Vindoline-A Natural Product from Catharanthus Roseus Reduces Hyperlipidemia and Renal Pathophysiology in Experimental Type 2 Diabetes

Evaluation of the impact of vindoline, an active components of Catharanthus roseus, on rat hepatic cytochrome P450 enzymes by using a cocktail of probe drugs

The objection of this study was to investigate the effects of vindoline(VDL) on the cytochrome P450 (CYP 450) isoforms (CYP1A2, 2B, 2C11, 2D1 and 3A) in rats. Firstly, the rats were randomly divided into VDL pretreatment group and blank group, each group had six rats. VDL pretreatment group was administrated VDL (20 mg·kg-1) by oral gavage for fifteen days consecutively, and the equivalent CMC-Na solution without VDL was given to the blank group by gavage. Secondly, a cocktail of caffeine, bupropion, diclofenac, dextromethorphan and midazolam was then administered on the sixteenth day. Finally, blood samples were collected at the specified time point, and the plasma concentration of the probe drug was determined by UHPLC-QTOF-MS/MS. The effects of VDL on the activity of these CYP enzymes in rats were evaluated by pharmacokinetic parameters. VDL pretreatment group compared with the blank group, accelerated the metabolism of diclofenac, and weakened the metabolism of caffeine. These results suggested that VDL could induce the activity of CYP2C11, and inhibits the activity of CYP1A2, but had no significant effects on CYP2B, CYP2D1 and CYP3A. The results in this study can provide beneficial information for the later clinical application of VDL.

Vindoline Exhibits Anti-Diabetic Potential in Insulin-Resistant 3T3-L1 Adipocytes and L6 Skeletal Myoblasts

Type 2 diabetes mellitus (T2DM) emerged as a major health care concern in modern society, primarily due to lifestyle changes and dietary habits. Obesity-induced insulin resistance is considered as the major pathogenic factor in T2DM. In this study, we investigated the effect of vindoline, an indole alkaloid of Catharanthus roseus on insulin resistance (IR), oxidative stress and inflammatory responses in dexamethasone (IR inducer)-induced dysfunctional 3T3-L1 adipocytes and high-glucose-induced insulin-resistant L6-myoblast cells. Results showed that dexamethasone-induced dysfunctional 3T3-L1 adipocytes treated with different concentrations of vindoline significantly enhanced basal glucose consumption, accompanied by increased expression of GLUT-4, IRS-1 and adiponectin. Similarly, vindoline-treated insulin-resistant L6 myoblasts exhibited significantly enhanced glycogen content accompanied with upregulation of IRS-1 and GLUT-4. Thus, in vitro studies of vindoline in insulin resistant skeleton muscle and dysfunctional adipocytes confirmed that vindoline treatment significantly mitigated insulin resistance in myotubes and improved functional status of adipocytes. These results demonstrated that vindoline has the potential to be used as a therapeutic agent to ameliorate obesity-induced T2DM-associated insulin resistance profile in adipocytes and skeletal muscles.

Extraction Methods, Quantitative and Qualitative Phytochemical Screening of Medicinal Plants for Antimicrobial Textiles: A Review

Medicinal plants are the product of natural drug discoveries and have gained traction due to their pharmacological activities. Pathogens are everywhere, and they thrive in ideal conditions depending on the nutrients, moisture, temperature, and pH that increase the growth of harmful pathogens on surfaces and textiles. Thus, antimicrobial agents and finishes may be the solution to the destruction of pathogens. This review article presents an analysis of various aspects of producing antimicrobial finishings, the microorganisms, their mechanism of attachment to natural and synthetic fibre, the effect of microbial growth, and the principle and mechanism of the microbial activity of the medicinal plants. Furthermore, the extraction methods, qualitative and quantitative phytochemical evaluations of antimicrobial efficacy, and developments of antimicrobial treated textiles using various agents are covered in this review.

Update of Indoles: Promising molecules for ameliorating metabolic diseases

Obesity and metabolic disorders have gradually become public health-threatening problems. The metabolic disorder is a cluster of complex metabolic abnormalities which are featured by dysfunction in glucose and lipid metabolism, and results from the increasing prevalence of visceral obesity. With the core driving factor of insulin resistance, metabolic disorder mainly includes type 2 diabetes mellitus (T2DM), micro and macro-vascular diseases, non-alcoholic fatty liver disease (NAFLD), dyslipidemia, and the dysfunction of gut microbiota. Strategies and therapeutic attention are demanded to decrease the high risk of metabolic diseases, from lifestyle changes to drug treatment, especially herbal medicines. Indole is a parent substance of numerous bioactive compounds, and itself can be produced by tryptophan catabolism to stimulate glucagon-like peptide-1 (GLP-1) secretion and inhibit the development of obesity. In addition, in heterocycles drug discovery, the indole scaffold is primarily found in natural compounds with versatile biological activity and plays a prominent role in drug molecules synthesis. In recent decades, plenty of natural or synthesized indole deriviatives have been investigated and elucidated to exert effects on regulating glucose hemeostasis and lipd metabolism. The aim of this review is to trace and emphasize the compounds containing indole scaffold that possess immense potency on preventing metabolic disorders, particularly T2DM, obesity and NAFLD, along with the underlying molecular mechanisms, therefore facilitate a better comprehension of their druggability and application in metabolic diseases.

Enhancement of Vindoline and Catharanthine Accumulation, Antioxidant Enzymes Activities, and Gene Expression Levels in Catharanthus roseus Leaves by Chitooligosaccharides Elicitation

Catharanthus roseus (L.) G. Don is a plant belonging to the genus Catharanthus of the Apocynaceae family. It contains more than one hundred alkaloids, of which some exhibit significant pharmacological activities. Chitooligosaccharides are the only basic aminooligosaccharides with positively charged cations in nature, which can regulate plant growth and antioxidant properties. In this study, the leaves of Catharanthus roseus were sprayed with chitooligosaccharides of different molecular weights (1 kDa, 2 kDa, 3 kDa) and different concentrations (0.01 μg/mL, 0.1 μg/mL, 1 μg/mL and 10 μg/mL). The fresh weights of its root, stem and leaf were all improved after chitooligosaccharides treatments. More importantly, the chitooligosaccharides elicitor strongly stimulated the accumulation of vindoline and catharanthine in the leaves, especially with the treatment of 0.1 μg/mL 3 kDa chitooligosaccharides, the contents of them were increased by 60.68% and 141.54%, respectively. Furthermore, as the defensive responses, antioxidant enzymes activities (catalase, glutathione reductase, ascorbate peroxidase, peroxidase and superoxide dismutase) were enhanced under chitooligosaccharides treatments. To further elucidate the underlying mechanism, qRT-PCR was used to investigate the genes expression levels of secologanin synthase (SLS), strictosidine synthase (STR), strictosidine glucosidase (SGD), tabersonine 16-hydroxylase (T16H), desacetoxyvindoline-4-hydroxylase (D4H), deacetylvindoline-4-O-acetyltransferase (DAT), peroxidase 1 (PRX1) and octadecanoid-responsive Catharanthus AP2-domain protein 3 (ORCA3). All the genes were significantly up-regulated after chitooligosaccharides treatments, and the transcription abundance of ORCA3, SLS, STR, DAT and PRX1 reached a maximal level with 0.1 μg/mL 3 kDa chitooligosaccharides treatment. All these results suggest that spraying Catharanthus roseus leaves with chitooligosaccharides, especially 0.1 μg/mL of 3 kDa chitooligosaccharides, may effectively improve the pharmaceutical value of Catharanthus roseus.

Green Synthesis of Metallic Nanoparticles Using Some Selected Medicinal Plants from Southern Africa and Their Biological Applications

The application of metallic nanoparticles (MNPs), especially that of silver, gold, cobalt, and zinc as antimicrobial, anticancer, drug delivery, contrast, and bioimaging agents has transformed the field of medicine. Their functions, which are attributed to their physicochemical properties, have gained prominence in various technological fields. Although MNPs can be produced via rigorous physical and chemical techniques, in recent years, a biological approach utilizing natural materials has been developed. With the increasing enthusiasm for safe and efficient nanomaterials, the biological method incorporating microorganisms and plants is preferred over physical and chemical methods of nanoparticle synthesis. Of these bio-entities, plants have received great attention owing to their capability to reduce and stabilize MNPs in a single one-pot protocol. South Africa is home to ~10% of the world's plant species, making it a major contributor to the world's ecological scenery. Despite the documented contribution of South African plants, particularly in herbal medicine, very few of these plants have been explored for the synthesis of the noble MNPs. This paper provides a review of some important South African medicinal plants that have been utilized for the synthesis of MNPs. The enhanced biological properties of the biogenic MNPs attest to their relevance in medicine. In this endeavour, more of the African plant biodiversity must be explored for the synthesis of MNPs and be validated for their potential to be translated into future nanomedicine.

Efficient production of vindoline from tabersonine by metabolically engineered Saccharomyces cerevisiae

Vindoline is a plant derived monoterpene indole alkaloid (MIA) with potential therapeutic applications and more importantly serves as the precursor to vinblastine and vincristine. To obtain a yeast strain for high yield production of vindoline from tabersonine, multiple metabolic engineering strategies were employed via the CRISPR/Cas9 mediated multiplex genome integration technology in the present study. Through increasing and tuning the copy numbers of the pathway genes, pairing cytochrome P450 enzymes (CYPs) with appropriate cytochrome P450 reductases (CPRs), engineering the microenvironment for functional expression of CYPs, enhancing cofactor supply, and optimizing fermentation conditions, the production of vindoline was increased to a final titer as high as ∼16.5 mg/L, which is more than 3,800,000-fold higher than the parent strain and the highest tabersonine to vindoline conversion yield ever reported. This work represents a key step of the engineering efforts to establish de novo biosynthetic pathways for vindoline, vinblastine, and vincristine.

The Use of Natural Compounds as a Strategy to Counteract Oxidative Stress in Animal Models of Diabetes Mellitus

Diabetes mellitus (DM) is a chronic metabolic disease characterised by insulin deficiency, resulting in hyperglycaemia, a characteristic symptom of type 2 diabetes mellitus (DM2). DM substantially affects numerous metabolic pathways, resulting in β-cell dysfunction, insulin resistance, abnormal blood glucose levels, impaired lipid metabolism, inflammatory processes, and excessive oxidative stress. Oxidative stress can affect the body’s normal physiological function and cause numerous cellular and molecular changes, such as mitochondrial dysfunction. Animal models are useful for exploring the cellular and molecular mechanisms of DM and improving novel therapeutics for their safe use in human beings. Due to their health benefits, there is significant interest in a wide range of natural compounds that can act as naturally occurring anti-diabetic compounds. Due to rodent models’ relatively similar physiology to humans and ease of handling and housing, they are widely used as pre-clinical models for studying several metabolic disorders. In this review, we analyse the currently available rodent animal models of DM and their advantages and disadvantages and highlight the potential anti-oxidative effects of natural compounds and their mechanisms of action.

Research progress of indole compounds with potential antidiabetic activity

New types of antidiabetic agents are continually needed with diabetes becoming the epidemic in the world. Indole alkaloids play an important role in natural products owing to their variable structures and versatile biological activities like anticonvulsant, anti-inflammatory, antidiabetic, antimicrobial, and anticancer activities, which are a promising source of novel antidiabetic drugs discovery. The synthesized indole derivatives possess similar properties to natural indole alkaloids. In the last two decades, more and more indole derivatives have been designed and synthesized for searching their bioactivities. This present review describes comprehensive structures of indole compounds with the potential antidiabetic activity including natural indole alkaloids and the synthetic indole derivatives based on the structure classification, summarizes their approaches isolated from natural sources or by synthetic methods, and discusses the antidiabetic effects and the mechanisms of action. Furthermore, this review also provides briefly synthetic procedures of some important indole derivatives.

Antioxidant status and hepato-protective role of Anchomanes difformis in streptozotocin-induced diabetes in male Wistar rats

Introduction: The liver is involved in the metabolism of xenobiotics and their metabolites and it is vulnerable to oxidative damage. Hyperglycaemia is highly implicated in the progression of diabetes mellitus, and adversely affects the liver. Though, conventional hypoglycaemic drugs may be effective in reducing blood glucose, they do not appear to be effective in attenuating the progression of diabetes and its complications.

Objective: This study evaluated the ameliorative effects of Anchomanes difformis on hyperglycaemia and hepatic injuries in type 2 diabetes.

Methods: Type 2 diabetes was induced in male Wistar rats with a single intraperitoneal injection of streptozotocin (40 mg/kg BW) after two weeks of fructose (10%) administration. Aqueous extract of A. difformis (200 and 400 mg/kg BW) and glibenclamide (5 mg/kg BW) were administered orally for six weeks. Blood glucose concentrations were measured. Serum levels of liver dysfunction markers (ALT, AST, and ALP), total cholesterol, triglycerides, HDL- and LDL-cholesterol were investigated. Total protein, albumin, and globulin were also assessed. Antioxidant parameters: ORAC, GSH, GSSG, SOD, CAT and FRAP were evaluated in the liver while ORAC, FRAP and lipid peroxidation were determined in the serum. Histological examination of the liver tissue was carried out.

Results: Treatment with aqueous extract of A. difformis significantly (p<0.05) reduced blood glucose and reversed steatosis in the diabetic-treated rats. The antioxidant status of diabetic-treated rats was significantly (p<0.05) improved. Serum levels of liver dysfunction markers were significantly (p<0.05) reduced in diabetic-treated rats.

Conclusion: The findings in this study revealed that 400 mg/kgBW Anchomanes difformis was more effective than 200 mg/kg BW in ameliorating diabetes-induced hepatopathy, however, both doses of Anchomanes difformis demonstrated more antidiabetic ability than glibenclamide. Anchomanes difformis may be a novel and potential therapeutic agent in the management of diabetes and resulted hepatic injuries.