Effect of walnut leaf, coriander and pomegranate on blood glucose and histopathology of pancreas of alloxan induced diabetic rats

Can daily consumption of enriched fatty acids diet be effective in improving metabolic syndrome? An attractive paradox for walnut kernel

Imagine consuming a daily diet rich in fatty acids to help treat diseases such as hypertension and obesity. This concept presents an attractive paradox. In particular, consuming walnut kernels is beneficial for treating diseases associated with metabolic syndrome (MetS), including type 2 diabetes, cardiovascular disease, dyslipidemia, and obesity. Different parts of the Juglans regia tree (family Juglandaceae), including its leaves, green husks, bark, and septum, have shown promising effects on pathological conditions related to MetS. The therapeutic advantages of consuming walnut kernels for MetS can be attributed to the presence of polyunsaturated fatty acids and polyphenolic compounds such as juglone and ellagic acid. Diets enriched with walnut kernel have a positive impact on MetS complications by reducing diastolic blood pressure, improving blood lipid profiles, lowering fasting blood sugar levels, and increasing insulin sensitivity. The potential cellular mechanisms responsible for these benefits involve activating the cholesterol hemostasis pathway by inhibiting sterol regulatory element-binding proteins (SREBPs), proprotein convertase subtilisin/kexin type 9 (PCSK9), and cholesteryl ester transfer protein (CETP). Furthermore, other by-products of walnuts, such as leaves and green husks, have also demonstrated effectiveness in managing MetS. These findings highlight the potential of incorporating walnut-based products into our diets as a natural approach to combating MetS and its complications.

Acute Toxicity, Anti-diabetic, and Anti-cancerous Potential of Trillium Govanianum-conjugated Silver Nanoparticles in Balb/c Mice

BACKGROUND

The current study aimed to develop an economic plant-based therapeutic agent to improve the treatment strategies for diseases at the nano-scale because Cancer and Diabetes mellitus are major concerns in developing countries. Therefore, in vitro and in vivo antidiabetic and anti-cancerous activities of Trillium govanianum conjugated silver nanoparticles were assessed.

METHODS

In the current study synthesis of silver nanoparticles using Trillium govanianum and characterization were done using a scanning electron microscope, UV-visible spectrophotometer, and FTIR analysis. The in vitro and in vivo anti-diabetic and anti-cancerous potential (200 mg/kg and 400 mg/kg) were carried out.

RESULTS

It was discovered that Balb/c mice did not show any major alterations during observation of acute oral toxicity when administered orally both TGaqu (1000 mg/kg) and TGAgNPs (1000 mg/kg), and results revealed that 1000 mg/kg is not lethal dose as did not find any abnormalities in epidermal and dermal layers when exposed to TGAgNPs. In vitro studies showed that TGAgNPs could not only inhibit alpha-glucosidase and protein kinases but were also potent against the brine shrimp. Though, a significant reduction in blood glucose levels and significant anti-cancerous effects was recorded when alloxan-treated and CCl4-induced mice were treated with TGAgNPs and TGaqu.

CONCLUSION

Both in vivo and in vitro studies revealed that TGaqu and TGAgNPs are not toxic at 200 mg/kg, 400 mg/kg, and 1000 mg/kg doses and possess strong anti-diabetic and anti-cancerous effects due to the presence of phyto-constituents. Further, suggesting that green synthesized silver nanoparticles could be used in pharmaceutical industries to develop potent therapeutic agents.

The Modulatory Bioeffects of Pomegranate (Punica granatum L.) Polyphenols on Metabolic Disorders: Understanding Their Preventive Role against Metabolic Syndrome

Modern research achievements support the health-promoting effects of natural products and diets rich in polyphenols. Pomegranate (PG) (Punica granatum L.) contains a considerable number of bioactive compounds that exert a broad spectrum of beneficial biological activities, including antimicrobial, antidiabetic, antiobesity, and atheroprotective properties. In this context, the reviewed literature shows that PG intake might reduce insulin resistance, cytokine levels, redox gene expression, blood pressure elevation, vascular injuries, and lipoprotein oxidative modifications. The lipid parameter corrective capabilities of PG-ellagitannins have also been extensively reported to be significantly effective in reducing hyperlipidemia (TC, LDL-C, VLDL-C, and TAGs), while increasing plasma HDL-C concentrations and improving the TC/HDL-C and LDL-C/HDL-C ratios. The health benefits of pomegranate consumption seem to be acheived through the amelioration of adipose tissue endocrine function, fatty acid utilization, GLUT receptor expression, paraoxonase activity enhancement, and the modulation of PPAR and NF-κB. While the results from animal experiments are promising, human findings published in this field are inconsistent and are still limited in several aspects. The present review aims to discuss and provide a critical analysis of PG's bioeffects on the components of metabolic syndrome, type-2 diabetes, obesity, and dyslipidemia, as well as on certain cardiovascular-related diseases. Additionally, a brief overview of the pharmacokinetic properties, safety, and bioavailability of PG-ellagitannins is included.

Evaluating the effects of Juglans regia L. extract on hyperglycaemia and insulin sensitivity in experimental type 2 diabetes in rat

OBJECTIVE

The present study aimed to investigate the effects of Juglans regia (JR) extract on hyperglycaemia and insulin sensitivity.

METHODS

Forty rats were divided into 4 groups: Control (C), Diabetes Control (DC), Diabetes + Juglans regia (D + JR) and Diabetes + Metformin (D + M).

RESULTS

In the D + JR group, Fasting blood glucose (FBG) levels decreased from day 14 onwards. There was a significant decrease in plasma levels of Fibronectin Type III Domain Containing 5 (FNDC5) and adiponectin (ADP) in the DC group compared to the C group (p < .01, p < .001 respectively). In the D + JR group, there was a significant increase in plasma FNDC5 and ADP (p < .05), while the plasma Tumour necrosis factor-alpha (TNF-α) levels were decreased compared to the DC group (p < .001).

CONCLUSIONS

In conclusion, the present study found that JR and its bioactive components alleviated insulin resistance by increasing ADP and FNDC5 and decreasing FBG in a rat model of streptozotocin (STZ) + nicotinamide (NAD)-induced type 2 diabetes (T2D).HighlightsJuglans regia extract increased insulin sensitivity.Juglans regia extract significantly reduced the level of fasting blood glucose.Juglans regia extract reduced TNF-α levels in rats with type 2 diabetes.Juglans regia extract prevent weight loss in type 2 diabetes.

Effects of empagliflozin on the expression of kisspeptin gene and reproductive system function in streptozotocin-induced diabetic male rats

One of the main health concerns of diabetes is testicular dysfunction and impairment of reproductive function and sperm quality which can cause male infertility. kisspeptin is a hypothalamic neuropeptide hormone that is involved in the regulation of energy metabolism, gonadotrophin-releasing hormone (GnRH), and reproductive function. In the present study, the therapeutic effects of empagliflozin (sodium-glucose co-transporter 2 inhibitors) on kisspeptin expression along with reproductive function were investigated in diabetic male Wistar rats. Diabetes was induced by a single dose injection of 60 mg/kg streptozotocin. Empagliflozin in doses of 10 and 25 mg/kg body weight was used for 8 weeks. Serum samples, testis, epididymis, and pancreas tissues were collected at the end of the experiments. Lipid profiles, oxidative stress markers, blood hormones, expression of kisspeptin along with pathological alterations of the testis were assayed using real-time PCR, biochemical, and histological technics. Data have shown that empagliflozin improved hyperglycemia, reproductive impairment, oxidative stress condition, and histopathological alterations of pancreatic and testis tissues in diabetic animals. It improved the serum levels of sex hormones, insulin, leptin, and the expression of kisspeptin in the testes tissues. Spermatogenesis is also improved in treated animals. Data indicated that the administration of empagliflozin can ameliorate symptoms of diabetes. It probably has promising antidiabetic potential and may improve the male infertility of diabetic subjects. To our knowledge, this is the first experimental evidence for the potential impact of empagliflozin on kisspeptin expression in diabetic male rats.

Redox ticklers and beyond: Naphthoquinone repository in the spotlight against inflammation and associated maladies

Cellular redox status has been considered as a focal point for the pathogenesis of multiple disorders. High and persistent levels of free radicals kick off inflammation and associated disorders. Though oxidative stress at high levels is harmful but at low levels it has been shown to exert cytoprotective effects. Therefore, cytoprotection by perturbation in cellular redox balance is a leading strategy for therapeutic interventions. Prooxidants are potent redox modifiers that generate mild oxidative stress leading to a spectrum of bioactivities. Naphthoquinones are a group of highly reactive organic chemical species that interact with biological systems owing to their prooxidants nature. Owing to the ability of naphthoquinones and its derivatives to perturb redox balance in a cell and modulate redox signaling, they have been in epicenter of drug development for plausible utilization in multiple clinical settings. The present review highlights the potential of 1,4-naphthoquinone and its natural derivatives (plumbagin, juglone, lawsone, menadione, lapachol and β-lapachone) as redox modifiers with anti-inflammatory, anti-cancer, anti-diabetic and anti-microbial activities for implication in therapeutic settings.

Efficacy of Pomegranate Seed Powder on Glucose and Lipid Metabolism in Patients with Type 2 Diabetes: A Prospective Randomized Double-Blind Placebo-Controlled Clinical Trial

INTRODUCTION

Pomegranate is known as a functional food which has multiple health-promoting activities. It has been assessed for patients with metabolic syndrome. Specifically, an antidiabetic activity of its juice and plausible mechanisms for its action have been shown in multitudinous studies. The aim of this study was assessing the effects of complementary treatment with pomegranate seed powder (PSP) oral supplementation on patients with type 2 diabetes mellitus (T2DM).

METHODS

Sixty patients were treated for 8 weeks by 5 g PSP or placebo, twice daily. Fasting blood glucose (FBG), glycated hemoglobin (HbA1c), total cholesterol, and triglyceride (TG) were recorded as the outcome measures at the beginning and after the intervention. The findings were analyzed using the independent t test and Mann-Whitney U test.

RESULTS

After 8 weeks, the mean differences of FBG, HbA1c, cholesterol, and TG were significantly decreased in the PSP group when compared with the placebo group (p value <0.05). In addition, post-intervention values of FBG and HbA1c were significantly lower in patients treated with PSP compared to the placebo group (p values = 0.02 and 0.01, respectively). However, the latter comparison regarding cholesterol and TG showed no significant differences (p values = 0.51 and 0.26, respectively).

CONCLUSION

It seems that complementary treatment with PSP may have beneficial effects on FBG and HbA1c of patients with T2DM. However, its effect on TG and cholesterol was equivocal.

Ellagic Acid as a Tool to Limit the Diabetes Burden: Updated Evidence

Oxidative stress contributes not only to the pathogenesis of type 2 diabetes (T2D) but also to diabetic vascular complications. It follows that antioxidants might contribute to limiting the diabetes burden. In this review we focus on ellagic acid (EA), a compound that can be obtained upon intestinal hydrolysis of dietary ellagitannins, a family of polyphenols naturally found in several fruits and seeds. There is increasing research on cardiometabolic effects of ellagitannins, EA, and urolithins (EA metabolites). We updated research conducted on these compounds and (I) glucose metabolism; (II) inflammation, oxidation, and glycation; and (III) diabetic complications. We included studies testing EA in isolation, extracts or preparations enriched in EA, or EA-rich foods (mostly pomegranate juice). Animal research on the topic, entirely conducted in murine models, mostly reported glucose-lowering, antioxidant, anti-inflammatory, and anti-glycation effects, along with prevention of micro- and macrovascular diabetic complications. Clinical research is incipient and mostly involved non-randomized and low-powered studies, which confirmed the antioxidant and anti-inflammatory properties of EA-rich foods, but without conclusive results on glucose control. Overall, EA-related compounds might be potential agents to limit the diabetes burden, but well-designed human randomized controlled trials are needed to fill the existing gap between experimental and clinical research.

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.

Effects of Juglans regia L. leaf extract supplementation on testicular functions in diabetic rats

Testicular dysfunction is a complication of diabetes mellitus (DM). Juglans regia L. (JRL) leaf extract is a source of phenolic compounds that exhibits hypoglycemic and antioxidative properties. We investigated whether JRL leaf extract could inhibit the adverse effects of DM on oxidative stress, testis histology and testosterone hormone production. We used four groups of male rats: control group (non-diabetic) given saline, diabetic group, diabetic + JRL group that received JRL leaf extract, and JRL group (nondiabetic) that received JRL leaf extract only. To evaluate the effects of JRL leaf extract on testicular functions in diabetic animals, we evaluated histopathological and histomorphometric changes; serum testosterone; and malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) levels. Decreased of MDA along with improved antioxidant status in the testis of diabetic rats; these abnormalities were attenuated by JRL leaf extract. We detected significantly decreased antioxidant biomarkers (GSH, SOD, CAT) and testosterone levels in the diabetic rats; these levels were normalized after JRL leaf extract administration. The MDA level and improved antioxidant status in the testis of diabetic rats was detected after JRL leaf extract administration. Our findings suggest that JRL leaf extract exerts preventive effects against diabetic dysfunction in the testis, which might be due to its antioxidant, anti-inflammatory and anti-apoptotic properties.

Identifying potential active components of walnut leaf that action diabetes mellitus through integration of UHPLC-Q-Orbitrap HRMS and network pharmacology analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Walnut leaf (WL) is a hypoglycemic herbal medication with blood glucose-lowering activity that can affect diabetes mellitus (DM). However, the active components of WL and the mechanisms by which these compounds affect DM are unclear.

AIM OF STUDY

This study aimed to determine these effective ingredients and elucidate the potential mechanisms by which they affect DM via ultra-high performance liquid chromatography-hybrid quadrupole-Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) coupled with network pharmacology analysis.

MATERIALS AND METHODS

First, UHPLC-Q-Orbitrap HRMS was utilized to identify components of WL. Second, the putative targets of the components were identified and predicted based on chemical similarity and online databases. Third, the key candidate targets and potential active components were identified through topological analysis of a component-disease target interaction network. Finally, interactions between active components and therapeutic targets were confirmed by molecular docking analysis.

RESULTS

One hundred and thirty components were identified in WL, among which 38 were considered potentially bioactive, as they showed hypoglycemic effects. Among these 38, 8 key active components possessed high similarities and shared 4 targets with approved drugs. These findings were confirmed by molecular docking analysis.

CONCLUSION

The approach combining UHPLC-Q-Orbitrap HRMS with network pharmacology analysis is a rapid and effective tool to identify potentially bioactive constituents in medicinal plants and prescriptions.

Antidiabetic and Anti-hyperlipidemic Effects of the Crude Hydromethanol Extract of Hagenia abyssinica (Rosaceae) Leaves in Streptozotocin-Induced Diabetic Mice

BACKGROUND

The leaves of Hagenia abyssinica (Rosaceae) have been used traditionally for the management of diabetes mellitus. Thus, this study aimed to evaluate the antidiabetic and anti-hyperlipidemic activity of Hagenia abyssinica leaves crude extract in streptozotocin-induced diabetic mice.

METHODS

Antidiabetic and anti-hyperlipidemic activity of the crude extract of Hagenia abyssinica was studied in streptozotocin-induced diabetic mice. The effects of the extract on fasting blood glucose level, body weight, and serum lipid profiles were analyzed. One-way ANOVA followed by Tukey's post hoc test was used for data analysis and p<0.05 was considered as statistically significant.

RESULTS

Hagenia abyssinica leaves crude extract showed significant (p<0.05-p<0.001) blood-glucose-lowering activity. Moreover, the crude extract of H. abyssinica reduced the fasting blood glucose level by 23.21%, 38.20%, 43.53%, and 58.99%, respectively, for CE100, CE 200, CE 400, and GLC 5 mg/kg on the 14th day of treatment. After diabetic mice were treated with H. abyssinica (100, 200 and 400 mg/kg) for 14 days, there was a significant decrease in serum total cholesterol, very-low-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and serum triglyceride and a significant increase in body weight, and HDL-cholesterol level as compared to diabetic control.

CONCLUSION

The present findings revealed that H. abyssinica leaves could be useful for the management of diabetes mellitus and other abnormalities related to this metabolic disorder. Thus, the present study may support the traditional use of H. abyssinica for diabetes mellitus treatment.

Cyclohexane extract of walnut leaves improves indices of oxidative stress, total homocysteine and lipids profiles in streptozotocin-induced diabetic rats

This study aimed to evaluate the effect of two doses of cyclohexane extract of walnut leaves on total homocysteine, lipids profiles, and indices of oxidative stress including superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), and malondialdehyde (MDA) in diabetic rats. Diabetes was induced by a single intraperitoneal (IP) injection of streptozotocin (50 mg/kg BW). Twenty-eight male Sprague Dawley rats were randomly divided into four groups, group I: control (received sesame oil as vehicle), group II: diabetic control (received sesame oil), group III and IV: diabetic rats treated by 150 and 250 mg/kg body weight (BW) per day extract of walnut leaves, respectively. All groups were treated for 28 days via oral gavage. Fasting blood glucose (FBG) level and body weight measured before injection, 3 days after injection, and on days 0, 7, 14, 21, and 28 of treatment. At the end the 28th day of the experiment, blood samples collected via heart puncture and the sera were used for estimation of the above-mentioned parameters. The results showed a decrease in FBS, TC, TG, LDL-c, VLDL-c, homocysteine, and MDA level and increase in the level of HDL-c in diabetics treated by walnut leave extracts in a dose-dependent manner after 28 days. The activity of antioxidant enzymes significantly increased in treated groups compared with diabetic control. It can be concluded that cyclohexane extract of walnut leaves has an overall beneficial effect on body weight, fasting blood glucose, lipids profile, antioxidant enzyme activities, and homocysteine.

Study of the Antidiabetic Activity of Punica granatum L. Fruits Aqueous Extract on the Alloxan-Diabetic Wistar Rats

Pancreatic β-cells dysfunction and impairment of insulin action usually leads to hyperglycemia. Punica granatum L. is a well-known traditional herbal remedy in Iran due to its positive effects on ameliorating blood glucose homeostasis. In this study, Alloxan-diabetic male Wistar rats were administrated with pomegranate fruits aqueous extract (PE) in different doses of 100, 200, and 350 mg/kg bw (PE+Da, PE+Db and PE+Dc, respectively), and the effects of PE polyphenols content on glucose metabolism in treated groups were examined using oral glucose tolerance test (OGTT), short-term and long-term PE consumption periods models followed by evaluation of plasma insulin, free fatty acids, and triglycerides levels and tissues contents of glycogen and triglycerides; compared with diabetic control (DC) and healthy control (NC) groups. By using Real-time PCR, the possibility of modulations of the Insulin receptor substrate 1 (IRS-1), Protein kinase B (Akt), Glucose transporter 2 and 4 (Glut-2, 4) mRNAs expression levels in PE treated rats were investigated. The obtained data showed noticeable reduction in fasting blood glucose (FBG) by 28.1% and 67.9% in short-term and long-term treatment models, respectively, in PE + Dc group. Also, there existed marked increase in the mRNAs expression levels of IRS-1, Akt, Glut-2, and Glut-4, which results in improvement of glucose uptake and promotes its storage. Taking together, it is suggested that PE administration contributes to the modulation of both hyperglycemia and hyperlipidemia in Alloxan-diabetic Wistar rats.

Hypoglycemic Activity of Tilia americana, Borago officinalis, Chenopodium nuttalliae, and Piper sanctum on Wistar Rats

Diabetes mellitus (DM) is considered the epidemic of the 21st century. Traditional medicine uses plants to treat DM; many of these have hypoglycemic effects in both animal models and diabetic patients. Our objective was to evaluate the hypoglycemic activity of Tilia americana, Borago officinalis, Chenopodium nuttalliae, and Piper sanctum on diabetic rats. The methanolic extracts of the plants under study were obtained by Soxhlet extraction. Toxicity was evaluated on Artemia salina; the antioxidant potential was evaluated using the DPPH technique. Hypoglycemic capacity at doses of 250 and 500 mg/kg was tested on Wistar rats with diabetes induced by alloxan (120 mg/kg). The toxicity on A. salina was null for the extracts of B. officinalis and P. sanctum, moderate for T. americana, and highly toxic for C. nuttalliae. The relevant extract of T. americana var. mexicana showed antioxidant activity. Three plants of the studied plants showed hypoglycemic activity: Tilia Americana (p = 0.0142), Borago officinalis (p = 0.0112), and Piper sanctum (p = 0.0078); P. sanctum was the one that showed the greatest reduction in glucose levels at a lower dose.

Juglans Regia L. Leaf Extract Attenuates Diabetic Nephropathy Progression in Experimental Diabetes: An Immunohistochemical Study

BACKGROUND

There is accumulating evidence that Juglans regia L. (GRL) leaf extract has hypoglycemic and antioxidative properties. The present study aimed to investigate the protective effects of GRL leaf extract against diabetic nephropathy (DN).

METHODS

In total, 28 male adult Sprague-Dawley rats were used. The DN rat model was generated by intraperitoneal injection of a single 55 mg/kg dose of streptozotocin (STZ). A subset of the STZ-induced diabetic rats received intragastric administration of GRL leaf extract (200 mg/kg/day) starting 1 week (preventive group) and 4 weeks (curative group) after the onset of hyperglycemia up to the end of the 8th week, whereas other diabetic rats received only isotonic saline (diabetic group) as the same volume of GRL leaf extract. To evaluate the effects of GRL leaf extract on the diabetic nephropathy, various parameters of apoptosis and inflammation were assessed. Statistical analysis was performed using the SPSS software, version 15.0. The data were compared between the groups using the Tukey's multiple comparison test and the analysis of the variance. P values ˂0.05 were considered statistically significant.

RESULTS

Fasting blood sugar (FBS) levels (P=0.001) and histopathological changes in the kidney of diabetic rats attenuated after GRL leaf extract consumption. Greater caspase-3 (P=0.004), COX-2 (P=0.008), PARP (P=0.007), and iNOS (P=0.005) expression could be detected in the STZ-diabetic rats, which were significantly (P=0.009) attenuated after GRL leaf extract consumption. In addition, attenuation of lipid peroxidation in the diabetic rats was detected after GRL consumption (P=0.01).

CONCLUSION

GRL leaf extract exerts preventive and curative effects against diabetic nephropathy.

Effects of a hydroalcoholic extract of Juglans regia (walnut) leaves on blood glucose and major cardiovascular risk factors in type 2 diabetic patients: a double-blind, placebo-controlled clinical trial

Background

We aimed to evaluate the effects of a hydroalcoholic extract of Juglans regia L. leaves on blood glucose level and cardiovascular risk factors in type 2 diabetic patients.

Methods

In this randomized, double-blind, placebo-controlled, parallel-group (2 arms) clinical trial, 50 diabetic patients were divided into two groups: treatment group (receive the capsules containing 100 mg J. regia leaf extract) and control group (receive the capsules containing placebo, microcrystallin cellulose). Baseline participant data were matched between the two arms of the study. We administered the prepared capsules to the patients twice daily for 8 weeks. Blood glucose level, glycosylated hemoglobin (HbA1c) level, body weight, body mass index, blood pressure, lipid profile, serum insulin, and insulin resistance were compared between the two groups before and after the intervention. P < 0.05 was considered significant.

Results

After excluding eleven patients, 20 received J. regia leaf extract and 20 patients received placebo. The J. regia leaf extract did not significantly change the blood glucose and insulin resistance condition. However, in this group, body weight, body mass index, and systolic blood pressure significantly decreased compared with the baseline measurements (P = 0.028, P = 0.030, and P = 0.005, respectively). The lipid profile did not change significantly compared with the baseline measurements. In the control group, postprandial glucose and HbA1c levels significantly decreased after the intervention (P = 0.030 and P = 0.028, respectively). The other variables were not significantly different in this group. At the end of the study, the variables were not significantly different between the two groups.

Conclusion

In this double-blind study, 200 mg/d of J. regia leaf extract had no significant effect on blood glucose level and HOMA-IR score in patients with type 2 diabetes. However, the J. regia leaf extract was effective in reducing body weight and blood pressure. An accidental finding of our study was that microcrystalline cellulose, a widely used placebo in clinical trials, led to a reduction in blood glucose level.

Trial registration

Iranian Registry of Clinical Trials (IRCT: 138901203180 N2, 2010/6/6); retrospectively registered.

Phytochemical study of Juglans regia L. leaves

A methanolic extract of Juglans regia L. leaves was fractioned by various chromatographic techniques yielding a total of 40 metabolites belonging to megastigmane, tetralone, phenylpropanoid, neolignane and juglone glycosides. Ten unknown megastigmane glucoside derivatives (juglanionosides A-K, 1-10) and six unknown tetralone glucoside derivatives (juglanosides J-O, 11-16) together with 24 known compounds - among them 16 described for the first time in Juglans - were isolated. As characteristic structural feature, the previously undescribed compounds showed acylation of the sugar units with sinapic, ferulic, coumaric, benzoic or salicylic acid. Their chemical structures were elucidated on the basis of 1D and 2D NMR techniques, HRESIMS as well as CD spectroscopy. Absolute stereochemistry was revealed by mild alkaline hydrolysis and comparison of CD and polarimetric data to literature values.

Protective effects of methanolic extract of Juglans regia L. leaf on streptozotocin-induced diabetic peripheral neuropathy in rats

Background

Oxidative stress has a pivotal role in the pathogenesis and development of diabetic peripheral neuropathy (DPN), the most common and debilitating complications of diabetes mellitus. There is accumulating evidence that Juglans regia L. (GRL) leaf extract, a rich source of phenolic components, has hypoglycemic and antioxidative properties. This study aimed to determine the protective effects of Juglans regia L. leaf extract against streptozotocin-induced diabetic neuropathy in rat.

Methods

The DPN rat model was generated by intraperitoneal injection of a single 55 mg/kg dose of streptozotocin (STZ). A subset of the STZ-induced diabetic rats intragastically administered with GRL leaf extract (200 mg/kg/day) before or after the onset of neuropathy, whereas other diabetic rats received only isotonic saline as the same volume of GRL leaf extract. To evaluate the effects of GRL leaf extract on the diabetic neuropathy various parameters, including histopathology and immunohistochemistry of apoptotic and inflammatory factors were assessed along with nociceptive and biochemical assessments.

Results

Degeneration of the sciatic nerves which was detected in the STZ-diabetic rats attenuated after GRL leaf extract administration. Greater caspase-3, COX-2, and iNOS expression could be detected in the STZ-diabetic rats, which were significantly attenuated after GRL leaf extract administration. Also, attenuation of lipid peroxidation and nociceptive response along with improved antioxidant status in the sciatic nerve of diabetic rats were detected after GRL leaf extract administration. In other word, GRL leaf extract ameliorated the behavioral and structural indices of diabetic neuropathy even after the onset of neuropathy, in addition to blood sugar reduction.

Conclusion

Our results suggest that GRL leaf extract exert preventive and curative effects against STZ-induced diabetic neuropathy in rats which might be due to its antioxidant, anti-inflammatory, and antiapoptotic properties.

Graphical abstract

Protection against neuropathy

Nuts and Dried Fruits: An Update of Their Beneficial Effects on Type 2 Diabetes

Nuts and dried fruit are essential foods in the Mediterranean diet. Their frequent consumption has been associated with the prevention and/or the management of such metabolic conditions as type 2 diabetes (T2D), metabolic syndrome and cardiovascular diseases. Several previous reviews of epidemiological studies and clinical trials have evaluated the associations of nuts and/or dried fruit with various metabolic disorders. However, no reviews have focused on the mechanisms underlying the role of nuts and/or dried fruit in insulin resistance and T2D. This review aims to report nut and dried-fruit nutritional interventions in animals and humans, and to focus on mechanisms that could play a significant role in the prevention and treatment of insulin resistance and T2D.

The Health Benefits of Selected Culinary Herbs and Spices Found in the Traditional Mediterranean Diet

The Mediterranean diet is considered one of the healthiest diets in the world. This is often attributed to low saturated fat consumption, moderate wine consumption, and high vegetable consumption. However, herbs and spices associated with these diets may also play an important role in the quality of this diet. This review summarizes the most recent research regarding the anti-diabetic, anti-inflammatory, anti-hyperlipidemic and anti-hypertensive properties of this collection of culinary species. Additionally, this review briefly summarizes studies performed on lesser known herbs from around the world, with the goal of identifying new culinary species that may be useful in the treatment or prevention of diseases.

The effect of pomegranate fresh juice versus pomegranate seed powder on metabolic indices, lipid profile, inflammatory biomarkers, and the histopathology of pancreatic islets of Langerhans in streptozotocin-nicotinamide induced type 2 diabetic Sprague-Dawley rats

BACKGROUND

Type 2 diabetes mellitus (T2DM) is associated with hyperglycemia, inflammatory disorders and abnormal lipid profiles. Several functional foods have therapeutic potential to treat chronic diseases including diabetes. The therapeutic potential of pomegranate has been stated by multitudinous scientists. The present study aimed to evaluate the effects of pomegranate juice and seed powder on the levels of plasma glucose and insulin, inflammatory biomarkers, lipid profiles, and health of the pancreatic islets of Langerhans in streptozotocin (STZ)-nicotinamide (NAD) induced T2DM Sprague Dawley (SD) rats.

METHODS

Forty healthy male SD rats were induced to diabetes with a single dose intra-peritoneal administration of STZ (60 mg/kg b.w.) - NAD (120 mg/kg b.w.). Diabetic rats were orally administered with 1 mL of pomegranate fresh juice (PJ) or 100 mg pomegranate seed powder in 1 mL distilled water (PS), or 5 mg/kg b.w. of glibenclamide every day for 21 days. Rats in all groups were sacrificed on day 22. The obtained data was analyzed by SPSS software (v: 22) using One-way analysis of variance (ANOVA).

RESULTS

The results showed that PJ and PS treatment had slight but non-significant reduction of plasma glucose concentration, and no impact on plasma insulin compared to diabetic control (DC) group. PJ lowered the plasma total cholesterol (TC) and triglyceride (TG) significantly, and low-density lipoproteins (LDL) non-significantly compared to DC group. In contrast, PS treatment significantly raised plasma TC, LDL, and high-density lipoproteins (HDL) levels compared to the DC rats. Moreover, the administration of PJ and PS significantly reduced the levels of plasma inflammatory biomarkers, which were actively raised in diabetic rats. Only PJ treated group showed significant repairment and restoration signs in islets of Langerhans. Besides, PJ possessed preventative impact against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals almost 2.5 folds more than PS.

CONCLUSIONS

Our findings suggest that active constituents with high antioxidant properties present in PJ are responsible for its anti-hyperlipidemic and anti-inflammatory effects, likewise the restoration effect on the damaged islets of Langerhans in experimental rats. Hence, the pharmacological, biochemical, and histopathological profiles of PJ treated rats obviously indicated its helpful effects in amelioration of diabetes-associated complications.

A Review Study on Phytochemistry and Pharmacology Applications of Juglans Regia Plant

In recent years, the use of medicinal plants increased considerably; so that today, the use of traditional medicine, as well as medicinal plants is necessary for the aim of producing more effective drugs with fewer side effects and determining the effective doses. With the scientific name of Juglans regia, walnut plant is a medicinal plant with different properties that is considered less, despite having great therapeutic potential in the traditional medicine. The aim of this study was to review the dispersal of walnut plants, the chemical compounds, and therapeutic effects of walnuts on antioxidant activity, antidiabetic, hypolipidemic, antimicrobial, and antihypertensive activities, as well as liver protection. Data of this review study have been collected from the books and scientific articles published in databases such as Science Direct, Web of Science, Scopus, PubMed, and Scientific Information Database. While this plant having high antioxidant capabilities, walnuts are composed of many chemical compounds such as ascorbic acid, flavonoids, quercetin, and caffeic acid. Experimental studies have shown that walnuts reduced blood glucose and lipids and also decreased blood pressure. They have antioxidant, antidiabetic, antimicrobial, and liver-protective properties. The use of walnuts in traditional medicine and review of experimental studies demonstrated the presence of multiple, effective, and useful compounds which may provide the opportunity for the production of lipid-lowering, antidiabetes, and liver protective drugs. Due to the effects of walnuts on improving the complications of various diseases, the need for doing comprehensive clinical trials for the use of walnuts in the treatment of diseases is necessary.

Butanol fraction of Parkia biglobosa (Jacq.) G. Don leaves enhance pancreatic β-cell functions, stimulates insulin secretion and ameliorates other type 2 diabetes-associated complications in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Ethnopharmacological surveys have reported that Parkia biglobosa (Jacq.) G. Don (Leguminosae) is among the plants commonly used in the traditional management of diabetes mellitus in Nigeria and Togo.

AIM OF THE STUDY

This study investigated the anti-diabetic activity of the butanol fraction of P. biglobosa leaves (PBBF) in a type 2 diabetes (T2D) model of rats and a possible bioactive compound in the fraction.

MATERIALS AND METHODS

T2D was induced by feeding rats with a 10% fructose solution ad libitum for two weeks followed by an intraperitoneal injection of 40mg/kg body weight streptozotocin and the animals were orally treated with 150 and 300mg/kg BW of the PBBF for five days in a week. Another group of rats was non-diabetic but similarly administered with 300mg/kg BW of the PBBF. Food and fluid intakes, body weight changes and blood glucose levels were monitored during the experiment while other relevant diabetes-associated parameters were measured at the end of the experiment.

RESULTS

The PBBF treatments significantly (P<0.05) decreased the blood glucose levels and improved the glucose tolerance ability compared to untreated diabetic rats. Furthermore, the treatments were found to improve pancreatic β cell function (HOMA-β), stimulate insulin secretions, decrease insulin resistance (HOMA-IR), restore liver glycogen, ameliorate serum dyslipidaemia and prevent hepatic and renal damages compared to untreated diabetic rats. Phytochemical analysis of the fraction led to the isolation of lupeol which inhibited α-glucosidase and α-amylase in non-competitive and uncompetitive inhibition patterns respectively.

CONCLUSION

It was concluded that PBBF possessed remarkable anti-T2D activity which is mediated through modulation of β-cell function and stimulation of insulin secretion and the lower dose (150mg/kg BW) was found optimum for anti-T2D activity compared to the high dose (300mg/kg BW) in this study.

Chemical Composition and the Effect of Walnut Hydrosol on Glycemic Control of Patients With Type 1 Diabetes

BACKGROUND

Walnut hydrosol (WH) is used extensively by Iranian people with diabetes in order to control blood sugar (BS). There are few data regarding the effect of walnut on controlling diabetes.

OBJECTIVES

A pilot study to determine the efficacy and safety of WH in patients with type 1 diabetes.

MATERIALS AND METHODS

Eight patients with diabetes mellitus (DM) type 1 were enrolled in the study. They did not use any medicine except insulin. They were advised to drink 250 mL WH after meals twice a day for four weeks. Their BS level was measured and their insulin dose was changed according to their BS. After four weeks, they discontinued WH use and their BS level was checked for two weeks. Descriptive statistics was used to analyze the data. Also, the essential oil of the sample was extracted using a liquid extractor and then analysis of the constituents was performed.

RESULTS

The average daily BS level and insulin dose decreased in seven subjects. Two subjects developed generalized pruritic erythematous skin rash. One patient presented hypoglycemic coma. She had no other coma risk factor. Seven compounds were identified in the walnut essential oil and the rate of monoterpenoid and sesquiterpenes hydrocarbons were 53.45% and 5.95%, respectively. The main constituents of the oil were carvacrol (33.21%), thymol (16%) and homoveratrole (15.83%).

CONCLUSIONS

WH may control the glycemic level in people with diabetes, but it may be associated with minor and major side effects. Further in vitro studies, using these seven compounds, are recommended to determine the efficacy and complications of WH in people with diabetes.

Diabetes mellitus and its management with medicinal plants: A perspective based on Iranian research

ETHNOPHARMACOLOGICAL RELEVANCE

Complementary and alternative medicine has been increasingly used to treat chronic illnesses, such as diabetes mellitus. However, various limitations in terms of their application and efficacies exist. Furthermore, there is still much to be done to discover the right herbal medicine for diabetes.

AIM OF THE STUDY

This paper aims to evaluate previous herbal studies on the management of diabetes mellitus, to address their strengths and weaknesses and propose a general framework for future studies.

APPROACH AND METHODS

Data sources such as PubMed, ScienceDirect, Scopus, SpringerLink, and Wiley were searched, limited to Iran, using 36 search terms such as herbal, traditional, medicine, and phytopharmacy in combination with diabetes and related complications. Reviewed articles were evaluated regarding the use of botanical nomenclature and included information on (1) identity of plants and plant parts used, (2) the processing procedure, and (3) the extraction process. The main outcomes were extracted and then surveyed in terms of the efficacies of herbs in the management of diabetes mellitus. Then a comparative study was performed between Iranian and non-Iranian studies with respect to herbs best studied in Iran.

RESULTS

Of the 82 herbs studied in Iran, only six herbs were endemic and 19 were studied in detail. Although most of the reviewed herbs were found to decrease the level of blood glucose (BG) and/or glycated hemoglobin (HbA1C) in both Iranian and non-Iranian studies, information on their pharmacological mechanisms is scarce. However, the level of HbA1C was measured in a limited number of clinical trials or animal studies. Available information on both short- and long-term use of studied herbs on diabetes related complications and functions of involved organs as well as comorbid depression and/or simultaneous changes in lifestyle is also insufficient. Furthermore, little or no information on their phytochemical, toxicological, and herb-drug interaction properties is available. It is worth noting that the efficacy of the reviewed herbs has been studied scarcely in both humans and animals regarding both Iranian and non-Iranian studies. A significant number of reviewed articles failed to cite the scientific name of herbs and include information on the processing procedure and the extraction process.

CONCLUSIONS

Treatment of diabetes mellitus as a multifactorial disease using herbal medicines requires a comprehensive approach. In order to discover the right herbal medicine for the management of diabetes many other important factors than the levels of BG, HbA1C and insulin should be considered. According to our criteria, all the reviewed herbs suffered from inadequate investigation in human, animal and in vitro models in this respect, whereas they are worth investigating further. However, more research on endemic plants and the traditional history of herbal medicine is warranted. In our opinion, the pharmacological, toxicological, and phytochemical information should be obtained before clinical trials. Furthermore, information such as botanical scientific nomenclature, side effects, and toxicity will improve the quality and validity of publications in herbal research. In particular, designing a database covering all valid information about herbs and/or diseases will decrease unnecessary costs and increase the efficiency of research.

Health Benefits of Punicic Acid: A Review

Punicic acid (PA) is a polyunsaturated fatty acid (18:3 n-5), which is classified as a conjugated linolenic acid. PA is also referred as a "super CLnA" whose effect is even more potent than that of an ordinary CLnA. It is found mainly in the seeds of pomegranate fruit (Punica granatum) and Trichoxanthes kirilowii and some other minor sources. It possesses a wide array of biological properties including antidiabetic, antiobesity, antiproliferative, and anticarcinogenic activity against various forms of cancer. In spite of this, PA has not been explored as a nutraceutical or as an ingredient of food products which can be aimed at specific consumer target groups. This review details the various health-beneficial properties of PA and explores the possibilities of its utilization as an active ingredient in various food products.

Antidiabetic activity of differently regioselective chitosan sulfates in alloxan-induced diabetic rats

The present study investigated and compared the hypoglycemic activity of differently regioselective chitosan sulfates in alloxan-induced diabetic rats. Compared with the normal control rats, significantly higher blood glucose levels were observed in the alloxan-induced diabetic rats. The differently regioselective chitosan sulfates exhibited hypoglycemic activities at different doses and intervals, especially 3-O-sulfochitosan (3-S). The major results are as follows. First, 3,6-di-O-sulfochitosan and 3-O-sulfochitosan exhibited more significant hypoglycemic activities than 2-N-3, 6-di-O-sulfochitosan and 6-O-sulfochitosan. Moreover, 3-S-treated rats showed a more significant reduction of blood glucose levels than those treated by 3,6-di-O-sulfochitosan. These results indicated that -OSO3- at the C3-position of chitosan is a key active site. Second, 3-S significantly reduced the blood glucose levels and regulated the glucose tolerance effect in the experimental rats. Third, treatment with 3-S significantly increased the plasma insulin levels in the experimental diabetic rats. A noticeable hypoglycemic activity of 3-S in the alloxan-induced diabetic rats was shown. Clinical trials are required in the future to confirm the utility of 3-S.

Coriander (Coriandrum sativum L.) and its bioactive constituents

Coriander (Coriandrum sativum L.), a member of the Apiaceae family, is among most widely used medicinal plant, possessing nutritional as well as medicinal properties. Thus, the aim of this updated review is to highlight the importance of coriander as a potential source of bioactive constituents and to summarize their biological activities as well as their different applications from data obtained in recent literature, with critical analysis on the gaps and potential for future investigations. A literature review was carried out by searching on the electronic databases including PubMed, Scopus, ScienceDirect, and Google Scholar for studies focusing on the biological and pharmacological activities of coriander seed and herb bioactive constituents. All recent English-language articles published between 2000 and 2014 were searched using the terms 'C. sativum', 'medicinal plant', 'bioactive constituents', and 'biological activities'. Subsequently, coriander seed and herb essential oils have been actively investigated for their chemical composition and biological activities including antimicrobial, antioxidant, hypoglycemic, hypolipidemic, anxiolytic, analgesic, anti-inflammatory, anti-convulsant and anti-cancer activities, among others. Although coriander has been reported to possess a wide range of traditional medicinal uses, no report is available in its effectiveness use in reactive airway diseases such as asthma and bronchiolitis. In brief, the information presented herein will be helpful to create more interest towards this medicinal species by defining novel pharmacological and clinical applications and hence, may be useful in developing new drug formulations in the future or by employing coriander bioactive constituents in combination with conventional drugs to enhance the treatment of diseases such as Alzheimer and cancer.

Pancreatic beta cell protection/regeneration with phytotherapy

Although currently available drugs are useful in controlling early onset complications of diabetes, serious late onset complications appear in a large number of patients. Considering the physiopathology of diabetes, preventing beta cell degeneration and stimulating the endogenous regeneration of islets will be essential approaches for the treatment of insulin-dependent diabetes mellitus. The current review focused on phytochemicals, the antidiabetic effect of which has been proved by pancreatic beta cell protection/regeneration. Among the hundreds of plants that have been investigated for diabetes, a small fraction has shown the regenerative property and was described in this paper. Processes of pancreatic beta cell degeneration and regeneration were described. Also, the proposed mechanisms for the protective/regenerative effects of such phytochemicals and their potential side effects were discussed.

Butanol fraction of Khaya senegalensis root modulates β-cell function and ameliorates diabetes-related biochemical parameters in a type 2 diabetes rat model

ETHNOPHARMACOLOGICAL RELEVANCE

Khaya senegalensis A. Juss (Meliaceae) is commonly exploited for the traditional treatment of diabetes mellitus in Nigeria and Togo. The present study was conducted to examine the anti-diabetic activity of Khaya senegalensis butanol fraction (KSBF) of root ethanolic extract in a type 2 diabetes (T2D) model of rats.

MATERIALS AND METHODS

T2D was induced in rats by feeding a 10% fructose solution ad libitum for two weeks followed by a single intraperitoneal injection of streptozotocin (40 mg/kg body weight) and the animals were treated with 150 and 300 mg/kg body weight (BW) of the fraction for five days in a week. Relevant diabetes-related parameters were analyzed in all experimental animals.

RESULTS

The KSBF treatment, at 300 mg/kg BW, significantly (p<0.05) reduced blood glucose level, improved oral glucose tolerance ability and β-cell function (HOMA-β), decreased insulin resistance (HOMA-IR), stimulated hepatic glycogen synthesis, ameliorated serum lipids alterations and prevented hepatic and renal damages compared to untreated diabetic rats. Additionally, the fraction insignificantly (p>0.05) improved weight gain, decreased food and fluid intake, stimulated insulin secretion and lowered serum fructosamine concentrations compared to untreated diabetic rats.

CONCLUSIONS

Data from this study suggests that orally administered KSBF, at 300 mg/kg BW, possess remarkable anti-type 2 diabetic activity and could ameliorate some diabetes-associated complications and hence can be considered as a source of potential anti-type 2 diabetic medicine.

Effects of Juglans regia L. leaf extract on hyperglycemia and lipid profiles in type two diabetic patients: a randomized double-blind, placebo-controlled clinical trial

ETHNOPHARMACOLOGICAL RELEVANCE

The Juglans regia L. leaf has been traditionally used for treatment of diabetes mellitus in Iran. But yet, no controlled human study has determined its efficacy in diabetic patients. The present study was designed to investigate the effects of the Juglans regia leaf extract on hyperglycemia and lipid profiles in type II diabetic patients.

MATERIALS AND METHOD

Total 61 patients, suffering from type II diabetes with fasting blood glucose (FBG) between 150 and 200mg/dL, glycated hemoglobin (HbA1c) between 7% and 9% and aged between 40 and 60 years were selected, and randomly divided in to two groups of Juglans regia and placebo. First group received 100mg Juglans regia leaf extract in capsules form two times a day for 3 months and other group received 100mg placebo capsule with the same dosage. The standard anti-diabetic therapy (metformin and glibenclamide, and nutritional regimen) was continued in both groups. At the baseline and after three months the FBG, insulin, HbA1c, cholesterol, triglyceride, HDL, LDL and liver and renal function tests were determined. In addition general satisfaction with the treatment was identified using health questionnaires.

RESULTS

The results indicated that FBG, HbA1c, total cholesterol and triglyceride levels in Juglans regia treated patients significantly decreased compared with the baseline and with placebo group. Patients in Juglans regia group were significantly satisfied with Juglans regia treatment compared with the placebo group. No liver, kidney and other side effects were observed in the groups, except more GI events (specially a mild diarrhea) associated with extract treatment at the beginning of the study.

CONCLUSION

In conclusion, treatment of type II diabetic patients with 100mg Juglans regia leaf extract two times a day for three months improves lipid profile and glycemic control without any tangible adverse effects.

The hypoglycemic effect of Juglans regia leaves aqueous extract in diabetic patients: A first human trial

BACKGROUND

Juglans regia L. (J. regia ) is one of the medicinal plants traditionally used for treatment of diabetes in Iranian medicine. The effect of this plant has already been investigated on animal models; however, this is the first study conducted on human subjects. The aim of this study is to investigate the hypoglycemic effect of J. regia leaves aqueous extract in type 2 diabetes patients. Fifty eight Iranian male and female patients with type 2 diabetes were enrolled. The patients were randomly allocated into two groups. One group (n = 30) received J. regia leaves extract while the other group (n = 28) received placebo. Fasting blood samples were collected at the beginning of the study and after two months for determination of HbA1c and blood glucose level as a main outcome and insulin, SGOT, SGPT, and ALP level as secondary outcome.

RESULTS

Our analysis showed that serum fasting HbA1C and blood glucose levels were significantly decreased and the insulin level was increased in patients in the J. regia arm.

CONCLUSIONS

The results indicate that J. regia aqueous extract favorably affects blood levels of glucose, insulin and HbA1C in type 2 diabetic patients.

Antihyperlipidemic effect of a polyherbal mixture in streptozotocin-induced diabetic rats

The effects of a polyherbal mixture containing Allium sativum, Cinnamomum zeylanicum, Citrullus colocynthis, Juglans regia, Nigella sativa, Olea europaea, Punica granatum, Salvia officinalis, Teucrium polium, Trigonella foenum, Urtica dioica, and Vaccinium arctostaphylos were tested on biochemical parameters in diabetic rats. The animals were randomized into three groups: (1) normal control, (2) diabetic control, and (3) diabetic rats which received diet containing 15% (w/w) of this mixture for 4 weeks. Diabetes was induced by intraperitoneal injection of streptozotocin (55 mg/kg). At the end of experiment, the mixture had no significant effect on serum hepatic enzymes, aspartate aminotransferase, and alanine aminotransferase activities. However, the level of fasting blood glucose, water intake, and urine output in treated group was lower than that in diabetic control rats (P < 0.01). Also, the levels of triglyceride and total cholesterol in polyherbal mixture treated rats were significantly lower than those in diabetic control group (P < 0.05). Our results demonstrated that this polyherbal mixture has beneficial effects on blood glucose and lipid profile and it has the potential to be used as a dietary supplement for the management of diabetes.

Pomegranate and type 2 diabetes

Over the last decade, various studies have linked pomegranate (Punica granatum Linn), a fruit native to the Middle East, with type 2 diabetes prevention and treatment. This review focuses on current laboratory and clinical research related to the effects of pomegranate fractions (peels, flowers, and seeds) and some of their active components on biochemical and metabolic variables associated with the pathologic markers of type 2 diabetes. This review systematically presents findings from cell culture and animal studies as well as clinical human research. One key mechanism by which pomegranate fractions affect the type 2 diabetic condition is by reducing oxidative stress and lipid peroxidation. This reduction may occur by directly neutralizing the generated reactive oxygen species, increasing certain antioxidant enzyme activities, inducing metal chelation activity, reducing resistin formation, and inhibiting or activating certain transcriptional factors, such as nuclear factor κB and peroxisome proliferator-activated receptor γ. Fasting blood glucose levels were decreased significantly by punicic acid, methanolic seed extract, and pomegranate peel extract. Known compounds in pomegranate, such as punicalagin and ellagic, gallic, oleanolic, ursolic, and uallic acids, have been identified as having anti-diabetic actions. Furthermore, the juice sugar fraction was found to have unique antioxidant polyphenols (tannins and anthocyanins), which could be beneficial to control conditions in type 2 diabetes. These findings provide evidence for the anti-diabetic activity of pomegranate fruit; however, before pomegranate or any of its extracts can be medically recommended for the management of type 2 diabetes, controlled, clinical studies, are needed.

In vitro and in vivo effects of standardized extract and fractions of Phaleria macrocarpa fruits pericarp on lead carbohydrate digesting enzymes

BACKGROUND

One vital therapeutic approach for the treatment of type 2 diabetes mellitus is the use of agents that can decrease postprandial hyperglycaemia by inhibiting carbohydrate digesting enzymes. The present study investigated the effects of bioassay-guided extract and fractions of the dried fruit pericarp of Phaleria macrocarpa, a traditional anti-diabetic plant, on α-glucosidase and α-amylase, in a bid to understand their anti-diabetic mechanism, as well as their possible attenuation action on postprandial glucose increase.

METHODS

Methanol extract (ME), obtained by successive solvent extraction, its most effective liquid-liquid n-butanol fraction (NBF) and the flash column chromatographic sub-fraction (SFI), were evaluated for in vitro α-glucosidase (yeast) and α-amylase (porcine) activity inhibition. Furthermore, confirmatory in vivo tests were carried out in streptozotocin-induced diabetic rats (SDRs) using oral glucose, sucrose and starch tolerance tests.

RESULTS

At the highest concentration employed (100 μg/ml), NBF showed highest inhibition against α-glucosidase (75%) and α-amylase (87%) in vitro (IC50 = 2.40 ± 0.23 μg/ml and 58.50 ± 0.13 μg/ml, respectively) in a dose-dependent fashion; an effect found to be about 20% higher than acarbose (55%), a standard α-glucosidase inhibitor (IC50 = 3.45 ± 0.19 μg/ml). The ME and SFI also inhibited α-glucosidase (IC50 = 7.50 ± 0.15 μg/ml and 11.45 ± 0.28 μg/ml) and α-amylase (IC50 = 43.90 ± 0.19 μg/ml and 69.80 ± 0.25 μg/ml), but to a lesser extent. In in vivo studies with diabetic rats, NBF and SFI effectively reduced peak blood glucose (PBG) by 15.08% and 6.46%, and the area under the tolerance curve (AUC) by 14.23% and 12.46%, respectively, after an oral sucrose challenge (P < 0.05); thereby validating the observed in vitro action. These reduction effects on PBG and AUC were also demonstrated in glucose and starch tolerance tests, but to a lesser degree.

CONCLUSIONS

These findings reveal that P. macrocarpa can attenuate hyperglycaemia in both in vitro and in vivo conditions by potently inhibiting carbohydrate hydrolysing enzymes, making it a viable plant for sourcing natural compounds for the management of type 2 diabetes mellitus.

Pomegranate: a fruit that ameliorates metabolic syndrome

Pomegranate is an ancient fruit that is still part of the diet in the Mediterranean area, the Middle East, and India. Health-promoting effects have long been attributed to this fruit. Modern research corroborates the use of pomegranate as a folk remedy for diabetes and metabolic syndrome, and is responsible for a new evaluation of nutritional and pharmaceutical aspects of pomegranate in the general public. In the last decade, industry and agricultural production have been adapted to meet higher market demands for pomegranate. In vivo and in vitro studies have demonstrated that pomegranate exerts hypoglycaemic effects, including increased insulin sensitivity, inhibition of α-glucosidase, and impact on glucose transporter type 4 function, but is also responsible for a reduction of total cholesterol, and the improvement of blood lipid profiles, as well as anti-inflammatory effects through the modulation of peroxisome proliferator-activated receptor pathways. These effects may also explain how pomegranate-derived compounds function in the amelioration of adverse health effects caused by metabolic syndrome. Pomegranate contains polyphenols such as ellagitannins and anthocyanins, as well as phenolic acids, fatty acids and a variety of volatile compounds. Ellagitannins are some of the most prevalent compounds present in pomegranate, and may be responsible for certain benevolent characteristics associated with pomegranate. A brief overview of rising health problems due to obesity will be provided, followed by characterisation of the biological activity, bioavailability, and safety of pomegranate and pomegranate-derived compounds. Although the fruit is consumed in many countries, epidemiological and clinical studies are unavailable. Additional research is necessary to corroborate the promise of current in vivo and in vitro findings.

Comparison of the effects of fresh leaf and peel extracts of walnut (Juglans regia L.) on blood glucose and β-cells of streptozotocin-induced diabetic rats

There is some report about the hypoglycemic effect of Juglans rejia L. leaf in alloxan induced diabetic rats and hypoglycemic effect of its fruit peel administered intra peritoneally. Thirty male Wistar rats divided into five groups, to evaluate the hypoglycemic and pancreas β-cells regenerative effects of oral methanolic extracts of leaf and fruit peel of walnut. Rats were made diabetic by intravenous (IV) injection of 50 mg kg(-1) streptozotocin (STZ). Negative control group did not get STZ and any treatment. Positive control, leaf extract, peel extract and insulin groups were treated orally by extract solvent, 200 mg kg(-1) leaf extract, 200 mg kg(-1) peel extract and 5 IU kg(-1) of subcutaneous neutral protamine Hagedorn (NPH) insulin, respectively. Four weeks later, blood was collected for biochemical analysis and pancreases were removed for β-cells counts in histological sections. Diabetes leads to increase of fast blood sugar (FBS) and HbA1c, and decrease of β-cell number and insulin. FBS decreased only in leaf extract group. HbA1c decreased in leaf extract and insulin groups. The β-cells number increased in leaf and peel extract groups. Insulin increased moderately in all treatment groups. We showed the proliferative properties of leaves and peel of Juglans regia L. methanolic extract in STZ- induced diabetic rats, which was accompanied by hypoglycemic effect of leaf extract.