore, the aim of this study was to evaluate the hypoglycemic effect of 80% methanol root extract of Acanthus polystachyus in normoglycemic, hyperglycemic, and streptozotocin–nicotinamide induced diabetic rats.

Methods

Male albino Wistar rats were divided into five groups (n=6) in all three models. In all models, group one rats served as a negative control and were received vehicle (10mL/kg distilled water), whereas group two (APRE100), three (APRE200), and four (APRE400) were treated with 100, 200, and 400mg/kg of extract, respectively, and group five were treated with glibenclamide (5mg/kg) and served as a positive control. Blood glucose levels were measured at different time points by taking blood from their tails. Data were analyzed using one-way ANOVA followed by Tukey’s post hoc test to carry out comparisons between and within-group and P < 0.05 was considered as statistically significant.

Results

The root of Acanthus polystachyus reduces peak blood sugar levels significantly after the loading of oral glucose at all tested doses. In streptozotocin–nicotinamide-induced type 2 diabetic rats, the daily oral administration of the crude extracts showed a significant reduction of blood glucose level at all tested doses compared to the negative control group. However, the extract did not reduce blood glucose levels in normoglycemic rats at all tested doses compared to both negative and positive control.

Conclusion

From this study, it can be concluded that the root extract of Acanthus polystachyus showed an antihyperglycemic effect in hyperglycemic and diabetic rats but lack hypoglycemic effect in normoglycemic rats. Hence, the plant root may be a good candidate for the development of new antidiabetic drugs.

Antidiabetic and In Vitro Enzyme Inhibition Studies of Methanol Extract of Ocimum tenuiflorum Linn Leaves and Its Fractions

The current study aimed to determine the best dose of methanol extract of Ocimum tenuiflorum L. leaves extract, and it is a fraction to blood-glucose-lowering in diabetic rats, and evaluated the α-amylase, α-glucosidase inhibitors and insulin level of diabetic rats used to achieve greater control over hyperglycemia. The result of the antihyperglycaemic of oral administration of a different dose of methanol extract in streptozotocin-induced rats showed that the highest dose of methanol extract significantly reduced the blood glucose level compared to another dose. Also, the result of repeated administration of methanol fractions indicates that ethyl acetate-butanol fraction exhibited a stronger antihyperglycemic effect than chloroform and ethanol-water fractions. Moreover, the result showed that effect of methanol extract and its fraction on α-glucosidase and α-amylase enzymes activities and its insulin level by in vitro study, ethyl acetate-butanol fraction could control with low concentration compared to other fractions and acarbose that used as a positive control. From the result of insulin level, methanol extract and fraction did not show any significant. These findings indicated that the active crude extract (methanol) and its active fractions (ethyl acetate/butanol) could exert significant glucose-lowering effect due to the presence of polyphenolics active constituents. In conclusion, isolation of the active components of Ocimum tenuiflorum L. may pave the way to the development of new agents for the treatment of diabetes and its complications.

A Grand Challenge. 3. Unbiased Phenotypic Function of Metabolites from Australia Plants Gloriosa superba and Alangium villosum against Parkinson's Disease

As part of a continuing research program aiming to identify chemical probes to interrogate Parkinson's disease (PD), we have investigated the Australian plants Gloriosa superba and Alangium villosum. The chemical investigations of G. superba resulted in the isolation of four new alkaloids, β-lumicolchicosides A-C (1-3) and γ-lumicolchicoside A (4), together with four lumicolchicine derivatives (5-8) and six colchicine analogues (9-14) as known structures. The chemical investigations of A. villosum resulted in the isolation of four new benzoquinolizidine N-oxides, tubulosine N_β⁵-oxide (15), isotubulosine N_α⁵-oxide (16), 9-demethyltubulosine N_β⁵-oxide (17), and 9-demethylisotubulosine N_α⁵-oxide (18), together with five known benzoquinolizidine alkaloids (19-23). The chemical structures of the new compounds (1-4 and 15-18) were characterized unambiguously by extensive analysis of their NMR and MS data. Unbiased multidimensional profiling was used to investigate the phenotypic profiles of all of the metabolites. The results show that the lead probes have different effects on cellular organelles that are implicated in PD in patient-derived cells.

Antihyperglycemic Activity of Murraya koenigii Leaves Extract on Blood Sugar Level in Streptozotocin-Nicotinamide Induced Diabetes in Rats

The effects of Murraya koenigii leaves are very less studied in streptozotocin-nicotinamide (STZ-NA) induced diabetes rat model, in spite of several studies reported its antidiabetic effects in alloxan and STZ induced diabetes. The present study was undertaken to assess the effects of Murraya koenigii leaves extract on the blood sugar level (BSL) of STZ-NA diabetic rats. Experimental diabetes was induced by STZ injection intraperitoneally (i. p) after 30 min of NA injection i. p in all groups apart from normal control group. Group I (normal control) and Group II (diabetic control) rats received distilled water. Group III rats treated Metformin, Group IV and Group V rats treated Murraya koenigii aqueous extract and Murraya koenigii methanolic extract respectively. BSL and body weights of rats were measured at each week of the period of 28 days. Our results indicate that oral administration of Murraya koenigii reduces BSL significantly compared with the diabetic group. No weight loss was observed in all groups. The findings of the present study suggest that Murraya koenigii is proven as anti-diabetic agent in diabetic rats.

A Protective Role of Paeoniflorin in Fluctuant Hyperglycemia-Induced Vascular Endothelial Injuries through Antioxidative and Anti-Inflammatory Effects and Reduction of PKCβ1

Hyperglycemia fluctuation is associated with diabetes mellitus (DM) complications when compared to persistent hyperglycemia. Previous studies have shown that paeoniflorin (PF), through its antiapoptosis, anti-inflammation, and antithrombotic properties, effectively protects against cardiovascular and cerebrovascular disease. However, the mechanism underlying the protection from PF against vascular injuries induced by hyperglycemia fluctuations remains poorly understood. Herein, we investigated the potential protective role of PF on human umbilical vein endothelial cells (HUVECs) subjected to intermittent glucose levels in vitro and in DM rats with fluctuating hyperglycemia in vivo. A remarkable increased apoptosis associated with elevated inflammation, increased oxidative stress, and high protein level of PKCβ1 was induced in HUVECs by intermittently changing glucose for 8 days, and PF recovered those detrimental changes. LY333531, a potent PKCβ1 inhibitor, and metformin manifested similar effects. Additionally, in DM rats with fluctuating hyperglycemia, PF protected against vascular damage as what has been observed in vitro. Taken together, PF attenuates the vascular injury induced by fluctuant hyperglycemia through oxidative stress inhibition, inflammatory reaction reduction, and PKCβ1 protein level repression, suggesting its perspective clinical usage.

Exploring the antidiabetic and anti-obesity properties of Samanea saman through in vitro and in vivo approaches

In recent years, diabetes and obesity have become a major problem in global health care because of changes in lifestyle, food habits, and age-related metabolic disorders. Diabetes mellitus is one of the most common diseases, affecting millions of people worldwide. Currently, herbal drugs are used to control obesity and diabetes. The present study investigates the anti-obesity, antidiabetic, and antioxidant activities of Samanea saman leaf extract. A methanolic extract of S. saman leaves was prepared by a maceration method. The S. saman leaf extract was studied for its inhibitory effect on glucose utilization using specific in vitro procedures to analyze its antioxidant, anti-obesity, and antidiabetic activities via different assays, such as α-amylase and α-glucosidase inhibition assay, glucose uptake by yeast cells, nonenzymatic glycosylation assay followed by glucose diffusion assay. The outcome of the study showed that the methanolic extract strongly inhibited the pancreatic lipase, α-amylase, and glucosidase activities, compared with the standard drug. The results showed that the extract possessed considerable antioxidant and antidiabetic activities, and further studies are needed to confirm the results using an in vivo model. Thus, it is proposed that S. saman can be used as a therapeutic agent.

Hypoglycemic and antioxidant effects of oral administration of garlic extract in the livers of type 1 diabetic rats

Background Liver dysfunction is a predominant complication of diabetes. Herbal remedies such as garlic are commonly used for reducing diabetic complications. In this study the effect of garlic extract on glucose level, liver enzymes activities in the serum and nitric oxide (NO) level, oxidative stress status, and histology in the liver tissues of streptozotocin-induced diabetes (type 1) was investigated. Methods Twenty-four adult male Wistar rats were randomized and divided into four groups: control rats, diabetic rats, diabetic rats treated with garlic, and garlic-treated normal rats. Glucose level and liver enzymes activities were determined by colorimetric assay in the serum. NO levels by Griess method, oxidative stress parameters including malondialdehyde (MDA), total oxidative status (TOS), and total antioxidant capacity (TAC) by spectrophotometric method, and histopathological examination by hematoxylin and eosin staining method were evaluated in the liver tissues. Results Glucose level, liver enzymes activities, MDA, TOS, and NO levels were increased and TAC level decreased significantly in diabetic rats in comparison with control rats (p<0.01); whereas, after oral administration of garlic, glucose level, liver enzymes activities, MDA, TOS, and NO levels were decreased and TAC level increased significantly near to the normal levels (p<0.05). Conclusion The results showed the hypoglycemic and antioxidant effects of garlic in the livers of type 1 diabetic rats.

Antihyperglycemic and Antihyperlipidemic Effects of Aqueous Extracts of Lannea edulis in Alloxan-Induced Diabetic Rats

Lannea edulis (Sond.) Engl. commonly known as wild grape is used traditionally for the treatment of diabetes. It is only found in Eastern and Southern Africa. Phytochemical screening, antihyperglycemic and antihyperlipidemic effects of aqueous extracts of L. edulis in alloxan induced diabetic rats were carried out. We report herein the findings of this research work. Lannea edulis crude aqueous extracts were obtained by hot infusion and evaporation method. Phytochemical screening was carried out and subsequently toxicity studies of the aqueous extracts were performed to establish the Lethal Dose 50 (LD50) in albino rats. Alloxan monohydrate was used to induce diabetes in the rats. Lannea edulis positive control group doses of 100, 300, and 500 mg/kg were administered to 3 groups for 14 days. The positive control group was administered 5 mg/kg of glibenclamide. The negative and normal control groups were administered distilled water. To determine fasting blood glucose, blood was drawn on days 0, 1, 3, 5, 7, and 14 while it was drawn on days 0 and 14 for the determination of lipids. Phytochemical screening revealed the presence of flavonoids, saponins, tannins, cardiac glycosides, alkaloids and steroids. L. edulis diabetic positive control groups showed significant (P < 0.05) dose dependent reductions in fasting blood glucose levels. When day 0 mean blood glucose levels were compared to day 3 mean blood glucose levels of their respective groups, the 300 mg/kg L. edulis group showed a 23.3% drop and the 500 mg/kg L. edulis group showed a 52.6% drop. The 100 mg/kg L. edulis diabetic positive control group showed a 25.1% drop by day 5, the day on which it showed statistical significance (P < 0.05) compared to the diabetic control. In addition, administration of aqueous extracts of L. edulis to diabetic rats for 14 days significantly decreased (P < 0.05) the levels of serum total cholesterol, triglycerides, Low Density Lipoprotein (LDL) and Very Low Density Lipoprotein (VLDL) whilst increasing the levels of High Density Lipoprotein (HDL), when compared to the diabetic control group. It was concluded that L. edulis showed significant and dose dependent antihyperglycemic and antihyperlipidemic effects thus confirming its traditional use.

Improvement of antihyperglycemic activity of nano-thymoquinone in rat model of type-2 diabetes

Thymoquinone is a bioactive constituent of Nigella sativa seeds. It has been reported to possess antihyperglycemic effect in rats. However, the effect of nanoformulation (NF) of thymoquinone has not been reported in literature. So, the present study was designed with the aim to investigate the effect of nanoformulation of thymoquinone in streptozotocin-nicotinamide induced type-2 diabetic rats and compare its effect with pure bioactive compound as well as metformin, a standard antidiabetic drug. It is the first study reporting the use of thymoquinone NF against diabetes. Polymeric nanocapsules (NCs) of thymoquinone and metformin were prepared by nanoprecipitation method using gum rosin, a biocompatible polymer. Box-Behnken statistical analysis tool was used for the optimization of polymer and other excipients. The NCs were then characterized with respect to particle size, stability, morphology, and in vitro drug dissolution profiles. Furthermore, thymoquinone (20, 40 & 80 mg/kg), metformin (150 mg/kg) and their nanoformulations (20, 40 & 80 mg/kg for thymoquinone and 80 mg/kg for metformin) per se were administered for 21 successive days to type-2 diabetic rats. Body weight and blood glucose levels were measured every week for 3 weeks. Serum lipid profile and glycosylated hemoglobin were estimated on 22^nd day. The nanocapsules were stable, spherical in shape and size was less than 100 nm. Thymoquinone-and metformin-loaded NCs showed sustained release profile as compared to their pure forms. Oral administration of thymoquinone, metformin and their nanoformulations significantly decreased blood glucose level and glycated haemoglobin; and improved the lipid profile of diabetic rats as compared to diabetic control rats. Thymoquinone-loaded NCs (containing 10, 20 and 40 mg of thymoquinone) produced dose-dependent antihyperglycemic effect and this effect was comparable to thymoquinone and metformin. In conclusion, thymoquinone nanocapsules (actually containing half of the doses of thymoquinone) produced better antihyperglycemic effect in type-2 diabetic rats as compared to thymoquinone alone.

Phytochemical screening and study of antioxidant, antimicrobial, antidiabetic, anti-inflammatory and analgesic activities of extracts from stem wood of Pterocarpus marsupium Roxburgh

AIMS

The main aims of the study were to evaluate the phytochemical constituents and to study the antioxidant, antimicrobial, antidiabetic, anti-inflammatory, and analgesic activities of extracts from stem wood of Pterocarpus marsupium.

MATERIALS AND METHODS

Ethanol, acetone and isopropyl alcohol (IPA) (1:1) extracts of stem wood of P. marsupium were subjected to phytochemical screening and analysis of biological activities from August 2015 to January 2016. The antioxidant assay was carried out using 2, 2-diphenyl-1-picrylhydrazyl scavenging method, antimicrobial activity testing by cup diffusion method, antidiabetic test evaluation by oral glucose tolerance test in mice, anti-inflammatory effect was evaluated by hind paw edema method in mice and analgesic test evaluation by a chemical writhing method in mice.

RESULTS

The results of the study revealed that P. marsupium is a source of various phytoconstituents such as alkaloids, glycosides, saponins, tannins, proteins, carbohydrates, cardiac glycosides, flavonoids, and terpenoids. Both the acetone and IPA extract as well as the ethanol extract of stem wood of P. marsupium exhibited a dose-dependent antioxidant activity. Acetone and IPA extract showed antibacterial activity against Gram-positive bacteria, while the ethanolic extract was found to possess antidiabetic activity. The antidiabetic activity of the extract was found to be time and dose-dependent. Similarly, the acetone and IPA extract was found to have anti-inflammatory activity, which was also time and dose-dependent. Furthermore, the ethanolic extract showed analgesic activity, which was dose-dependent. The ethanolic extract was found to be nontoxic.

CONCLUSIONS

Thus, this study laid sufficient background for the further research on extracts from stem wood of P. marsupium for identification, subsequent purification and isolation of compounds having antibacterial, antidiabetic, anti-inflammatory, and analgesic activities.

Applicability of Isolates and Fractions of Plant Extracts in Murine Models in Type II Diabetes: A Systematic Review

Type II diabetes mellitus is one of the most common public health problems worldwide. Its increasing prevalence in several countries and the difficult metabolic control of individuals with the disease justify studying strategies for primary prevention. The population has sought alternative and cheaper ways to treat the disease, including the use of plants considered medicinal by the population. In this study, we carried out a systematic review on the applicability of isolates and fractions of plant extracts in animal models in type II diabetes. A literature search was performed in MEDLINE/PubMed and Scopus databases. Studies using other experimental animals (horses, rabbits, and monkeys) and humans as well as articles in Chinese, German, and Russian were excluded. We assessed the quality of the studies included by using the criteria described in the ARRIVE guidelines. In general, the animals that received fractions or isolates presented reduced blood glucose levels, normalization of body weight and plasma insulin levels, and reduced total triglycerides and cholesterol. In addition, we observed wide variation among the analyzed parameters, which hindered comparison between the studies found. In further studies, standardized reports and experimental design would help to establish comparable study groups and advance the overall knowledge, thus facilitating translatability from animal data to human clinical conditions.

Antidiabetic, antihyperlipidaemic, and antioxidant activity of Syzygium densiflorum fruits in streptozotocin and nicotinamide-induced diabetic rats

Context Syzygium densiflorum Wall. ex Wight & Arn (Myrtaceae) has been traditionally used by local tribes of the Nilgiris, Tamil Nadu, India, for the treatment of diabetes, however, no definitive experimental studies are available. Objective This study investigates the antidiabetic, antihyperlipidaemic and antioxidant activities of ethanol extract of S. densiflorum (EFSD) fruits in streptozotocin (STZ) and nicotinamide (NA)-induced diabetic rats. Materials and methods Acute oral toxicity and oral glucose tolerance were assessed in normal rats. The antidiabetic, antihyperlipidaemic and antioxidant activities were investigated in STZ - NA-induced diabetic rats. Diabetic rats were orally administered with glibenclamide (10 mg/kg b.wt), EFSD (200, 400 and 800 mg/kg b.wt) for 28 d. Further, changes in the blood glucose level (BGL), biochemical parameters, antioxidants were observed and histology of pancreas was performed. Results No toxicity and lethality were observed. Results of the following parameters are represented by treated versus disease control (STZ + NA) groups. BGL (161.33 ± 22.8 versus 476.17 ± 56.58 mg/dl), glycosylated haemoglobin (5.285 ± 0.19 versus 8.05 ± 0.55%), urea (40.32 ± 1.96 versus 75.37 ± 2.91 mg/dl), uric acid (1.2 ± 0.07 versus 2.16 ± 0.05 mg/dl), total cholesterol (89.3 ± 5.14 versus 139.7 ± 5.95 mg/dl) and triglycerides (79.65 ± 2.52 versus 108.9 ± 3.61 mg/dl) were significantly decreased, whereas haemoglobin (11.75 ± 0.73 versus 7.95 ± 0.42 g/dl), high-density lipoprotein cholesterol (14.2 ± 1.11 versus 6.97 ± 0.84 mg/dl), total protein (45%) and liver glycogen (87%) were significantly increased in EFSD-treated diabetic group. Significant changes were observed in the enzymatic and non-enzymatic antioxidants in EFSD-treated groups (p < 0.001). Histopathological examination showed the regeneration of β-cells in Islets of Langerhans. Conclusion This study confirms the antidiabetic, antihyperlipidaemic and antioxidant activities of S. densiflorum fruits.

Investigation of hypoglycemic, hypolipidemic and antioxidant activities of aqueous extract of Terminalia paniculata bark in diabetic rats

OBJECTIVE

To investigate the hypoglycemic, hypolipidemic and antioxidant activities of aqueous extract of Terminalia paniculata bark (AETPB) in streptozotocin (STZ)-induced diabetic rats.

METHODS

Acute toxicity was studied in rats after the oral administration of AETPB to determine the dose to assess hypoglycemic activity. In rats, diabetes was induced by injection of STZ (60 mg/kg, i.p.) and diabetes was confirmed 72 h after induction, and then allowed for 14 days to stabilize blood glucose level. In diabetic rats, AETPB was orally given for 28 days and its effect on blood glucose and body weight was determined on a weekly basis. At the end of the experimental day, fasting blood sample was collected to estimate the haemoglobin (Hb), glycosylated haemoglobin (HbA1c), serum creatinine, urea, serum glutamate-pyruvate transaminase (SGPT), serum glutamate-oxaloacetate transaminase (SGOT) and insulin levels. The liver and kidney were collected to determine antioxidants levels in diabetic rats.

RESULTS

Oral administration of AETPB did not exhibit toxicity and death at a dose of 2 000 mg/kg. AETPB treated diabetic rats significantly (P<0.001, P<0.01 and P<0.05) reduced elevated blood glucose, HbA1c, creatinine, urea, SGPT and SGOT levels when compared with diabetic control rats. The body weight, Hb, insulin and total protein levels were significantly (P<0.001, P<0.01 and P<0.05) increased in diabetic rats treated with AETPB compared to diabetic control rats. In diabetic rats, AETPB treatment significantly reversed abnormal status of antioxidants and lipid profile levels towards near normal levels compared to diabetic control rats.

CONCLUSIONS

Present study results confirm that AETPB possesses significant hypoglycemic, hypolipidemic and antioxidant activities in diabetic condition.

Antidiabetic and hypolipidemic activities of ethanolic leaf extract and fractions of Melanthera scandens

OBJECTIVE

To evaluate the antidiabetic and hypolipidemic activities of ethanolic leaf extract and fraction of Melanthera scandens (M. scandens) in alloxan-induced diabetic rats.

METHODS

M. scandens leaf extract/fractions (37-111 mg/kg) were administered to alloxan-induced diabetic rats for 14 days and blood glucose levels (BGL) of the diabetic rats were monitored at intervals of 7 hours for acute study and 14 days for prolonged study. Lipid profiles of the treated diabetic rats were determined after the period of treatment.

RESULTS

Treatment of alloxan-induced diabetic rats with the extract/fractions caused a significant (P<0.001) reduction in fasting bloodglucose levels (BGL) of the diabetic rats both in acute study and prolonged treatment (2 weeks). The activities of the extract and fractions were more than that of the reference drug, glibenclamide. The extract/fractions exerted a significant reduction in the levels of serum total cholesterol, triglycerides, LDL and VLDL of extract with increases in HDL levels of the diabetic rats.

CONCLUSIONS

These results suggest that the leaf extract/fractions of M. scandens possesses antidiabetic effect on alloxan induced diabetic rats and this justifies its use in ethno medicine and can be exploited in the management of diabetes.

Antidiabetic and hypolipidemic activities of Kigelia pinnata flowers extract in streptozotocin induced diabetic rats

OBJECTIVE

To evaluate antidiabetic and hypolipidemic activities of Kigelia pinnata methanolic flowers extract in streptozotocin (STZ) induced diabetic wistar rat.

METHODS

Rats were made diabetic by a single dose of STZ at 60 mg/kg body weight i.p. The blood glucose level was checked before and 72 h after STZ injection to confirm the development of diabetes. The flower extract and glibenclamide were administered orally at the doses of 250 and 500 mg/kg body weight for 21 days.

RESULTS

Daily oral treatment with the extract and standard drug for 21 days significantly reduced blood glucose, serum cholesterol and triglycerides levels. High density lipoprotein-cholesterol level was found to be improved (P<0.01) as compared to diabetic control group.

CONCLUSIONS

It is concluded that Kigellia pinnata flowers extract have significant antidiabetic and hypolipidemic effect.

Antidiabetic activities of ethanolic extract and fraction of Anthocleista djalonensis

OBJECTIVE

To evaluate the antidiabetic activities of ethanolic root extract/fraction of Anthocleista djalonensis (A. djalonensis) in alloxan-induced diabetic rats.

METHODS

A. djalonensis root extract/fractions (37-111 mg/kg) were administered to alloxan-induced diabetic rats for 14 days and blood glucose levels (BGLs) of the diabetic rats were monitored at intervals of hours and days throughout the duration of the treatment.

RESULTS

Treatment of alloxan-induced diabetic rats with the extract/fractions caused a significant (P<0.001) reduction in fasting BGLs of the diabetic rats both in acute study and prolonged treatment (2 weeks). The activities of the extract and fractions were more than that of the reference drug, glibenclamide.

CONCLUSIONS

These results suggest that the root extract/fractions of A. djalonensis possess antidiabetic effect on alloxan-induced diabetic rats and this justifies its use in ethnomedicine and can be exploited in the management of diabetes.

Indigenous plant medicines for health care: treatment of Diabetes mellitus and hyperlipidemia

Medicinal plants have played an important role in treating and preventing a variety of diseases throughout the world. Metabolic syndrome had become a global epidemic, defined as a cluster of three of five criteria: insulin resistance and glucose intolerance, abdominal obesity, hypertension, low high-density cholesterol, and hypertriglyceridemia. The current review focuses on Indian medicinal plant drugs and plants used in the treatment of diabetes and hyperlipidemia. Though there are various approaches to reduce the ill-effects of diabetes and hyperlipidemia and its secondary complications, plant-based drugs are preferred due to lesser side effects and low cost. The current review focuses on twenty-three medicinal plants used in the treatment of Diabetes mellitus and nine medicinal plants used in the treatment of hyperlipidemia. The wealth of knowledge on medicinal plants points to a great potential for research and the discovery of new drugs to fight diseases, including diabetes and hyperlipidemia.

Anti-diabetic effects of the acetone fraction of Senna singueana stem bark in a type 2 diabetes rat model

ETHNOPHARMACOLOGICAL RELEVANCE

Senna singueana is currently used in the traditional treatment of diabetes mellitus in Nigeria. The present study examined the anti-diabetic activity of the Senna singueana acetone fraction (SSAF) of stem bark in a type 2 diabetes (T2D) rat model.

MATERIALS AND METHODS

Crude ethyl acetate extract of the Senna singueana stem bark was fractionated with various solvents and the acetone fraction was selected for in vivo studies based on the high α-glucosidase and α-amylase inhibitory activities. In the in vivo study, male Sprague-Dawley rats were induced with T2D and treated with the SSAF at 150 and 300 mg/kg body weight. Several T2D-related parameters were measured in the study.

RESULTS

After 4 weeks of intervention, non-fasting blood glucose concentrations were significantly decreased and the glucose tolerance ability was significantly improved in the SSAF treated groups compared to the diabetic control group. Serum insulin concentrations, pancreatic β-cell function (HOMA-β) and liver glycogen were significantly (P<0.05) increased while serum alanine transaminase, alkaline phosphatase and urea were significantly decreased in the SSAF treated diabetic rats compared to the diabetic control group. Though insignificantly (P>0.05), other T2D-induced abnormalities such as food and fluid intake, body weight, serum lipids, serum fructosamine level and peripheral insulin resistance (HOMA-IR) were also partially ameliorated by the SSAF treatment.

CONCLUSION

Data of this study suggest that orally administered SSAF could ameliorate most of the T2D-induced abnormalities in a T2D model of rats.

Evaluation of metabolic and immunological changes in streptozotocin-nicotinamide induced diabetic rats

Type 2 diabetes is a chronic disease with growing public health concern globally. Finding remedies to assist this health issue requires recruiting appropriate animal model for experimental studies. This study was designated to evaluate metabolic and immunologic changes in streptozotocin-nicotinamide induced diabetic rats as a model of type 2 diabetes. Male rats were induced diabetes using nicotinamide (110 mg/kg) and streptozotocin (65 mg/kg). Following 42 days, biochemical and immunological tests showed that diabetic rats had higher levels of blood glucose, WBC, certain abnormalities in lipid profile and insufficient mitogenic responses of lymphocytes (p<0.05). However, the status of the total antioxidant, inflammatory biomarkers and other parameters of full blood count (except HCT) were not significantly altered. Phenotyping assay indicated insignificant lymphocyte subtype imbalances excluding a significant rise in the level of CD4+CD25+ marker (p<0.05). This model of diabetic animals may represent some but not all symptoms of human type 2 diabetes.

Antidiabetic effect of Merremia emarginata Burm. F. in streptozotocin induced diabetic rats

OBJECTIVE

To investigate the antidiabetic property of Merremia emarginata (M. emarginata) Burm. F. plant in streptozotocin induced diabetic rats.

METHODS

The dose dependent effects of 28 days oral treatment with methanol extract (100, 200 and 400 mg/kg) from the plant of M. emarginata on blood glucose level, body weight, insulin, total hemoglobin, glycosylated haemoglobin (HbA1C), total protein, serum urea, serum creatinine and carbohydrate metabolizing enzymes were evaluated in streptozotocin induced diabetic rats. Histology of pancreas was also studied.

RESULTS

A significant decrease in blood glucose, serum urea and serum creatinine and significant increase in body weight, insulin and protein level were observed in diabetic rats treated with M. emarginata. Treatment with M. emarginata resulted in a significant reduction of HbA1C and an increase in total hemoglobin level. The activities of carbohydrate metabolizing enzymes such as hexokinase were significantly increased whereas glucose-6-phosphatase, fructose-1, 6-bisphosphatase were significantly decreased by the administration of M. emarginata in diabetic rats. Histology of diabetic rats treated with M. emarginata showed the pancreatic β-cells regeneration.

CONCLUSIONS

These findings suggest that M. emarginata has potent antidiabetic activity in streptozotocin induced diabetic rats.