Antidiabetic and antioxidant activities of Toddalia asiatica (L.) Lam. leaves in streptozotocin induced diabetic rats

Neokestose suppresses the increase in plasma glucose caused by oral administration of sucrose in a streptozotocin‑induced diabetic rat

Neokestose is considered to have a prebiotic function. However, the physiological activity of neokestose remains unknown. Neokestose has a blastose, a sucrose analog, in its structure. We previously demonstrated that oral administration of blastose to diabetic rats suppressed the increase in plasma glucose (PG) concentration after sucrose administration. Therefore, neokestose might have a similar effect. In this study, we investigated the effects of neokestose on PG concentrations and the mechanism of its action. We first administered neokestose orally to streptozotocin-induced diabetic rats and observed that the expected consequent increase in PG concentration was significantly suppressed. Next, we examined the inhibitory effect of neokestose on glycosidase activity, but observed only a slight inhibitory effect. Therefore, we hypothesized that neokestose might be hydrolyzed by gastric acid to produce blastose. We performed an acid hydrolysis of neokestose using artificial gastric juice. After acid hydrolysis, peaks corresponding to neokestose and its decomposition products including blastose were observed. Therefore, we suggest that neokestose and blastose, a decomposition product, synergistically inhibit glycosidase activity. These findings support the potential use of neokestose as a useful functional oligosaccharide that can help manage plasma glucose concentrations in patients with diabetes mellitus.

Antidiabetic Effect of Star Anise (Illicium verum) in Streptozotocin-induced Diabetic Rats

AIM

The current study aimed to evaluate the antidiabetic potential of Illicium verum fruits.

BACKGROUND

Illicium verum fruits are frequently used by the Moroccan population in the treatment of diabetes.

METHODS

The antihyperglycemic effect of the aqueous extract of Illicium verum fruits (AEIVF) in rats was assessed. The effects of AEIVF (20 mg/kg) on glycemia and lipid profile as well as its phytochemical and antioxidant properties were evaluated.

RESULTS

In normal and diabetic rats, AEIVF reduced blood glucose levels 6 hours after administration. Furthermore, after 7 days of treatment, glycemia was lowered in diabetic rats, and this extract exhibited an antioxidant activity.

CONCLUSION

The study shows that Illicium verum possesses a potent antidiabetic activity. In addition, the toxicity of AEIVF was evaluated and the LD50 value was found to be greater than the 2 g/kg dose.

Antidiabetic Activity of Mung Bean or Vigna radiata (L.) Wilczek Seeds in Alloxan-Induced Diabetic Mice

Introduction

Despite the development of oral hypoglycemic medications, diabetes and its associated complications continue to be significant clinical issues. The purpose of this study was to examine the antidiabetic effects of Vigna radiata (L.) Wilczek seeds in mice that had been given alloxan to cause diabetes.

Methods

In Swiss albino mice, diabetes was brought on by a single intraperitoneal injection of the drug alloxan (150 mg/kg). For 14 days, glibenclamide (5 mg/kg) and methanol extract of V. radiata seeds (100, 200, and 400 mg/kg) were given orally. Following oral administration of V. radiata to mice, the blood glucose levels (BGL) and body weight were measured at 7 and 14 days. The mice were sacrificed at the end of the trial, and blood samples were taken for the evaluation of insulin, glycated hemoglobin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), high-density lipoprotein (HDL), total cholesterol (TC), and triglyceride (TG) levels. It was determined how much glycogen was present in the liver. Additionally, the total phenolic and flavonoid contents of V. radiata were determined, along with the in vitro DPPH (2, 2 diphenyl-1-picrylhrazyl) free radical-scavenging activity. P < 0.05 was chosen as the cutoff for statistical significance.

Results

Following oral administration of V. radiata for 14 days, diabetic mice's BGL and bad cholesterol (TC and TG) levels significantly decreased, while HDL levels increased. Treatment with V. radiata significantly decreased the levels of AST, ALT, and glycated hemoglobin when compared with diabetes control. On the other hand, it raised insulin levels and the amount of liver glycogen. V. radiata underwent phytochemical analysis, which identified the presence of tannins, saponins, phenols, alkaloids, terpenoids, steroids, flavonoids, and glycosides. Per gram of V. radiata seed extract, the total phenolic content was 43.12 ± 3.14 mg of gallic acid equivalents, while the total flavonoid content was 38.35 ± 2.6 mg of quercetin equivalents. Ascorbic acid was shown to have an IC₅₀ value of 18.64 µg/ml during a DPPH-scavenging assay, while V. radiata had an IC₅₀ value of 73.35 µg/ml.

Conclusion

According to the findings of the current study, the methanolic extract of the seeds from the plant V. radiata possesses significant antidiabetic characteristics that are on par with those of the commonly used drug glibenclamide. Hence, V. radiata seems to be effective as a natural antidiabetic.

Antidiabetic with antilipidemic and antioxidant effects of flindersine by enhanced glucose uptake through GLUT4 translocation and PPARγ agonism in type 2 diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Medicinal plants have been used by the people of developing countries to treat various diseases. WHO also recommends the use of medicines from plants source. In that, diabetes also one of the diseases that have been treated traditionally by several people all over the world. In India, Toddalia asiatica (L.) Lam. (Rutaceae) is also a medicinal plant used traditionally for the treatment of diabetes in Ayurveda. Moreover, T. asiatica is also used in a polyherbal formulation to treat diabetes.

AIM OF THE STUDY

This study examined the antidiabetic with antilipidemic and antioxidant effects of flindersine isolated from T. asiatica leaves.

MATERIALS AND METHODS

Diabetes was induced in Wistar rats by feeding a high-fat diet (HFD) for 15 days and injecting a single dose of 40 mg/kg b. wt. of Streptozotocin (STZ). Five days post-injection, the grouped diabetic rats were treated with 20 and 40 mg/kg of flindersine.

RESULTS

Flindersine resulted in a clear decline of blood glucose levels during 28 days of treatment in two different doses. Flindersine also significantly (P ≤ 0.05; P ≤ 0.005) reduced the body weight gain, plasma insulin concentration, urea, creatinine, total cholesterol (TC), triglycerides (TG) and free fatty acids (FFA) levels and significantly increased (P ≤ 0.05; P ≤ 0.005) the total protein level, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities compared to the standard drug, pioglitazone. Additionally, flindersine restored the glucose transporter protein 4 (GLUT4), adenosine monophosphate protein kinase (AMPK) and peroxisome proliferator-activated receptor γ (PPARγ) expressions in adipose tissues and skeletal muscles.

CONCLUSION

It has been found that flindersine has potent antilipidemic and antidiabetic activities by improving insulin sensitivity by enhancing the phosphorylation of AMPK, GLUT4 translocation, and PPARγ agonism on adipose tissue and skeletal muscles of diabetic rats.

Methanolic Extract of Myrsine africana Leaf Ameliorates Hyperglycemia and Dyslipidemia in Alloxan-Induced Diabetic Albino Mice

Background. Diabetes mellitus is one of the leading public health problems globally, and its prevalence is increasing in Ethiopia. The current drugs for people with diabetes are costly, less effective, and less safe with a challenging administration method. Thus, globally, the need for alternative herbal antidiabetic medicines is increasing. In the previous studies, antioxidant activities have been seen in crude extracts of M. africana leaves, which is an auspicious sign of antidiabetic property. Accordingly, this study has evaluated the antidiabetic and antidyslipidemic activities of methanolic extract of M. africana leaves. Methods. Hypoglycemic and antihyperglycemic activities of the three doses (250 mg/kg, 500 mg/kg, and 1000 mg/kg) of crude methanolic extract of M. africana leaf were studied on normoglycemic, oral glucose-loaded, and alloxan-induced diabetic mice models. The effect of the extract on diabetic dyslipidemia, insulin and glycated hemoglobin levels, carbohydrate-metabolizing enzymes, and body weight was also studied in alloxan-induced diabetic mice. Glibenclamide (5 mg/kg) was used as a standard drug in all cases. Data analysis was carried out using mixed-design ANOVA. A $P$ value of ≤0.05 was considered a statistically significant difference. Results. The methanolic extract of M. africana leaf did not show acute toxicity up to the dose of 5000 mg/kg and showed better glucose utilization in the oral glucose tolerance test. After 14 days of treatment, M. africana leaf extract decreased the blood glucose level, glycated hemoglobin, glucose-6-phosphatase, and fructose-1-6-bisphosphatase in diabetic mice. In contrast, it increased hexokinase and insulin levels in diabetic mice. Moreover, weight loss and dyslipidemia profiles have been corrected significantly in diabetic mice. Conclusion. M. africana leaves showed antihyperglycemic and antidyslipidemic effects in alloxan-induced diabetic mice. That suggests M. africana may be a potential treatment option for diabetes in the future. However, further molecular studies are required to analyze the mechanisms.

Diplazium esculentum (Retz.) Sw.: Ethnomedicinal, Phytochemical, and Pharmacological Overview of the Himalayan Ferns

The genus Diplazium (family: Athyriaceae) comprises approximately 350 species of pteridophytes. Diplazium esculentum (Retz.) Sw. is an important member of this genus and commonly known as a wild vegetable in the Himalayan and sub-Himalayan communities. According to the literature analysis, D. esculentum was traditionally used for the prevention or treatment of several diseases such as diabetes, smallpox, asthma, diarrhea, rheumatism, dysentery, headache, fever, wounds, pain, measles, hypertension, constipation, oligospermia, bone fracture, and glandular swellings. Various extracts of D. esculentum were evaluated to elucidate their phytochemical and pharmacological activities. A wide array of pharmacological properties such as antioxidant, antimicrobial, antidiabetic, immunomodulatory, CNS stimulant, and antianaphylactic activities have been recognized in different parts of D. esculentum. The review covers a systematic examination of pharmacognosy, phytochemistry, and pharmacological applications of D. esculentum, but scientifically, it is not fully assessed regarding complete therapeutic effects, toxicity, and safety in the human body. The published literature on D. esculentum and its therapeutic properties were collected from different search engines including Wiley online, PubMed, Springer Link, Scopus, Science Direct, Web of Science, Google Scholar, and ACS publications by using specific terms such as "Diplazium esculentum, bioactive compounds, biological activities and health benefits" from 1984 to 2021 (March). Therefore, further studies are required to identify the detailed action mechanism of D. esculentum in vitro/in vivo, and also, more studies should focus on conservation, cultivation, and sustainable utilization of the species.

A systematic review on traditional medicine Toddalia asiatica (L.) Lam.: Chemistry and medicinal potential

Toddalia asiatica (L.) Lam., belonging to Toddalia genus of Rutaceae family, is a folk medicine in China used for hundreds of years. The whole plant can be used as medicine, especially the root that used to be applied in the folk. In recent decades, with the in-depth research from domestic and foreign researchers, it has gradually been discovered that the chemical components in T. asiatica are mainly coumarins and alkaloids. Its pharmacological effects are manifested in anti-inflammatory and analgesic, hemostatic coagulation, anti-tumor, treatment of cardiovascular diseases, etc. It has a wide range of clinical applications and significant effects on rheumatism, pain, wound bleeding, and bruises. Due to its important research value, in this article, the chemical compositions and pharmacological effects of T. asiatica are comprehensively expounded in recent years in order to provide a reference for the related research and application of this medicinal material, which were carried out through a bibliometric search using the Science Citation Index- Expanded (SCIE) database, web of science, Google scholar and Chinese National Knowledge Infrastructure (CNKI) and all that.

Pimpinellin Inhibits Collagen-induced Platelet Aggregation and Activation Through Inhibiting Granule Secretion and PI3K/Akt Pathway

Pimpinellin is a coumarin-like compound extracted from the root of Toddalia asiatica. Its effects on platelet function has not been investigated. This study found that pimpinellin pretreatment effectively inhibited collagen-induced platelet aggregation, but did not alter ADP- and thrombin-induced aggregation. Platelets pretreated with pimpinellin showed reduced α granule (CD62) level and secretion of dense granule (ATP release). Pimpinellin-treated platelets also exhibited decreased clot reaction and TxB2 production. Pimpinellin pretreatment suppressed adhesion and spreading of human platelets on the fibrinogen coated surface. Analysis of tail bleeding time of mice administered with pimpinellin (40 mg/kg) revealed that pimpinellin did not change tail bleeding time significantly, number of blood cells, and APTT and PT levels. Pimpinellin inhibited collagen-induced ex vivo aggregation of mice platelets. Immunoblotting results showed that pimpinellin suppressed collagen-induced phosphorylation of PI3K-Akt-Gsk3β and PKC/MAPK in platelets.

In vitro antidiabetic, antioxidant activities and GC-MS analysis of Rhynchostylis Retusa and Euphorbia Neriifolia leaf extracts

This study aimed to assess the antidiabetic, and antioxidant potential of Rhynchostylis retusa and Euphorbia neriifolia, well known for traditional ethnomedicinal uses in North-east India. Leaf extracts prepared in water, methanol and petroleum ether were evaluated for in vitro antidiabetic and antioxidant assay using α-amylase inhibition, glucose diffusion method and DPPH radical scavenging activity. The α-amylase inhibition with E. neriifolia methanolic extract at 400 μg/ml (66.67%) and R. retusa aqueous extract at 300 μg/ml (58.15%) were stronger than in equivalent concentrations of acarbose, i.e., 62.17, and 51.52%, respectively. Aqueous extract R. retusa showed a maximum 67.65% inhibition of glucose diffusion at 180 min in comparison to control without leaf extract. The DPPH radical scavenging activity of E. neriifolia extract in methanol was significantly better than equivalent aqueous or ether extract. However, the solvent choice had little impact on antioxidant activity in R. retusa. GC-MS analysis revealed the presence of a large number of phytochemicals in methanol fraction of E. neriifolia aqueous extracts in comparison to R. retusa. Though the in vitro α-amylase inhibition or glucose diffusion retardation implied potential medicinal use of endangered orchid R. retusa and E. neriifolia, further investigation may be warranted for identification of relevant bio-active compounds and in vivo validation of their pharmacological properties.

Contributions from Mexican Flora for the Treatment of Diabetes Mellitus: Molecules of Psacalium decompositum (A. Gray) H. Rob & Brettell

Diabetes mellitus (DM) is cited as a serious worldwide health problem that occupies second place in causes of annual mortality in Mexico. Among Mexican flora, nearly 300 plant species have been employed as hypoglycemic in popular use. Thus, their study entertains great relevance In this context, this work contributes a clear and timely review of the plant species utilized in Traditional Mexican Medicine and experimental biological models in which not only have the hypoglycemic properties of the extracts and the isolated compounds been considered, but also the anti-inflammatory and antioxidant properties, taking into account an integral focus based on the complex mechanisms involved in the pathogenesis and physiopathology of DM. Among the species reviewed, we highlight Psacalium decompositum (Asteraceae), due to the potent hypoglycemic, anti-inflammatory, and antioxidant activity of the sesquiterpenes identified as majority compounds isolated from the root, such as cacalol and cacalone that also possess the capacity of increasing insulin levels. In this manner, the present manuscript attempts to contribute necessary information for the future study of bioactive molecules that are useful in the treatment of DM, as well as also being a contribution to the knowledge and diffusion of Mexican Traditional Medicine.

Friedelin exhibits antidiabetic effect in diabetic rats via modulation of glucose metabolism in liver and muscle

ETHNOPHARMACOLOGICAL RELEVANCE

Demand for plant-based medications and therapeutics is increasing worldwide as of its potential effects and no toxic. Traditionally, so many medicinal plants are used to treat diabetes. Subsequently, investigation on medicinal plants was enduring to discover potential antidiabetic drugs. A. tetracantha is used traditionally to cure diabetes mellitus, cough, dropsy, chronic diarrhea, rheumatism, phthisis and smallpox. Scientifically, A. tetracantha has been reported as an antidiabetic agent. Friedelin, the isolated compound has been reported as hypolipidemic, antioxidant, scavenging of free radicals, antiulcer, anti-inflammatory, analgesic and antipyretic agent.

AIM OF THE STUDY

To scrutinize the mechanism of antidiabetic activity of friedelin isolated from the leaves of A. tetracantha.

MATERIALS AND METHODS

A. tetracantha leaves powder (5 kg) was soaked in hexane (15 L) to obtain hexane extract. Using column chromatography, the hexane extract was fractionated using a combination of solvents like hexane and ethyl acetate. 25 fractions were obtained and the fractions 13 and 14 yielded the compound, friedelin. Friedelin at the doses of 20 and 40 mg/kg was used to treated STZ -induced diabetic rats for 28 days. Later 28 days of treatment, the bodyweight changes, levels of blood glucose, insulin, SGOT, SGPT, SALP, liver glycogen and total protein were assessed.

RESULTS

Friedelin significantly brought these altered levels to near normal. Moreover, friedelin also enhanced the translocation as well as activation of GLUT2 and GLUT4 through PI3K/p-Akt signaling cascade in skeletal muscles and liver on diabetic rats.

CONCLUSION

This finding proved that friedelin has an anti-diabetic effect through insulin-dependent signaling cascade mechanism, thus it may lead to establishing a drug to treat type 2 diabetes mellitus.

Chemical Composition and Pharmacological Evaluation and of Toddalia asiatica (Rutaceae) Extracts and Essential Oil by in Vitro and in Silico Approaches

Toddalia asiatica (L.) Lam. is extensively used in traditional medicinal systems by various cultures. Despite its frequent use in traditional medicine, there is still a paucity of scientific information on T. asiatica growing on the tropical island of Mauritius. Therefore, the present study was designed to appraise the pharmacological and phytochemical profile of extracts (methanol, ethyl acetate and water) and essential oil obtained from aerial parts of T. asiatica. Biological investigation involved the evaluation of in vitro antioxidant and enzyme inhibitory potentials. The chemical profile of the EO was determined using gas chromatography coupled to mass spectrometry (GC/MS) analysis, while for the extracts, the total phenolic (TPC) and flavonoid content were quantified as well as their individual phenolic compounds by LC/MS/MS. Quinic acid, fumaric acid, chlorogenic acid, quercitrin and isoquercitrin were the main compounds in the extracts. Highest total phenolic (82.5±0.94 mg gallic acid equivalent (GAE/g)) and flavonoid (43.8±0.31 mg rutin equivalent (RE/g)) content were observed for the methanol extract. The GC/MS analysis has shown the presence of 26 compounds with linalool (30.9 %), linalyl acetate (20.9 %) and β-phellandrene (7.9 %) being most abundant components in the EO. The extracts and EO showed notable antioxidant properties, with the methanol extract proved to be superior source of antioxidant compounds. Noteworthy anti-acetylcholinesterase (AChE) and anti-butyrylcholinesterase (BChE) effects were recorded for the tested samples, while only the methanol and ethyl acetate extracts were active against tyrosinase. With respect to antidiabetic effects, the extracts and EO were potent inhibitors of α-glucosidase, while modest activity was recorded against α-amylase. Docking results showed that linalyl acetate has the highest affinity to interact with the active site of BChE with docking score of -6.25 kcal/mol. The findings amassed herein act as a stimulus for further investigations of this plant as a potential source of bioactive compounds which can be exploited as phyto-therapeutics.

Glucose, lipid and oxidative stress lowering activity of the aqueous extract from leafy stems of Cissus polyantha Gilg & Brandt in dexamethasone-induced hyperglycemia in rats

Background

Diabetes mellitus is a metabolic disorder characterised by chronic hyperglycemia. The present research work aimed to evaluate the hypoglycaemic, hypolipidemic and antioxidant effects of leafy stems of Cissus polyantha Gilg & Brandt in insulin resistant rats.

Methods

The oral glucose tolerance test (OGTT) was performed in normal rats. Hyperglycemia was induced for 8 days by a daily subcutaneous injection of dexamethasone (1 mg/kg) one hour after pretreatment of animals with metformin (40 mg/kg) and C. polyantha extract (111, 222 and 444 mg/kg). Body weight, blood glucose, insulin level, lipid profile, insulin biomarkers, cardiovascular indices and oxidative stress biomarkers were evaluated.

Results

For OGTT, the extract (444 mg/kg) produced a significant drop in blood sugar at the 60th (p < 0.01), 90th (p < 0.01) and 120th min (p < 0.05). Morever, the extract at doses of 222 and 111 mg/kg significantly reduced blood sugar at the 60th (p < 0.01) and 90th min (p < 0.05) respectively. Otherwise, C. polyantha (444 and 222 mg/kg) significantly (p < 0.001) increased body weight and decreased blood sugar on the 4th and 8th days of treatment in insulin resistant rats. The extract also significantly decreased (p < 0.001) serum insulin level, hyperlipidemia, insulin resistance index and cardiovascular indices, and increased gluthathione level, and superoxide dismutase and catalase activity.

Conclusion

The aqueous extract of Cissus polyantha leafy stems (AECPLS) possess hypoglycemic, hypolipidemic and antioxidant activities that could justify its use in traditional medicine for the prevention and treatment of diabetes mellitus and its complications.

Anti-diabetic and lipid-lowering effects of drimane sesquiterpenoids isolated from Zygogynum pancheri

Recently, it has been shown that drimane-type sesquiterpenoids isolated from Zygogynum pancheri, a species native to New Caledonia, possessed significant α-amylase inhibitory activities. To further explore their antidiabetic potential, we investigated the effect of 1β-O-(E-cinnamoyl)-6α-hydroxy-9epi-polygodial (D) and 1β-E-O-p-methoxycinnamoyl-bemadienolide (L), two of the most active compounds of the series, on diabetic model rats. Compounds D and L (2 mg kg/day) were daily and orally administrated for 30 days to streptozotocin (STZ) (150 mg/kg) induced male diabetic Wistar rats. Animals were allocated into five groups of six rats. Comparatively to diabetic rats, treatments with D and L compounds were able to significantly (P < 0.05) decrease Fasting Blood Glucose (FBG) (70.15%, 71.02%), serum total cholesterol (46.27% and 39.38%), triglycerides (56.60% and 58.15%), creatinine (37.31% and 36.49%) and uric acid levels (67.76% and 69.68%), respectively. Compounds D and L also restored the altered plasma enzyme (aspartate aminotransferase, AST (47.83% and 43.20%), alanine aminotransferase, ALT (49.76% and 48.35%, alkaline phosphatase, ALP (72.78% and 73.21%)) and lactate dehydrogenase, LDH (47.95% and 53.93%) levels to near normal, respectively. Administration of Glymepiride, significantly (p < 0.05) reduced FBG (73.94%) in STZ induced diabetic rats. Additionally, the compounds D and L exhibited inhibitory effects in vivo on lipase activity of diabetic rats (54.83% and 52.25%), respectively. The outcomes of this study suggested that these two drimanes could be considered as efficient hypoglycemic, hypolipidemic and antiobesity agents for diabetes management and its complications.

Molecular docking analysis and anti-hyperglycaemic activity of Synacinn™ in streptozotocin-induced rats

Synacinn™ is a standardized polyherbal supplement formulated from Cinnamomum zeylanicum Blume, Curcuma zanthorrhiza Roxb., Syzygium polyanthum (Wight) Walp., Orthosiphon stamineus Benth. and Andrographis paniculata (Burm.f.) Nees. It is designed for the synergistic treatment of diabetes mellitus and its complications. Although the beneficial effects are yet to be verified scientifically, it is traditionally used to improve general health in patients with diabetes. This study aimed to evaluate the anti-hyperglycemic effects of Synacinn™ in a streptozotocin-induced type 1 diabetes rat model. Initially, Synacinn™ was used for in vivo acute oral toxicity tests and 14 day repeated dose toxicity tests to determine the toxicity levels. An efficacy study of Synacinn™ was carried out via the oral administration of 10, 50, 100, 250, and 250 (b.i.d.) mg kg-1 doses to streptozotocin-induced diabetic rats. After 28 days, blood serum was collected to measure the fasting blood glucose, triglyceride, cholesterol, alanine aminotransferase, alkaline phosphatase, creatinine, and uric acid levels. The liver, kidney, and pancreas structures were histopathologically analyzed. In silico binding interaction studies of five phytochemicals in Synacinn™ identified via HPLC with glucokinase were performed using molecular docking analysis. The results showed that although no mortality was observed during the acute oral toxicity tests, notable damage to the liver and kidney occurred during the 14 day repeated dose testing at Synacinn™ levels of 600 mg kg-1 and 2000 mg kg-1. Treatment with 250 mg kg-1 (b.i.d.) Synacinn™ of the streptozotocin-induced type 1 diabetic rats significantly (p < 0.05) improved the fasting blood glucose (59%), triglyceride (58%), cholesterol (47%), alanine aminotransferase (60%), alkaline phosphatase (90%), and creatinine (32%) levels. Synacinn™ also improved the relative weights of liver (35%), kidney (36%), and pancreatic (36%) tissue. Histological analysis showed improvements in the conditions of the central vein of the liver, the kidney Bowman's capsule and glomerulus, and the pancreatic islets of Langerhans. HPLC analysis of a standardized extract identified five active phytochemicals: andrographolide (17.36 mg g-1), gallic acid (11.5 mg g-1), curcumin (2.75 mg g-1), catechin (3.9 mg g-1), and rosmarinic acid (5.54 mg g-1). Molecular docking studies with glucokinase showed that andrographolide yields the highest binding energy (-12.1 kcal mol-1), followed by catechin (-10.2 kcal mol-1), rosmarinic acid (-8.6 kcal mol-1), curcumin (-7.8 kcal mol-1), and gallic acid (-5.6 kcal mol-1). These current findings suggest that Synacinn™ at a dose of 250 mg kg-1 was non-toxic to rats. A twice-daily 250 mg kg-1 dose of Synacinn™ is an effective anti-hyperglycemic agent, lowering blood glucose, triglyceride, and cholesterol levels, and assisting the recovery of organ impairment caused by streptozotocin in type 1 diabetic rats.

Diabetes and plant-derived natural products: From ethnopharmacological approaches to their potential for modern drug discovery and development

Diabetes is a disease of serious concern faced by the health care industry today. Primary diabetes mellitus and its complications are still costly to manage with modern drugs. Extensive research on the screening of anti-diabetic agents in past decades established natural products as one of the major potential sources of drug discovery. However, only a few drugs of plant origin have been scientifically validated. Therefore, the development of new anti-diabetic drugs is of great demand. Hence, natural products could be explored as potential anti-diabetic drugs. Natural plants derived extracts and molecules like berberine, ginsenosides, curcumin, stevioside, gingerols, capsaicin, catechins, simple phenolic compounds, anthocyanins, resveratrol, genistein and hesperidin obtained from different species are used for curing diabetes and found to possess different action mechanisms. In this review, the importance of medicinal plants and their active constituents for anti-diabetic agents are described. The present study also emphasized the importance of diabetes control, reduction in its complications and use of the anti-diabetic agents. The detailed action mechanism of these extracts/compounds for their activities are also described. However, the anti-diabetic drugs from plant origin require scientific validation through animal and clinical studies to exploit in terms of modern commercial medicines.

Diabetic complications and oxidative stress: The role of phenolic-rich extracts of saw palmetto and date palm seeds

Recently, we reported that the date palm seed (DP) and saw palmetto seed (SP) extracts possessed a great amount of phenolic contents with potent antioxidant, antimicrobial, and anti-inflammatory activities. Therefore, this study aimed to assess the role of DP and SP phenolic-rich extracts in modulating diabetic complications and oxidative stress in the STZ- diabetic rat. DP and SP extracts significantly inhibited both microbial and pancreatic α-amylases. The STZ-induced diabetic rat groups treated with DP and SP extracts exhibited reversed hyperglycemia (40% and 54%, p < .001-.01) and body weight (70%, p < .001) alteration close to normal. Moreover, DP and SP extracts modulated serious damages in the structures of the pancreas, kidney, and liver of diabetic rats. DP and SP extracts improved the decline of the activities of antioxidant enzymes: Catalase, glutathione-S-transferase, glutathione reductase, and glutathione peroxidase in liver, kidney, and pancreas of the diabetic rats. PRACTICAL APPLICATIONS: Generally, date seed is a rich source of dietary fibers, polyphenols, and antioxidants and used in foods and pharmaceuticals. Our study reported that date palm seed (DP) and saw palmetto seed (SP) phenolic-rich extracts attenuated diabetes and its complications, probably tissue regeneration and normalizing the oxidative stress in the STZ-induced diabetic rat.

Prunus amygdalus extract exert antidiabetic effect via inhibition of DPP-IV: in-silico and in-vivo approaches

Prunus amygdalus (PA) is a popular invasive seed utilized in the management of diabetes in Jammu and Kashmir, India. The objective of the current study was to scrutinize the antidiabetic effect of Prunus amygdalus (PA) against Streptozotocin (STZ) induced diabetic rats and explore the possible mechanism of action at cellular and sub-cellular levels. Box Benkan Design (BBD) was performed to determine the effect of PA powder to methanol, extraction time and extraction temperature on DPPH and ABTS free radical scavenging activity of decoction. In-silico study was performed on GLUT1 (5EQG) and dipeptidyl peptidase IV (DPPIV) (2G63) protein. Type II diabetes mellitus was initiated by single intra-peritoneal injection of STZ. The Blood Glucose Level (BGL) and body weight were estimated at regular interval of time. The different biochemical parameters such as hepatic, antioxidant, and lipid parameters were estimated. At end of the study, pancreas was used for histopathological observation. The variation in DPPH antiradical scavenging activity 40.0-90.0% and ABTS antiradical scavenging activity 34-82%, were estimated respectively. STZ induced DM rats showed increased BGL at end of the experimental study. PA treatment significantly (p < 0.001) down-regulated the BGL level. PA significantly (p < 0.001) altered the biochemical, hepatic and antioxidant parameters in a dose-dependent manner. Histopathological examination demonstrated the constructive mass of β-cells in pancreas. Overall, the current study indicates that the PA treatment down-regulated the hyperglycemic, oxidative stress and hyperlipidaemia in diabetic rats, due to inhibition of enzymes or amelioration of oxidative stress. [Formula: see text] Communicated by Ramaswamy H. Sarma.

Dhanwantaram kashayam, an Ayurvedic polyherbal formulation, reduces oxidative radicals and reverts lipids profile towards normal in diabetic rats

Background

Hyperglycemia and hyper oxidative stress are indicators of diabetes mellitus which is also accompanied with decreased levels of antioxidant enzymes. While oxidative stress is important in increasing insulin secretion and controlling blood sugar level at the same time excess oxidative stress leads to the destruction of beta cells of pancreas resulting in to low insulin production and hyperglycemia. A balance between the levels of oxidative radicals and insulin production is needed, but is not defined yet. Hyperglycemia also leads to hyperlipidemia which can contribute to various health conditions like cardiovascular diseases.

Objectives

This study was designed to study the oxidative stress and lipid levels in diabetic rats. This also was designed to elucidate the effect of Dhanwantaram Kashayam, an Ayurvedic polyphenolic derived from plants on lipid metabolism and oxidative radical scavenging in diabetic rats.

Methods

Rats were made diabetic by injecting streptozotocin. Different enzymes involved in oxidative radical scavenging and lipid profiles including triglycerides, total cholesterol, free fatty acids and phospholipids were estimated using standard methods reported elsewhere.

Results

Level of antioxidant enzymes were lower in diabetic rats compared to normal controls. Administration of Dhanwantaram Kashayam restored the enzyme activity as well as reduced levels of different lipids in diabetic rats.

Conclusions

Administration of Dhanwantaram Kashayam increased the activity levels of antioxidant enzymes and reduced the levels of total cholesterol, phospholipids and triglycerides. The results of this study point to the possibility of developing Dhanwantaram Kashayam as a dietary supplement which can alleviate the complications associated with diabetes or prevent them altogether.

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Hyperglycemia and excess oxidative stress are major health defect in diabetic patients.

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Dhanwantharam Kashayam, an Ayurvedic polyphenolic from plants reduced lipid levels in diabetic rats.

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Dhanwantharam Kashayam exhibited oxidative radical scavenging in diabetic rats.

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Dhanwantharam Kashayam increased the activity levels of antioxidant enzymes to the normal levels in diabetic rats.

Toddalia asiatica L. - A Rich Source of Phytoconstituents with Potential Pharmacological Actions, an Appropriate Plant for Recent Global Arena

Toddalia asiatica L. is used for a long period against various chronic diseases. The main objective of the present review is to search the literature for the folklore uses, phytochemicals isolated and their pharmacological properties of Toddalia asiatica L. The individual plant parts possess many phytoconstituents with therapeutic actions. The root bark of the plant is antimalarial, antipyretic and carminative. Plant leaves and stems have bitter taste and analgesic in nature. Leaf essential oil is used in relieving rheumatic arthritis, sprains, contusions, intercostal neuralgia, cough, malaria, dysentery and gastralgia. This compiled data may be helpful for the researchers to focus on the areas of research yet to be discovered. Complete information about the plant has been collected from various books, journals etc.

Retinal proteomic evaluation of rats following streptozotocin‑injection using shotgun proteomics

It is important to elucidate how retinal stimulation leads to retinal protection and dysfunction. The current study aimed to identify factors that are up‑ and downregulated in the retinas of streptozotocin (STZ)‑induced diabetic rats with acute retinal dysfunction. Retinal function was measured and changes in protein expressions were determined using electroretinograms (ERGs) and liquid chromatography/mass spectroscopy‑based shotgun proteomics, respectively. The results revealed that the plasma glucose levels of STZ rats were markedly higher when compared with normal rats. Furthermore, levels of a‑waves, b‑waves and oscillatory potential amplitudes on ERGs in STZ rats were decreased compared with healthy animals. With use of shotgun proteomics, 391 proteins were identified in the retinas of normal rats and 541 proteins were found in the retinas of STZ rats. Of the 560 proteins identified in rat retinas, 372 (66.4%) were present in both normal and STZ rats. Of these, 19 (3.39%) were unique to normal rats and 169 (30.1%) were unique to STZ rats. Gene Ontology analysis was performed on the candidate proteins that were differentially regulated in the retinas of STZ rats and focused on those classified as 'protein binding', which serve important roles in retinal neurodegeneration. The results revealed an excessive expression of retinol‑binding protein 1 (RBP1) and a negative expression of rod outer segment membrane protein 1 (Rom-1) in the retinas of STZ rats. Therefore, retinal function may be decreased with STZ‑induced injury, and expressions of Rom‑1 and RBP1 may be altered in the retinas of STZ rats.

Regulating role of ethyl acetate fraction of Tephrosia tinctoria pers. in carbohydrate metabolism and oxidative stress in diabetic rats

Traditionally, Tephrosia tinctoria (TT) is used as antimicrobial, larvicidal, antidiabetic and antioxidant agents. In the present study, the diabetes was induced in male albino - rats using alloxan (140 mg/kg b.w.) and treated with ethyl acetate extract (100 and 200 mg/kg b.w.) of T. tinctoria (TTEA) orally for 28 days. The effects of TTEA on biochemical paramets were studied. The results of this comprehensive study revealed that the TTEA significantly restored the altered parameters in alloxan-induced diabetic rats. The diabetes-induced elevated levels of glycogenolysis and gluconeogenesis metabolism were significantly controlled by TTEA. In the same, the decreased glycogenesis, glycolysis and TCA cycle metabolisms were significantly increased by TTEA. The enzymatic and non- enzymatic antioxidant levels were significantly elevated in TTEA treated diabetic rats and also the total non-enzymatic antioxidants capacity of serum and liver homogenate were calculated though DPPH inhibition. To conclude, this study demonstrates the anti-diabetic effect of TTEA possibly mediated through regulating carbohydrate metabolism and antioxidant status.

A Proteomic Approach for Understanding the Mechanisms of Delayed Corneal Wound Healing in Diabetic Keratopathy Using Diabetic Model Rat

Diabetes mellitus is a widespread metabolic disorder, and long-term hyperglycemia in diabetics leads to diabetic keratopathy. In the present study, we used a shotgun liquid chromatography/mass spectrometry-based global proteomic approach using the cornea of streptozotocin-induced diabetic (STZ) rats to examine the mechanisms of delayed corneal wound healing in diabetic keratopathy. Applying a label-free quantitation method based on spectral counting, we identified 188 proteins that showed expression changes of >2.0-fold in the cornea of STZ rats. In particular, the level of lumican expression in the cornea of STZ rats was higher than that of the normal rats. In the cornea of the normal rat, the expression level of lumican was elevated during the wound healing process, and it returned to the same expression level as before cornea injury after the wound was healed completely. On the other hand, a high expression level of lumican in the cornea of STZ rats was still maintained even after the wound was healed completely. In addition, adhesion deficiency in corneal basal cells and Bowman’s membrane was observed in the STZ rat. Thus, abnormally overexpressed lumican may lead to adhesion deficiency in the cornea of STZ rats.

Antibacterial mechanism of chelerythrine isolated from root of Toddalia asiatica (Linn) Lam

Background

Antimicrobial resistance was one of serious worldwide problems confused many researchers. To solve this problem, we explored the antibacterial effect of chelerythrine, a natural compound from traditional Chinese medicine and studied its action.

Methods

The contents of chelerythrine from different fractions of Toddalia asiatica (Linn) Lam (T. asiatica) were determined. The anti-bacterial activities of chelerythrine were tested by disc diffusion method (K-B method). Scanning electron microscopy (SEM), alkaline phosphatase (AKP), bacterial extracellular protein leakage and SDS-PAGE analysis were also used to investigate the antibacterial mechanism of chelerythrine.

Results

Analytic results of High Performance Liquid Chromatography showed that the content of chelerythrine (1.97 mg/g) in the ethyl acetate fraction was the highest, followed by those of methanol fraction and petroleum ether fraction. The in vitro anti-bacterial mechanisms of chelerythrine from T. asiatica were assessed. Chelerythrine showed strong antibacterial activities against Gram-positive bacteria, Staphylococcus aureus (SA), Methicillin-resistant S. aureus (MRSA), and extended spectrum β-lactamase S. aureus (ESBLs-SA). The minimum inhibitory concentrations (MICs) of chelerythrine on three bacteria were all 0.156 mg/mL. Furthermore, results suggested that the primary anti-bacterial mechanism of chelerythrine may be attributed to its destruction of the channels across the bacterial cell membranes, causing protein leakage to the outside of the cell, and to its inhibition on protein biosynthesis. Images of scanning electron microscope revealed severe morphological changes in chelerythrine-treated bacteria except control, damage of parts of the cell wall and cell membrane as well as the leakage of some substances.

Conclusions

Chelerythrine isolated from root of Toddalia asiatica (Linn) Lam possesses antibacterial activities through destruction of bacterial cell wall and cell membrance and inhibition of protein biosynthesis.

Evaluation of Aculeatin and Toddaculin Isolated from Toddalia asiatica as Anti-inflammatory Agents in LPS-Stimulated RAW264 Macrophages

Anti-inflammatory activity of aculeatin and toddaculin, which are coumarins with a similar structure isolated from Toddalia asiatica (L.) LAM., was evaluated using lipopolysaccharide (LPS)-stimulated RAW264 mouse macrophage cells. Both aculeatin and toddaculin significantly inhibited mRNA expression of inflammatory mediators and nitric oxide production. Furthermore, Toddaculin suppressed LPS-induced phosphorylation of p38 and extracellular signal-regulated kinase (ERK)1/2 and inhibited LPS-induced activation of nuclear factor-kappaB (NF-κB). However, aculeatin did not exhibit such effects, suggesting that aculeatin and toddaculin suppress LPS-induced inflammation of RAW264 cells via different mechanisms. The cellular uptake of these compounds was also evaluated. Toddaculin was detected in RAW264 cells after 4 and 24 h. However, aculeatin levels were not observed in RAW264 cells at all incubation intervals. These results indicate that de-epoxidation of a prenyl group can increase hydrophobicity of molecule and is thought to accelerate cellular uptake and/or interactions with the phospholipid bilayers of cell membranes.

Cell Cycle Arrest and Apoptosis in HT-29 Cells Induced by Dichloromethane Fraction From Toddalia asiatica (L.) Lam

The roots of Toddalia asiatica (L.) Lam. (TA) has been often used in Chinese folk medicine to treat different diseases, including but not limited to arthritis, injuries, stomachache, and even tumors. However, the anti-cancer effects and the action mechanisms of TA remain elusive. Therefore, we firstly evaluated the effects of different extracts of TA on the growth of human colon cancer cells, and then tried to further elucidate their underlying molecular mechanisms. As a result, the dichloromethane fraction (DF) was found to possess the highest anti-proliferative activity with IC50 value at 18 μg/mL among all of the four extracts from TA, and strongly inhibited HT-29 cell growth and halted cell cycle progression in G2/M phase. DF also induced phosphatidylserine externalization and activated caspases -8, -9, and -3, suggesting DF induced apoptosis through intrinsic and extrinsic pathways. Furthermore, we found that HT-29 cell cycle arrest induced by DF could be the result of reactive oxygen species (ROS), as the ROS scavenger N-acetyl cysteine (NAC) attenuating it. Taken together, these results indicated that DF induced cell cycle arrest at G2/M phase and apoptosis in HT-29 cells, and could be a promising source for developing natural therapeutics for colon cancer.

The Effects of Hesperidin and Quercetin on Serum Tumor Necrosis Factor-Alpha and Interleukin-6 Levels in Streptozotocin-induced Diabetes Model

Background:

Diabetes mellitus (DM) is a metabolic disorder that occurs as a result of absolute or relative insufficiency of insulin release and/or insulin effect due to impairment of carbohydrate, fat and protein metabolism, and it is characterized by hyperglycemia and leads to various complications.

Objective:

In this study, it was aimed to investigate the effects of hesperidin (HP) and quercetin, which are natural flavonoids, on serum malondialdehyde (MDA), glutathione (GSH), tumor necrosis factor alpha (TNF-α), and interleukin-6 (IL-6) levels in rats with streptozotocin (STZ)-induced diabetes.

Materials and Methods:

The experimental animals were divided into four groups, each group comprising ten rats designated as follows: Group 1 served as control rats (C); Group 2 served as diabetic rats (DM); Group 3 served as diabetic rats administered HP (DM + HP) (100 mg/kg b. w.); and Group 4 served as diabetic rats administered quercetin (DM + Q) (100 mg/kg b. w.).

Results:

Serum MDA and GSH levels were significantly higher in STZ-induced DM group than control group (P < 0.05). In DM + HP and DM + Q groups, MDA levels were significantly decreased compared to DM groups (P < 0.05), but there was no significant difference GSH levels between DM, DM + HP, and DM + Q groups (P > 0.05). TNF-α levels in STZ-induced DM group were significantly decreased compared to control group (P < 0.05), and groups of DM + HP and DM + Q had higher serum TNF-α levels than STZ-induced DM group (P < 0.05). In STZ-induced DM group, serum IL-6 levels were decreased compared to control group (P < 0.05).

Conclusion:

As a result, in this study, we determined that HP and quercetin may play an effective role in regulating insulin metabolism metabolism in diabetes. However, considering the incompatibility of various results in the literature as well as our own results, we think that the actual role of cytokines in the pathogenesis of diabetes is one of the issues that need to be clarified in further studies.

SUMMARY

Hesperidin (HP) and quercetin reduced the insulin, total cholesterol, triglyceride, low-density lipoprotein cholesterol, and malondialdehyde (MDA) serum levels and raised the glutathione (GSH) levels compared to diabetes mellitus (DM) group

SZT-induced DM increased the MDA serum levels and decreased the GSH levels compared to control group

HP and quercetin-treated rats showed higher interleukin-6 and tumor necrosis factor alpha cytokine levels than DM group

HP and quercetin may play an effective role in regulating insulin metabolism in diabetes.

Abbreviations used: DM: Diabetes mellitus, MDA: Malondialdehyde, GSH: Glutathione; IL-6: Interleukin-6, TNF-α: Tumor necrosis factor alpha, HP: Hesperidin, Q; Quercetin, STZ: Streptozotocin, TC: Total cholesterol, TG: Triglyceride, HDL-C: High density lipoprotein cholesterol, LDL-C: Low density lipoprotein cholesterol, VLDL-C: Very-low-density lipoprotein cholesterol.

Phytochemical characterization of polyphenolic compounds with HPLC-DAD-ESI-MS and evaluation of lipid-lowering capacity of aqueous extracts from Saharan plant Anabasis aretioides (Coss & Moq.) in normal and streptozotocin-induced diabetic rats

OBJECTIVE

Anabasis aretioides (Coss & Moq.), a Saharan plant belonging to Chenopodiaceae family, is widely distributed in semi-desert areas from the Tafilalet region of Morocco. This plant is extensively used by local population against diabetes and cardiovascular disorders. The purpose of the study was to investigate the effect of the aqueous A. aretioides extract on lipid metabolism in normal and streptozotocin (STZ)-induced diabetic rats and to identify the polyphenolic compounds present. In addition, the in vitro antioxidant activity of the aqueous A. aretioides extract was also evaluated.

METHODS

The effect of an aerial part aqueous extract (APAE) of A. aretioides (5 mg/kg of lyophilized A. aretioides APAE) on plasma lipid profile was investigated in normal and STZ-induced diabetic rats (n = 6) after once daily oral administration for 15 days. The aqueous extract was tested for its 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity. Polyphenolic compounds in the extracts were definitively characterized by high-performance liquid chromatography-diode array detection-electrospray ionization-mass spectrometry.

RESULTS

In diabetic rats, oral administration of A. aretioides APAE provoked a significant decrease in both plasma cholesterol and triglyceride levels from the first to the second week (P < 0.01). A significant decrease on plasma triglyceride levels was also observed in normal rats (P < 0.01), where the reduction was 53%. In addition, the phytochemical analysis revealed the presence of 12 polyphenolic compounds. Moreover, according to the DPPH radical-scavenging activity, the aqueous extract showed an in vitro antioxidant activity.

CONCLUSION

Aqueous A. aretioides APAE exhibits lipid-lowering and in vitro antioxidant activities. Many polyphenols were present in this extract and these phytoconstituents may be involved in the pharmacological activity of this plant.

Hypoglycaemic and Antioxidant Effects of Propolis of Chihuahua in a Model of Experimental Diabetes

Propolis is a bee-collected natural product that has been proven to have various bioactivities. This study tested the effects of a Mexican propolis on streptozotocin-induced diabetes mellitus in a murine model. The results showed that an ethanolic extract of propolis of Chihuahua (EEPCh) significantly inhibited increases in blood glucose and the loss of body weight in diabetic mice. EEPCh increased plasma insulin levels in STZ-diabetic mice, whereas, in untreated diabetic mice, there was no detection of insulin. EEPCh had a high antioxidant capacity (SA₅₀ = 15.75 μg/mL), which was directly related to the concentrations of total phenols (314 mg GAE/g of extract) and flavonoids (6.25 mg QE/g of extract). In addition, increased activities of the enzymes superoxide dismutase, catalase, and glutathione peroxidase were observed in diabetic mice treated with EEPCh. Compounds such as pinocembrin, quercetin, naringin, naringenin, kaempferol, acacetin, luteolin, and chrysin were identified by HPLC-MS analysis. This investigation demonstrated that propolis of Chihuahua possesses hypoglycaemic and antioxidant activities and can alleviate symptoms of diabetes mellitus in mice. These effects may be directly related to the chemical composition of propolis, as most of the compounds identified in propolis are reportedly active in terms of the different parameters evaluated in this work.

Protective effects of Ficus carica leaves on glucose and lipids levels, carbohydrate metabolism enzymes and β-cells in type 2 diabetic rats

CONTEXT

The decoctions of Ficus carica Linn. (Moraceae) leaves are used in the folklore treatment of diabetes.

OBJECTIVE

To evaluate the effect of F. carica on glucose and lipids levels, carbohydrate metabolism enzymes and β-cells protective effects in type 2 diabetes.

MATERIAL AND METHODS

Diabetes was induced in 15 days high-fat diet (HFD)-fed Wistar rats by intraperitoneal injection of streptozotocin (STZ) (40 mg/kg). The ethyl acetate extract (250 and 500 mg/kg) of F. carica leaves was administered for 28 days. Oral glucose tolerance (OGTT) and intraperitoneal insulin tolerance tests (ITT) were evaluated on 15th and 25th days, respectively.

RESULTS

The ethyl acetate extract (250 and 500 mg/kg) of n F. carica leaves showed significant effect (p < 0.005) in the levels of blood glucose, total cholesterol (TC), triglycerides (TG), body weight and hepatic glycogen. In OGTT, F. carica (250 and 500 mg/kg) significantly (p < 0.005) detained the increase in blood glucose levels at 60 and 120 min and in ITT, F. carica enhanced the glucose utilization significantly (p < 0.005) over 30 and 60 min compared to diabetic control. Further, the altered activities of key carbohydrate metabolizing enzymes such as glucose-6-phosphatase, fructose-1,6-bisphosphatase and hexokinase in the liver tissue of diabetic rats were significantly (p < 0.005) reverted to near normal levels upon treatment with F. carica. Immumohistochemical studies of islets substantiated the cytoprotective effect on pancreatic β-cells.

DISCUSSION AND CONCLUSIONS

F. carica leaves exerted significant effect on carbohydrate metabolism enzymes with promising hypoglycemic and hypolipidemic activities in type 2 diabetic rats.

Protective Effects of Parkia biglobosa Protein Isolate on Streptozotocin-Induced Hepatic Damage and Oxidative Stress in Diabetic Male Rats

This study sought to investigate the possible protective role of Parkia biglobosa seed protein isolate (PBPi) against streptozotocin-induced hepatic damage and oxidative stress in diabetic male rats. Prior to animal experiments, a HPLC fingerprint of PBPi was recorded. Diabetes was induced in rats by a single intraperitoneal injection of streptozotocin (STZ; 60 mg/kg body weight). Diabetic rats were orally treated daily with PBPi (200 or 400 mg/kg body weight) or insulin (5 U/kg, i.p.) for 28 days. The degree of protection was evaluated using biochemical parameters such as malondialdehyde (MDA) levels, serum transaminases (ALT and AST), total protein, total glutathione (Total GSH), glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), and interleukin-6 (IL-6) activities. Histology of liver sections was also performed. The HPLC fingerprint of PBPi revealed eleven distinct peaks; PBPi at tested doses significantly attenuates STZ-induced elevated levels of serum IL-6, ALT and AST; and hepatic TBARS levels. Hepatic antioxidants (Total GSH, GST, SOD, CAT) as well as total protein were markedly restored in a dose-dependent manner. Histopathological results strongly support the protective role of PBPi. These results suggest PBPi could confer protection by ameliorating hepatic damage and oxidative stress caused by STZ in animal model possibly via its anti-inflammatory and antioxidant properties.

Proteomic profile of the lens in a streptozotocin-induced diabetic rat model using shotgun proteomics

Streptozotocin (STZ)-induced diabetic rats (STZ rats) were used to investigate diabetic cataracts. In the current study, a shotgun liquid chromatography (LC)/mass spectrometry (MS)-based global proteomic analysis method was used to examine the mechanism of lens opacification as a result of hyperglycemia in STZ rats. The 6-week old Wistar rats were injected with STZ for 2 days (100 mg/kg/day, i.p.) and housed for 3 weeks. The plasma glucose levels were identified to be significantly higher when compared with the normal rats and insulin was not detected in the STZ rats. Furthermore, opacification of the cortical epithelium was observed in the lenses of STZ rats. A total of 235 proteins were identified in the lenses of the STZ rats and 229 in the lenses of the normal rats. A label-free semi-quantitative method, based on spectral counting, identified 52 proteins that were differentially expressed in the lenses of STZ rats compared with normal rats. In particular, superoxide dismutase, which is a critical antioxidant enzyme that detoxifies superoxide through redox cycling, was downregulated when analyzed by the semi-quantitative method. In addition, phosphorylated-p38, which is important in the signaling pathway involved in the oxidative stress response, was significantly increased in the lenses of STZ rats when compared with normal rats (P<0.05). Thus, the changes in protein expression were evaluated in the lenses of STZ rats using a shotgun LC/MS-based global proteomic analysis approach, and a decrease in antioxidant enzymes and an increase in oxidative stress were identified in the lenses of STZ rats. Further studies are required to examine the role of these proteins in the onset or progression of diabetic cataracts.

Anti-Diabetic Effects of Phenolic Extract from Rambutan Peels (Nephelium lappaceum) in High-Fat Diet and Streptozotocin-Induced Diabetic Mice

Recent studies have shown that rambutan peel phenolic (RPP) extract demonstrate high antioxidant and antiglycation activities in vitro and in vivo. This study further evaluated the anti-diabetic activity of RPP in a mouse model of Type II diabetes induced by streptozotocin combined with high-fat diet. Results showed that RPP increased the body weight and reduced the fasting blood glucose level of the diabetic mice. RPP significantly reduced the serum levels of total cholesterol, triglyceride, creatinine, and glycated serum protein in diabetic mice in a dose-dependent manner. Glycogen content in mice liver was recovered by RPP, which further increased the activity of superoxide dismutase and glutathione peroxidase and reduced lipid peroxidation in diabetic mice. Histological analysis showed that RPP effectively protected the tissue structure of the liver, kidney, and pancreas. In addition, RPP decreased the mesangial index and inhibited the expression of TGF-β in the kidney of diabetic mice.

Coumarins as potential antidiabetic agents

OBJECTIVES

Even with great advances in modern medicine and therapeutic agent development, the search for effective antidiabetic drugs remains challenging. Coumarins are secondary metabolites found widely in nature plants and used mainly in anticoagulation and antithrombotic therapy. Over the past two decades, however, there has been an increasing body of literatures related to the effects of coumarins and their derivatives on diabetes and its complications. This review aimed to focus on research findings concerning the effects of coumarins against diabetes and its complications using in-vitro and in-vivo animal models, and also to discuss cellular and molecular mechanisms underlying these effects.

KEY FINDINGS

The search for new coumarins against diabetes and it complications, either isolated from traditional medicine or chemically synthesized, has been constantly expanding. The cellular and molecular mechanisms involved include protecting pancreatic beta cells from damage, improving abnormal insulin signalling, reducing oxidative stress/inflammation, activating AMP-activated protein kinase (AMPK), inhibiting α-glucosidases and ameliorating diabetic complications.

CONCLUSIONS

The effects and mechanisms of coumarins and their derivatives upon diabetes and its complications are discussed in current review. Further investigations remain to be carried out to develop a promising antidiabetic agent based on coumarin cores.

Averrhoa bilimbi fruits attenuate hyperglycemia-mediated oxidative stress in streptozotocin-induced diabetic rats

Hyperglycemia-mediated oxidative stress plays a major role in the development of diabetic complications. Averrhoa bilimbi Linn. (Oxalidaceae) is a medicinal plant with fruits reported to possess antidiabetic activity. This study evaluated the beneficial effects of the ethyl acetate fraction of A. bilimbi fruit (ABAEE) on the antioxidant/oxidant status in diabetes mellitus. Diabetic rats were treated orally with the ethyl acetate fraction of A. bilimbi fruits at a dose of 25 mg/kg body weight for 60 days. Serum glucose, glycated hemoglobin, plasma insulin, hepatic toxicity markers, antioxidant enzymes, lipid peroxidation products, and liver histopathology were assayed checked after 60 days of extract treatment. Diabetic rats administered ABAEE showed a significant decline in serum glucose, glycated hemoglobin, and also significantly increases the level of plasma insulin, as well as a notable attenuation in thiobarbituric acid-reactive substances, conjugated dienes, and hydroperoxides. ABAEE also modulated hepatic antioxidant potential by significantly increasing the activities of catalase, glutathione peroxidase, glutathione reductase, superoxide dismutase, and reducing glutathione content. The results associated with ABAEE were more significant than those observed following treatment with the standard drug metformin. Histopathological observations showed that ABAEE effectively rescued hepatocytes from oxidative damage without affecting cellular function and structural integrity. High-performance liquid chromatography analysis of ABAEE indicated the presence of phenolic compound, quercetin, indicating that the anti-diabetic effect of the extract might be related to quercetin. These results demonstrated the potential beneficial effect of ABAEE on streptozotocin-induced diabetes in rats.

Ashanti pepper (Piper guineense Schumach et Thonn) attenuates carbohydrate hydrolyzing, blood pressure regulating and cholinergic enzymes in experimental type 2 diabetes rat model

BACKGROUND

Ashanti pepper (Piper guineense Schumach et Thonn) seed is well known in folkloric medicine in the management of type 2 diabetes (T2DM) with little or no scientific documentation for its action. This study investigated the effect of Ashanti pepper seed on some enzymes relevant to carbohydrate hydrolysis, blood regulation and the cholinergic system, as well as the blood glucose level, lipid profile, antioxidant parameters, and hepatic and renal function markers in T2DM rats.

METHODS

T2DM was induced by feeding rats with high-fat diet (HFD) for 14 days followed by a single intraperitoneal dose of 35 mg/kg body weight of streptozotocin (STZ). Three days after STZ induction, diabetic rats were placed on a dietary regimen containing 2%-4% Ashanti pepper.

RESULTS

Reduced blood glucose level with decreased α-amylase, α-glucosidase and angiotensin I converting enzyme (ACE) activities were observed in Ashanti pepper seed and acarbose-treated rat groups when compared to that of the diabetic control rat group. Furthermore, the results revealed that inclusion of 2%-4% Ashanti pepper seed in diabetic rat fed group diets may ameliorate the lipid profile, antioxidant status, and hepatic and renal function in T2DM rats as much as in the acarbose-treated groups. In addition, a chromatographic profile of the seed revealed the presence of quercitrin (116.51 mg/g), capsaicin (113.94 mg/g), dihydrocapsaicin (88.29 mg/g) and isoquercitrin (74.89 mg/g).

CONCLUSIONS

The results from this study clearly suggest that Ashanti pepper could serve as a promising source of phenolic compounds with great alternative therapeutic potentials in the management of T2DM.

Safety and Analgesic Properties of Ethanolic Extracts of Toddalia Asiatica (L) Lam. (Rutaceae) Used for Central and Peripheral Pain Management Among the East African Ethnic Communities

Background

Although herbs are often perceived as “natural” and therefore safe, many different side effects have been reported. Additionally, there is limited scientific evidence to establish the safety and efficacy of most herbal products. The aim of this study was to evaluate the biochemical and haematological effects of Toddaliaasiatica (L) Lam. (Rutaceae) (T. asiatica (L.) in albino Wistar rats.

Materials and methods

The phytochemicals present in the plant were determined. The analgesic activity was determined using the hot plate technique. The whole blood with anticoagulant was used for assay of the haematological parameters using the COULTERAc•T5diff AL Hematology Analyzer (Fullerton, CA, USA). The biochemical parameters determined with HumaLyzer 2000, a semi-automatic, microprocessor-controlled photometer fromchem-labs, Nairobi.

Results

The effect of extract on serum biochemical parameters after 14 days treatment with the crude ethanolic extract of T. asiatica (L.) revealed significant difference in the Cholesterol (P = 0.041), alanine transaminase (P = 0.007), gamma-glutamyl transferase (P = 0.045). There was no significance in the alkaline phosphatase (ALP), aspartate transaminase (AST) levels compared to the untreated controls. Peripheral blood films (PBFs) of the treated animals were performed and stained with leishman's stain. Major morphological changes were observed including anisocytosis, burr cells, anisochromia, hypochromia and reactive lymphocytes among others.

Conclusion

The crude extract of T. asiatica (L.) showed better analgesic effect (28.2±13.16) than Acetylsalicylate used as control (4±0.31). The potential of T. asiatica (L.) asananalgesic was remarkable. However, the crude extract of T. asiatica (L.) induced nephrotoxicity and liver enzymes modulation and elevated total cholesterol in the test organisms compared to the untreated negative controls.