The Renal Effects of Blood Glucose-Lowering Plant-Derived Extracts in Diabetes Mellitus—an Overview

Anti-Diabesity Middle Eastern Medicinal Plants and Their Action Mechanisms

Over the last four decades, the escalation in diabetes and obesity rates has become epidemic all over the world. Diabesity describes the strong link between T2D and obesity. It correlates deeper with the elevated risks of developing cardiovascular disease hypertension, stroke, and several malignancies. Therapeutic usage of medicinal plants and natural products in the treatment of diabetes and obesity has long been known to physicians of Greco-Arab and Islamic medicine. Improved versions of their abundant medicinal plant-based formulations are at present some of the most popular herbal treatments used. Preclinical and clinical data about medicinal plants along with their bioactive constituents are now available, justifying the traditionally known therapeutic uses of products derived from them for the prevention and cure of obesity-related T2D and other health problems. The aim of this review is to systematize published scientific data dealing with the efficiency of active ingredients or extracts from Middle Eastern medicinal plants and diet in the management of diabesity and its complications. Google Scholar, MEDLINE, and PubMed were searched for publications describing the medicinal plants and diet used in the management of T2D, obesity, and their complications. The used keywords were “medicinal plants” or “herbals” in combination with “obesity,” “diabetes,” “diabetes,” or nephropathy. More than 130 medicinal plants were identified to target diabesity and its complications. The antidiabetic and anti-obesity effects and action mechanisms of these plants are discussed here. These include the regulation of appetite, thermogenesis, lipid absorption, and lipolysis; pancreatic lipase activity and adipogenesis; glucose absorption in the intestine, insulin secretion, glucose transporters, gluconeogenesis, and epigenetic mechanisms.

Safety assessment of oral administration of ethanol extract of Justicia carnea leaf in healthy wistar rats: hematology, antioxidative and histology studies

Background

Consumption of medicinal plants has diverse therapeutic benefits and could also have toxic effect. Justicia carnea is a medicinal plant that is used conventionally as blood tonic from time immemorial in Nigeria. The aim of this study is to evaluate the safety of ethanol extract of J. carnea leaf assessing the hematology indices, organ antioxidant system and histology in healthy male wistar rats.

Methods

Powdered sample was extracted using absolute ethanol and concentrated to obtain a slurry paste of J. carnea ethanol extracts. Acute toxicity was determined in two phases using Lorke method. In subacute study, rats were randomized into six groups of five rats per group: Group 1 (control) received distilled water, group 2, 3, 4, 5, 6 received 50, 100, 500, 800 and 1200 mg/kg body weight of J. carnea ethanol extract once daily using oral gavage. At the end of 14th day of administration, rats were allowed to fast overnight, sacrificed to collect samples for biochemical analysis and histopathological examination.

Results

The LD50 of extract was greater than 5000 mg/kg body weight. Higher doses (> 500 mg/kg) of extract significantly (p < 0.05) increased RBC, hemoglobin and platelet compared to the control. Liver superoxide dismutase (SOD) activity was significantly (p < 0.05) increased at 1200 mg/kg while other tested doses caused no detrimental effect on glutathione, catalase, SOD and malondialdehyde level in liver and kidney. Histopathological examination of liver and kidney showed mild to severe pathological lesion in a dose dependent manner.

Conclusions

The results of this study suggests that ethanol extract of J. carnea leaf is relatively safe, could be beneficial in alleviating hematology related abnormalities without causing adverse effects on endogenous antioxidant system. However, caution should be taken as higher dose at 1200 mg/kg could cause noticeable tissue injury.

Toxicological evaluation of a flavonoid, chrysin: morphological, behavioral, biochemical and histopathological assessments in rats

Nowadays, medicines from plant sources play a vital role in healthcare management. Chrysin, a plant flavonoid, possesses a wide range of pharmacological activities. The aim of present investigation was to evaluate the safety of chrysin by determining toxicity after acute and sub-chronic oral administration in rats. Acute oral toxicity (AOT) and sub-chronic oral toxicity studies of chrysin were carried out according to OECD 425 and OCED 408 in Sprague Dawley rats. In AOT, oral administration of chrysin (5000 mg/kg) showed 40% mortality. In the sub-chronic toxicity study, daily oral administration of chrysin (1000 mg/kg) showed significantly decreased body weight whereas liver weight was increased significantly in male rats. A significant alteration in the hematology (RBC, MCH, MCHC, TLC, lymphocytes, and neutrophil) and blood chemistry (albumin, bilirubin, ALT, AST, creatinine, and GGT) were found in chrysin (1000 mg/kg) treated rats which were either limited to one sex or lacked dose-response or were within the normal laboratory ranges. There was a significant increase in hepatic and renal oxido-nitrosative stress in chrysin (1000 mg/kg) treated rats. There was no significant change in electrocardiographic (except heart rate), hemodynamic, the left ventricular function, and lung function test. Renal and hepatic histological aberrations were induced in chrysin (1000 mg/kg) treated rats. In conclusion results of the present investigation determined the LD₅₀ value of chrysin to be 4350 mg/kg whereas NOAEL and LOAEL of chrysin was found to be 500 and 1000 mg/kg, respectively for both the sexes.

Toxicity study of dibutyl phthalate of Rubia cordifolia fruits: in vivo and in silico analysis

Natural toxins from plant sources with wide ranges of biological activities reflect the upswing of drug design in the pharmaceutical industry. Rubia cordifolia L. is one of the most important red dye yielding plants. Most of the former researches have focused on the bioactive compounds from the roots of R. cordifolia, while no attention was paid towards the fruits. For the first time, here we report the presence of dibutyl phthalate in the fruits of R. cordifolia. Structural characterization was carried out using Ultraviolet-Visible spectrophotometer (UV-Vis), Fourier transform infrared (FTIR), gas chromatography-mass spectrophotometer (GC-MS), Nuclear magnetic resonance (NMR). Acute toxicity of the crude ethanolic extracts of the R. cordifolia fruits was examined in Swiss albino mice. No mortality was observed in all treated mice with 100, 500, 1000 mg/kg body weight of crude extract of R. cordifolia fruit and it indicates that the LD50 value is higher than 1000 mg/kg body weight. This study exhibited a significant change in the body weight. Alanine transaminase (ALT), total protein, triglycerides, glucose, and also the histopathological analysis of liver for all treated mice showed difference from the control group. The dibutyl phthalate was further evaluated for the toxicity study through in silico analysis. Together, the results highlighted that the toxic potential of R. cordifolia fruits extracts and also the toxicity profile of the fruit should be essential for the future studies dealing with the long term effect in animals. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1059-1067, 2016.

Toxicological assessment of the hydroethanolic leaf extract of clerodendrum capitatum in Wistar rats

Introduction

Clerodendrum capitatum (Willd) Schumach. & Thonn (Lamiaceae) is used in African traditional medicine for the treatment of malaria, hypertension, obesity, jaundice and diabetes however there is lack of experimental data on its possible toxicity. This study investigated the acute and 28 days sub-chronic toxicity of C. capitatum in Wistar rats.

Methods

In acute toxicity tests, a single administration of the hydroethanolic C. capitatum leaf extract (5 g/kg) was given orally to 5 female rats. The general behavior, adverse effects and mortality were recorded for up to 14 days post treatment. On the 15^th day, the rats were weighed and euthanized for necropsy. In sub-chronic toxicity tests, the extract (4, 8 and 16 g/kg/day) was given orally to both male and female rats for 28 days. The animal body weight was recorded throughout the experiment, while hematological and biochemical parameters of blood and relative organs weights were evaluated on the 29^th day.

Results

Clerodendrum Capitatum did not cause any death or any hazardous symptoms of acute toxicity, showing an LD₅₀ higher than 5 g/kg. Sub-chronic administration of C. capitatum resulted in no noticeable changes in weight gain and water or food consumption. White blood cells and hemoglobin increased while urea concentration, liver enzymes, total cholesterol and glucose concentrations significantly decreased in treated animals. No changes in macroscopical aspect of organs were observed in the animals.

Conclusion

These results showed that acute or sub-chronic oral administration of the hydroethanolic leaf extract of Clerodendrum capitatum may be considered as relatively free of toxicity.

In vitro alpha-amylase inhibition and in vivo antioxidant potential of Momordica dioica seeds in streptozotocin-induced oxidative stress in diabetic rats

Momordica dioica Roxb. Commonly known as "Kakora" in Telugu, is used in the Indian traditional system of medicine for the treatment of diabetes. The aim of this study was to investigate the antidiabetic activity of methanolic extract of M. dioica seeds (MEMD) in streptozotocin (STZ) induced diabetic rats. The in vitro α-amylase inhibitory activity of the MEMD was done by spectrophotometric method. Diabetes was induced by STZ (45 mg/kg; i.p), MEMD (100 & 200 mg/kg; b.wt) and standard drug metformin (50 mg/kg; b.wt) were administered to the diabetic rats. Blood glucose was estimated on the 11th day and the level of MDA, SOD and CAT was estimated in the liver tissue homogenate after the 15 days of experimental period. MEMD showed significant inhibition of alpha amylase activity and the IC₅₀ was found to be 48 μg/ml. Oral administration of MEMD significantly reduced blood glucose level (P < 0.05), diminished the MDA level and refurbished depleted antioxidant enzymes and Insulin level to normalcy. These findings revealed that M. dioica seeds possess antihyperglycemic, antioxidant and anti lipid peroxidative activity and thus mitigate STZ-induced oxidative damage.

The effects of medicinal plants on renal function and blood pressure in diabetes mellitus

Abstract

Diabetes mellitus is one of the most common chronic global diseases affecting children and adolescents in both the developed and developing nations. The major types of diabetes mellitus are type 1 and type 2, the former arising from inadequate production of insulin due to pancreatic β-cell dysfunction, and the latter from reduced sensitivity to insulin in the target tissues and/or inadequate insulin secretion. Sustained hyperglycaemia is a common result of uncontrolled diabetes and, over time, can damage the heart, eyes, kidneys and nerves, mainly through deteriorating blood vessels supplying the organs. Microvascular (retinopathy and nephropathy) and macrovascular (atherosclerotic) disorders are the leading causes of morbidity and mortality in diabetic patients. Therefore, emphasis on diabetes care and management is on optimal blood glucose control to avert these adverse outcomes.

Studies have demonstrated that diabetic nephropathy is associated with increased cardiovascular mortality. In general, about one in three patients with diabetes develops end-stage renal disease (ESRD) which proceeds to diabetic nephropathy (DN), the principal cause of significant morbidity and mortality in diabetes. Hypertension, a well-established major risk factor for cardiovascular disease contributes to ESRD in diabetes. Clinical evidence suggests that there is no effective treatment for diabetic nephropathy and prevention of the progression of diabetic nephropathy. However, biomedical evidence indicates that some plant extracts have beneficial effects on certain processes associated with reduced renal function in diabetes mellitus. On the other hand, other plant extracts may be hazardous in diabetes, as reports indicate impairment of renal function. This article outlines therapeutic and pharmacological evidence supporting the potential of some medicinal plants to control or compensate for diabetes-associated complications, with particular emphasis on kidney function and hypertension.

Acute and sub-chronic (28days) oral toxicity evaluation of hydroethanolic extract of Bridelia ferruginea Benth root bark in male rodent animals

The present investigation was carried out to evaluate the safety of hydro-ethanol extract of Bridelia ferruginea Benth (Euphorbiaceae) root bark. For acute toxicity study, a single dose of 2000 and 5000 mg/kg of the B. ferruginea root bark extract was given orally to healthy male Wistar rats and Balb/c mice. The animals were observed for mortality and clinical signs for 3 h and then daily for 14 days. In the sub-chronic toxicity study, the extract was administered orally at doses of 250, 500 and 1000 mg/kg/day for 28 days to male Wistar rats. Animals were sacrificed to examine their organs, and urine and blood serum were analyzed. In the acute toxicity study, B. ferruginea root bark extract caused neither significant visible signs of toxicity, nor mortality in Wistar rats and Balb/c mice. In sub-chronic toxicity study, administration of the B. ferruginea root bark extract at 250, 500, and 1000 mg/kg for 28 consecutive days to Wistar rats did not produce mortality. No significant differences were found in relative organ weights, biochemical studied parameters in treated groups compared to control group. No obvious histological changes were observed in organs of B. ferruginea extract treated animals compared to controls.

Renal toxicity caused by oral use of medicinal plants: the yacon example

AIM OF THE STUDY

Yacon [Smallanthus sonchifolius (Poepp. & Endl.) H. Robinson, Asteraceae] is an Andean species that has traditionally been used as an anti-diabetic herb in several countries around the world, including Brazil. Its hypoglycaemic action has recently been demonstrated in normal and diabetic rats. However, studies about the safety of prolonged oral consumption of yacon leaf extracts are lacking. Thus, this work was undertaken to evaluate the repeated-dose toxicity of three extracts from yacon leaves: the aqueous extract (AE) prepared as a tea infusion; the leaf-rinse extract (LRE), which is rich in sesquiterpene lactones (STLs); and a polar extract from leaves without trichomes, or polar extract (PE), which lacks STLs but is rich in chlorogenic acids (CGAs).

MATERIALS AND METHODS

The major classes of the compounds were confirmed in each extract by IR spectra and HPLC-UV-DAD profiling as well as comparison to standard compounds. The toxicity of each extract was evaluated in a repeated-dose toxicity study in Wistar rats for 90 days.

RESULTS

The PE was rich in CGAs, but we did not detect any STLs. The AE and LRE showed the presence of STLs. The polar extract caused alterations in some biochemical parameters, but the animals did not show signs of behavioural toxicity or serious lesions in organs. Alterations of specific biochemical parameters in the blood (creatinine 7.0 mg/dL, glucose 212.0 mg/dL, albumin 2.8 g/dL) of rats treated with AE (10, 50 and 100 mg/kg) and LRE (10 and 100 mg/kg) pointed to renal damage, which was confirmed by histological analysis of the kidneys.

CONCLUSIONS

The renal damage was associated with increased blood glucose levels after prolonged oral administration of the AE. This observation suggested that the hypoglycaemic effect observed after treatment for 30 days in an earlier study is reversible and was likely the result of renal injury caused by the toxicity of yacon. Because STLs were detected in both AE and LRE, there is strong evidence that these terpenoids are the main toxic compounds in the leaves of the yacon. Based on our results, we do not recommend the oral use of yacon leaves to treat diabetes.