Protective Effect of Eugenia jambolana Seed Kernel on Tissue Antioxidants in Streptozotocin-Induced Diabetic Rats

Physicochemical, microbiological, and sensory properties of healthy juices containing aloe vera gel and probiotics and their antidiabetic effects on albino rats

The consumption of fruit and vegetable juices is widely recognized as a healthy choice across all age groups. Orange, carrot, and aloe vera are renowned for their functional properties and health benefits. In this study, we investigated the potential incorporation of aloe vera gel into blended orange and carrot juices. We also evaluated the resulting mixed probiotic juices (chemical, microbiological, and sensory aspects) during a 14-day storage period at refrigerator temperature. The chemical composition and phytochemical structure of aloe vera gel were examined, followed by an assessment of the biological effects of these healthy juices on diabetic albino rats. The results indicated improvements in total soluble solids, reducing sugars, and total sugars with increasing storage duration. Furthermore, the study demonstrated that incorporating aloe vera into the natural mixed juices enhanced their phytochemical quality. The treatment supplemented with aloe vera gel gave the highest total content of phenolic and flavonoid substances, which were 310 mg of GAE/100 g and 175 mg of quercetin/100 g, respectively. Probiotic strains (Bifidobacterium animalis subsp lactis Bb12, Lactiplantibacillus plantarum 299V, and Lactobacillus acidophilus L10) exhibited good viable cell counts in orange and mixed orange and carrot probiotics juices with viable counts of 7.42-8.07 log CFU/mL. Regarding sensory attributes, the study found that increasing the ratio of orange juice improved the taste while increasing the ratio of carrot juice enhanced the color in juice mixtures. Incorporation of aloe vera into mixed natural juices also enhanced the reduction of blood glucose, triglyceride, cholesterol, LDL, creatinine, ALT, AST, and urea levels while increasing total protein and HDL levels in diabetic rats. Based on these findings, oranges, carrots, and aloe vera offer the potential to produce new, flavorful, nutritious, and appealing juices. Moreover, this study determined that a functional juice with favorable sensory properties can be created by blending 75% orange juice, 20% carrot juice, and 5% aloe vera gel. Additionally, aloe vera demonstrated greater efficacy as an antidiabetic agent in rats. Further research is suggested to explore the potential advantages of aloe vera gel and probiotic juices in mitigating diabetes and other metabolic syndromes.

A comprehensive survey of warfarin-induced hepatic toxicity using histopathological, biomarker, and molecular evaluation

Warfarin finds human application as anticoagulant therapy. Warfarin usage can cause liver damage and hemorrhage. Besides functioning as anticoagulant and causing continuous bleeding of pests, the mechanism of toxicity of warfarin is unknown. In this study, Wild female and male rats were administrated orally with warfarin for 18 days at 9, 18, 27.5, and 55 mg/kg, respectively. Hepatoxicity was determined by assessing, LD50, leukocyte counts, immunochemistry, histopathology, serum proteins, Western blotting, especially of markers of liver injury, such as AST, ALT & ALP, and markers of antioxidant and oxidative stress markers. Warfarin treatment decreased Nrf2 levels while it increased caspase 3, CYP2C9, COLL1A1. It caused cellular damage and fibrosis of liver. The plasma levels of markers of liver injury, AST, ALT, ALP, bilirubin and transferrin were increased. The plasma levels of albumin, IgG and antitrypsin were decreased. Warfarin treatment decreased RBC and total lymphocyte count while increasing selectively neutrophils. Warfarin exposure caused increased oxidative stress; increased LPO and decreased GSH, SOD, CAT and NO production. Oral exposure of rats with Warfarin leads to increased oxidative stress resulting into liver damage via CYP2C9 mediated by Nrf2 depletion.

Traditional Herbal Medications Utilized in the Indian Medical System forthe Management of Diabetes: An Updated Review and Clinical Implications

Phytomedicine, also called botanical medicine, is the practice of using plants to treat disease. Diabetes, for example, has been treated and prevented with herbal medication for a lot longer than Western medicine. Worldwide, diabetes has become a major health concern. The management of diabetes and hyperglycemia, two of the most common public health threats, is far from ideal. When hyperglycemia persists or is not under control, diabetes-related complications, like blindness, lower limb amputations, renal disease, and cardiovascular disease, play a significant role in the morbidity and mortality of the disease. Although chemicals and biochemical agents can assist in managing diabetes, there is currently no complete cure for the disease. Herbal remedies are one of many methods that can be used to treat and prevent diabetes and its subsequent problems. Numerous traditional treatments have been discovered for diabetes as a result of extensive research efforts. However, there are many factors to consider when deciding which herbs to use, such as the patient's financial status, the presence or absence of co-morbidities, and the accessibility, cost-effectiveness, and safety profile of the herbs. This article focuses on the use of herbal and natural remedies in the treatment and prevention of diabetes, the mechanisms by which these remedies lower blood glucose levels, and the specific herbal items now utilized in the management of diabetes.

Antidiabetic and Liver Histological and Ultrastructural Effects of Cynara scolymus Leaf and Flower Head Hydroethanolic Extracts in Nicotinamide/Streptozotocin-Induced Diabetic Rats

This study aims to investigate the effect of hydroethanolic extracts of Cynara scolymus (C. scolymus) leaf (CLHE) and C. scolymus flower (CFHE) on the hepatic histopathological lesions and functional biochemical changes induced by type 2 diabetes mellitus (T2DM). The rat model of T2DM was induced by intraperitoneal injection of streptozotocin (STZ) in a dose of 60 mg/kg for 15 minutes following nicotinamide (NA) (60 mg/kg). The rats were allocated into four groups: group 1 (negative control), group 2 (diabetic control), group 3 (diabetic rats supplemented with 100 mg/kg/day CLHE), and group 4 (diabetic rats supplemented with 100 mg/kg/day CFHE). Treatment with CLHE and CFHE, for the study duration of 28 days, significantly improved the deteriorated hepatic glycogen content, glycogen phosphorylase, glucose-6-phosphatase activities, serum fructosamine levels, lipid profile, aspartate transaminase activities, and alanine transaminase activities as well as serum insulin and C-peptide levels. The elevated liver lipid peroxidation and the decreased activities of superoxide dismutase and glutathione peroxidase were significantly alleviated. The elevated expression of the proinflammatory cytokine tumor necrosis factor-α in the liver of diabetic rats was significantly reduced by treatments with CLHE and CFHE. NA/STZ-induced T2DM exhibited hepatic histopathological changes in the form of disordered hepatocytes, cytoplasm dissolution, and mononuclear leukocytic infiltration. The electron microscopic ultrastructure study revealed damaged mitochondria with ill-defined cristae and fragmentation of the rough endoplasmic reticulum. Treatments with CLHE and CFHE remarkably amended these histopathological and EM ultrastructural changes. In conclusion, both CLHE and CFHE may have antidiabetic and improvement effects on the liver function and structural integrity, which may be mediated, at least in part, via suppression of inflammation and oxidative stress and enhancement of the antioxidant defence system.

Pharmacological Studies on the Antidiabetic, Antioxidant, and Antimicrobial Efficacies of Commiphora myrrha Resin in Streptozotocin-Induced Diabetes in Rats: A Preclinical Study

RESULTS

The aqueous extracts of MAE were phytochemically analyzed, and the results revealed the presence of high concentrations of tannins, sterols, and isoprenoids (terpenoids), while steroids and flavonoids were found in moderate concentrations. The plant extract showed promising inhibition of the growth of gram-positive and gram-negative pathogens. It also showed that MAE has potential antihyperglycemic and antioxidant activities. Microscopic examination of the pancreas showed degenerative changes and atrophy associated with dilatation of the exocrine ducts in the STZ-induced diabetic rats, while the treatment revealed that the Langerhans islets were close to normal without any histopathological alteration.

CONCLUSION

The present results suggested that an aqueous extract of MAE could be considered an efficient antidiabetic, antioxidant, and antimicrobial treatment in the future.

Inhibitory effects of Syzygium jambos extract on biomarkers of endothelial cell activation

Background

Disordered endothelial cell activation plays an important role in the pathophysiology of atherosclerosis, cancer, sepsis, viral infections, and inflammatory responses. There is interest in developing novel therapeutics to regulate endothelial cell function in atherothrombotic, metabolic, vascular, and hematological diseases. Extracts from leaves of the Syzygium jambos (L.) Alston (S. jambos) trees have been proposed to treat cardiovascular diseases and diabetes through unclear mechanisms. We investigated the effects of the S. jambos extract on biomarkers of endothelial dysfunction and immune responses in the human endothelial cell line, EA.hy926.

Methods

Leaves of S. jambos were collected, concocted and lyophilized. To study the effects of S. jambos on endothelial cell activation, we used the human endothelial cell line. IL-6 levels were measured using qPCR and ELISA. PDI activity was measured using Insulin Turbidity and Di-E-GSSG assays. CM-H2DCFDA was used to study ROS levels. Migration assay was used to study S. jambos effect on ex vivo human polymorphonuclear and human mononuclear cells.

Results

Our results show that incubation of EA.hy926 cells with ET-1 led to a 6.5 ± 1.6 fold increase in IL-6 expression by qPCR, an event that was blocked by S. jambos. Also, we observed that ET-1 increased extracellular protein disulfide isomerase (PDI) activity that was likewise dose-dependently blocked by S. jambos (IC₅₀ = 14 μg/mL). Consistent with these observations, ET-1 stimulated ex vivo human polymorphonuclear and mononuclear cell migration that also was dose-dependently blocked by S. jambos. In addition, ET-1 stimulation led to significant increases in ROS production that were sensitive to S. jambos.

Conclusion

Our results suggest that the S. jambos extract represents a novel cardiovascular protective pharmacological approach to regulate endothelial cell activation, IL-6 expression, and immune-cell responses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03572-7.

Biological Activity of Extracts of Red and Yellow Fruits of Cornus mas L.-An In Vitro Evaluation of Antioxidant Activity, Inhibitory Activity against α-Glucosidase, Acetylcholinesterase, and Binding Capacity to Human Serum Albumin

Although extracts are broadly used in order to support the treatment of numerous diseases, only in a limited number of cases is the process of applying and establishing their mechanisms of action scientifically analyzed. Fruits of Cornelian cherry are an abundant source of iridoids, anthocyanins, flavonols and phenolic acids. The aim of the present study was to evaluate the in vitro bioactivity of red and yellow Cornelian cherry fruits’ extracts. The biological potential of extracts, in a broad sense, involved antioxidant activity in relation to phosphatidylcholine liposomes, inhibitory ability against α-glucosidase and acetylcholinesterase enzymes, as well as interactions with human serum albumin. Studies showed that both extracts were more effective in protecting liposome membranes against free radicals produced by AAPH in an aqueous environment due to the fact that they can be better eliminated by the hydrophilic components of the extracts than those produced by UVB radiation. Extracts exhibited inhibitory activity against acetylcholinesterase and α-glucosidase, wherein loganic acid extract showed noncompetitive inhibition of the enzyme. Moreover, extracts binded to albumin mainly through hydrogen bonds and van der Waals forces. Taken together, red and yellow cherry fruits’ extracts exhibit diverse biological properties and can be exploited as a source of natural therapeutic agents.

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.

Metformin hydrochloride entrapment in sorbitan monostearate for intestinal permeability enhancement and pharmacodynamics

Penetration enhancement of metformin hydrochloride via its molecular dispersion in sorbitan monostearate microparticles is reported. This represents basic philosophy to maximize its entrapment for maximum penetration effect. Drug dispersion in sorbitan monostearate with different theoretical drug contents (TDC) were prepared. Products showed excellent micromeritics and actual drug content (ADC) increased by increasing TDC. The partition coefficient of the drug products showed huge improvement. This indicates the drug entrapped in the polar part of sorbitan monostearate as a special image which effects on the drug release. The drug permeation profiles from the different products are overlapped with nearly equal permeation parameters. The permeation results suggested the main driving force for improving the drug paracellular pathway is its dispersion in sorbitan monostearate and is independent of ADC. Pharmacodynamic of the products showed a significant improvement than the drug alone at p ˂ 0.05. ANOVA test indicated the insignificant pharmacodynamic difference between the low, middle, and high ADC of the products. An excellent correlation founded between the drug permeation and pharmacodynamic precents. Drug permeation driving force via the paracellular pathway is its entrapment in sorbitan monostearate and independent on ADC. The technique is simple and the products had excellent micromeritics.

Biofunctionalities of unprocessed and processed flours of Australian lupin cultivars: Antidiabetic and organ protective potential studies

As lupin has emerged popularity as dietary protein and nutritional source, our present research was aimed to demonstrate the antidiabetic and organ-protective activities of nine cultivars of Australian sweet lupin seed flours by means of in vitro and in vivo assays accompanied by identification of their bioactive phytocompounds and exploration of underlying mechanisms of their hypoglycemic activity using in silico approach. In vitro α-amylase and α-glucosidase activities inhibition and glucose uptake assays identified Jenabillup seed flours for exhibiting the most potential antidiabetic activity amongst the nine cultivars. In vivo antidiabetic and major organ-protective activities were investigated on streptozotocin-induced hyperglycemia and organ damages in Wister rat model. Along with attenuating hyperglycemia and retreating major organ damages, the biochemical imbalance in cardiac, hepatic and renal markers were well-balanced by Jenabillup seed flours treatment. These activities of lupin seed flours were insignificantly affected by thermal processing. Moreover, in silico investigation of 106 phytochemicals identified by gas chromatography-mass spectroscopy (GC-MS) analysis of the seed flour extracts of nine cultivars revealed that more than 35% of compounds possess moderate to high binding affinity to α-amylase and α-glucosidase enzymes. These bioactive compounds act synergistically to exert potential hypoglycemic activity. Cross-docking and binding energy calculation by molecular mechanics/generalized Born volume integration (MM/GBVI) model suggest actinomycin C2 as a potential inhibitor of both α-amylase and α-glucosidase enzymes. These findings acclaim that Australian sweet lupin seed flours may be considered not only as functional food, but also for further development of effective drugs in pharmaceuticals in the treatment of diabetes mellitus and resultant organ damages.

Antimicrobial effects of silver nanoparticles and extracts of Syzygium cumini flowers and seeds: Periodontal, cariogenic and opportunistic pathogens

OBJECTIVE

This study aimed to analyze the antimicrobial effects of lyophilized hydroalcoholic extract (HEScSeed and HEScFlower) and silver nanoparticles (AgNPs-HEScSeed and AgNPs-HEScFlower) of S. cumini seed and flower, and to characterize some compounds of these extracts and their NPs.

DESIGN

Phytochemical screening was performed by GC-MS. Nanoparticles were characterized by UV-vis spectroscopy, energy-dispersive X-ray (EDX) spectrophotometry, scanning electron microscopy (SEM) and field emission gun (FEG), dynamic light scattering (DLS) and zeta potential (ZP). Antimicrobial susceptibility tests were analyzed by broth microdilution and agar diffusion methods.

RESULTS

HEScSeed and HEScFlower showed 7 and 17 phytochemical compounds, respectively. AgNPs-plant extracts were reported as stable and with variable shapes and sizes. All studied species (A. naeslundii, C. albicans, F. nucleatum, S. aureus, S. epidermidis, S. mutans, S. oralis and V. dispar) were susceptible to extracts and AgNPs-plant extracts, with varying degrees of antimicrobial activities (extract: 648.4-5,187.5 μg/mL; AgNPs-plant: 31.2-2,000 μg/mL).

CONCLUSION

The extracts of S. cumini seed and flower have antimicrobial action against pathogens of medical and dental interest, whose MIC and MMC are species-dependent. The AgNPs-HEScSeed and AgNPs-HEScFlower have different shapes, sizes, organic compounds, stability and electronegativity (capping), characteristics that contribute to their bacteriostatic and fungistatic effects, but at significantly lower concentrations than plant extracts.

Hypoglycemic, Anti-Hyperglycemic and Anti-Hyperlipidemic Effects of Bersama abyssinica Fresen (Melianthaceae) Leaves' Solvent Fractions in Normoglycemic and Streptozotocin-Induced Diabetic Mice

Background

The leaves of Bersama abyssinica are used by traditional healers and the community for the treatment of diabetes mellitus. Thus, the current study intended to evaluate the hypoglycemic, anti-diabetic, and anti-hyperlipidemic effects of Bersama abyssinica.

Methods

The solvent fractions of Bersama abyssinica leaves were prepared. A total of 132 healthy, male Swiss albino mice weighing 20-28 grams (age of 6-10 weeks) were used. The antidiabetic activity of all the doses (100, 200, and 400 mg/kg) of Bersama abyssinica solvent fractions was evaluated by animal models: normoglycemic mice, oral glucose loaded mice, and diabetic mice. Diabetes was induced by a single intraperitoneal injection of streptozotocin (150mg/kg body weight). The effect of the plant extract on body weight and serum lipid levels were measured in diabetic mice. Statistical analysis was performed by using statistical package for social sciences version 24. The analyses were carried out using one-way ANOVA, followed by Tukey's multiple comparison tests. The result was considered significant when p <0.05.

Results

The solvent fractions of B. abyssinica at all tested doses (100, 200, and 400 mg/kg) exhibited significant (P<0.05-0.001) BGL reduction in all animal models. In hypoglycemic activity, the percentage reduction of baseline BGL was 25.90%, 26.36%, 38.43%, 30.96% and 49.42% for EAF200mg/kg, AQF200mg/kg, EAF400mg/kg, AQF400mg/kg, and GLC 5mg/kg, respectively. B. abyssinica at the dose of AQF 200 mg/kg (p<0.05), AQF 400mg/kg (p<0.001), EAF 200mg/kg (p<0.01), and GLC 5mg/kg (p<0.001) significantly reduced the BGL following 1-hour post-treatment as compared to the negative control. Likewise, the higher doses of the solvent fractions (400mg/kg) significantly (p<0.001) reduced the BGL following 2- and 3-hours post-treatment as compared to the negative control. Daily administration of aqueous fraction of B. abyssinica caused a maximum reduction in fasting BGL at the fourteenth day of administration by 33.29%, 38.59%, 52.71%, and 59.66%, respectively, for AQF100, AQF200, AQF400, and GLC 5mg/kg. The aqueous fraction of B. abyssinica and the glibenclamide significantly (p<0.05) prevent loss of body weight and showed improvement in serum lipid levels.

Conclusion

The solvent fractions of Bersama abyssinica exhibit noticeable antidiabetic activity in all animal models (normoglycemic mice, oral glucose loaded mice, and diabetic mice) and showed improvement in body weight and serum lipid profile levels, which rationalizes the claimed use of the B. abyssinica in the treatment of diabetes mellitus.

Gongronema latifolium Benth. leaf extract attenuates diabetes-induced neuropathy via inhibition of cognitive, oxidative stress and inflammatory response

BACKGROUND

Gongronema latifolium (G. latifolium) Benth. leaves are traditionally used to treat diabetes mellitus (DM) and other diseases in Nigeria and West Africa. This study was performed to evaluate the neuroprotective effect of aqueous extract of G. latifolium leaf against DM. Antidiabetic activity of G. latifolium extracts (6.36, 12.72 and 25.44 mg kg^-1 , i.p.) was determined in alloxan-induced diabetic rats. Fasting blood glucose level and oxidative stress markers catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA), and nitric oxide (NO) levels were measured. Cognitive biomarkers acetylcholinesterase (AChE), butyrylcholinesterase (BChE), dopamine (DOPA), serotonin, epinephrine and norepinephrine and cyclooxygenase (COX-2) were measured in the brain of controls and of G. latifolium-treated diabetic rats.

RESULTS

Administration of G. latifolium leaf extract to diabetic rats significantly restored the alterations in the levels of fasting blood glucose (FBG). The MDA and NO levels were significantly reduced with an improvement in CAT, SOD, and GPx activity in the kidneys and brains of diabetic rats treated with G. latifolium. Gongronema latifolium also significantly decreased the levels of AChE, BChE, DOPA, serotonin, epinephrine, and nor-epinephrine in diabetic rats. G. latifolium effectively ameliorated COX-2 in diabetic rats.

CONCLUSION

This study showed that leaf extract of G. latifolium improved antioxidant defense against oxidative stress. It displays a neuroprotective effect resulting in the modulation of brain neurotransmitters, which could be considered as a promising treatment therapy. © 2020 Society of Chemical Industry.

Gongronema latifolium leaf extract modulates hyperglycaemia, inhibits redox imbalance and inflammation in alloxan-induced diabetic nephropathy

Background

Gongronema latifolium leaf is used traditionally to treat diabetes and other diseases. The present study aimed to provide the modulatory effect of G. latifolium on hyperglycemia, inhibitory effect of redox imbalance and inflammation in alloxan-induced nephropathy in Wistar rats.

Methods

Alloxan monohydrate was used to induce diabetes by an intraperitoneal injection of (150 mg/kg). Three diabetic groups were administered aqueous leaf extract of G. latifolium at 6.36, 12.72 and 25.44 mg/kg bodyweight (BW) respectively; a group was administered with metformin (5 mg/kg BW), while the other two were served as positive and negative control. Thereafter, fasting blood glucose, antioxidant enzymes, malondialdehyde (MDA) level, interleukin 2 and 6 were determined.

Results

G. latifolium leaf significantly (p < 0.05) reduced the alloxan-induced increases in blood glucose, MDA, interleukin 2 and interleukin 6 level and increased the alloxan-induced decreases in superoxide dismutase, catalase, glutathione peroxidase, glutathione reduced and glutathione transferase activity. All these changes compared with those of metformin-treated diabetic rats.

Conclusion

The data from this study suggest that G. latifolium modulates glucose homeostasis as well as inhibiting redox imbalance and inflammation in diabetic rats, which may be attributed to the effects of its phytochemical constituents such as saponins, flavonoids and alkaloids. It also indicated that inhibition of inflammatory cytokines and redox imbalance are likely mechanisms by which G. latifolium leaf exert its antidiabetic action.

Molecular and biochemical monitoring of the possible herb-drug interaction between Momordica charantia extract and glibenclamide in diabetic rats

Momordica charantia is used in folk medicine to manage diabetes mellitus. In this study, we investigated the possible herb-drug interaction between M. charantia fruit extract (MCFE) and glibenclamide (GLB) in streptozotocin-diabetic rats. Rats were divided into 7 groups. The 1st group received 3% Tween 80. The 2nd–5th groups were diabetic rats received vehicle, GLB (5 mg/kg), MCFE (250 and 500 mg/kg), respectively. The 6th–7th groups administered GLB plus MCFE (250 and 500 mg/kg), respectively. After 8 weeks, fasting blood glucose (FBG), insulin and glycosylated hemoglobin (HbA1c) levels were assessed. Histopathological and immunohistochemical examinations of the pancreases were done. Quantitative RT-PCR was used to analyze hepatic mRNA expression of insulin receptor (INR), glucose transporter 2 (Slc2a2) and peroxisome proliferator-activated receptor α (PPAR-α) genes. All medicaments greatly reduced FBG in diabetic rats when compared with diabetic control group. GLB plus MCFE combination was better than GLB alone in improving levels of insulin and HbA1c. All medicaments restored insulin content of pancreatic β-cells and reduced glucagon and somatostatin of alpha and delta endocrine cells. Moreover, GLB plus MCFE-500 was the most efficient in restoring INR, Slc2a2 and PPAR-α mRNA expression to their normal levels. In conclusion, MCFE in combination with GLB gives greater glycemic improvement than GLB monotherapy.

Antidiabetic and Antioxidant Effects of Apple Cider Vinegar on Normal and Streptozotocin-Induced Diabetic Rats

Abstract. Diabetes mellitus (DM) is a globally growing health problem and one of the most prevalent endocrine disorders worldwide. Chronic hyperglycemia status favors the manifestation of oxidative stress by increasing the production of reactive oxygen species and/or by reducing the antioxidant defense system activity. In this study, the beneficial effects of apple cider vinegar (ACV) supplementation on blood glucose level, hepatic and renal toxicity and antioxidant enzyme activities in normal and diabetic rats were investigated. Four groups (8 animals/group) of male Wistar rats were used. The animals were fasted overnight and DM was induced by an intraperitoneal injection of freshly prepared streptozotocin (STZ). Control rats were injected with citrate buffer only. ACV was administrated orally for 4 weeks. Our findings indicated that ACV increased the activity of antioxidant enzymes (superoxide dismutase (p < 0.001), catalase and glutathione peroxidase) as well as thiol concentration (p < 0.05). It also reduced lipid peroxidation levels (TBARS) and the indices of toxicity in liver and kidneys, by significantly decreasing aspartate and lactate transaminase (AST & ALT) activity, total and direct bilirubin (p < 0.001), urea (p < 0.001) and creatinine (p < 0.001) levels. Moreover, the plasma concentration of magnesium, calcium (p < 0.001) and copper increased after ACV administration. Iron levels however decreased. The concentration of vitamin E, an important antioxidant in vivo, was raised. In conclusion, the findings show that ACV possesses significant antihyperglycemic and antioxidant effects in an experimental model of DM, by preventing diabetic complications in liver and kidneys.

Anti-Hyperglycemic and Anti-Inflammatory Activities of Polyphenolic-Rich Extract of Syzygium cumini Linn Leaves in Alloxan-Induced Diabetic Rats

In this study, anti-hyperglycemic and anti-inflammatory activities of polyphenolic-rich extract of Syzygium cumini leaves in alloxan-induced diabetic rats were determined. Diabetes was induced by a single intraperitoneal injection of alloxan (150 mg/kg body weight) in female Wistar rats. The rats were orally administered with 400 mg/kg free phenol, 400 mg/kg bound phenol, and 5 mg/kg metformin, respectively. On the 14th day of oral administration, the animals were sacrificed, anti-hyperglycemic and anti-inflammatory were assessed. Fasting blood glucose and glycated hemoglobin levels; homeostasis model assessment-insulin resistance scores, lipid peroxidation concentration, glucose-6-phosphatase activity, and all concentrations of anti-inflammatory studied in alloxan-induced diabetic rats were significantly ( P < .05) reduced with the administration of polyphenolic-rich extract of Syzygium cumini leaves. Also there was significant ( P < .05) increase in glycogen and insulin concentrations, pancreatic β-cell scores, antioxidant enzymes and hexokinase activities, as well as glucose transporter levels in diabetic animals administered with polyphenolic-rich extract of S cumini leaves. The results indicate that S cumini leaves possess anti-hyperglycemic and anti-inflammatory activities.

Balanites aegyptiaca ameliorates insulin secretion and decreases pancreatic apoptosis in diabetic rats: Role of SAPK/JNK pathway

SAPK-JNK pathway performs a significant role in the pathogenesis of type 2 diabetes. Balanites aegyptiaca (BA) is used as an anti-diabetic agent in folk medicine however its hypoglycemic mechanism is not fully elucidated. The current study aimed to evaluate the effect of crude extract, butanol, and dichloromethane fractions from BA on the stress-activated protein kinase/c-Jun N-terminal kinase (SAPK-JNK) pathway in experimental diabetic rats. Six groups of male Wistar rats were included: normal control, diabetic, diabetic rats treated with crude, butanol or dichloromethane fraction from BA (50 mg/kg BW) and diabetic rats treated with gliclazide as a reference drug for one month. Our results suggested a protective role of treatment of diabetic rats with BA against oxidative stress-induced SAPK-JNK pathway. Moreover, BA treatment produced a reduction in plasma glucose, HbA_1c, lactic acid, lipid profile, malondialdehyde levels and produced an increase in insulin, reduced glutathione levels, catalase and superoxide dismutase activities compared with untreated diabetic rats. Moreover, it decreased apoptosis signal-regulating kinase 1, c-Jun N-terminal kinase 1, protein 53 and increased insulin receptor substrate 1 in rat pancreas while it increased glucose transporter 4 in rat muscle. Analysis of BA extracts by LC-HRMS revealed the presence of different saponins with reported hypoglycemic effect. In conclusion, BA exerted hypoglycemic, hypolipidemic, insulinotropic and antioxidant effects. Additionally, it reduced apoptosis in pancreatic β-cells and increased glucose uptake in muscle. These results suggest that the hypoglycemic effect of BA is due to the inhibition of the SAPK-JNK pathway.

Syzygium cumini leaf extract inhibits LDL oxidation, but does not protect the liproprotein from glycation

ETNOPHARMACOLOGICAL RELEVANCE

Syzygium cumini (L.) Skeels is a plant widely used in folk medicine to treat diabetes mellitus (DM). The tea from its leaves is frequently used by diabetics for lowering hyperglycemia. There is a close relationship between DM and atherosclerosis, a chronic immuno-inflammatory disease, were the early stages encompass oxidative and glycative modifications in the structure of low density lipoprotein (LDL).

AIM OF THIS STUDY

To investigate the potential protective effects of aqueous-leaf extract from Syzygium cumini (S.cExt) against CuSO₄-induced oxidation and methylglyoxal (MG)-induced glycation of human LDL in vitro.

MATERIALS AND METHODS

LDL oxidative changes were evaluated by measuring conjugated dienes (CD) formation, thiobarbituric acid reactive substances (TBARS) levels, quenching of tryptophan (Trp) fluorescence and structural modifications in LDL particle. In LDL glycated by MG (glyLDL), we determined the levels of fluorescent advanced glycation end products (AGEs) and mobility by agarose gel electrophoresis.

RESULTS

S.cExt blocked oxidative events induced by CuSO₄ in human LDL, plasma and serum. Fourier transform infrared spectroscopy (FT-IR) revealed that specific regions of apoB100 were oxidized by CuSO₄ in human LDL and that S.cExt reduced these oxidations. Unlike, the increased AGEs levels and eletrophoretic mobility observed in LDL MG-glycated were not modified by S.cExt.

CONCLUSION

The findings herein indicate that S.cExt could be tested in atherogenesis models as potential protective agent against LDL oxidation.

Post-thyroidectomy hypothyroidism increases the expression and activity of ectonucleotidases in platelets: Possible involvement of reactive oxygen species

Signaling mediated by purines is a widespread mechanism of cell-cell communication related to vasomotor responses and the control of platelet function in the vascular system. However, little is known about the involvement of this signaling as well as the role of reactive oxygen species (ROS) in the development of hypothyroidism. Therefore, the present study investigates changes in the purinergic system, including enzyme activities and expression in platelets, and oxidative profiles in patients with post-thyroidectomy hypothyroidism. The nucleoside triphosphate diphosphohydrolase 1 (NTPDase/CD39) expression in patients increased by 40%, and the adenosine triphosphate (ATP) or adenosine diphosphate (ADP) hydrolyzing activity increased by 82% and 70%, respectively. The activities of ecto-5´-nucleotidase and adenosine deaminase (ADA) also significantly enhanced (39% and 52%, respectively), which correlates with a 45% decrease in adenosine concentration. Furthermore, these patients demonstrated an increased production of ROS (42%), thiobarbituric acid reactive substances (TBARS) (115%), carbonyl protein (30%) and a decreased glutathione S-transferase (GST) activity (20%). This study demonstrates that hypothyroidism interferes with adenine nucleoside and nucleotide hydrolysis and this is correlated with oxidative stress, which might be responsible for the increase in ADA activity. This increase causes rapid adenosine deamination, which can generate a decrease in their concentration in the systemic circulation, which can be associated with the development of vascular complications.

Phytoecdysteroids from Ajuga iva act as potential antidiabetic agent against alloxan-induced diabetic male albino rats

The present study investigated the protective effect of phytoecdysteroids extracted from the Ajuga iva plant on body weight changes, blood glucose, insulin total protein, blood urea nitrogen (BUN), creatinine, triglycerides (TG), cholesterol, lipid peroxidation, antioxidant enzymes, pancreatic histopathology and hexokinase-I expression in the alloxan-induced diabetic rats. Experimental diabetes was induced following 15day intraperitoneal administration of alloxan. The rats were divided into four groups. Group I served as a sham group, and group II served as the diabetic control. Group III served as a treatment for phytoecdysteroids (10mg/kg), and group IV served as a treatment for phytoecdysteroids (20mg/kg). Phytoecdysteroids restored body weight loss to its antihyperglycemic effect. Blood glucose was reduced 19.2 and 52.9% in group III and IV respectively. Blood insulin (54.9 and 105.88%) and total protein (25 and 72.2%) was increased in group III and IV respectively. BUN, creatinine, TG, cholesterol and lipid peroxidation was significantly reduced following treatment. Catalase, superoxide dismutase (SOD), and glutathione peroxidase activity were significantly increased following treatment. Islet β-cells are lost in alloxan-induced diabetic rats. Regeneration of islets and reduced atrophy of acinar cells were noted. The number of insulin-secreting cells was tremendously reduced in alloxan-induced diabetic rats. Insulin-secreting cells were increased 48 and 61% in group III and IV respectively. Hexokinase-I mRNA (28.3 & 93.5%) and protein (27.9 and 55.3%) expression were significantly increased following treatment. Taking all these data together, it is suggested that the phytoecdysteroid could be a potential therapeutic agent against experimental diabetes.

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.

Naringenin ameliorates streptozotocin-induced diabetic rat renal impairment by downregulation of TGF-β1 and IL-1 via modulation of oxidative stress correlates with decreased apoptotic events

CONTEXT

Naringenin, a flavonone and a nutritive antioxidant which is mostly obtained from grapefruit, orange or tomato skin, has been extensively studied due to its radical scavenging activity.

OBJECTIVE

The present study investigates the protective effect of naringenin on rat kidney after streptozotocin-induced diabetes.

MATERIALS AND METHODS

Sixty male Wistar rats were divided into six groups. Diabetes was induced by a single intraperitoneal injection of streptozotocin (50 mg/kg) in groups II, III and IV. Naringenin 5 mg/kg body weight was given to groups III and V, but 10 mg/kg was given to groups IV and VI, orally once a day for 10 weeks. After which all animals were sacrificed, and the biochemical, histopathological, immunohistochemical and apoptotic assays were conducted.

RESULTS

Naringenin treatment with 5 and 10 mg/kg significantly decreased (p < 0.05) the serum biochemical parameters, elevated tissue malondialdehyde levels and increased (p < 0.01) the reduced superoxide dismutase, catalase and reduced glutathione enzyme activities in the diabetic kidney. Diabetes-induced naringenin-treated groups showed an improved histology and revealed a significant reduction in apoptosis activity (7.2 ± 0.01 and 1.8 ± 0.05) and in expression of TGF-β1 (18.9 ± 3.4 and 10.2 ± 2.1) at a dose of 5 and 10 mg/kg, respectively. Similarly, in contrast to the diabetic group, a significant difference was observed in the IL-1 expression (15.68 ± 4.3) in 5 mg/kg and (9.85 ± 2.1) in 10 mg/kg naringenin-treated groups.

CONCLUSION

Naringenin acts as a protective agent in diabetic renal impairment by altering oxidative stress, modulation of cytokines expression and apoptotic events.

Anti-diabetic Effect of FriedelanTriterpenoids in Streptozotocin Induced Diabetic Rat

We herein report the anti-diabetic effect of the natural friedelan tritepenoid, 4-oxa-3, 4-secofriedelan (cerin), isolated from cork tissue of Quercus suber L. and its oxygenated derivative, 4-oxa-3, 4-secofriedelan-3-oic acid (cerinox) in streptozotocin (STZ)-induced diabetic rat. Male Sprague Dawley rats were randomized into four groups: non-diabetic control (Group I), STZ-induced diabetic rats (Group II), STZ-induced diabetic rats treated with cerin (Group III), and STZ-induced diabetic rats treated with cerinox (Group IV). Administration of cerin (3mg/kg) and cerinox (3mg/kg) orally to STZ-diabetic rats for three weeks improved the body weight, reduced serum glucose level and activities of alkaline phosphatase, acid phosphatase, glutamate-oxaloacetate transaminase and glutamate-pyruvate transaminase, and restored liver antioxidant status.

A novel PPARgamma agonist monascin's potential application in diabetes prevention

Edible fungi of the Monascus species have been used as traditional Chinese medicine in eastern Asia for several centuries. Monascus-fermented products possess a number of functional secondary metabolites, including the anti-inflammatory pigments monascin and ankaflavin. Monascin has been shown to prevent or ameliorate several conditions, including hypercholesterolemia, hyperlipidemia, diabetes, and obesity. Recently, monascin has been shown to improve hyperglycemia, attenuate oxidative stress, inhibit insulin resistance, and suppress inflammatory cytokine production. In our recent study, we have found that monascin is a peroxisome proliferator-activated receptor-gamma (PPARgamma) agonist. The PPARgamma agonist activity had been investigated and its exerted benefits are inhibition of inflammation in methylglyoxal (MG)-treated rats, prevention of pancreas impairment causing advanced glycation endproducts (AGEs), promotion of insulin expression in vivo and in vitro, and attenuated carboxymethyllysine (CML)-induced hepatic stellate cell (HSC) activation in the past several years. Moreover, our studies also demonstrated that monascin also activated nuclear factor-erythroid 2-related factor 2 (Nrf2) in pancreatic RIN-m5F cell line thereby invading methylglyoxal induced pancreas dysfunction. In this review, we focus on the chemo-preventive properties of monascin against metabolic syndrome through PPARgamma and Nrf2 pathways.

Aqueous Extract of Phyllanthus niruri Leaves Displays In Vitro Antioxidant Activity and Prevents the Elevation of Oxidative Stress in the Kidney of Streptozotocin-Induced Diabetic Male Rats

P. niruri has been reported to possess antidiabetic and kidney protective effects. In the present study, the phytochemical constituents and in vitro antioxidant activity of P. niruri leaf aqueous extract were investigated together with its effect on oxidative stress and antioxidant enzymes levels in diabetic rat kidney. Results. Treatment of diabetic male rats with P. niruri leaf aqueous extract (200 and 400 mg/kg) for 28 consecutive days prevents the increase in the amount of lipid peroxidation (LPO) product, malondialdehyde (MDA), and the diminution of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activity levels in the kidney of diabetic rats. The amount of LPO showed strong negative correlation with SOD, CAT, and GPx activity levels. P. niruri leaf aqueous extract exhibits in vitro antioxidant activity with IC₅₀ slightly lower than ascorbic acid. Phytochemical screening of plant extract indicates the presence of polyphenols. Conclusion. P. niruri leaf extract protects the kidney from oxidative stress induced by diabetes.

Distribution of glutathione peroxidase 1 in liver tissues of healthy and diabetic rats treated with capsaisin

We investigated the immunohistochemical localization of glutathione peroxidase 1 (GPx 1) and the structural changes that occur in the livers of healthy and diabetic rats that were treated with capsaisin (CAP). Fifty female rats were divided into five groups: group 1, sham; group 2, untreated control; group 3, CAP-treated; group 4, streptozotocin (STZ) diabetic; group 5, STZ diabetic + CAP-treated. STZ was administered to groups 4 and 5; after verifying diabetes, CAP was administered daily for 2 weeks to groups 3 and 5. Diffuse, microvesicular and some macrovesicular fatty degeneration were observed in the cytoplasms of hepatocytes in the livers of the diabetic group. In the CAP-treated diabetic group, fat degeneration in the livers decreased slightly by day 7. Irregularity of the external contours of nuclei of the hepatocytes, swelling of the nuclei, and slight anisocytosis and anisokaryosis were observed in the hepatocytes of the diabetic group. In the CAP-treated diabetic groups, the severity of anisocytosis and anisokaryosis decreased slightly by day 7. In all groups, GPx 1 showed similar immunolocalization, but in the diabetic and diabetic + CAP groups, GPx 1 immunoreactivity was less than in the other groups. GPx 1 immunoreactivity in the CAP-treated diabetic group was weaker than in the diabetic group. In all groups, GPx 1 immunoreactivity was diffusely cytoplasmic in some of the hepatocytes, and diffusely cytoplasmic and diffusely nuclear in other hepatocytes. Also, GPx 1 immunoreactivity in the liver was more intense in the hepatocytes around Kiernan's space. We found that CAP caused a decrease in GPx 1.

Dipeptidyl peptidase-4 inhibition by Pterocarpus marsupium and Eugenia jambolana ameliorates streptozotocin induced Alzheimer's disease

Alzheimer's disease (AD), the most common form of dementia, is characterized by the loss of normal functions of brain cells and neuronal death, ultimately leading to memory loss. Recent accumulating evidences have demonstrated the therapeutic potential of anti-diabetic agents, such as dipeptidyl peptidase-4 (DPP-4) inhibitors, for the treatment of Alzheimer's disease (AD), providing opportunities to explore and test the DPP-4 inhibitors for treating this fatal disease. Prior studies determining the efficacy of Pterocarpus marsupium (PM, Fabaceae) and Eugenia jambolana (EJ, Myrtaceae) extracts for ameliorating type 2 diabetes have demonstrated the DPP-4 inhibitory properties indicating the possibility of using of these extracts even for the treating AD. Therefore, in the present study, the neuroprotective roles of PM and EJ for ameliorating the streptozotocin (STZ) induced AD have been tested in rat model. Experimentally, PM and EJ extracts, at a dose range of 200 and 400mg/kg, were administered orally to STZ induced AD Wistar rats and cognitive evaluation tests were performed using radial arm maze and hole-board apparatus. Following 30 days of treatment with the extracts, a dose- and time-dependent attenuation of AD pathology, as evidenced by decreasing amyloid beta 42, total tau, phosphorylated tau and neuro-inflammation with an increase in glucagon-like peptide-1 (GLP-1) levels was observed. Therefore, PM and EJ extracts contain cognitive enhancers as well as neuroprotective agents against STZ induced AD.

Effect of Alpinia calcarata on glucose uptake in diabetic rats-an in vitro and in vivo model

BACKGROUND

Diabetes mellitus is a heterogeneous metabolic disorders characterized by abnormally high levels of blood glucose The main objective of the present work is to study the effect of Alpinia calcarata on glucose uptake in streptozotocin (STZ) induced diabetic rats.

METHODS

The diabetes was induced by single dose of STZ (45 mg/kg) in citrate buffer, while the normal control group was given the vehicle (citrate buffer) only. After induction of diabetes, the diabetic animals were treated with ethanolic extract of Alpinia calcarata (200 mg/kg) and glibenclamide (2 mg/kg) for 30 days. Blood glucose estimation was performed every week of the study. At the end of study period, animals were sacrificed for biochemical studies.

RESULTS

Streptozotocin induced diabetic rats shows the altered levels of various biochemical profiles. Those levels were brought back to near normal upon treatment with ethanolic extract of Alpinia calcarata and standard drug glibanclamide. No significant changes were observed on treatment with plant extract alone group indicated that there are no toxic substances present in Alpinia calcarata. The antidiabetic activity of plant extract was also further confirmed by histopathological studies. The ethanolic extract of Alpinia calcarata shows significant inhibition of alpha glucosidase activity and also enhancing the glucose uptake in rat hemidiaphragm.

CONCLUSIONS

In conclusion, the ethanolic extract of Alpinia calcarata ameliorates the condition associated with diabetes.

Chlorophytum borivilianum root extract maintains near normal blood glucose, insulin and lipid profile levels and prevents oxidative stress in the pancreas of streptozotocin-induced adult male diabetic rats

The effect of C. borivilianum root on blood glucose, glycated hemoglobin (HbAIc), insulin and lipid profile levels in diabetes mellitus are not fully understood. This study therefore investigated the effect of C. borivilianum root on the above parameters and oxidative stress of the pancreas in diabetes.

METHODS

C. borivilianum root aqueous extract (250 and 500 mg/kg/day) was administered to streptozotocin (STZ)-induced male diabetic rats for 28 days. Body weight, blood glucose, HbA1c, insulin, lipid profile levels and glucose homeostasis indices were determined. Histopathological changes and oxidative stress parameters i.e. lipid peroxidation (LPO) and antioxidant enzymes activity levels of the pancreas were investigated.

RESULTS

C. borivilianum root extract treatment to diabetic rats maintained near normal body weight, blood glucose, HbA1c, lipid profile and insulin levels with higher HOMA-β cell functioning index, number of Islets/pancreas, number of β-cells/Islets however with lower HOMA-insulin resistance (IR) index as compared to non-treated diabetic rats. Negative correlations between serum insulin and blood glucose, HbA1c, triglyceride (TG) and total cholesterol (TC) levels were observed. C. borivilianum root extract administration prevented the increase in lipid peroxidation and the decrease in activity levels of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) with mild histopathological changes in the pancreas of diabetic rats.

CONCLUSIONS

C. borivilianum root maintains near normal levels of these metabolites and prevented oxidative stress-induced damage to the pancreas in diabetes.

Kolaviron, a Garcinia biflavonoid complex ameliorates hyperglycemia-mediated hepatic injury in rats via suppression of inflammatory responses

BACKGROUND

Chronic inflammation plays a crucial role in hyperglycemia-induced liver injury. Kolaviron (KV), a natural biflavonoid from Garcinia kola seeds have been shown to possess anti- inflammatory properties which has not been explored in diabetes. To our knowledge, this is the first study to investigate the effect of KV on pro-inflammatory proteins in the liver of diabetic rats.

METHODS

Diabetes was induced by a single intraperitoneal injection of streptozotocin (STZ) (50 mg/kg) in male Wistar rats. Kolaviron (100 mg/kg) was administered orally five times a week for six weeks. The concentrations of cytokines and chemokine were measured using Bio-plex Pro™ magnetic bead-based assays (Bio-Rad Laboratories, Hercules, USA). Plasma glucose and serum biomarkers of liver dysfunction were analyzed with diagnostic kits in an automated clinical chemistry analyzer. Insulin concentration was estimated by radioimmunoassay (RIA).

RESULT

Kolaviron (100mg/kg) treatment significantly ameliorated hyperglycemia and liver dysfunction. Serum levels of hepatic marker enzymes were significantly reduced in kolaviron treated diabetic rats. Kolaviron prevented diabetes induced increase in the hepatic levels of proinflammatory cytokines; interleukin (IL)-1beta, IL-6, tumour necrosis factor (TNF-α) and monocyte chemotactic protein (MCP-1).

CONCLUSION

The results of this study demonstrate that the hepatoprotective effects of kolaviron in diabetic rats may be partly associated with its modulating effect on inflammatory responses.

Protective Effect of Free and Bound Polyphenol Extracts from Ginger (Zingiber officinale Roscoe) on the Hepatic Antioxidant and Some Carbohydrate Metabolizing Enzymes of Streptozotocin-Induced Diabetic Rats

This study investigated the hepatoprotective effects of polyphenols from Zingiber officinale on streptozotocin-induced diabetic rats by assessing liver antioxidant enzymes, carbohydrate-metabolizing enzymes and liver function indices. Initial oral glucose tolerance test was conducted using 125 mg/kg, 250 mg/kg, and 500 mg/kg body weight of both free and bound polyphenols from Z. officinale. 28 day daily oral administration of 500 mg/kg body weight of free and bound polyphenols from Z. officinale to streptozotocin-induced (50 mg/kg) diabetic rats significantly reduced (P < 0.05) the fasting blood glucose compared to control groups. There was significant increase (P < 0.05) in the antioxidant enzymes activities in the animals treated with both polyphenols. Similarly, the polyphenols normalised the activities of some carbohydrate metabolic enzymes (hexokinase and phosphofructokinase) in the liver of the rats treated with it and significantly reduced (P < 0.05) the activities of liver function enzymes. The results from the present study have shown that both free and bound polyphenols from Z. officinale especially the free polyphenol could ameliorate liver disorders caused by diabetes mellitus in rats. This further validates the use of this species as medicinal herb and spice by the larger population of Nigerians.

Protective nature of mangiferin on oxidative stress and antioxidant status in tissues of streptozotocin-induced diabetic rats

Oxidative stress plays an important role in the progression of diabetes complications. The aim of the present study was to investigate the beneficial effect of oral administration of mangiferin in streptozotocin (STZ)-induced diabetic rats by measuring the oxidative indicators in liver and kidney as well as the ameliorative properties. Administration of mangiferin to diabetic rats significantly decreased blood glucose and increased plasma insulin levels. The activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) and level of reduced glutathione (GSH) were significantly (P < 0.05) decreased while increases in the levels of lipidperoxidation (LPO) markers were observed in liver and kidney tissues of diabetic control rats as compared to normal control rats. Oral treatment with mangiferin (40 mg/kg b.wt/day) for a period of 30 days showed significant ameliorative effects on all the biochemical and oxidative parameters studied. Diabetic rats treated with mangiferin restored almost normal architecture of liver and kidney tissues, which was confirmed by histopathological examination. These results indicated that mangiferin has potential ameliorative effects in addition to its antidiabetic effect in experimentally induced diabetic rats.

Pharmacological potentials of Syzygium cumini: a review

In the last few years there has been an exponential growth in the field of herbal medicine, and these drugs are gaining popularity in both developing and developed countries because of their natural origin and lesser side effects. Syzygium cumini (syn. Eugenia jambolana, Syzygium jambolana, Eugenia cumini, Syzygium jambos), commonly known as jamun in India, is an evergreen tree distributed throughout the Indian subcontinent, Southeast Asia and East Africa. It is mainly utilised as a fruit producer and for its timber. Medicinally, the fruit is reported to have antidiabetic, antihyperlipidaemic, antioxidant, antiulcer, hepatoprotective, antiallergic, antiarthritic, antimicrobial, anti-inflammatory, antifertility, antipyretic, antiplaque, radioprotective, neuropsychopharmacological, nephroprotective and antidiarrhoeal activities. Among these beneficial physiological effects, the antidiabetic property of S. cumini has the most promising nutraceutical value. The health-beneficial effects of S. cumini are mainly attributed to various phytoconstituents such as tannins, alkaloids, steroids, flavonoids, terpenoids, fatty acids, phenols, minerals, carbohydrates and vitamins present in the fruit. This review paper presents an overview of experimental evidence for the pharmacological potential of S. cumini.

Syzygium cumini (L.) Skeels., a novel therapeutic agent for diabetes: folk medicinal and pharmacological evidences

OBJECTIVES

During the past few decades numerous folk medicinal and scientific investigations on the antidiabetic effects of jambolan (Syzygium cumini (L.) Skeels) have been reported. However no comprehensive evidence-based review is available. Hence this review was aimed to summarize the antidiabetic effects of different parts and active principles of jambolan.

METHODS

The review is based on the available electronic literature indexed in the PubMed. The search terms were: Syzygium cumini, Eugenia jambolana, jambolan, jamun, and java plum with and without antidiabetic effect.

RESULTS

Based on experimental studies and folk medicinal evidences, we summarized an up to date and comprehensive report on the antidiabetic activity of jambolan. The mode of action of some of the parts and active principles is also included. Preclinical and clinical studies suggest that, different parts of this plant especially fruits, seeds and stem bark were reported for promising activity against diabetes.

CONCLUSIONS

Till date no review is available for the evidence based preclinical/clinical study of jambolan with its antidiabetic effect. There is an immediate attention need for detailed analysis to identify its active principles. It could be used to produce safer drugs to treat diabetes.

Antioxidant and antibacterial activities of crude extracts and essential oils of Syzygium cumini leaves

This research highlights the chemical composition, antioxidant and antibacterial activities of essential oils and various crude extracts (using methanol and methylene chloride) from Syzygium cumini leaves. Essential oils were analyzed by gas chromatography-mass spectrometry (GC-MS).The abundant constituents of the oils were: α-pinene (32.32%), β-pinene (12.44%), trans-caryophyllene (11.19%), 1, 3, 6-octatriene (8.41%), delta-3-carene (5.55%), α-caryophyllene (4.36%), and α-limonene (3.42%).The antioxidant activities of all extracts were examined using two complementary methods, namely diphenylpicrylhydrazyl (DPPH) and ferric reducing power (FRAP). In both methods, the methanol extract exhibited a higher activity than methylene chloride and essential oil extracts. A higher content of both total phenolics and flavonoids were found in the methanolic extract compared with other extracts. Furthermore, the methanol extract had higher antibacterial activity compared to methylene chloride and the essential oil extracts. Due to their antioxidant and antibacterial properties, the leaf extracts from S. cumini may be used as natural preservative ingredients in food and/or pharmaceutical industries.

Decreasing the diabetic complication by vanadyl(VO)2+/vitamin B 6 complex in alloxan-induced diabetic mice

The scope of this work was to synthesize a novel bifunctionalized vanadyl(VO)(2+)/vitamin B 6 complex. The diabetic therapeutic efficacy of the new complex was investigated in alloxan-induced diabetic mice. The results suggested that vanadyl(VO)(2+)/vit B6 complex has an anti-diabetic potency, improved the lipid profile and liver and kidney functions. The new complex possesses an antioxidant activity. The current results support the therapeutic potentiality of vanadyl(VO)(2+)/vitamin B 6 complex for the management of diabetes.

Zinc supplementation attenuates metallothionein and oxidative stress changes in kidney of streptozotocin-induced diabetic rats

Zinc is an element that under physiological conditions preferentially binds to and is a potent inducer of metallothionein under physiological conditions. The present study was conducted to explore whether zinc supplementation morphologically and biochemically protects against diabetic nephropathy through modulation of kidney metallothionein induction and oxidative stress in streptozotocin-induced diabetic rats. Thirty-two Wistar albino male rats were equally divided into four groups. The first group was used as untreated controls and the second group was supplemented with 30 mg/kg/day zinc as zinc sulfate. The third group was treated with streptozotocin to induce diabetes and the fourth group was treated with streptozotocin and supplemented with zinc as described for group 2. The blood glucose and micro-albuminuria levels, body and kidney weights were measured during the 42-day experimental period. At the end of the experiment, the kidneys were removed from all animals from the four groups. Diabetes resulted in degenerative kidney morphological changes. The metallothionein immunoreactivity level was lower and the kidney lipid peroxidation levels were higher in the diabetes group than in the controls. The metallothionein immunoreactivity levels were higher in the tubules of the zinc-supplemented diabetic rats as compared to the non-supplemented diabetic group. The zinc and metallothionein concentrations in kidney tissue were higher in the supplemented diabetic group compared to the non-supplemented diabetes group. The activity of glutathione peroxidase did not change in any of the four groups. In conclusion, the present study shows that zinc has a protective effect against diabetic damage of kidney tissue through stimulation of metallothionein synthesis and regulation of the oxidative stress.