Raffia palm (Raphia hookeri G. Mann & H. Wendl) wine modulates glucose homeostasis by enhancing insulin secretion and inhibiting redox imbalance in a rat model of diabetes induced by high fructose diet and streptozotocin

Butanol fraction of Alstonia boonei De Wild. leaves ameliorate oxidative stress and modulate key hypoglycaemic processes in diabetic rats

OBJECTIVE

The effect of Alstonia boonei fractions on glucose homeostasis was investigated via in vitro enzyme inhibition activity, ex vivo glucose uptake assay, and in vivo methods in diabetic rats.

METHODOLOGY

A. boonei fractions were subjected to in vitro α-glucosidase inhibitory assay and then ex vivo glucose uptake activity. The butanol fraction of the leaves (ABBF) was picked for the in vivo assay since it showed more activity in the initial tests conducted. ABBF was administrated via oral dosing to six-weeks old fructose-fed STZ-induced type 2 diabetic rats over a 5-week experimental period.

RESULTS

ABBF treatment at a low dose of 150 mg/kg bw, significantly (p < .05) reduced blood glucose level, enhanced oral glucose tolerance ability, restored insulin secretion and hepatic glycogen synthesis as well as promoted islet regeneration than the high dose (300 mg/kg bw).

CONCLUSION

These results suggest that ABBF could be exploited as a therapeutic potential for treating T2D.

Antidiabetic and antioxidant activities of Mitragyna speciosa (kratom) leaf extract in type 2 diabetic rats

Mitragyna speciosa is a medicinal plant with a reputation for treating pains, diabetes as well as increasing energy and sexual desires. However, there is no scientific evidence to validate the antidiabetic effect of M. speciosa. This study investigated the antidiabetic effects of M. speciosa (Krat) ethanolic extract on fructose and streptozocin (STZ)-induced type 2 diabetic rats. In vitro antioxidant and antidiabetic effects were evaluated using DPPH, ABST, FRAP and α-glucosidase inhibitory assays. Rats with fructose/STZ induced T2D were treated with Krat (100 and 400 mg/kg) or metformin (200 mg/kg) for 5 weeks via oral gavage. Krat showed good antioxidant activity and also displayed potent α-glucosidase inhibitory activity. Administration of Krat to the diabetic rats significantly improved body weight gain, restored alterations in blood glucose level, glucose tolerance, dyslipidemia (increased cholesterol, triglycerides, low-density lipoprotein-cholesterol and reduced high-density lipoprotein), hepatorenal biomarkers alterations (alanine transaminase, aspartate transaminase, alanine phosphatase, creatinine and blood urea nitrogen) and oxidative stress indices (superoxide dismutase, glutathione and malondialdehyde)in the treated diabetic rats. Furthermore, Krat also restored pancreatic histological and increased immunohistochemical aberrations in the diabetic rats. These results for the first time demonstrated the antidiabetic and antihyperlipidemic potentials of M. speciosa, thus providing scientific reinforcement for the traditional use of the plant in the treatment of diabetes.

Ferulic acid improves glucose homeostasis by modulation of key diabetogenic activities and restoration of pancreatic architecture in diabetic rats

There are increasing concerns on the rising cases of diabetes mellitus with type 2 diabetes (T2D) being of major interest as well as the cost of its treatment. Plant phenolic compounds are natural and potent antioxidants that have been widely reported for their antidiabetic activities properties, one of which is ferulic acid. The effect of ferulic acid (FA) on major diabetogenic activities and pancreatic architecture linked to T2D was investigated in T2D rats. T2D was induced in male Sprague-Dawley rats using the fructose-streptozotocin model. Diabetic rats were treated with FA at 150 or 300 mg/kg bodyweight (bw). Normal control consisted of rats administered with food and water, while diabetic control consisted of untreated diabetic rats. Metformin was used as the standard drug. The rats were humanely sacrificed after 5 weeks of treatment. Their blood, liver, and pancreas were collected for analysis. Total glycogen content and carbohydrate metabolic enzymes activities were analyzed in the liver, while the pancreas and serum from blood were analyzed for oxidative stress biomarkers, purinergic and cholinergic enzyme activities, and amylase and lipase activities. The pancreatic tissue was further subjected to microscopic and histological examinations. FA caused a significant (p < 0.05) decrease in blood glucose level, with concomitant increase in serum insulin level. Treatment with FA also led to elevated levels of GSH, HDL-c, SOD, and catalase activities, while concomitantly suppressing malondialdehyde, cholesterol, triglyceride, LDL-c, NO, ALT, AST, creatinine, urea, and uric acid levels, acetylcholinesterase, ATPase, ENTPDase, 5'-nucleotidase, lipase, glycogen phosphorylase, glucose-6-phosphatase, and fructose-1,6-biphosphatase activities. Histology analysis revealed an intact pancreatic morphology in FA-treated diabetic rats. While transmission electron microscopy (TEM) analysis revealed an intact pancreatic ultrastructure and increased number of insulin granules in β-cells. Taken together, these results portray that the antidiabetic potentials of ferulic acid involves modulation of major diabetogenic activities and maintenance of the pancreatic ultrastructure architecture.

Dynamics of microbial populations and metabolites of fermenting saps throughout tapping process of ron and oil palm trees in Côte d'Ivoire

Palm wine fermentation is a complex microbial process that evolves with tapping times. The dynamics in microbiota and metabolites throughout palm wine tapping days is still not established, which are critical for the distinctive characteristics of palm wine taste and quality, and thus the mastery of the daily quality fluctuation during tapping. We analyzed the changes in microbial community structure by amplicon sequencing of bacterial 16S rRNA gene and fungal internal transcribed spacer (ITS) region, and metabolite profile changes using mass spectrometry in palm wine collected over 25-30 days tapping of ron (Borassus aethiopum) and oil palms (Elaeis guineensis) from Côte d'Ivoire. The stage-wise collected palm wine samples showed distinct changes in microbial diversity and pH, supporting microbial community dynamics during palm wine tapping. Results highlighted the dominance of Saccharomyces cerevisiae in early stages and the emergence of non-Saccharomyces yeasts, particularly Hanseniaspora spp. in the later stages of oil palm wine tapping, vice versa in the case of ron palm wine tapping, with a unique presence of Saccharomycodes in the later stages (15-30 days). Fructophilic lactic acid bacteria (FLAB), mainly Fructobacillus and Leuconostoc, encountered in both types of palm wine tapping showed a decline at later stages of oil palm wine tapping. In this type of palm wine, acetic acid bacteria with genera Acetobacter and Glucanoacetobacter, by surpassing Lactobacillus in the last stage become dominant, whereas Lactobacillus remained dominant in ron palm wine throughout tapping days. The decline in the relative abundance of gevotroline and essential amino acids during the later stages of palm wine tapping (15-25 days) supports the difference in the health benefits of the palm wine obtained from different days of tapping, indicating that early stages of tapping is more nutritional and healthy than the later stages. The microbial dynamics may be a potential indicator of metabolite changes during palm sap fermentation, thus contributing to establish particular features of palm wines in different stages of tapping. This understanding of microbial ecology and chemical composition changes during palm wine tapping can be used as biomarkers to assess palm wine's quality and help to design an optimum starter culture.

Micronized Dietary Okara Fiber: Characterization, Antioxidant, Antihyperglycemic, Antihyperlipidemic, and Pancreato-Protective Effects in High Fat Diet/Streptozotocin-Induced Diabetes Mellitus

Diabetes mellitus (DM) is a lifelong devastating and debilitating disease with serious chronic complications. Okara is a byproduct generated from soymilk or tofu production and it has been reported to have antioxidant and lipid-lowering effects. However, the antidiabetic effects and pancreatic β-cells' secretory functions of micronized okara fiber (MOF) have not been reported. Therefore, this study explored the antidiabetic effects and modulatory potentials of MOF on pancreatic β-cells' secretory functions in a high fat/high sugar/streptozotocin rat model of diabetes mellitus. Fiber-rich okara was prepared by removing fat and proteins from freshly obtained okara, followed by micronization. Fiber-rich okara was prepared, micronized, and characterized for hydrophobicity, thermal stability, structure-function relationship, and antioxidant potentials. We then established a rat model of DM and MOF and two doses (100 and 400 mg kg^-1) were administered to see its anti-DM effect. Four weeks of MOF supplementation significantly reduced blood glucose, increased serum insulin level, improved hepatorenal functions, glucose tolerance, and regenerated pancreatic β-cells in the treated DM rats. Furthermore, MOF significantly improved the pancreatic antioxidant defense system by significantly elevating glutathione peroxidase, catalase, and superoxide dismutase activities while depleting the malonaldehyde level in the pancreas of the treated diabetic rats. Our results indicated that MOF ameliorated DM by impeding hyperglycemia, hyperlipidemia, and oxidative stress and enhancing the secretory functions of the beta cells, suggesting that MOF might be used as a protective nutrient in DM.

LC/ESI/TOF-MS Characterization, Anxiolytic and Antidepressant-like Effects of Mitragyna speciosa Korth Extract in Diabetic Rats

In this study, the attenuative effects of the hydro-alcoholic extract from Mitragyna speciosa (MSE) against diabetes-induced anxiety and depression-like behaviors were examined. In addition, UPLC/ESI/TOF-MS analysis was performed to identify the phytochemical nature of MSE. DM was induced using a combination of high fructose/streptozotocin, and the diabetic rats were treated with MSE (50 and 200 mg/kg) for 5 weeks. After treatment, the animals were subjected to a forced swim test, open field test and elevated plus-maze tests. Additionally, proinflammatory cytokines and oxidative stress parameters were evaluated in the brain tissues of the rats. UPLC/ESI/TOF-MS analysis revealed that MSE is abundantly rich in polyphenolic constituents, notably flavonoid and phenolic glycosides. Behavioral tests and biochemical analyses indicated that diabetic rats showed significantly increased anxiety and depressive-like behavioral deficits, brain oxidative stress and pro-inflammatory cytokines levels (IL-1β, IL-6 and TNF-α). Treatment with MSE (50 and 200 mg/kg) significantly attenuated increased blood glucose level, depressive and anxiety-like behaviors in diabetic rats. Additionally, the antioxidant enzymes activities were markedly increased in MSE-treated animals, while TNF-α, IL-1β and IL-6 cytokines were notably suppressed. Taken together, these results suggested that MSE has potentials as antidepressant and anxiolytic-like effects and improves the brain oxido-inflammatory status in diabetic rats.

Anti-Inflammatory and Antinociceptive Effects of Boesenbergia rotunda Polyphenol Extract in Diabetic Peripheral Neuropathic Rats

Introduction

Methods

Results

Conclusion

Flavonoid constituents of Amomum tsao-ko Crevost et Lemarie and their antioxidant and antidiabetic effects in diabetic rats - in vitro and in vivo studies

Amomum tsao-ko Crevost et Lemarie (A. tsao-ko) is a well-known dietary spice and traditional Chinese medicine. This study aimed to identify the flavonoids in A. tsao-ko and evaluate their antioxidant and antidiabetic activities in in vitro and in vivo studies. A. tsao-ko methanol extracts possessed a high flavonoid content (1.21 mg QE per g DW) and a total of 29 flavonoids were identified by employing UPLC-MS/MS. In vitro, A. tsao-ko demonstrated antioxidant activity (ORAC value of 34276.57 μM TE/100 g DW, IC₅₀ of ABTS of 3.49 mg mL^-1 and FRAP value of 207.42 μM Fe²⁺ per g DW) and α-amylase and α-glucosidase inhibitory ability with IC₅₀ values of 14.23 and 1.76 mg mL^-1, respectively. In vivo, type 2 diabetes mellitus (T2DM) models were induced by a combined high-fat diet (HFD) and streptozotocin (STZ) injection in rats. Treatment with the A. tsao-ko extract (100 mg freeze-dried powder per kg bw) for 6 weeks could significantly improve impaired glucose tolerance, decrease the levels of fasting blood glucose (FBG), insulin, and malondialdehyde (MDA), and increase the superoxide dismutase (SOD) level. Histopathology revealed that the A. tsao-ko extract preserved the architecture and function of the pancreas. In conclusion, the flavonoid composition of A. tsao-ko exhibits excellent antioxidant and antidiabetic activity in vitro and in vivo. A. tsao-ko could be a novel natural material and developed as a related functional food and medicine in T2DM management.

Approaches to Decrease Hyperglycemia by Targeting Impaired Hepatic Glucose Homeostasis Using Medicinal Plants

Liver plays a pivotal role in maintaining blood glucose levels through complex processes which involve the disposal, storage, and endogenous production of this carbohydrate. Insulin is the hormone responsible for regulating hepatic glucose production and glucose storage as glycogen, thus abnormalities in its function lead to hyperglycemia in obese or diabetic patients because of higher production rates and lower capacity to store glucose. In this context, two different but complementary therapeutic approaches can be highlighted to avoid the hyperglycemia generated by the hepatic insulin resistance: 1) enhancing insulin function by inhibiting the protein tyrosine phosphatase 1B, one of the main enzymes that disrupt the insulin signal, and 2) direct regulation of key enzymes involved in hepatic glucose production and glycogen synthesis/breakdown. It is recognized that medicinal plants are a valuable source of molecules with special properties and a wide range of scaffolds that can improve hepatic glucose metabolism. Some molecules, especially phenolic compounds and terpenoids, exhibit a powerful inhibitory capacity on protein tyrosine phosphatase 1B and decrease the expression or activity of the key enzymes involved in the gluconeogenic pathway, such as phosphoenolpyruvate carboxykinase or glucose 6-phosphatase. This review shed light on the progress made in the past 7 years in medicinal plants capable of improving hepatic glucose homeostasis through the two proposed approaches. We suggest that Coreopsis tinctoria, Lithocarpus polystachyus, and Panax ginseng can be good candidates for developing herbal medicines or phytomedicines that target inhibition of hepatic glucose output as they can modulate the activity of PTP-1B, the expression of gluconeogenic enzymes, and the glycogen content.

GC-MS metabolomics reveals dysregulated lipid metabolic pathways and metabolites in diabetic testicular toxicity: Therapeutic potentials of raffia palm (Raphia hookeri G. Mann & H. Wendl) wine

ETHNOPHARMACOLOGICAL RELEVANCE

Raffia palm (Raphia hookeri G. Mann & H. Wendl) wine (RPW) is a natural beverage obtained from the R. hookeri consumed for refreshment and medicinal purposes. For medicinal purposes, it is used singly or as macerating agent for other medicinal plants for the treatment of several diseases.

AIM

This study investigates the effect of Raffia palm wine on dysregulated lipid metabolic pathways in testicular tissues of type 2 diabetic (T2D) rats.

METHODS

Raffia palm wine (150 and 300 mg/kg bodyweight) was administered to two T2D groups respectively, another T2D group was not administered treatment and served as negative control, while metformin served as the standard drug. After 6 weeks of treatment, the rats were sacrificed, and the testes collected. After weighing, the organs were homogenized in 20% methanol/ethanol and centrifuged at 20,000 g to extract the lipid metabolites.

RESULTS

GC-MS analysis of the supernatants revealed an alteration of the metabolites on induction of T2D, with concomitant generation of 10 metabolites. Raffia palm wine inhibited the T2D-generated metabolites while replenishing cholesterol and squalene levels, with concomitant generation of 7 and 8 metabolites for low and high dose treatment respectively. Pathway enrichment analysis of the metabolites revealed a decreased level of steroid biosynthesis and increased level of fatty acid biosynthesis. Raffia palm wine inactivated glycerolipid, fatty acid, and arachidonic acid metabolisms, fatty acid biosynthesis and fatty acid elongation in mitochondria pathways, and activated pathways for plasmalogen synthesis, mitochondrial beta-oxidation of long chain saturated fatty acids.

CONCLUSION

The replenishment and generation of these metabolites and additional ones as well as activation of pathways involved in energy generation, phospholipids, antioxidant activity, steroidogenesis and spermatogenesis suggest a therapeutic effect of Raffia palm wine against hyperglycemic-induced testicular dysfunction.

Vanillin modulates activities linked to dysmetabolism in psoas muscle of diabetic rats

Skeletal muscles are important in glucose metabolism and are affected in type 2 diabetes (T2D) and its complications. This study investigated the effect of vanillin on redox imbalance, cholinergic and purinergic dysfunction, and glucose-lipid dysmetabolism in muscles of rats with T2D. Male albino rats (Sprague-Dawley strain) were fed 10% fructose ad libitum for 2 weeks before intraperitoneally injecting them with 40 mg/kg streptozotocin to induce T2D. Low (150 mg/kg bodyweight (BW)) and high (300 mg/kg BW) doses of vanillin were orally administered to diabetic rats. Untreated diabetic rats and normal rats made up the diabetic control (DC) and normal control (NC) groups, respectively. The standard antidiabetic drug was metformin. The rats were humanely put to sleep after 5 weeks of treatment and their psoas muscles were harvested. There was suppression in the levels of glutathione, activities of SOD, catalase, ENTPDase, 5'Nucleotidase and glycogen levels on T2D induction. This was accompanied by concomitantly elevated levels of malondialdehyde, serum creatine kinase-MB, nitric oxide, acetylcholinesterase, ATPase, amylase, lipase, glucose-6-phosphatase (G6Pase), fructose-1,6-biphophastase (FBPase) and glycogen phosphorylase activities. T2D induction further resulted in the inactivation of fatty acid biosynthesis, glycerolipid metabolism, fatty acid elongation in mitochondria and fatty acid metabolism pathways. There were close to normal and significant reversals in these activities and levels, with concomitant reactivation of the deactivated pathways following treatment with vanillin, which compared favorably with the standard drug (metformin). Vanillin also significantly increased muscle glucose uptake ex vivo. The results suggest the therapeutic effect of vanillin against muscle dysmetabolism in T2D as portrayed by its ability to mitigate redox imbalance, inflammation, cholinergic and purinergic dysfunctions, while modulating glucose-lipid metabolic switch and maintaining muscle histology.

Vanillin exerts therapeutic effects against hyperglycemia-altered glucose metabolism and purinergic activities in testicular tissues of diabetic rats

Testicular dysfunctions leading to male infertility has been reported in type 2 diabetes (T2D), with glucose dysmetabolism, cholinergic and purinergic dysfunction being major contributors. In the present study, the effect of vanillin on glucose metabolism, purinergic and cholinergic dysfunctions were investigated in testicular tissues of T2D rats. Male Sprague-Dawley rats were divided into 6 groups containing 5 rats each. T2D was induced in rats by administering 10 % fructose ad libitum for 14 days followed by a single intraperitoneal injection (40 mg/kg body weight) of streptozotocin. T2D rats were orally administered with vanillin at 150 and 300 mg/kg body weight (bw). Diabetic control (DC) consisted of untreated diabetic rats, while normal control (NC) consisted of normal rats and they were administered with distilled water only. Metformin was used as the standard antidiabetic drug. After 5 weeks treatment, the rats were sacrificed, and the testes were harvested. Induction of T2D led to significantly depleted testicular levels of glutathione, glycogen content, superoxide dismutase and catalase enzyme activities, with concomitantly elevated levels of nitric oxide, malondialdehyde, acetylcholinesterase, glucose-6-phosphatase, fructose-1,6-biphophastase, glycogen phosphorylase, amylase and lipase activities. These activities and levels were significantly reversed to near normal in rats treated with both doses of vanillin as compared with metformin. These results, when taken together, suggest the therapeutic effect of vanillin against hyperglycemia-mediated metabolic dysfunctions in testes of T2D rats. This is depicted by the ability of the phenolic to attenuate oxidative imbalance, purinergic and cholinergic dysfunctions, while suppressing glucose dysmetabolism.

Ferulic acid promotes muscle glucose uptake and modulate dysregulated redox balance and metabolic pathways in ferric-induced pancreatic oxidative injury

The antidiabetic properties of ferulic acid and its protective role against Fe²⁺ -induced oxidative pancreatic injury were investigated in this study using in vitro and ex vivo models. Induction of oxidative injury in the pancreas was achieved by incubating normal pancreatic tissue with 0.1 mM FeSO₄ and treated by co-incubating with different concentrations of ferulic acid for 30 min at 37°C. Ferulic acid inhibited the activities of α-glucosidase, α-amylase, and pancreatic lipase significantly (p < .05) and promoted glucose uptake in isolated rat psoas muscles. Induction of oxidative pancreatic injury caused significant (p < .05) depletion of glutathione (GSH) level, superoxide dismutase (SOD), and catalase activities, as well as elevation of malondialdehyde (MDA) and nitric oxide (NO) levels, acetylcholinesterase and chymotrypsin activities. Treatment of tissues with ferulic acid significantly (p < .05) reversed these levels and activities. LC-MS analysis of the extracted metabolites revealed 25% depletion of the normal metabolites with concomitant generation of m-Chlorohippuric acid, triglyceride, fructose 1,6-bisphosphate, and ganglioside GM1 in oxidative-injured pancreatic tissues. Treatment with ferulic acid restored uridine diphosphate glucuronic acid and adenosine tetraphosphate and generated P1,P4-Bis(5'-uridyl) tetraphosphate and L-Homocysteic acid, while totally inactivating oxidative-generated metabolites. Ferulic acid also inactivated oxidative-activated pathways, with concomitant reactivation of nucleotide sugars metabolism, starch and sucrose metabolism, and rostenedione metabolism, estrone metabolism, androgen and estrogen metabolism, porphyrin metabolism, and purine metabolism pathways. Taken together, our results indicate the antidiabetic and protective potential of ferulic acid as depicted by its ability to facilitate muscle glucose uptake, inhibit carbohydrate and lipid hydrolyzing enzymes, and modulate oxidative-mediated dysregulated metabolisms. PRACTICAL APPLICATIONS: There have been increasing concerns on the side effects associated with the use of synthetic antidiabetic drug, coupled with their expenses particularly in developing countries. This has necessitated continuous search for alternative treatments especially from natural products having less or no side effects and are readily available. Ferulic acid is among the common phenolics commonly found in fruits and vegetables. In this present study, ferulic acid was able to attenuate oxidative stress, cholinergic dysfunction, and proteolysis in oxidative pancreatic injury, as well as inhibit carbohydrate digesting enzymes. Thus, indicating the ability of the phenolic to protect against complications linked to diabetes. Crops rich in ferulic acid maybe beneficial in managing this disease.

Optimization of extraction flavonoids from Exocarpium Citri Grandis and evaluation its hypoglycemic and hypolipidemic activities

ETHNOPHARMACOLOGICAL RELEVANCE

Exocarpium Citri Grandis (ECG; Huajuhong in Chinese) is a precious traditional Chinese medicine with a history of hundreds of years in China. It has been demonstrated to possess numerous pharmacological properties, including antitussive, expectorant, anti-inflammatory, hypoglycemic, and hypolipidemic. However, no in-depth report exists on the hypoglycemic and hypolipidemic properties of ECG.

AIM OF THE STUDY

This study aimed to evaluate the hypoglycemic and hypolipidemic properties of ECG flavonoids extract in vitro and in vivo so as to lay the foundation for further researches in this field.

MATERIALS AND METHODS

Total flavonoids (TF) and naringin were separately extracted from ECG, and the components of TF were identified by HPLC-MS. The antioxidant capacities of TF and naringin were determined by 2,2,1-diphenyl-1-picrylhydrazyl (DPPH)-free radical scavenging tests, and digestive enzymes activity inhibition assays in vitro in order to evaluate their hypoglycemic properties. Furthermore, diabetic mice experiments were performed to assess the hypoglycemic and hypolipidemic properties of TF and naringin in vivo.

RESULTS

Five compounds were identified from TF, including naringin, rhoifolin, poncirin, bergaptol, and naringenin. The half maximal inhibitory concentration (IC₅₀) of TF and naringin to DPPH-free radicals were 0.269 and 1.946 mg/mL, respectively. TF and naringin demonstrated a certain inhibitory effect on α-glucosidase and a weaker inhibitory effect on α-amylase. The results of animal experiments showed that TF and naringin had no significant effect on the blood glucose levels, but they could lead to significant (p < 0.05 or p < 0.01) increase in the serum insulin level and high-density lipoprotein cholesterol (HDL-C) levels with concomitant reduction in the total cholesterol (TC), total triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) levels in diabetic mice. In addition, TF and naringin could reduce the liver index of diabetic mice (p < 0.01) and reduce the kidney index at low doses (p < 0.05).

CONCLUSIONS

Our study revealed that the hypoglycemic and hypolipidemic activities of TF is mainly derived from naringin, and other active ingredients in TF also have the effects of alleviating oxidative stress, inhibiting digestive enzyme activity and reducing blood lipids. Our results thus provide a scientific basis for the application of ECG in antidiabetic treatment.

Hyperglycemia alters lipid metabolism and ultrastructural morphology of cerebellum in brains of diabetic rats: Therapeutic potential of raffia palm (Raphia hookeri G. Mann & H. Wendl) wine

The present study investigated the effect of raffia palm (Raphia hookeri) wine (RPW) on hyperglycemia-mediated lipid metabolites and pathways, functional chemistry and ultrastructural morphology of cerebellums in type 2 diabetes (T2D). T2D was induced in male Sprague-Dawley rats by feeding with 10% fructose ad libitum for 2 weeks before injecting intraperitoneally with 40 mg/kg bodyweight (bw) streptozotocin. Following confirmation of hyperglycemia at blood glucose >200 mg/dL, diabetic rats were treated with RPW at 150 and 300 mg/kg bw respectively. Metformin served as the standard drug. Negative and normal controls consisted of untreated diabetic and non-diabetic rats, respectively. After 5 weeks of treatment, the rats were humanely sacrificed, and their cerebellum excised from the harvested brains. GC-MS analysis revealed significant alterations in cerebellar lipid metabolites depicted by changes in unsaturated and saturated fatty acids, fatty - esters, alcohols, and amides, glycols and steroids on induction of T2D. Pathway enrichment analysis of the lipid metabolites revealed inactivation of arachidonic metabolic pathway following T2D induction. Treatment with both doses of RPW restored most of the metabolites, while reactivating arachidonic acid metabolism (high dose only). Low dose of RPW led to the activation of retinol metabolism. Both doses of RPW maintained cerebellar functional chemistry as revealed by FTIR analysis. TEM analysis revealed swollen mitochondria, depleted numbers of synaptic vesicles, and shrunk synaptic clefts following induction of T2D. These ultrastructural morphologies were improved in RPW-treated rats. These results portray the therapeutic potential of raffia palm wine in the management of neurodegenerative complications in T2D.

Cola Nitida (Kola Nuts) Attenuates Hepatic Injury in Type 2 Diabetes by Improving Antioxidant and Cholinergic Dysfunctions and Dysregulated Lipid Metabolism

BACKGROUND

The therapeutic effect of Cola nitida hot infusion against diabetes hepatic injury was investigated in livers of diabetic rats. Cola nitida was infused in boiling water and concentrated.

METHODS

The concentrated infusion was administered to T2D rats at low and high doses (150 and 300 mg/kg body weight (bw), respectively). The normal group (positive control) and another diabetic group (negative control) were administered distilled water, while metformin served as the standard drug. A toxic group that consists of normal rats administered a high dose of C. nitida. After 6 weeks, the rats were sacrificed, and their livers were collected. They were assayed for oxidative stress markers, myeloperoxidase, acetylcholinesterase and ATPase activities. Hepatic lipid metabolites were profiled with GC-MS and their metabolic pathways were analyzed using the MetaboAnalyst 4.0 online server.

RESULTS

Treatment with C. nitida caused a significant elevation of glutathione level and SOD activity, while concomitantly inhibiting lipid peroxidation, myeloperoxidase, acetylcholinesterase and ATPase activities in hepatic tissues of the rats. Treatment with C. nitida also caused significant depletion of diabetes-generated lipid metabolites, with concomitant generation of fatty esters and steroids as well as inactivation of diabetes-activated pathways.

CONCLUSION

These data demonstrate the therapeutic effect of C. nitida against diabetic hepatotoxicity in diabetic rats.

Dacryodes edulis (G. Don) H.J. Lam modulates glucose metabolism, cholinergic activities and Nrf2 expression, while suppressing oxidative stress and dyslipidemia in diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Dacryodes edulis L. is an evergreen tree indigenous to western and eastern Africa which is utilized for nutritional and medicinal purposes. Folklorically, different parts of the tree are used in treating and managing diabetes and its complications.

AIMS

The antidiabetic effect of the butanol fraction of D. edulis ethanol extract (BFDE) was studied in fructose-streptozotocin induced type 2 diabetic rats.

METHODS

The ethanol extract was fractionated to yield the hexane, dichloromethane, ethyl acetate, butanol and aqueous fractions. The in vitro antidiabetic activities of the fractions were determined by their ability to inhibit α-glucosidase activity. BDFE was the most active and showed no cytotoxic effect while stimulating glucose uptake in 3T3-L1 adipocytes. Thus, selected for in vivo study. Diabetic rats were grouped into 4. The negative control group was administered water only, another group was treated with metformin (200 mg/kg bodyweight), while the other groups were administered BDFE at 150 and 300 mg/kg bodyweight respectively. Two other groups consisting of normal rats were given water and BFDE (300 mg/kg bodyweight) respectively, with the former serving as normal control. After 6 weeks of intervention, the rats were humanely sacrificed using appropriate anaesthesia.

RESULTS

Treatment with the fraction significantly (p < 0.05) reduced the blood glucose level of the diabetic rats, with concomitant increase in serum insulin secretion. It also caused significant (p < 0.05) elevation of reduced glutathione level, superoxide dismutase, catalase, α-amylase, and ATPase activities, with concomitant depletion in myeloperoxidase activity, NO and MDA levels of the serum and pancreas. The pancreatic morphology and β-cell function were significantly improved in BFDE-treated rats, with restoration of the pancreatic capillary networks. Treatment with BFDE significantly (p < 0.05) inhibited the activities of glycogen phosphorylase, fructose 1,6 biphosphatase, glucose 6 phosphatase, and acetylcholinesterase, while suppressing the expression of Nrf2. HPLC analysis revealed the presence of gallic acid, vanillic acid, vanillin, and (-)-epicatechin in the fraction.

CONCLUSION

These results portray the antidiabetic and antioxidative properties of BFDE, which may be a synergistic consequence of the identified phenolics.

Fructose Feeding and Hyperuricemia: a Systematic Review and Meta-Analysis

High fructose feeding has been suggested to involve in several features of metabolic syndrome including hyperuricemia (HP). We designed and implemented a study to determine the effect size of fructose intake and the relative risk of HP based on the type of fructose feeding (diet or solution), duration of treatment (2–6, 7–10, and > 10 weeks), and animal race. The required information was accepted from international databases, including PubMed/MEDLINE, Science Direct, Scopus, and etc., from 2009 until 2019 on the basis of predetermined eligibility criteria. The data selection and extraction and quality assessment were performed independently by two researchers. Results were pooled as random effects weighting and reported as standardized mean differences with 95% confidence intervals. Thirty-five studies including 244 rats with fructose consumption were included in the final analysis. The heterogeneity rate of parameters was high (I2 = 81.3%, p < 0.001) and estimated based on; 1) type of fructose feeding (diet; I2 = 79.3%, solution 10%; I2 = 83.4%, solution 20%; I2 = 81.3%), 2) duration of treatment (2–6 weeks; I2 = 86.8%, 7–10 weeks; I2 = 76.3%, and > 10 weeks; I2 = 82.8%), 3) the animal race (Wistar; I2 = 78.6%, Sprague-Dawley; I2 = 83.9%). Overall, the pooled estimate for the all parameters was significant (p < 0.001). The results of this study indicated that a significant relationship between HP and fructose intake regardless of the treatment duration, animal race, fructose concentration and route of consumption.

Microbial Diversity and Metabolite Profiles of Palm Wine Produced From Three Different Palm Tree Species in Côte d'Ivoire

Palm wine, the most commonly consumed traditional alcoholic beverage in Western Africa, harbours a complex microbiota and metabolites, which plays a crucial role in the overall quality and value of the product. In the present study, a combined metagenomic and metabolomic approach was applied to describe the microbial community structure and metabolites profile of fermented saps from three palm species (Elaeis guineensis, Raphia hookeri, Borassus aethiopum) in Côte d'Ivoire. Lactobacillaceae (47%), Leuconostocaceae (16%) and Acetobacteriaceae (28%) were the most abundant bacteria and Saccharomyces cerevisiae (87%) the predominant yeasts in these beverages. The microbial community structure of Raphia wine was distinctly different from the others. Multivariate analysis based on the metabolites profile clearly separated the three palm wine types. The main differentiating metabolites were putatively identified as gevotroline hydrochloride, sesartemin and methylisocitrate in Elaeis wine; derivative of homoserine, mitoxantrone in Raphia wine; pyrimidine nucleotide sugars (UDP-D-galacturonate) and myo-Inositol derivatives in Borassus wine. The enriched presence of gevotroline (an antipsychotic agent) and mitoxantrone (an anticancer drug) in palm wine supports its therapeutic potential. This work provides a valuable insight into the microbiology and biochemistry of palm wines and a rationale for selecting functional microorganisms for potential biotechnology applications.

Type 2 diabetes induced oxidative brain injury involves altered cerebellar neuronal integrity and elemental distribution, and exacerbated Nrf2 expression: therapeutic potential of raffia palm (Raphia hookeri) wine

Neurodegenerative diseases, such as Alzheimer's disease have been recognized as one of the microvascular complications of type 2 diabetes (T2D). In this study, the effect of T2D on neuronal integrity and elemental distribution in the cerebellar cortex, as well as the therapeutic effect of Raffia Palm (Raphia hookeri) wine (RPW) were investigated in male albino rats. T2D was induced in 4 groups of rats using fructose and streptozotocin. One group served as negative control which was administered water, the second and third group were administered 150 and 300 mg/kg bodyweight of RPW, while the fourth was administered metformin (200 mg/kg bodyweight). Two other groups of normal rats were administered distilled water (control) and of RPW (300 mg/kg bodyweight). The rats were sacrificed after 5 weeks of treatment, and brains were collected. The cerebellum was removed, and several parts analyzed by immunochemistry, histology and scanning electron microscopy (SEM). Remaining brain tissues were used to analyze for the oxidative stress biomarkers and acetylcholinesterase activity. These analyses revealed oxidative damage with concomitantly increased acetylcholinesterase activity and upregulation of Nrf2 expression in the diabetic brain cerebellar cortexes. Histological and microscopic analysis also revealed altered distribution of neurons and axonal nodes with concomitant elevated levels of several heavy metals. Treatment with RPW significantly elevated glutathione (GSH) level, superoxide dismutase (SOD) and catalase activities, as well as depleted acetylcholinesterase and malondialdehyde (MDA) level and concomitantly inhibited Nrf2 expression. It also improved neuronal integrity and reduced the levels of heavy metals in brain. Taken together, the results of this study suggest that the RPW may afford a novel neuroprotective potential against diabetic neurodegeneration.