Extract of Ocimum canum lowers blood glucose and facilitates insulin release by isolated pancreatic beta-islet cells

Natural Products in Renal-Associated Drug Discovery

The global increase in the incidence of kidney failure constitutes a major public health problem. Kidney disease is classified into acute and chronic: acute kidney injury (AKI) is associated with an abrupt decline in kidney function and chronic kidney disease (CKD) with chronic renal failure for more than three months. Although both kidney syndromes are multifactorial, inflammation and oxidative stress play major roles in the diversity of processes leading to these kidney malfunctions. Here, we reviewed various publications on medicinal plants with antioxidant and anti-inflammatory properties with the potential to treat and manage kidney-associated diseases in rodent models. Additionally, we conducted a meta-analysis to identify gene signatures and associated biological processes perturbed in human and mouse cells treated with antioxidants such as epigallocatechin gallate (EGCG), the active ingredient in green tea, and the mushroom Ganoderma lucidum (GL) and in kidney disease rodent models. We identified EGCG- and GL-regulated gene signatures linked to metabolism; inflammation (NRG1, E2F1, NFKB1 and JUN); ion signalling; transport; renal processes (SLC12A1 and LOX) and VEGF, ERBB and BDNF signalling. Medicinal plant extracts are proving to be effective for the prevention, management and treatment of kidney-associated diseases; however, more detailed characterisations of their targets are needed to enable more trust in their application in the management of kidney-associated diseases.

Callus Culture of Thai Basil Is an Effective Biological System for the Production of Antioxidants

Thai basil is a renowned medicinal plant and a rich source of bioactive antioxidant compounds with several health benefits, with actions to prevent of cancer, diabetes and cardiovascular disease. Plant cell and tissue culture technologies can be routinely established as an important, sustainable and low-cost biomass source to produce high-value phytochemicals. The current study aimed at developing an effective protocol to produce Thai basil leaf-derived callus cultures with sustainable and high production of biomass and antioxidants as an alternative of leaves production. MS basal medium with various concentrations of plant growth regulators (PGRs) compatible with nutraceutical applications (i.e., gibberellic acid (GA₃) and 6-benzylaminopurine (BAP) either alone or in combination with naphthalene acetic acid (NAA)) were evaluated. Among all tested PGRs, the combination BAP:NAA (5 mg/L:1 mg/L) yields the maximum biomass accumulation (fresh weight (FW): 190 g/L and dry weight (DW): 13.05 g/L) as well as enhanced phenolic (346.08 mg/L) production. HPLC quantification analysis indicated high productions of chicoric acid (35.77 mg/g DW) and rosmarinic acid (7.35 mg/g DW) under optimized callus culture conditions. Antioxidant potential was assessed using both in vitro cell free and in vivo cellular antioxidant assays. Maximum in vitro antioxidant activity DPPH (93.2% of radical scavenging activity) and ABTS (1322 µM Trolox equivalent antioxidant capacity) was also observed for the extracts from callus cultures grown in optimal conditions. In vivo cellular antioxidant activity assay confirmed the effective protection against oxidative stress of the corresponding extract by the maximum inhibition of ROS and RNS production. Compared to commercial leaves, callus extracts showed higher production of chicoric acid and rosmarinic acid associated with higher antioxidant capacity. In addition, this biological system also has a large capacity for continuous biomass production, thus demonstrating its high potential for possible nutraceutical applications.

Antidiabetic activity of aqueous stem bark extract of Annickia polycarpa in alloxan-induced diabetic mice

Background and aim

There is a growing need to develop new drugs for type II diabetes mellitus (DM) from plant sources due to the high cost and adverse side effects of current drug therapies. To this end, the antidiabetic activity of aqueous stem-bark extract of A. polycarpa (APE) in alloxan-induced diabetic ICR mice was investigated.

Experimental procedure

The effect of APE (20, 100 and 500 mg/kg), glibenclamide and metformin as positive controls, were determined over 4 weeks on fasting blood glucose (FBG). An oral glucose tolerance test (OGTT) was also conducted. The effects of these treatments on the morphology of the pancreas were assessed. In addition, phytochemical constituents and antioxidant properties of APE were determined.

Results and conclusion

APE, like glibenclamide and metformin, showed significant hypoglycaemic effect. The OGTT supported the hypoglycaemic effect. The destroyed pancreatic beta-cells in diabetic control mice were restored to normal by APE or drug treatment. APE showed antioxidant activity by scavenging DPPH free radicals; this may be due to the presence of phenolic compounds, particularly flavonoids. Thus, APE may act by restoring pancreatic beta-cell integrity through mopping of reactive oxygen species (ROS) associated with the diabetic state, and thereby improving pancreatic function and consequently, the lowering of FBG levels. These findings provide ample evidence to validate the traditional use of A. polycarpa in the management of DM.

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Aqueous stem bark extract of A. polycarpa (APE) possesses significant antidiabetic activity.

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APE has the ability to cause the regeneration of beta cells of the pancreas.

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APE’s possess antioxidant activity and may scavenge ROS, thus help in overcoming advanced complications of DM.

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Alkaloids and phenolics (flavonoids) detected may be responsible for the hypoglycaemic and antioxidant activity of APE.

Anil Kumar N, Sharopov F, Ramírez-Alarcón K, Ruiz-Ortega A, Abdulmajid Ayatollahi S, Valere Tsouh Fokou P, Kobarfard F, Amiruddin Zakaria Z, Iriti M, Taheri Y, Martorell M, Sureda A, N. Setzer W, Durazzo A, Lucarini M, Santini A, Capasso R, Adrian Ostrander E, -ur-Rahman A, Iqbal Choudhary M, C. Cho W, Sharifi-Rad J. Antidiabetic Potential of Medicinal Plants and Their Active Components

Diabetes mellitus is one of the major health problems in the world, the incidence and associated mortality are increasing. Inadequate regulation of the blood sugar imposes serious consequences for health. Conventional antidiabetic drugs are effective, however, also with unavoidable side effects. On the other hand, medicinal plants may act as an alternative source of antidiabetic agents. Examples of medicinal plants with antidiabetic potential are described, with focuses on preclinical and clinical studies. The beneficial potential of each plant matrix is given by the combined and concerted action of their profile of biologically active compounds.

In vitro and in vivo anti-diabetic and anti-oxidant activities of methanolic leaf extracts of Ocimum canum

Background:

Diabetes is a metabolic disorder with a highly complex, multifaceted and intricate etiologies and thus may require management options that proffers multimodal mechanism of action. This present study evaluated the antidiabetic and antioxidant potential of the methanolic extract/fractions of leaves of Ocimum canum.

Methods:

The antidiabetic potential was evaluated and using STZ-induced diabetic Wistar rat model (in vivo) and inhibition of α-amylase and α-glucosidase activity (in vitro). Antioxidant activity was assessed in vitro by free radical scavenging and reducing power assays and in vivo via monitoring SOD and CAT activities; GSH and MDA levels.

Results:

The total phenolic content (221.0±3.0 mg catechol/g of sample) and tannins (146.0±4.0 mg tannic acid/g of sample) of the crude extract; and flavonoid of the aqueous-methanol fraction (216.0.0±1.0 mg of rutin/g of sample) were found to be significantly higher relative to others. The crude extract and the aqueous-methanol fraction exhibited a significantly (p<0.05) higher percentage reduction in fasting blood glucose and a concomitant increase in serum insulin level relative to the diabetic control group. The highest radical scavenging activity and reducing power were observed in the aqueous-methanol fraction. The aqueous-methanol solvent fraction also significantly reversed the alterations in oxidative stress markers occasioned by the diabetic condition.

Conclusion:

In conclusion, the result of the present study has demonstrated evidently that extracts of Ocimum canum leaves ameliorates hyperglycemia and the associated oxidative stress in STZ-induced rats.

Phytomedicines Used for Diabetes Mellitus in Ghana: A Systematic Search and Review of Preclinical and Clinical Evidence

BACKGROUND

Available data indicate that diabetes mellitus leads to elevated cost of healthcare. This imposes a huge economic burden on households, societies, and nations. As a result many Ghanaians, especially rural folks, resort to the use of phytomedicine, which is relatively less expensive. This paper aims at obtaining information on plants used in Ghana to treat diabetes mellitus, gather and present evidence-based data available to support their uses and their mechanisms of action, and identify areas for future research.

METHOD

A catalogue of published textbooks, monographs, theses, and peer-reviewed articles of plants used in Ghanaian traditional medicine between 1987 and July 2018 for managing diabetes mellitus was obtained and used.

RESULTS

The review identified 76 plant species belonging to 45 families that are used to manage diabetes mellitus. Leaves were the part of the plants frequently used for most preparation (63.8%) and were mostly used as decoctions. Majority of the plants belonged to the Euphorbiaceae, Lamiaceae, Asteraceae, and Apocynaceae families. Pharmacological data were available on 23 species that have undergone in vitro studies. Forty species have been studied using in vivo animal models. Only twelve plants and their bioactive compounds were found with data on both preclinical and clinical studies. The records further indicate that medicinal plants showing antidiabetic effects did so via biochemical mechanisms such as restitution of pancreatic β-cell function, improvement in insulin sensitivity by receptors, stimulating rate of insulin secretion, inhibition of liver gluconeogenesis, enhanced glucose absorption, and inhibition of G-6-Pase, α-amylase, and α-glucosidase activities.

CONCLUSION

This review contains information on medicinal plants used to manage diabetes mellitus, including their pharmacological properties and mechanisms of action as well as models used to investigate them. It also provides gaps that can form the basis for further investigations and development into useful medications for effective treatment of diabetes mellitus.

Anti-hyperglycemic effects and signaling mechanism of Perilla frutescens sprout extract

BACKGROUND/OBJECTIVES

Perilla frutescens (L.) Britton var. (PF) sprout is a plant of the labiate family. We have previously reported the protective effects of PF sprout extract on cytokine-induced β-cell damage. However, the mechanism of action of the PF sprout extract in type 2 diabetes (T2DM) has not been investigated. The present study was designed to study the effects of PF sprout extract and signaling mechanisms in the T2DM mice model using C57BL/KsJ-db/db (db/db) mice.

MATERIALS/METHODS

Male db/db mice were orally administered PF sprout extract (100, 300, and 1,000 mg/kg of body weight) or rosiglitazone (RGZ, positive drug, 1 mg/kg of body weight) for 4 weeks. Signaling mechanisms were analyzed using liver tissues and HepG2 cells.

RESULTS

The PF sprout extract (300 and 1,000 mg/kg) significantly reduced the fasting blood glucose, serum insulin, triglyceride and total cholesterol levels in db/db mice. PF sprout extract also significantly improved glucose intolerance and insulin sensitivity, decreased hepatic gluconeogenic protein expression, and ameliorated histological alterations of the pancreas and liver. Levels of phosphorylated AMP-activated protein kinase (AMPK) protein expression also increased in the liver after treatment with the extract. In addition, an increase in the phosphorylation of AMPK and decrease in the phosphoenolpyruvate carboxykinase and glucose 6-phosphatase proteins in HepG2 cells were also observed.

CONCLUSIONS

Our results sugges that PF sprout displays beneficial effects in the prevention and treatment of type 2 diabetes via modulation of the AMPK pathway and inhibition of gluconeogenesis in the liver.

Herbal therapy: A review of emerging pharmacological tools in the management of diabetes mellitus in Africa

BACKGROUND

Diabetes mellitus is a chronic physiological glucose metabolic disorder. It has affected millions of people all over the world thereby having a significant impact on quality of life. The management of diabetes includes both nonpharmacological and conventional interventions. Drawbacks in conventional therapy have led to seeking alternative therapy in herbal medicine. Therefore, the need to review, elucidate and classify their mode of action in therapy for diabetes disease arises.

MATERIALS AND METHODS

Comprehensive literature reports were used to review all conventional agents and herbal therapy used in the management of diabetes. An online database search was conducted for medicinal plants of African origin that have been investigated for their antidiabetic therapeutic potentials.

RESULTS

The results showed that of the documented sixty five plants used, fourteen inhibit intestinal absorption of glucose, three exhibit insulin-mimetic properties, seventeen stimulate insulin secretion from pancreatic beta cells, twelve enhance peripheral glucose uptake, one promotes regeneration of beta-cell of islets of Langerhans, thirteen ameliorate oxidative stress and twenty induces hypoglycemic effect (mode of action is still obscure). Thirteen of these plants have a duplicate mode of actions while one of them has three modes of actions. These agents have a similar mechanism of action as the conventional drugs.

CONCLUSION

In conclusion, antidiabetic activities of these plants are well established; however, the molecular modulation remains unknown. It is envisaged that the use of herbal therapy will promote good health and improve the status of diabetic patients.

Rosmarinic acid content in antidiabetic aqueous extract of Ocimum canum sims grown in Ghana

Rosmarinic acid (RA) is an important antioxidant polyphenol that is found in a variety of spices and herbs, including Ocimum canum Sims (locally called eme or akokobesa in Ghana). Aqueous extracts from the leaves of O. canum are used as an antidiabetic herbal medicine in Ghana. Analytical thin-layer chromatography was used to examine the composition of the polyphenols in leaf extracts. The polyphenol content in the aqueous and methanol extracts from the leaf, as determined by the Folin-Ciocalteu method, were 314 and 315 mg gallic acid equivalent/g leaf sample, respectively. The total flavonoid concentration as determined by the aluminum(III) chloride method was 135 mg catechin equivalent/g leaf sample. High-performance liquid chromatography coupled to an electrospray Quadrupole time-of-flight mass spectrometer was also used to determine the polyphenol fingerprint profile in the leaf extracts of O. canum. Although the average RA concentration in the O. canum leaf extracts from Ghana was 1.69 mg/g dry weight (reported values range from 0.01 to 99.62 mg/g dry weight), this polyphenol was still a prominent peak in addition to caffeic acid derivatives.

Production of extracellular polysaccharides by submerged mycelial culture of Laetiporus sulphureus var. miniatus and their insulinotropic properties

In the present study, optimum culture conditions for the production of extracellular polysaccharides (EPS) in submerged culture of an edible mushroom, Laetiporus sulphureus var. miniatus and their stimulatory effects on insulinoma cell (RINm5F) proliferation and insulin secretion were investigated. The maximum mycelial growth (4.1 g l(-1)) and EPS production (0.6 g l(-1)) in submerged flask culture were achieved in a medium containing 30 g l(-1) maltose, 2 g l(-1) soy peptone, and 2 mM MnSO(4).5H2O at an initial pH 2.0 and temperature 25 degrees C. In the stirred-tank fermenter under optimized medium, the concentrations of mycelial biomass and EPS reached a maximum level of 8.1 and 3.9 g l(-1), respectively. Interestingly, supplementation of deep sea water (DSW) into the culture medium significantly increased both mycelial biomass and EPS production by 4- and 6.7-fold at 70% (v/v) DSW medium, respectively. The EPS were proved to be glucose-rich polysaccharides and were able to increase proliferation and insulin secretary function of rat insulinoma RINm5F cells, in a dose-dependent manner. In addition, EPS also strikingly reduced the streptozotocin-induced apoptosis in RINm5F cells indicating the mode of the cytoprotective role of EPS on RINm5F cells.

Ethnomedicines used in Trinidad and Tobago for urinary problems and diabetes mellitus

BACKGROUND

This paper is based on ethnobotanical interviews conducted from 1996-2000 in Trinidad and Tobago with thirty male and female respondents.

METHODS

A non-experimental validation was conducted on the plants used for urinary problems and diabetes mellitus: This is a preliminary step to establish that the plants used are safe or effective, to help direct clinical trials, and to inform Caribbean physicians of the plants' known properties to avoid counter-prescribing.

RESULTS

The following plants are used to treat diabetes: Antigonon leptopus, Bidens alba, Bidens pilosa, Bixa orellana, Bontia daphnoides, Carica papaya, Catharanthus roseus, Cocos nucifera, Gomphrena globosa, Laportea aestuans, Momordica charantia, Morus alba, Phyllanthus urinaria and Spiranthes acaulis. Apium graviolens is used as a heart tonic and for low blood pressure. Bixa orellana, Bontia daphnoides, Cuscuta americana and Gomphrena globosa are used for jaundice. The following plants are used for hypertension: Aloe vera, Annona muricata, Artocarpus altilis, Bixa orellana, Bidens alba, Bidens pilosa, Bonta daphnoides, Carica papaya, Cecropia peltata, Citrus paradisi, Cola nitida, Crescentia cujete, Gomphrena globosa, Hibiscus sabdariffa, Kalanchoe pinnata, Morus alba, Nopalea cochinellifera, Ocimum campechianum, Passiflora quadrangularis, Persea americana and Tamarindus indicus. The plants used for kidney problems are Theobroma cacao, Chamaesyce hirta, Flemingia strobilifera, Peperomia rotundifolia, Petiveria alliacea, Nopalea cochinellifera, Apium graveolens, Cynodon dactylon, Eleusine indica, Gomphrena globosa, Pityrogramma calomelanos and Vetiveria zizanioides. Plants are also used for gall stones and for cooling.

CONCLUSION

Chamaesyce hirta, Cissus verticillata, Kalanchoe pinnata, Peperomia spp., Portulaca oleraceae, Scoparia dulcis, and Zea mays have sufficient evidence to support their traditional use for urinary problems, "cooling" and high cholesterol. Eggplant extract as a hypocholesterolemic agent has some support but needs more study. The plants used for hypertension, jaundice and diabetes that may be safe and justify more formal evaluation are Annona squamosa, Aloe vera, Apium graveolens, Bidens alba, Carica papaya, Catharanthus roseus, Cecropia peltata, Citrus paradisi, Hibsicus sabdariffa, Momordica charantia, Morus alba, Persea americana, Phyllanthus urinaria, Tamarindus indicus and Tournefortia hirsutissima. Several of the plants are used for more than one condition and further trials should take this into account.

The antidiabetic activity of the herbal preparation ADD-199 in mice: a comparative study with two oral hypoglycaemic drugs

The antidiabetic and antioxidant effects of the herbal preparation ADD-199 were investigated in STZ-induced diabetic C(3)H mice and results were compared with two allopathic hypoglycaemic drugs, glibenclamide and metformin. Plasma glucose, insulin and lipids as well as liver glycogen, lipids and lipid peroxidation were measured following treatment for 8 weeks. The results indicated that plasma insulin levels in normal controls at termination were about 76 micromol/L compared to trace levels in untreated diabetic mice. Glibenclamide and ADD-199 increased insulin levels in diabetic mice up to 70% of levels in untreated non-diabetic mice whilst metformin had no effect. Basal plasma glucose levels in diabetic controls (18.8 mM) were reduced to 14.0 mM by 100 mg/kg ADD-199 in <2 weeks compared to 4 and 6 weeks for glibenclamide and metformin, respectively. This hypoglycaemic effect of ADD-199 appeared to be associated with the alkaloidal content of the extract. Treatment with ADD-199 or the hypoglycaemic agents reversed the observed elevation in plasma lipids but increased hepatic glycogen, triacylglycerol and cholesterol levels. Treatment also increased glucose uptake by isolated diaphragms and attenuated hepatic lipid peroxidation. These antihyperglycaemic and antioxidant actions of ADD-199 at a dose of 100mg/kg/day are comparable to those of the maximum daily therapeutic doses of glibenclamide (0.25 mg/kg) and metformin (50 mg/kg). These could explain the basis for use of this plant extract to manage diabetes mellitus (DM).

Insulin-secretagogue activity and cytoprotective role of the traditional antidiabetic plant Scoparia dulcis (Sweet Broomweed)

Scoparia dulcis (Sweet Broomweed) has been documented as a traditional treatment of diabetes. The administration of an aqueous extract of Scoparia dulcis at a dose of 200 mg/kg body weight significantly decreased the blood glucose with significant increase in plasma insulin level in streptozotocin diabetic rats at the end of 15 days treatment. The insulin secretagogue action of Scoparia dulcis plant extract (SPEt) was further investigated using isolated pancreatic islets from mice. SPEt at a dose of 10 microg/ml evoked 6.0 fold stimulation of insulin secretion from isolated islets indicating its insulin secretagogue activity. In addition the effect of SPEt on streptozotocin induced cell death and nitric oxide (NO) in terms of nitrite production were also examined. SPEt protected against streptozotocin- mediated cytotoxicity (88%) and NO production in rat insulinoma cell line (RINm5F). Above results suggest the glucose lowering effect of SPEt to be associated with potentiation of insulin release from pancreatic islets. Our results revealed the possible therapeutic value of Scoparia dulcis for the better control, management and prevention of diabetes mellitus progression.

Aqueous extract of Ocimum canum decreases levels of fasting blood glucose and free radicals and increases antiatherogenic lipid levels in mice

The basis for managing diabetes mellitus with aqueous extract of Ocimum canum Sim (Lamiaceae), in Ghana was investigated in diabetic and normoglycemic mice. In the diabetic mice, fasting blood glucose decreased by 60% compared to 10% in control mice after 13 weeks of extract administration. Body weight, serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) decreased while serum high-density lipoprotein cholesterol (HDL-C) increased in the extract-treated group. In vitro hydroxyl (OH) and superoxide (O2) radical formation, and lipid peroxidation of isolated human LDL and mouse liver homogenates decreased in extract-treated experimental systems. These findings justify the use of O. canum extract as an antidiabetic folk medicine.