Antiplatelets and profibrinolytic activity of Citrullus colocynthis in control and high-fat diet-induced obese rats: mechanisms of action

Medicinal Plant Extracts against Cardiometabolic Risk Factors Associated with Obesity: Molecular Mechanisms and Therapeutic Targets

Obesity has increasingly become a worldwide epidemic, as demonstrated by epidemiological and clinical studies. Obesity may lead to the development of a broad spectrum of cardiovascular diseases (CVDs), such as coronary heart disease, hypertension, heart failure, cerebrovascular disease, atrial fibrillation, ventricular arrhythmias, and sudden cardiac death. In addition to hypertension, there are other cardiometabolic risk factors (CRFs) such as visceral adiposity, dyslipidemia, insulin resistance, diabetes, elevated levels of fibrinogen and C-reactive protein, and others, all of which increase the risk of CVD events. The mechanisms involved between obesity and CVD mainly include insulin resistance, oxidative stress, inflammation, and adipokine dysregulation, which cause maladaptive structural and functional alterations of the heart, particularly left-ventricular remodeling and diastolic dysfunction. Natural products of plants provide a diversity of nutrients and different bioactive compounds, including phenolics, flavonoids, terpenoids, carotenoids, anthocyanins, vitamins, minerals, fibers, and others, which possess a wide range of biological activities including antihypertensive, antilipidemic, antidiabetic, and other activities, thus conferring cardiometabolic benefits. In this review, we discuss the main therapeutic interventions using extracts from herbs and plants in preclinical and clinical trials with protective properties targeting CRFs. Molecular mechanisms and therapeutic targets of herb and plant extracts for the prevention and treatment of CRFs are also reviewed.

Antidiabetic and hepato-renal protective effects of medicinal plants in STZ induced diabetic rats

Abstract The antidiabetic and hepato-renal protective effects of Citrullus colocynthis and Momordica charantia ethanol extracts were investigated in streptozotocin (STZ) induced diabetic male albino rats. Diabetic rats were treated with C. colocynthis, M. charantia or C. colocynthis + M. charantia mixed extract at a dose of 250 mg /kg body weight per oral per day for 21 days. The mean body weight of all the diabetic rat groups on day 1 of treatment (day 10 of diabetes) was significantly lower than the normal control rat group (P<0.05). The blood glucose level of all the diabetic rat groups on day 1 of treatment (day 10 of diabetes) was significantly (P<0.05) higher (> 200 mg/dl) than the normal control rat group (95.5 ± 2.7). At the end of treatment (day 21), the diabetic rats treated with plant extracts showed significant increase (P<0.05) in body weight and significant (P<0.05) reduction in blood glucose level when compared to diabetic control animals. Significant increase (< 0.05) was observed in the serum bilirubin, alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), urea and creatinine levels of diabetic control rat group. The serum levels of these liver and kidney-related parameters of diabetic rats treated with plant extract were significantly lower when compared to diabetic control rat group (p < 0.05). Photomicrographs of liver and kidney microsections from diabetic rats treated with these plant extracts showed amelioration in the hepato-renal histoarchitectures. It was concluded that the C. colocynthis and M. charantia methanol extracts are antidiabetic and hepato-renal protective in STZ induced diabetic male rats. Treatment of the diabetic rats with C. colocynthis + M. charantia mixed extract is more effective in the amelioration of diabetes and hepato-renal injuries in STZ induced diabetic male rats.

Citrullus colocynthis (L.) Schrad.: A Promising Pharmaceutical Resource for Multiple Diseases

Citrullus colocynthis (L.) Schrad. (Cucurbitaceae) is widely distributed in the desert areas of the world. The fruit bodies of C. colocynthis are recognized for their wide range of nutraceutical potential, as well as medicinal and pharmaceutical uses. The plant has been reported for various uses, such as asthma, bronchitis, cancer, colic, common cold, cough, diabetes, dysentery, and jaundice. The fruit has been extensively studied for its biological activities, which include insecticide, antitumor, and antidiabetic effects. Numerous bioactive compounds have been reported in its fruit bodies, such as essential oils, fatty acids, glycosides, alkaloids, and flavonoids. Of these, flavonoids or caffeic acid derivatives are the constituents associated with the inhibition of fungal or bacterial growth, whereas eudesmane sesquiterpenes or sesquiterpene lactones are most active against insects, mites, and nematodes. In this review, the scientific evidence for the biological activity of C. colocynthis against insecticide, cytotoxic, and antidiabetic effects is summarized.

Differential expression of gluconeogenic enzymes in early- and late-stage diabetes: the effect of Citrullus colocynthis (L.) Schrad. Seed extract on hyperglycemia and hyperlipidemia in Wistar-Albino rats model

Background

The medicinal plant Citrullus colocynthis (L.) Schrad. (C. colocynthis) may benefit patients at different phases of diabetes by attuning to contrasting situations. Our primary objective was to find the mechanism(s) behind the antidiabetic/anti-hyperlipidemic effects of C.colocynthis seed aqueous extract (CCAE) in two different stages of type 2 diabetes (T2D) in rats.

Methods

Fasting blood sugar (FBS) levels, body weights, and the degree of impaired glucose tolerance (IGT) were measured in healthy nondiabetic control rats (Con), as well as rats with early and late stages of T2D, denoted as ET2D and LT2D, respectively. CCAE was intraperitoneally (IP) injected for 28 days. In the end, the hepatic mRNA expression levels of the following genes were determined by RT-PCR: glucose-6-phosphatase (G6Pase), phosphoenolpyruvate carboxykinase (PEPCK), insulin-dependent sterol regulatory element-binding protein-1c (SREBP-1c), acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), peroxisome proliferator-activated receptor alpha (PPARα), and carnitine palmitoyltransferase I (CPT1). The liver was examined by hematoxylin and eosin (H&E) and Oil-Red O staining. CCAE was partially analyzed by HPLC-DAD.

Results

ET2D and LT2D were characterized by differentially elevated FBS, deteriorated bodyweight, and significant IGT compared to Con. Hepatosteatoses of varying morphologies and higher hepatic expression of G6Pase than PRPCK in ET2D versus the opposite in LT2D further confirmed the divergent nature of metabolic aberrations. At the end of 28 days, the high levels of FBS, alkaline phosphatase (ALP), triglyceride (TG), urea, hepatic protein carbonyl content (PCC), and alanine and aspartate aminotransferases (AST and ALT, respectively) persisted in untreated LT2D. CCAE ameliorated oxidative stress and upregulated PPARα expression in diabetic groups and Con; it downregulated CPT1 expression in the LT2D group. CCAE’s ability to lower FBS and serum and hepatic TG in both ET2D and LT2D indicated its ability to act via different mechanisms. Ferulic acid (Fer A) and rutin hydrate (RH) were detected in CCAE.

Conclusion

CCAE lowered the FBS in ET2D via inhibiting the hepatic G6Pase expression (glycogenolysis). In LT2D, CCAE abated sugar levels by diverting PEPCK activity, preferably towards glyceroneogenesis than gluconeogenesis. The preserved triglyceride/fatty acid (TG/FA) cycle, the upregulated PPARα, and the downregulated CPT1 gene expressions reduced serum and hepatic TG.

Methanolic extract of Citrullus colocynthis suppresses growth and proliferation of breast cancer cells through regulation of cell cycle

Breast cancer is a major cause of cancer related deaths in women worldwide. Available treatments pose serious limitations such as systemic toxicity, metastasis, tumor recurrence, off-target effects, and drug resistance. In recent years, phytochemicals such as secondary metabolites due to their effective anticancer potential at very low concentration have gained attention. Aim of the study was to evaluate anticancer potential of Citrullus colocynthis and its possible molecular targets on MCF-7, a human breast cancer cell line. Methanolic extract of leaves was prepared and fractionated by solvents (n-hexane, chloroform, ethyl acetate and n-butanol) with increasing polarity. Bioassays and gene expression regulation was conducted to evaluate the anticancer activity, proliferation rate and cell cycle regulation of breast cancer cells treated with extract and its fractions, separately. Results showed a significant anticancer activity of methanolic extract of C. colocynthis and two of its fractions prepared with chloroform and ethyl acetate. Bioassays depicted significant decrease in proliferation and growth potential along with cell cycle arrest of treated cells compared to control untreated cells. Expression regulation of genes further confirmed the cell cycle arrest through significant upregulation of cyclin-CDK inhibitors (p21 and p27) and cell cycle checkpoint regulators (HUS1, RAD1, ATM) followed by downregulation of downstream cell cycle progression genes (Cyclin A, Cyclin E, CDK2). It is concluded that C. colocynthis arrests cell cycle in human breast cancer cells through expression regulation of cyclin-CDK inhibitors and with further research can be proposed for therapeutic interventions.

Analysis of platelets from a diet-induced obesity rat model: elucidating platelet dysfunction in obesity

Obesity is one of the main health problems in industrialized countries. The contribution of multiple factors developed in obesity can hardly be modeled in vitro. In this context, the development of animal models mimicking human obesity could be essential. The aim of the present study was to compare platelets from a diet-induced obesity (DIO) rat model with their lean control group in order to elucidate platelet dysfunction mechanisms in obesity and correlate the results with previous data from morbid obese patients. In parallel, we also established a blood collection and platelet isolation methodology to study the DIO rat model at biochemical and functional level. Optimal blood collection was obtained from vena cava and platelet isolation was based on a serial of centrifugations avoiding platelet activation. Our results show that the DIO rat model simulate obesity pathologically since weight gain, fasting glucose and platelet counts are increased in obese rats. Interestingly, platelet levels of the active form of Src (pTyr⁴¹⁹) showed a tendency to increase in DIO rats pointing towards a potential dysfunction in Src family kinases-related signalling pathways in obesity. Moreover, platelets from DIO rats adhere more to collagen compared with the control group, pointing towards Glycoprotein VI (GPVI) as one of the dysregulated receptors in obesity, in agreement with our recent studies in humans. These results confirm that obesity, in line with human studies, present a platelet dysregulation, and highlight the relevance of considering novel antithrombotic drug targets in these patients, such as GPVI.

Topical Anti-Inflammatory and Analgesic Activities of Citrullus colocynthis Extract Cream in Rats

Background and objectives:Citrullus colocynthis (CC), known as bitter apple, is used to treat diabetes in Iranian traditional medicine. The aim of this study is to evaluate the anti-inflammatory and analgesic activities of CC cream in rats. Materials and Methods: The carrageenan-induced edema in a rat hind paw was carried out to evaluate the topical anti-inflammatory effect of the CC fruit extract cream (2–8%) and the tissue levels of IL-6 and TNF-α were estimated by using a commercial ELISA kit. The topical antinociceptive activity of CC cream (2–8%) was evaluated in the rat formalin test. To determine the role of opioid receptors in the local antinociceptive effect of the CC cream, naloxone (20 μg/paw, i.pl.), a non-selective opioid antagonist, was used. Results: The results showed that the CC cream (2–8%) dose-dependently reduced the carrageenan-induced paw edema and reversed the changes in the level of TNF-α and IL-6 due to carrageenan-induced edema (p < 0.01). The anti-inflammatory effect of CC cream 8% was comparable to that of hydrocortisone ointment 1%. Furthermore, the application of CC cream (2–8%) dose-dependently inhibited both first and second phases of the formalin test (p < 0.05). The antinociceptive effect of the CC cream (8%) was comparable to that of methyl salicylate cream 30%. Moreover, the administration of naloxone significantly reversed the topical antinociceptive effect of the CC cream (p < 0.05). Conclusions: For the first time, this study indicated that the topical application of CC cream possesses significant anti-inflammatory and antinociceptive activities in animal models, which were probably mediated by opioid receptors and the suppression of pro-inflammatory cytokines (TNF-α and IL-6). Thus, the CC cream can be used to treat inflammatory pain and inflammatory diseases.