Antihyperglycemic and antihyperlipidemic effects of fruit extract of Hodgsonia heteroclita (Roxb.) Hook. f. & Thomson in diabetic mice

ETHNOPHARMACOLOGICAL RELEVANCE

Hodgsonia heteroclita has been known as an important traditionally consumed medicinal plant of North-East India known to have antidiabetic properties. This study aims to investigate the effects of the ethanolic fruit extract of Hodgsonia heteroclita against hyperglycemia and hyperlipidemia by using streptozotocin (STZ) treated diabetic mice.

MATERIALS AND METHODS

The fruits of H. heteroclita were collected from the various parts of Kokrajhar district, Assam India (Geographic coordinates: 26°24'3.85″ N 90°16'22.30″ E). Basic morphological evaluations were carried out by the Botanical Survey of India, Eastern circle, Shillong, who also certified and identified the plant. Hexane, chloroform, and ethanolic extracts of the fruit of H. heteroclita were investigated for α-amylase inhibition assay as a rapid screening tool for examining anti-diabetic activity. The efficacy of ethanolic extract at a dose of 100, 200, and 300 mg/kg body weight was tested for 21 days in STZ-induced diabetic mice. The body weight, fasting plasma glucose and serum lipids, and hepatic glycogen levels were measured in experimental animals to examine the antihyperglycemic and antihyperlipidemic efficacy of the extract. Both HPTLC and LC-MS analysis was performed to examine the phyotochemicals present in the ethanolic extract of H. heteroclita.

RESULTS

It has been observed that treatment with the ethanolic extract dose-dependently reduced the plasma glucose levels, total cholesterol, low density lipoprotein-cholesterol, very low-density lipoprotein-cholesterol, triglyceride, and increased the body weight, liver glycogens and high-density lipoprotein-cholesterol in STZ treated diabetic mice. HPTLC demonstrated the presence of triterpene compounds and LC-MS analysis revealed the presence Cucurbitacin I, Cucurbitacin E, and Kuguacin G as the triterpene phytoconstituents.

CONCLUSION

The present study demonstrated that ethanolic fruit extract of H. heteroclita improved both glycemic and lipid parameters in mice model of diabetes.

Elucidation of anti-hyperglycemic activity of Psidium guajava L. leaves extract on streptozotocin induced neonatal diabetic Long-Evans rats

BACKGROUND

Psidium guajava L (Guava) belongs to the Myrtaceae family and has been claimed to possess several pharmacological properties including antidiabetic.

OBJECTIVE

This study was designed to evaluate the anti-hyperglycemic activity of P guajava L leaves aqueous extract on neonatal streptozotocin-induced type 2 diabetic model rats.

METHODS

Streptozotocin was induced (90 mg/kg) intraperitoneally to 48 h old Long Evans rat pups. After three months, 18 male type-2 diabetic model rats were confirmed by OGTT (FG > 7 mmol/L). Therefore, experimental rats were divided into three groups 2) Diabetic water control (10 ml/kg), 3) Gliclazide treated (20 mg/kg), and 4) Extract treated group (1.25g/kg)] Six normal female rats comprised group 1 [Non-diabetic water control (10 ml/kg)]. All rats were treated orally with their respective treatment for 28 consecutive days. Blood samples were collected on 0 days (by tail cut method) and the end day (by cardiac puncture) of the experiment. The anti-hyperglycemic activity was evaluated by measuring fasting glucose, serum insulin, lipid profile, hepatic glycogen content, and intestinal glucose absorption by standard methods.

RESULTS

The serum glucose level of extract treated group was decreased by 16% as well as significantly (p<0.05) increased the serum insulin level (M±SD, 0 day vs 28thday; 0.319 ± 0.110 vs 0.600 ± 0.348, μg/L). Moreover, the extract-treated group also significantly (p<0.05) enhanced liver glycogen content and inhibited glucose absorption from the upper intestine. Besides, a significant (p < 0.05) reduction of LDL-cholesterol level was found in the extract-treated group (M±SD, 55 ± 33 vs 14 ± 9, mg/dl) compared with baseline values where other groups did not show any statistically remarkable changes.

CONCLUSION

Current study concludes that P guajava leaves aqueous extract enhances insulin secretion from pancreatic beta-cells and promotes glycogen synthesis in the liver. The extract also inhibits glucose absorption from the upper intestine and improves dyslipidemia to some extent. Therefore, possesses the potential for drug development against T2DM.

Structurally diverse polycyclic polyprenylated acylphloroglucinols with protective effect on human vein endothelial cells injured by high-glucose from Hypericum acmosepalum N. Robson

Hyperacmotone A, a polycyclic polyprenylated acylphloroglucinol (PPAP) with an unprecedented skeleton, along with five undescribed congeners and eleven reported ones, was isolated from Hypericum acmosepalum. Hyperacmotone A possesses a unique monocyclic ring skeleton based on a cyclopent-4-ene-1,3-dione acylphloroglucinol core. Their structures were elucidated by extensive analysis of HRESIMS, NMR, biogenetic pathway, and quantum-chemical calculations. In addition, hypercohone G exhibited significant protective effects on high-glucose-injured HUVECs.

Preparation, structure characterization, and specific gut microbiota properties related to anti-hyperlipidemic action of type 3 resistant starch from Canna edulis

Type 3 resistant starch (RS3) was developed from Canna edulis (Ce) native starch (NS) through dual enzymatic hydrolysis and recrystallization. Thereafter, the processed Ce-RS3 was subjected to systematic characterizations for its structural properties, anti-hyperlipidemic effect, and in vivo gut microbiota modulatory function. The Ce-RS3 content was increased to 49.11% after processing under optimal conditions. Compared with NS, Ce-RS3 maintained its B-type crystallization without introducing new chemical groups. Meanwhile, it displayed coarse surfaces, higher crystallinity, more ordered structures, and a higher proportion of chains with degree of polymerization (DP) 37-100. Ce-RS3 intervention significantly alleviated dyslipidemia in hyperlipidemic mice, which was associated with increased gut microbial diversity and unique microbial enrichment, potentially mediated by its fine structure. These observations are valuable for developing RS3 from C. edulis for prebiotics applications and support the potential strategy that utilizes well-designed RS to modulate specific bacterial populations to improve health.

Pharmacological properties and underlying mechanisms of curcumin and prospects in medicinal potential

Curcumin, isolated from Curcuma longa L., is a fat-soluble natural compound that can be obtained from ginger plant tuber roots, which accumulative evidences have demonstrated that it can resist viral and microbial infection and has anti-tumor, reduction of blood lipid and blood glucose, antioxidant and removal of free radicals, and is active against numerous disorders various chronic diseases including cardiovascular, pulmonary, neurological and autoimmune diseases. In this article is highlighted the recent evidence of curcuminoids applied in sevral aspects of medical problem particular in COVID-19 pandemics. We have searched several literature databases including MEDLINE (PubMed), EMBASE, the Web of Science, Cochrane Library, Google Scholar, and the ClinicalTrials.gov website via using curcumin and medicinal properties as a keyword. All studies published from the time when the database was established to May 2021 was retrieved. This review article summarizes the growing confirmation for the mechanisms related to curcumin's physiological and pharmacological effects with related target proteins interaction via molecular docking. The purpose is to provide deeper insight and understandings of curcumin's medicinal value in the discovery and development of new drugs. Curcumin could be used in the prevention or therapy of cardiovascular disease, respiratory diseases, cancer, neurodegeneration, infection, and inflammation based on cellular biochemical, physiological regulation, infection suppression and immunomodulation.

Flowers of Clerodendrum volubile modulates redox homeostasis and suppresses DNA fragmentation in Fe2+ - induced oxidative hepatic and pancreatic injuries; and inhibits carbohydrate catabolic enzymes linked to type 2 diabetes

INTRODUCTION

Medicinal plants have long been recognized for their roles in the treatment and management of diabetes and its complications. The antioxidative and antidiabetic properties of Clerodendrum volubile flowers were investigated in vitro and ex vivo.

METHODS

The flowers were sequentially extracted with solvents of increasing polarity (n-hexane, ethyl acetate, ethanol and water). The concentrated extracts were subjected to in vitro antioxidant assays using the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) scavenging and Ferric reducing antioxidant power (FRAP) protocols. Their inhibitory activities were investigated on α-glucosidase, pancreatic lipases, pancreatic ATPase and glucose-6-phosphatase activities. Their anti-oxidative and anti-apoptotic effects on Fe2+-induced oxidative injuries were also investigated in pancreatic and hepatic tissues ex vivo.

RESULTS

The extracts showed potent free radical scavenging activity and significantly (p < 0.05) inhibited all studied enzymes. The GSH level was significantly (p < 0.05) elevated in both tissues with concomitant increase in superoxide dismutase (SOD) and catalase activities as well as reduced levels of malondialdehyde (MDA). The extracts significantly (p < 0.05) suppressed DNA fragmentation in hepatic tissue. These activities were dose-dependent. The ethanol extract showed the best activity and can be attributed to the synergetic effect of its chemical constituents identified via gas chromatography-mass spectroscopy (GC-MS).

CONCLUSION

These results suggest the antioxidative, antidiabetic and anti-obesogenic potentials of C. volubile flowers.

Identification of baicalin from Bofutsushosan and Daisaikoto as a potent inducer of glucose uptake and modulator of insulin signaling-associated pathways

Type 2 diabetes mellitus (T2DM) is a chronic disease characterized by hyperglycemia that can lead to long-term complications including heart diseases, stroke, retinopathy, and renal failure. Treatment strategies include stimulating glucose uptake and controlling blood glucose level. Bofutsushosan (BOF) and Daisaikoto (DAI) are two herb-based kampo medicines that have been demonstrated to improve metabolism-associated disorders including obesity, hyperlipidemia, and nonalcoholic fatty liver. Given their bioactivities against metabolic syndromes, we explored in this study the effect of BOF and DAI extracts on glucose absorption and used them as source to identify phytochemical stimulator of glucose absorption. Glucose uptake and mechanistic studies were evaluated in differentiated C2C12 skeletal muscle cells, and HPLC analysis was used to determine the molecular bioactive constituents. Our results indicated that the ethanolic extracts of BOF and DAI (BOFEE and DAIEE, respectively) enhanced the glucose uptake ratio in the differentiated C2C12 cells, and further analysis identified the flavone baicalin as a major constituent capable of efficiently stimulating glucose absorption. Mechanistic studies revealed that the effect from baicalin involved the activation of IRS-1 and GLUT-4, and implicated the AMPK, PI3K/Akt, and MAPK/ERK signaling cascades. Due to its potency, we suggest that baicalin merit further evaluation as a potential candidate anti-hyperglycemic agent for the treatment and management of T2DM.

In vitro, in vivo and in silico anti-hyperglycemic inhibition by sinigrin

OBJECTIVE

To evaluate the anti-hyperglycemic potential of sinigrin using in vitro, in silico and in vivo streptozotocin (STZ) induced hyperglycemic zebrafish model.

METHODS

The in vitro enzyme inhibition assay was carried out to determine the IC₅₀ value against α-glucosidase and α-amylase, in silico molecular docking was performed against both enzymes with PyRx tool and simulations were performed using GROMACS tool. Hyperglycemia was induced in zebrafishes using three intraperitoneal injections on alternating days for 1 week at 350 mg/kg of STZ. Hyperglycemic fishes were treated intraperitoneally with 50, 100 and 150 mg of sinigrin/kg of body weight for 24 h and glucose levels were measured.

RESULTS

The sinigrin showed very strong inhibition against α-glucosidase and α-amylase with 0.248 and 0.00124 μM while reference drug acarbose showed IC₅₀ value of 73.0700 and 0.0017 μM against α-glucosidase and α-amylase, respectively. Kinetic analysis revealed that sinigrin has the mixed type mode of inhibition against α-glucosidase. Molecular docking results revealed its strong binding affinity with α-glucosidase (-10.00 kcal/mol) and α-amylase (-8.10 kcal/mol). Simulations graphs confirmed its stability against both enzymes. Furthermore, in hyperglycemic zebrafishes most significant (P < 0.001) reduction of glucose was occurred at 150 mg/kg, moderate significant reduction of glucose was observed at 100 mg/kg and no any significant reduction of glucose was measured at 50 mg/kg.

CONCLUSIONS

It can be evident from the present results that sinigrin has potent anti-hyperglycemic activity and it may prove to be effective treatment for the hyperglycemia.

Phenolic constituents and modulatory effects of Raffia palm leaf (Raphia hookeri) extract on carbohydrate hydrolyzing enzymes linked to type-2 diabetes

This study sought to investigate the effects of Raffia palm (Raphia hookeri) leaf extract on enzymes linked to type-2 diabetes mellitus (T2DM) and pro-oxidant induced oxidative stress in rat pancreas. The extract was prepared and its α-amylase and α-glucosidase inhibitory effects were determined. Radical [2,2-diphenyl-1-picrylhydrazyl (DPPH)] scavenging and Fe²⁺-chelating abilities, and inhibition of Fe²⁺-induced lipid peroxidation in rat pancreas homogenate were assessed. Furthermore, total phenol and flavonoid contents, reducing property, and high performance liquid chromatography diode array detector (HPLC-DAD) fingerprint of the extract were also determined. Our results revealed that the extract inhibited α-amylase (IC₅₀ = 110.4 μg/mL) and α-glucosidase (IC₅₀ = 99.96 μg/mL) activities in concentration dependent manners which were lower to the effect of acarbose (amylase: IC₅₀ = 18.30 μg/mL; glucosidase: IC₅₀ = 20.31 μg/mL). The extract also scavenged DPPH radical, chelated Fe²⁺ and inhibited Fe²⁺-induced lipid peroxidation in rat pancreas all in concentration dependent manners with IC₅₀ values of 402.9 μg/mL, 108.9 μg/mL and 367.0 μg/mL respectively. The total phenol and flavonoid contents were 39.73 mg GAE/g and 21.88 mg QAE/g respectively, while the reducing property was 25.62 mg AAE/g. The HPLC analysis revealed the presence of chlorogenic acid (4.17 mg/g) and rutin (5.11 mg/g) as the major phenolic compounds in the extract. Therefore, the ability of the extract to inhibit carbohydrate hydrolyzing enzymes and protect against pancreatic oxidative damage may be an important mechanisms supporting its antidiabetic properties and could make Raffia palm leaf useful in complementary/alternative therapy for management of T2DM. However, further studies such as in vivo should be carried out.

Evaluation of fish oil-rich in MUFAs for anti-diabetic and anti-inflammation potential in experimental type 2 diabetic rats

The advantages of monounsaturated fatty acids (MUFAs) on insulin resistance and type 2 diabetes mellitus (T2DM) have been well established. However, the molecular mechanisms of the anti-diabetic action of MUFAs remain unclear. This study examined the anti-hyperglycemic effect and explored the molecular mechanisms involved in the actions of fish oil- rich in MUFAs that had been acquired from hybrid catfish (Pangasius larnaudii×Pangasianodon hypophthalmus) among experimental type 2 diabetic rats. Diabetic rats that were fed with fish oil (500 and 1,000 mg/kg BW) for 12 weeks significantly reduced the fasting plasma glucose levels without increasing the plasma insulin levels. The diminishing levels of plasma lipids and the muscle triglyceride accumulation as well as the plasma leptin levels were identified in T2DM rats, which had been administrated with fish oil. Notably, the plasma adiponectin levels increased among these rats. The fish oil supplementation also improved glucose tolerance, insulin sensitivity and pancreatic histological changes. Moreover, the supplementation of fish oil improved insulin signaling (p-Akt^Ser473 and p-PKC-ζ/λ^Thr410/403), p-AMPK^Thr172 and membrane GLUT4 protein expressions, whereas the protein expressions of pro-inflammatory cytokines (TNF-α and nuclear NF-κB) as well as p-PKC-θ^Thr538 were down regulated in the skeletal muscle. These data indicate that the effects of fish oil-rich in MUFAs in these T2DM rats were partly due to the attenuation of insulin resistance and an improvement in the adipokine imbalance. The mechanisms of the anti-hyperglycemic effect are involved in the improvement of insulin signaling, AMPK activation, GLUT4 translocation and suppression of pro-inflammatory cytokine protein expressions.

Clerodane Diterpenoids with Anti-hyperglycemic Activity from Tinospora crispa

Four new clerodane diterpenoids, tinosporols A-C (2-4) and tinosporoside A (5), together with six known analogues were isolated from the vines of Tinospora crispa. Their structures were established by extensive spectroscopic analysis. The relative configuration at C-12 in the known diterpenoid borapetoside E (1), the major component of the plant, was firstly established with the aid of molecular model. Compound 1 significantly reduced serum glucose levels at dose-dependent manners in alloxan-induced hyperglycemic mice and db/db type 2 diabetic mice.

In vitro and in vivo reduction of post-prandial blood glucose levels by ethyl alcohol and water Zingiber mioga extracts through the inhibition of carbohydrate hydrolyzing enzymes

Background

Type 2 diabetes is a serious problem for developed and developing countries. Prevention of prediabetes progression to type 2 diabetes with the use of natural products appears to be a cost-effective solution. Zingiber mioga has been used as a traditional food in Asia. Recent research has reported the potential health benefits of Zingiber mioga, but the blood glucose reducing effect has not been yet evaluated.

Methods

In this study Zingiber mioga extracts (water and ethanol) were investigated for their anti-hyperglycemic and antioxidant potential using both in vitro and animal models. The in vitro study evaluated the total phenolic content, the oxygen radical absorbance capacity (ORAC) and the inhibitory effect against carbohydrate hydrolyzing enzymes (porcine pancreatic α-amylase and rat intestinal sucrase and maltase) of both Zingiber mioga extracts. Also, the extracts were evaluated for their in vivo post-prandial blood glucose reducing effect using SD rat and db/db mice models.

Results

Our findings suggest that the ethanol extract of Zingiber mioga (ZME) exhibited the higher sucrase and maltase inhibitory activity (IC₅₀, 3.50 and 3.13 mg/mL) and moderate α-amylase inhibitory activity (IC50, >10 mg/mL). Additionally, ZME exhibited potent peroxyl radical scavenging linked antioxidant activity (0.53/TE 1 μM). The in vivo study using SD rat and db/db mice models also showed that ZME reduces postprandial increases of blood glucose level after an oral administration of sucrose by possibly acting as an intestinal α-glucosidase inhibitor (ZME 0.1 g/kg 55.61 ± 13.24 mg/dL)

Conclusion

The results indicate that Zingiber mioga extracts exhibited significant in vitro α-glucosidase inhibition and antioxidant activity. Additionally, the tested extracts demonstrated in vivo anti-hyperglycemic effects using SD rat and db/db mice models. Our findings provide a strong rationale for the further evaluation of Zingiber mioga for the potential to contribute as a useful dietary strategy to manage postprandial hyperglycemia.