In Vitro Alpha-Amylase and Alpha-Glucosidase Inhibitory Activity and In Vivo Antidiabetic Activity of Withania frutescens L. Foliar Extract

Different extraction methods shape the phenolic signature and biological activity of Morinda lucida extracts: A novel source of bioactive compounds preparing functional applications

The extraction of bioactive compounds is based on the application of various extraction techniques. Therefore, the stem and root bark of the plant species Morinda lucida L. were used in this research, while the extraction procedure was performed using three extraction techniques: HAE (homogenizer extraction), UAE (ultrasound extraction) as modern, and MAC (maceration) as conventional extraction technique. The presence of different classes of secondary metabolites was determined using the UHPLC method, while the content of total phenols and flavonoids was determined spectrophotometrically. The biological potential was investigated by in vitro antioxidant and enzyme assays. Different extraction technologies showed significant differences in only two classes of phenols, namely lignans and phenolic acids, which were significantly higher in HAE than in UAE and MAC. These findings highlight the significant effect of stem and bark extracts of M. lucida, opening the way for innovative industrial exploitation of these matrices.

Phytochemical analysis, identification of bioactive compounds using GC-MS, in vitro and in silico hypoglycemic potential, in vitro antioxidant potential, and in silico ADME analysis of Chlorophytum comosum root and leaf

Chlorophytum comosum is a plant with medicinal potential traditionally used to treat different diseases. The present study aimed to determine the bioactive compounds, hypoglycemic and antioxidant potential of C. comosum root and leaf. The ethyl acetate extracts of C. comosum root and leaf were analyzed by GC-MS to determine the bioactive compounds. The hypoglycemic potential of the extracts was evaluated by α-amylase, α-glucosidase, glucose diffusion inhibitory assays, and glucose adsorption assay. The ethyl acetate extract of C. comosum root inhibited α-amylase, α-glucosidase, and glucose diffusion in a concentration-dependent manner with IC50 values of 205.39 ± 0.15, 179.34 ± 0.3 and 535.248 μg/mL, respectively, and the leaf extract inhibited α-amylase and α-glucosidase enzymes with IC50 values of 547.99 ± 0.09, and 198.18 ± 0.25 μg/mL respectively. C. comosum root and leaf extracts also improved glucose adsorption. Heptadecanoic acid and dodecanoic acid were identified as potential compounds with hypoglycemic properties through molecular docking. The extracts were also assessed for their antioxidant activity using DPPH, ABTS, and FRAP assays. C. comosum root and leaf extracts were also able to scavenge DPPH radicals with IC50 values of 108.37 ± 0.06 and 181.79 ± 0.09 µM and ABTS radicals with IC50 values of 126.24 ± 0.13 and 264.409 ± 0.08 µM, respectively. The root and leaf extracts also reduced the ferricyanide complex to ferrocyanide with higher reducing powers of 2.24 ± 0.02 and 1.65 ± 0.03, respectively. The results showed that the ethyl acetate extract of C. comosum root has significant antioxidant and hypoglycemic potential compared to the leaf extract. Thus, it can also be studied to isolate the potential compounds with antihyperglycemic activities.

Unveiling the Bioactive Efficacy of Cupressus sempervirens 'Stricta' Essential Oil: Composition, In Vitro Activities, and In Silico Analyses

Prior studies have extensively investigated the essential oil derived from the Mediterranean cypress, Cupressus sempervirens. However, the 'Stricta' variety, known for its ornamental value, has received less attention in terms of its oil composition and potential health benefits. The objective of this research was to comprehensively analyze the chemical components and medicinal properties of the essential oil extracted from C. sempervirens 'Stricta' (CSSLEO) grown in Egypt. Utilizing gas chromatography-mass spectrometry (GC-MS), the investigation identified 22 compounds within CSSLEO, with α-pinene and δ-3-carene being predominant, accounting for 96.01% of the oil. In vitro assays evaluated CSSLEO's cytotoxic effects on cancer cell lines, revealing notable anticancer potential. Additionally, the oil displayed antidiabetic properties by impeding crucial enzymes involved in glucose metabolism. Complementary in silico network pharmacology and molecular docking studies provided insights into the possible interactions between CSSLEO's key compounds and essential proteins and pathways in cancer treatment. The results underscored CSSLEO's intricate composition and its promising applications in cancer prevention and diabetes management. The conclusions drawn from this research underscore the need for further investigation to validate CSSLEO's clinical effectiveness and to gain a deeper understanding of its therapeutic mechanisms, with a view to harnessing its potential in oncology and endocrinology.

Parkia javanica Edible Pods Reveal Potential as an Anti-Diabetic Agent: UHPLC-QTOF-MS/MS-Based Chemical Profiling, In Silico, In Vitro, In Vivo, and Oxidative Stress Studies

According to the World Health Organization, over 422 million people worldwide have diabetes, with the majority residing in low- and middle-income countries. Diabetes causes 1.5 million fatalities a year. The number of diabetes cases and its prevalence have progressively increased over the last few decades. This study aims to determine the phytochemicals in the edible part of Perkia javanica, predict their α-glucosidase inhibitory potential, one of the promising targets for diabetes, and then carry out in vitro and in vivo studies. The phytochemicals present in the n-butanol fraction of the methanol extract of P. javanica pods were analyzed using UHPLC-QTOF-MS/MS (Ultra-High-Performance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry). The UHPLC-QTOF analysis revealed the presence of 79 different compounds in the n-butanol fraction. Among these, six compounds demonstrated excellent binding affinities with α-glucosidase, surpassing the performance of two standard inhibitors, Miglitol and Voglibose. In vitro α-glucosidase inhibitory activities were assessed by the n-butanol fraction, followed by in vivo studies. According to the in vitro study, the inhibitory efficiency against α-glucosidase was determined to have an IC50 value of 261.9 µg/mL. The in vivo findings revealed a significant reduction in blood glucose levels in Swiss albino mice treated with the same extract, decreasing from 462.66 mg/dL to 228.66 mg/dL. Additionally, the extract significantly increased the activity of the enzymes catalase and superoxide dismutase (SOD) and decreased the amount of malondialdehyde (MDA) in the liver and kidney tissue. The predicted physicochemical parameters indicated that most of the compounds would be excreted from the body after inhibition in the small intestine without being absorbed. Considering the low cost and wide availability of raw materials, P. javanica pods can serve as a good food supplement that may help prevent type 2 diabetes management.

Pichia pastoris Mediated Digestion of Water-Soluble Polysaccharides from Cress Seed Mucilage Produces Potent Antidiabetic Oligosaccharides

Diabetes mellitus is a heterogeneous metabolic disorder that poses significant health and economic challenges across the globe. Polysaccharides, found abundantly in edible plants, hold promise for managing diabetes by reducing blood glucose levels (BGL) and insulin resistance. However, most of these polysaccharides cannot be digested or absorbed directly by the human body. Here we report the production of antidiabetic oligosaccharides from cress seed mucilage polysaccharides using yeast fermentation. The water-soluble polysaccharides extracted from cress seed mucilage were precipitated using 75% ethanol and fermented with Pichia pastoris for different time intervals. The digested saccharides were fractionated through gel permeation chromatography using a Bio Gel P-10 column. Structural analysis of the oligosaccharide fractions revealed the presence of galacturonic acid, rhamnose, glucuronic acid, glucose and arabinose. Oligosaccharide fractions exhibited the potential to inhibit α-amylase and α-glucosidase enzymes in a dose-dependent manner in vitro. The fraction DF73 exhibited strong inhibitory activity against α-amylase with IC50 values of 38.2 ± 1.12 µg/mL, compared to the positive control, acarbose, having an IC50 value of 29.18 ± 1.76 µg/mL. Similarly, DF72 and DF73 showed the highest inhibition of α-glucosidase, with IC50 values of 9.26 ± 2.68 and 50.47 ± 5.18 µg/mL, respectively. In in vivo assays in streptozotocin (STZ)-induced diabetic mice, these oligosaccharides significantly reduced BGL and improved lipid profiles compared to the reference drug metformin. Histopathological observations of mouse livers indicated the cytoprotective effects of these sugars. Taken together, our results suggest that oligosaccharides produced through microbial digestion of polysaccharides extracted from cress seed mucilage have the potential to reduce blood glucose levels, possibly through inhibition of carbohydrate-digesting enzymes and regulation of the various signaling pathways.

Synthesis and Characterization of Baicalein-loaded Aquasomes: An In vitro and In silico Perspective for Diabetes Mellitus

BACKGROUND

Millions of individuals worldwide suffer from metabolic abnormalities induced by diabetes. Baicalein, a flavonoid, has shown several properties in various treatments with potential properties, including anti-inflammatory, antioxidant, and anti-diabetic properties. Practically, its application is hindered due to low solubility in aqueous media. Overcoming this challenge, aquasomes can offer an effective approach for delivering drugs and bioactive molecules to target various diseases.

OBJECTIVE

The study aimed to develop and evaluate baicalein-loaded aquasomes for improving solubility and comparing their antidiabetic properties to acarbose through in silico docking.

METHODS

Baicalein-loaded aquasomes were prepared through a three-step process: core preparation, lactose coating, and drug loading. The evaluation included assessing particle size, drug-excipient interactions, drug entrapment efficiency, loading capacity, in vitro drug release, and the kinetics of drug release. In silico docking and in vitro α-amylase inhibition activity was evaluated to assess the anti-diabetic potential of baicalein.

RESULTS

The baicalein-loaded aquasomes were spherical with sizes ranging from 300-400 nm. FTIR analysis indicated no interaction between the components. The formulation exhibited drug entrapment efficiency of 94.04±0 4.01% and drug loading of 17.60 ± 01.03%. Drug release study showed sustained and complete (97.30 ± 02.06%) release, following first-order kinetics. Docking analysis revealed comparable binding affinity to acarbose, while the α-amylase inhibition assay showed greater inhibition potential of the aquasomes compared to the baicalein solution.

CONCLUSION

Aquasomes offer an alternative approach to conventional delivery methods. The selfassembling characteristics of aquasomes greatly simplify their preparation process, adding to their appeal as a drug delivery system.

Phytoconstituents of Endiandra kingiana; antidiabetic effects and molecular docking studies on alpha-amylase and alpha-glucosidase

Phytochemical investigation on the bark of E. kingiana plant afforded ten compounds, including six polyketides namely kingianin A 1, kingianin B 2, kingianin E 3, kingianin F 4, kingianin K 5 and kingianin L 6, three endiandric acids; kingianic acid A 7, tsangibeilin B 8 and endiandric acid M 9, and one sesquiterpene; daibuoxide 10. All compounds were separated as racemic mixture by recycling high-performance liquid chromatography (RHPLC), except for daibuoxide. Their structures were elucidated by detailed spectroscopic and comparative literature data analysis. This is the first report on the presence of the sesquiterpene; daibuoxide in Endiandra genus. In vitro enzymatic bio-evaluation of the isolated compounds against α-amylase and α-glucosidase showed that 4 demonstrated the best α-amylase and α-glucosidase inhibitory activity with IC50 values of 181.54 ± 6.27 µg/mL and 237.87 ± 0.07 µg/mL, respectively. In addition, molecular docking analysis confirmed the α-amylase and α-glucosidase inhibitory activities demonstrated by 4.

Enhanced alpha-amylase inhibition activity of amine-terminated PAMAM dendrimer stabilized pure copper-doped magnesium oxide nanoparticles

The present work aims to prepare copper-doped MgO nanoparticles via a sol-gel approach and study their antidiabetic alpha-amylase inhibition activity with undoped MgO nanoparticles. The ability of G5 amine-terminated polyamidoamine (PAMAM) dendrimer for the controlled release of copper-doped MgO nanoparticles to exhibit alpha-amylase inhibition activity was also evaluated. The synthesis of MgO nanoparticles via sol-gel approach and optimization of calcination temperature and time has led to the formation of nanoparticles with different shapes (spherical, hexagonal, and rod-shaped) and a polydispersity in size ranging from 10 to 100 nm with periclase crystalline phase. The presence of copper ions in the MgO nanoparticles has altered their crystallite size, eventually modifying their size, morphology, and surface charge. The efficiency of dendrimer to stabilize spherical copper-doped MgO nanoparticles (ca. 30 %) is higher than in other samples, which was confirmed by UV-Visible, DLS, FTIR, and TEM analysis. The amylase inhibition assay emphasized that the dendrimer nanoparticles stabilization has led to the prolonged enzyme inhibition ability of MgO and copper-doped MgO nanoparticles for up to 24 h.

Chemical characterization, antioxidant and antidiabetic activities of a novel polyherbal formulation comprising of Hordeum vulgare, Elettaria cardamomum and Cicer arietinum extracts

Diabetes mellitus (DM) is the most prevalent endocrine disorder. Numerous individual herbs possess anti-diabetic activity. The seeds of Hordeum vulgare, Elettaria cardamomum and Cicer arietinum are traditionally used to manage DM. The ambition of this work was to formulate the poly-herbal granules (PHGs) comprising of these three functional foods and evaluate their in-vitro antioxidant and antidiabetic potential. The dried seed extracts of Hordeum vulgare, Elettaria cardamomum and Cicer arietinum were used in a ratio of 2.5:1:1 to formulate PHGs by wet granulation method. The ratio of extracts was selected on the basis of traditional phytotherapies popularly used by local Hakeems of Pakistan to achieve glycemic control in diabetic patients resistant to traditional allopathic regime of medicine. The flow properties of developed PHGs were evaluated. The UV-Visible spectroscopic, Fourier Transform Infrared (FTIR) and HPLC-DAD of all seed extracts and PHGs were performed. The in-vitro antioxidant DPPH, FRAP, total antioxidant capacity (TAC) and Nitric Oxide (NO) scavenging assays were carried out on PHGs. The in-vitro antidiabetic activity of PHGs was investigated by alpha-amylase and alpha-glucosidase enzyme inhibition activity. The developed PHGs exhibited excellent flow properties. The UV-Vis spectra of all seed extracts and PHGs demonstrated peak at 278 nm showing the presence of flavonoids and phenols. The FTIR spectra confirmed the existence of flavonoids, and phenols along with amines in seed extracts as well as PHGs. The HPLC-DAD test revealed the existence of gallic acid, ascorbic acid, Quercetin-3-(caffeoyldiglucoside)-7-glucoside, Rosmarinic acid, delphinidin-3,5-diglucosides, Kaempferol-3-feruloylsophoroside-7-glucoside and Phloroglucinol in PHGs. The PHGs exhibited IC50 of 51.23, 58.57, 55.41 and 53.13 μg/mL in DPPH assay, FRAP assay, TAC, Nitric oxide scavenging assays respectively. The PHGs also demonstrated IC50 of 49.97 and 36.16 μg/mL in alpha-amylase and in alpha-glucosidase inhibition assays respectively in dose dependent manner. The developed PHGs exhibited an excellent flow property. These exhibit significant in-vitro antioxidant and antidiabetic profile by virtue of flavonoid and phenolic acid derivatives.

Formulation and Evaluation of Plumbagin-Loaded Niosomes for an Antidiabetic Study: Optimization and In Vitro Evaluation

Diabetes treatment requires focused administration with quality systemic circulation to determine the optimal therapeutic window. Intestinal distribution through oral administration with nanoformulation provides several benefits. Therefore, the purpose of this study is to create plumbagin enclosed within niosomes using the quality by design (QbD) strategy for efficient penetration and increased bioavailability. The formulation and optimization of plumbagin-loaded niosomes (P-Ns-Opt) involved the use of a Box-Behnken Design. The particle size (PDI) and entrapment efficiency of the optimized P-Ns-Opt were 133.6 nm, 0.150, and 75.6%, respectively. TEM, DSC, and FTIR were used to analyze the morphology and compatibility of the optimized P-Ns-Opt. Studies conducted in vitro revealed a controlled release system. P-Ns-Opt's antioxidant activity, α-amylase, and α-glucosidase were evaluated, and the results revealed a dose-dependent efficacy with 60.68 ± 0.02%,90.69 ± 2.9%, and 88.43 ± 0.89%, respectively. In summary, the created P-Ns-Opt demonstrate remarkable potential for antidiabetic activity by inhibiting oxygen radicals, α-amylase, and α-glucosidase enzymes and are, therefore, a promising drug delivery nanocarrier in the management and treatment of diabetes.

Inhibitory Potential of Different Bilberry (Vaccinium myrtillus L.) Extracts on Human Salivary α-Amylase

Recently, consumer preferences for bilberries have increased markedly. This fact is probably related to their natural constituents, such as phenolic compounds including anthocyanins and tannins, as well as the vitamins and minerals they contain. Phenolic compounds are known for their numerous beneficial effects on human health. Moreover, bilberry fruits have been shown to inhibit the activity of carbohydrate hydrolyzing enzymes, which can significantly decrease the postprandial increase in blood glucose levels. Thus, the aim of the present study is to investigate the inhibitory effect of Vaccinium myrtillus L. extracts on key enzyme α-amylase, linked to type 2 diabetes. No data have been published on the inhibitory properties of Vaccinium myrtillus L. fruits growing wild in Bulgaria against carbohydrate enzymes. Bilberry extracts were analyzed for total polyphenols, total anthocyanin content, antioxidant activity and their inhibitory properties against α-amylase. The contents of flavonols, anthocyanins and stilbenes were determined by HPLC analysis. The identified flavonols in the analyzed bilberry extracts were mainly represented by quercetin derivatives as rutinoside. The predominant anthocyanins for both aqueous and organic solvents were delphinidin-3-galactoside and malvidin-3-glucoside. The results revealed that bilberry extracts are effective inhibitors of α-amylase, with IC50 values from 20.8 to 194.8 μg GAE/mL. All the samples proved to have antioxidant activity measured by three different in vitro assays (FRAP, CUPRAC and DPPH). The inhibitory properties of V. myrtillus L. extracts may provide a new direction in the development and research of new pharmaceuticals for the suppression of postprandial hyperglycemia in diabetic patients.

A pre-clinical study to investigate the anti-diabetic potential of p-propoxybenzoic acid as a multi-target inhibitor in streptozotocin-nicotinamide induced type-2 diabetic rats

Purpose

The study was undertaken to evaluate the anti-diabetic potential of p-propoxybenzoic acid (p-PBA).

Methods

36 Sprague-Dawley rats of either sex were utilized for the study. Animals were injected with nicotinamide (230 mg/kg) followed by streptozotocin (65 mg/kg) to induce Type-2 Diabetes (T2DM). Animals with blood glucose levels (BGL) over 200 mg/kg were allocated in six groups. Three groups were treated with p-PBA dose of 100 mg/kg, 200 mg/kg and 300 mg/kg respectively; standard control group was treated with 5 mg/kg glibenclamide, while the other two groups were considered as normal control and disease control group. Body weight (BW) and BGL were recorded on Day 0, Day 7, Day 14, and Day 28. Glycosylated hemoglobin (HbA1c), serum insulin levels and lipid profile were recorded on Day 28. Animals were euthanized on Day 28 and the pancreas was isolated for histopathological examination.

Results

Diabetic animals treated with p-PBA showed significant improvements in BW (P < 0.05) and BGL (P < 0.001) over 28 days. Levels of HbA1c (P < 0.05) and serum insulin (P < 0.001) were significantly regulated in animals treated with p-PBA. A significant decrease (P < 0.001) was observed in elevated levels of TC, TG, LDL cholesterol and VLDL cholesterol in animals treated with p-PBA. p-PBA significantly regulated the levels of HDL cholesterol (P < 0.001). A notable protective effect of p-PBA was observed through the histopathological examination of pancreas.

Conclusion

p-PBA can be characterized as a multi-target inhibiting anti-diabetic agent which can be evaluated against diabetic complications.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-022-01177-y.

The Ethnopharmacological Properties of Green-Engineered Metallic Nanoparticles against Metabolic Disorders

Metabolic syndrome is a multifaceted pathophysiologic condition that is largely caused by an imbalance between caloric intake and energy expenditure. The pathogenesis of metabolic syndrome is determined by an individual's genetic/epigenetics and acquired factors. Natural compounds, notably plant extracts, have antioxidant, anti-inflammatory, and insulin-sensitizing properties and are considered to be a viable option for metabolic disorder treatment due to their low risk of side effects. However, the limited solubility, low bioavailability, and instability of these botanicals hinder their performance. These specific limitations have prompted the need for an efficient system that reduces drug degradation and loss, eliminates unwanted side effects, and boosts drug bioavailability, as well as the percentage of the drug deposited in the target areas. The quest for an enhanced (effective) drug delivery system has led to the formation of green-engineered nanoparticles, which has increased the bioavailability, biodistribution, solubility, and stability of plant-based products. The unification of plant extracts and metallic nanoparticles has helped in the development of new therapeutics against metabolic disorders such as obesity, diabetes mellitus, neurodegenerative disorders, non-alcoholic fatty liver, and cancer. The present review outlines the pathophysiology of metabolic diseases and their cures with plant-based nanomedicine.

A Review of Fibraurea tinctoria and Its Component, Berberine, as an Antidiabetic and Antioxidant

Diabetes mellitus is a group of metabolic disorders characterized by hyperglycemia caused by resistance to insulin action, inadequate insulin secretion, or excessive glucagon production. Numerous studies have linked diabetes mellitus and oxidative stress. People with diabetes usually exhibit high oxidative stress due to persistent and chronic hyperglycemia, which impairs the activity of the antioxidant defense system and promotes the formation of free radicals. Recently, several studies have focused on exploring natural antioxidants to improve diabetes mellitus. Fibraurea tinctoria has long been known as the native Borneo used in traditional medicine to treat diabetes. Taxonomically, this plant is part of the Menispermaceae family, widely known for producing various alkaloids. Among them are protoberberine alkaloids such as berberine. Berberine is an isoquinoline alkaloid with many pharmacological activities. Berberine is receiving considerable interest because of its antidiabetic and antioxidant activities, which are based on many biochemical pathways. Therefore, this review explores the pharmacological effects of Fibraurea tinctoria and its active constituent, berberine, against oxidative stress and diabetes, emphasizing its mechanistic aspects. This review also summarizes the pharmacokinetics and toxicity of berberine and in silico studies of berberine in several diseases and its protein targets.

Antidiabetic activity of Anredera cordifolia (Ten.) Stennis extracts with different ethanol percentages: an evaluation based on in vitro, in vivo, and molecular studies

Anredera cordifolia (Ten.) Stennis, also known as Binahong (B), is an Indonesian plant used to treat diabetes. The purpose of this study was to determine the best extragent for preparing Binahong extract as an antidiabetic agent using different concentrations of ethanol (50%, 70%, and 96%), labelled as BE50%, BE70%, and BE96%. An alpha-glucosidase inhibiting assay was used to assess the activity. The most active extract was tested in vivo assay using an oral glucose tolerance test (OGTT) and alloxan-high feed diet (alloxan-HFD)-induced diabetes in rats, with glucose level and beta cell Langerhans repair as parameters. A molecular assay was also performed to look into the expression of homeostasis regulator genes on 3T3-L1 adipose cells. The results showed that 96% ethanol extract (BE96%) inhibited alpha-glucosidase the most effectively (IC50 119.78± 11.14 μg/mL). The in vivo assay revealed that the treatment BE96% at 250 mg/kg BW for 21 consecutive days significantly reduced plasma glucose levels in Type 2 DM rats compared to the control group (p ≤ .05) with improved of Langerhans beta cells. BE96% also significantly reduced postprandial glucose levels. At the cellular level, Oil-Red-O staining revealed that differentiated adipocytes treated with BE96% had the highest lipid absorbance (p ≤ .05), compared to the control. BE96% significantly increased the expression of Glucose Transporter Isoform 4 (GLUT4) at the molecular level. It could be concluded that BE96% exhibited the best antidiabetic properties.

A Review on Experimental Models to Test Medicinal Plants on Postprandial Blood Glucose in Diabetes

Due to the gravity of postprandial hyperglycemia in the development of microvascular and macrovascular diseases in diabetics, many medicinal plants are tested to determine their effectiveness in glycemic control and the mechanisms of action of the products. Consequently, various diabetic models have been developed and enhanced over the years. The objective of this review is to describe some of the experimental models to study the effect of medicinal plants used to control postprandial hyperglycemia. Data was collected from PubMed, ScienceDirect, Scopus, and Google scholar (1953-2021). Fiftyseven (57) studies were included in this review article. Ten models were identified and described. For each model, we described the targets involved and their roles in postprandial blood glucose control. The experimental design and procedures described the targets such as an α-glucosidase enzyme, SGLT1, GLUT2, DPP-IV, Na+/K+ ATPase pump, or intestinal motility in the models, experiment design and procedures were described. This review will facilitate the selection of the most appropriate model for studying agents used to investigate postprandial blood glucose.

Tissue specific changes of phytochemicals, antioxidant, antidiabetic and anti-inflammatory activities of tea [Camellia sinensis (L.)] extracted with different solvents

Different parts of Camellia sinensis (L.) were extracted with solvents according to polarity, and the extracts' phytochemical profiling and biological activities were examined. The total phenolic (TPC) and total flavonoid (TFC) contents increased with the increasing polarity of the solvent which met its maximum in polar solvents. The increasing antioxidant, anti-inflammatory and antidiabetic activities were recorded with increasing polarity of solvents which showed hydroalcoholic as best solvent. The strong and significant correlation was among the TPC, TFC, DPPH, anti-inflammatory and antidiabetic activities for different parts of tea. HPTLC study of individual phenolic acids, epigallocatechin gallate, gallocatechin and theaflavin met their maximum level of content with polar solvents like hydroalcohol, methanol and water mostly in mainly tea leaves. Our finding suggested that the polar solvents and young leaves of tea were beneficial for obtaining extracts. On the other hand, phenolics were found to be potent antioxidant, anti-inflammatory and antidiabetic agent.

Antidiabetic Potential of Commonly Available Fruit Plants in Bangladesh: Updates on Prospective Phytochemicals and Their Reported MoAs

Diabetes mellitus is a life-threatening disorder affecting people of all ages and adversely disrupts their daily functions. Despite the availability of numerous synthetic-antidiabetic medications and insulin, the demand for the development of novel antidiabetic medications is increasing due to the adverse effects and growth of resistance to commercial drugs in the long-term usage. Hence, antidiabetic phytochemicals isolated from fruit plants can be a very nifty option to develop life-saving novel antidiabetic therapeutics, employing several pathways and MoAs (mechanism of actions). This review focuses on the antidiabetic potential of commonly available Bangladeshi fruits and other plant parts, such as seeds, fruit peals, leaves, and roots, along with isolated phytochemicals from these phytosources based on lab findings and mechanism of actions. Several fruits, such as orange, lemon, amla, tamarind, and others, can produce remarkable antidiabetic actions and can be dietary alternatives to antidiabetic therapies. Besides, isolated phytochemicals from these plants, such as swertisin, quercetin, rutin, naringenin, and other prospective phytochemicals, also demonstrated their candidacy for further exploration to be established as antidiabetic leads. Thus, it can be considered that fruits are one of the most valuable gifts of plants packed with a wide spectrum of bioactive phytochemicals and are widely consumed as dietary items and medicinal therapies in different civilizations and cultures. This review will provide a better understanding of diabetes management by consuming fruits and other plant parts as well as deliver innovative hints for the researchers to develop novel drugs from these plant parts and/or their phytochemicals.

Prediction of α-Glucosidase Inhibitory Activity of LC-ESI-TQ-MS/MS-Identified Compounds from Tradescantia pallida Leaves

Diabetes is a chronic disease that leads to abnormal carbohydrate digestion and hyperglycemia. The long-term use of marketed drugs results in secondary infections and side effects that demand safe and natural substitutes for synthetic drugs. The objective of this study is to evaluate the antidiabetic potential of compounds from the leaves of Tradescantia pallida. Thirteen phenolic compounds were identified from the ethyl acetate fraction of leaves of Tradescantia pallida using liquid chromatography-mass spectrometry. The compounds were then studied for the type of interactions between polyphenols and human α-glucosidase protein using molecular docking analysis. Prime Molecular Mechanics/Generalized Born Surface Area (MM-GBSA) calculations were performed to measure the binding free energies responsible for the formation of ligand-protein complexes. The compounds were further investigated for the thermodynamic constraints under a specified biological environment using molecular dynamic simulations. The flexibility of the ligand-protein systems was verified by Root Mean Square Deviation (RMSD), Root Mean Square Fluctuation (RMSF) and molecular interactions. The results authenticated the antidiabetic potential of polyphenols identified from the leaves of Tradescantia pallida. Our investigations could be helpful in the design of safe antidiabetic agents, but further in vitro and in vivo investigations are required.

Chemical Composition, Antibacterial, Antifungal and Antidiabetic Activities of Ethanolic Extracts of Opuntia dillenii Fruits Collected from Morocco

Opuntia dillenii (Ker Gawl.) Haw. belongs to the Cactaceae family and is native to the arid and semi-arid regions of Mexico and the southern United States. O. dillenii are now used as medicinal plants in various countries. In this study, we investigated the chemical composition of ethanolic extracts obtained from seeds, juice, and peel of O. dillenii fruits collected from Morocco, and we evaluated their antibacterial, antifungal, and antidiabetic activities. Phytochemical screening revealed high quantities of polyphenols (193.73 ± 81.44 to 341.12 ± 78.90 gallic acid eq [g/100 g dry weight]) in the extracts. The major phenolic compounds determined by HPLC were gallic acid, vanillic acid, and syringic acid. Regarding flavonoids, quercetin 3-O-β-D-glucoside and kaempferol were the predominant molecules. Juice extracts showed weak to moderate antibacterial activity against the bacteria species Listeria monocytogenes, Escherichia coli, and Salmonella braenderup. All tested extracts displayed a significant inhibitory effect on α-glucosidase and α-amylase activities in vitro, with the peel extracts showing the greatest inhibitory effects. Together, these findings suggest that O. dillenii fruits are a promising source for the isolation of novel compounds with antibacterial or antidiabetic activities. For the most abundant phytochemicals identified in O. dillenii peel ethanolic extract, molecular docking simulations against human pancreatic α-amylase enzyme were performed. These indicated the presence of bioactive compounds in the extract with a better potential to decrease the enzyme activity than the commercial drug acarbose.

Aqueous Ethanolic Extract of Adiantum incisum Forssk. Protects against Type 2 Diabetes Mellitus via Attenuation of α-Amylase and Oxidative Stress

Purpose : This study was designed to investigate the antidiabetic effects of the aqueous ethanolic extract of Adiantum incisum Forssk. whole plant (AE-AI) in order to validate the folkloric claim. Methods : Streptozotocin (STZ) was used to induce type 2 diabetes mellitus (TII DM) in male Sprague-Dawley rats. STZ-induced diabetic rats were later treated orally with either AE-AI (125, 250, and 500 mg/kg) or glibenclamide for 35 days. Blood glucose levels were measured weekly and on day 35, animals were sacrificed, and blood samples and tissues were harvested for subsequent antioxidant and histopathological analyses. AE-AI was also analyzed in vitro for phytochemical, antioxidant, and α-amylase inhibitory assays. Results : The phytochemical screening of AE-AI confirmed the presence of essential bioactive compounds like cardiac glycosides, flavonoids, phenolic compounds, saponins, and fixed oils. AE-AI demonstrated abundant amounts of total phenolic and flavonoid contents and displayed prominent antioxidant activity as assessed via DPPH, phosphomolybdate, and nitric oxide scavenging assays. AE-AI treatment also showed α-amylase inhibitory activity comparable to acarbose. In addition, AE-AI treatment exhibited a wide margin of safety in rats and dose-dependently reduced STZ-induced blood glucose levels. Moreover, AE-AI increased the levels of GSH, SOD, catalase, and reduced MDA, and therefore prevented pathological effects of STZ on the kidney, liver, and pancreas. The blood glucose regulatory effect and antioxidant activity of AE-AI also aided in normalizing TII DM-mediated dyslipidemias. GC-MS analysis also demonstrated several potential antidiabetic phytoconstituents in AE-AI. Conclusion : These findings reveal that AE-AI possesses certain pharmacologically active compounds that can effectively treat STZ-induced TII DM owing to its antioxidant and α-amylase inhibitory potentials.

Phytochemical Composition and In Vitro Antioxidant, Anti-Inflammatory, Anticancer, and Enzyme-Inhibitory Activities of Artemisia nilagirica (C.B. Clarke) Pamp

Plants have been employed in therapeutic applications against various infectious and chronic diseases from ancient times. Various traditional medicines and folk systems have utilized numerous plants and plant products, which act as sources of drug candidates for modern medicine. Artemisia is a genus of the Asteraceae family with more than 500 species; however, many of these species are less explored for their biological efficacy, and several others are lacking scientific explanations for their uses. Artemisia nilagirica is a plant that is widely found in the Western Ghats, Kerala, India and is a prominent member of the genus. In the current study, the phytochemical composition and the antioxidant, enzyme-inhibitory, anti-inflammatory, and anticancer activities were examined. The results indicated that the ethanol extract of A. nilagirica indicated in vitro DPPH scavenging (23.12 ± 1.28 µg/mL), ABTS scavenging (27.44 ± 1.88 µg/mL), H2O2 scavenging (12.92 ± 1.05 µg/mL), and FRAP (5.42 ± 0.19 µg/mL). The anti-inflammatory effect was also noticed in the Raw 264.7 macrophages, where pretreatment with the extract reduced the LPS-stimulated production of cytokines (p < 0.05). A. nilagirica was also efficient in inhibiting the activities of α-amylase (38.42 ± 2.71 µg/mL), α-glucosidase (55.31 ± 2.16 µg/mL), aldose reductase (17.42 ± 0.87 µg/mL), and sorbitol dehydrogenase (29.57 ± 1.46 µg/mL). It also induced significant inhibition of proliferation in breast (MCF7 IC50 = 41.79 ± 1.07, MDAMB231 IC50 = 55.37 ± 2.11µg/mL) and colon (49.57 ± 1.46 µg/mL) cancer cells. The results of the phytochemical screening indicated a higher level of polyphenols and flavonoids in the extract and the LCMS analysis revealed the presence of various bioactive constituents including artemisinin.

High-performance thin-layer chromatography coupled attenuated total reflectance-Fourier-transform infrared and NMR spectroscopy-based identification of α-amylase inhibitor from the aerial part of Asparagus racemosus Willd

INTRODUCTION

α-Amylase inhibitors from natural sources are of interest for new drug development for the treatment of diabetes mellitus (DM). High-performance thin-layer chromatography (HPTLC) coupled bioassay guided isolation of bioactive compounds has been improved within last few years.

OBJECTIVE

A microchemical derivatised HPTLC-coupled attenuated total reflectance-Fourier-transform infrared (ATR-FTIR) and nuclear magnetic resonance (NMR) spectroscopy was employed for profiling α-amylase inhibitor from the aerial part of Asparagus racemosus Willd.

METHODOLOGY

Asparagus racemosus Willd. aerial part extracted with different solvents (n-hexane, chloroform, ethyl acetate, and methanol) and assayed to detect free radical scavengers and α-amylase inhibitor by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and starch-iodine assay method, respectively. HPTLC-coupled ATR-FTIR and NMR spectroscopy was used to identify the α-amylase inhibitor.

RESULTS

Methanolic extract of A. racemosus showed highest antioxidant activity (21.99 μg GAE/μL) where n-hexane extract showed lowest antioxidant activity (5.87 μg GAE/μL). The α-amylase inhibition was recorded as highest and lowest in ethyl acetate extract (13.13 AE/μL) and n-hexane extract (3.92 AE/μL), respectively. The deep blue zone of α-amylase sprayed TLC plate of extracts with hR_F  = 72 analysed for ATR-FTIR and NMR spectroscopy which revealed the presence of stigmasterol is responsible for α-amylase inhibition.

CONCLUSION

The present work establishes the α-amylase inhibiting properties of A. racemosus maintaining its use for the treatment of DM as a traditional medicine. Bioassay guided isolation through HPTLC-coupled ATR-FTIR and NMR spectroscopy offers an effective method for the exploration of bioactive compounds such as α-amylase inhibitor from complex plant extracts.

Determination of Chemical Compounds and Investigation of Biological Properties of Matricaria chamomilla Essential Oils, Honey, and Their Mixture

This exploratory investigation aimed to determine the chemical composition and evaluate some biological properties, such as antioxidant, anti-inflammatory, antidiabetic, and antimicrobial activities, of Matricaria chamomilla L. essential oils (EOs). EOs of M. chamomilla were obtained by hydrodistillation and phytochemical screening was performed by gas chromatography-mass spectrophotometry (GC-MS). The antimicrobial activities were tested against different pathogenic strains of microorganisms by using disc diffusion assay, the minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) methods. The antidiabetic activity was performed in vitro using the enzyme inhibition test. The antioxidant activity of EOs was tested using the free radical scavenging ability (DPPH method), ferrous ion chelating (FIC) ability, and β-carotene bleaching assay. The anti-inflammatory effects were tested in vivo using the carrageenan-induced paw edema method and in vitro using the inhibition of the lipoxygenase test. The analysis of the phytochemical composition by GC-MS revealed that camphor (16.42%) was the major compound of EOs, followed by 3-carene (9.95%), β-myrcene (8.01%), and chamazulene (6.54%). MCEO, honey, and their mixture exhibited antioxidant activity against the DPPH assay (IC50 ranging from 533.89 ± 15.05 µg/mL to 1945.38 ± 12.71 µg/mL). The mixture exhibited the best radical scavenging activity, with an IC50 of 533.89 ± 15.05 µg/mL. As antidiabetic effect, EO presented the best values against α-glucosidase (265.57 ± 0.03 μg/mL) and α-amylase (121.44 ± 0.05 μg/mL). The EOs and honey mixture at a dose of 100 mg/kg exhibited a high anti-inflammatory effect, with 63.75% edema inhibition after 3 h. The impact of EOs on the studied species showed an excellent antimicrobial (Staphylococcus aureus ATCC 29213 (22.97 ± 0.16 mm)), antifungal (Aspergillus niger (18.13 ± 0.18 mm)) and anti-yeast (Candida albicans (21.07 ± 0.24 mm) effect against all the tested strains. The results obtained indicate that the EOs of M. chamomilla could be a potential drug target against diabetes, inflammation and microbial infections; however, further investigations to assess their bioactive molecules individually and in combination are greatly required.

Chemical Analysis and Investigation of Biological Effects of Salvia officinalis Essential Oils at Three Phenological Stages

Salvia officinalis is a medicinal plant used to treat some diseases, including microbial infections and diabetes. Different studies showed the biological and pharmacological properties of this species. The aim of this study was the determination of the chemical compounds of S. officinalis essential oils and the investigation of their antimicrobial, antioxidant, antidiabetic, and anti-inflammatory properties. The chemical compounds of S. officinalis were determined by GC-MS analysis. The antioxidant activity was assessed by DPPH, ABTS, H₂O₂, and FRAP assays. The in vitro antidiabetic effect was evaluated by the inhibition of α-amylase, α-glucosidase, and lipase activities, and the anti-inflammatory effect was evaluated using the 5-lipoxygenase assay. Moreover, antibacterial activity was assessed against six bacterial strains using agar well diffusion assay and microdilution method. The main compounds in essential oils of S. officinalis at three phenological stages were naphthalenone, camphor, 1.8-cineole, and α-thujone. The full flowering stage essential oil showed the best antioxidant activity with different IC₅₀ values according to the used tests. This oil also exhibited important inhibitory effects at the full flowering stage against α-amylase (IC₅₀ = 69.23 ± 0.1 μg/mL), α-glucosidase (IC₅₀ = 22.24 ± 0.07 μg/mL), and lipase (IC₅₀ = 37.3 ± 0.03 μg/mL). The 5-lipoxygenase inhibitory effect was the best at the full flowering stage (IC₅₀ = 9.24 ± 0.03 μg/mL). The results of the antibacterial evaluation revealed that, at three seasonal periods, S. officinalis essential oil demonstrated strong antibacterial activity. Although the full flowering stage had the best antibacterial activity, there were no significant differences between the three stages. Additionally, the essential oils showed bactericidal effects on Listeria monocytogenes, Staphylococcus aureus, Bacillus subtilis, Proteus mirabilis, Escherichia coli, and Salmonella typhimurium, respectively. The findings of this work showed remarkably that S. officinalis synthesizes essential oils according to different developmental stages. Moreover, it has exhibited interesting biological and pharmacological properties justifying its medicinal effects and suggesting it as a very important source of natural drugs.

A Review of the Potential Consequences of Pearl Millet (Pennisetum glaucum) for Diabetes Mellitus and Other Biomedical Applications

Diabetes mellitus has become a troublesome and increasingly widespread condition. Treatment strategies for diabetes prevention in high-risk as well as in affected individuals are largely attributed to improvements in lifestyle and dietary control. Therefore, it is important to understand the nutritional factors to be used in dietary intervention. A decreased risk of diabetes is associated with daily intake of millet-based foods. Pearl millet is a highly nutritious grain, nutritionally comparable and even superior in calories, protein, vitamins, and minerals to other large cereals, although its intake is confined to lower income segments of society. Pearl millet contains phenolic compounds which possess antidiabetic activity. Thus, it can be used to prepare a variety of food products for diabetes mellitus. Moreover, it also has many health benefits, including combating diabetes mellitus, cancer, cardiovascular conditions, decreasing tumour occurrence, lowering blood pressure, heart disease risk, cholesterol, and fat absorption rate. Therefore, the current review addresses the role of pearl millet in managing diabetes.

Evaluation of Biological Activity of Natural Compounds: Current Trends and Methods

Natural compounds have diverse structures and are present in different forms of life. Metabolites such as tannins, anthocyanins, and alkaloids, among others, serve as a defense mechanism in live organisms and are undoubtedly compounds of interest for the food, cosmetic, and pharmaceutical industries. Plants, bacteria, and insects represent sources of biomolecules with diverse activities, which are in many cases poorly studied. To use these molecules for different applications, it is essential to know their structure, concentrations, and biological activity potential. In vitro techniques that evaluate the biological activity of the molecules of interest have been developed since the 1950s. Currently, different methodologies have emerged to overcome some of the limitations of these traditional techniques, mainly via reductions in time and costs. These emerging technologies continue to appear due to the urgent need to expand the analysis capacity of a growing number of reported biomolecules. This review presents an updated summary of the conventional and relevant methods to evaluate the natural compounds' biological activity in vitro.

Anti-Diabetic Activity of Silver Nanoparticles Synthesized from the Hydroethanolic Extract of Myristica fragrans Seeds

Myristica fragrans, also known as nutmeg, is a spice that cures various diseases. This study aimed to synthesize silver nanoparticles from a hydroethanolic extract of Myristica fragrans seeds (MFHE) and evaluate their anti-diabetic properties. To MFHE, AgNO3 solution was added and exposed to sunlight to produce silver nanoparticles from hydroethanolic seed extract of Myristica fragrans (MFHENP). The MFHENP was characterized by numerous techniques. UV-visible spectroscopy confirmed the formation of silver nanoparticles by the absorption peak at 430nm. Scanning electron microscopy (SEM) studies revealed the shape and size of the particles at the range of 50-60nm. Energy-dispersive X-ray spectroscopy (EDX) disclosed the presence of silver ions. X-ray diffraction spectrum confirmed the crystalline nature of silver nanoparticles by the peak at 39°. FTIR analysis revealed the functional groups present in MFHE as well as in MFHENP and zeta potential analysis was found to be 14mV. Furthermore, in vitro anti-diabetic activity was investigated. MFHENP showed significant efficiency against the inhibition of alpha-amylase and alpha-glucosidase enzymes and also MFHENP retarded the glucose transport across the membrane which is analyzed by glucose diffusion and glucose uptake assays. Acarbose is used as a standard for all these methods and MFHENP efficiency proves their therapeutic potential for the treatment of diabetes mellitus.

Protective effect of vanillic acid against diabetes and diabetic nephropathy by attenuating oxidative stress and upregulation of NF-κB, TNF-α and COX-2 proteins in rats

Diabetes is the most prevalent disorder in the world characterized by uncontrolled high blood glucose levels and nephropathy is one of the chief complications allied with hyperglycemia. Vanillic acid; the main bioactive compound derived from natural sources such as vegetables, fruits and plants possesses various pharmacological activities such as antioxidant, anti-inflammatory and anti-proliferative. The current study was designed to investigate the antidiabetic and renoprotective effects of vanillic acid by its various pharmacological activities. Streptozotocin (50 mg/kg)/nicotinamide (110 mg/kg) was used to induce diabetes in rats. Oral administration of vanillic acid once daily for 6 weeks (25, 50 and 100 mg/kg) significantly reduced the hyperglycemia, increased liver enzymes and normalized lipid profile that was altered in diabetic rats. Moreover, vanillic acid attenuated the impaired renal function as evidenced by a reduction in serum creatinine, urea, uric acid and urinary microproteinuria levels with a concomitant increase in urinary creatinine clearance in the nephropathic rats. Diabetic rats showed a marked increase in thiobarbituric acid reactive substances (TBARS) and superoxide anion generation (SAG) along with decreased reduced glutathione (GSH) in the renal tissue which was ameliorated in the vanillic acid-treated rats. Histopathologically, vanillic acid treatment was associated with reduced damage with normalized structural changes in renal tissue. Furthermore, treatment groups showed the suppression of upregulation of nuclear factor (NF)-κB, tumor necrosis factor (TNF)-α, cyclo-oxygenase (COX)-2 and up-regulation of Nuclear factor-erythroid 2-related factor 2 (Nrf-2) in the renal tissue. In conclusion, vanillic acid's ameliorative impact on diabetic nephropathic rats may be attributed to its powerful free radical scavenging property, down-regulation of NF-κB, TNF-α, COX-2 and up-regulation of Nrf-2 proteins in renal tissue.

Antidiabetic Phytochemicals From Medicinal Plants: Prospective Candidates for New Drug Discovery and Development

Diabetes, a chronic physiological dysfunction affecting people of different age groups and severely impairs the harmony of peoples' normal life worldwide. Despite the availability of insulin preparations and several synthetic oral antidiabetic drugs, there is a crucial need for the discovery and development of novel antidiabetic drugs because of the development of resistance and side effects of those drugs in long-term use. On the contrary, plants or herbal sources are getting popular day by day to the scientists, researchers, and pharmaceutical companies all over the world to search for potential bioactive compound(s) for the discovery and development of targeted novel antidiabetic drugs that may control diabetes with the least unwanted effects of conventional antidiabetic drugs. In this review, we have presented the prospective candidates comprised of either isolated phytochemical(s) and/or extract(s) containing bioactive phytoconstituents which have been reported in several in vitro, in vivo, and clinical studies possessing noteworthy antidiabetic potential. The mode of actions, attributed to antidiabetic activities of the reported phytochemicals and/or plant extracts have also been described to focus on the prospective phytochemicals and phytosources for further studies in the discovery and development of novel antidiabetic therapeutics.

Citrus Flavanone Narirutin, In Vitro and In Silico Mechanistic Antidiabetic Potential

Citrus fruits and juices have been studied extensively for their potential involvement in the prevention of various diseases. Flavanones, the characteristic polyphenols of citrus species, are the primarily compounds responsible for these studied health benefits. Using in silico and in vitro methods, we are exploring the possible antidiabetic action of narirutin, a flavanone family member. The goal of the in silico research was to anticipate how narirutin would interact with eight distinct receptors implicated in diabetes control and complications, namely, dipeptidyl-peptidase 4 (DPP4), protein tyrosine phosphatase 1B (PTP1B), free fatty acid receptor 1 (FFAR1), aldose reductase (AldR), glycogen phosphorylase (GP), alpha-amylase (AAM), peroxisome proliferator-activated receptor gamma (PPAR-γ), alpha-glucosidase (AGL), while the in vitro study looked into narirutin’s possible inhibitory impact on alpha-amylase and alpha-glucosidase. The results indicate that the studied citrus flavanone interacted remarkably with most of the receptors and had an excellent inhibitory activity during the in vitro tests suggesting its potent role among the different constituent of the citrus compounds in the management of diabetes and also its complications.

Improved Biomedical Properties of Polydopamine-Coated Carbon Nanotubes

Carbon nanotubes (CNTs) due to their outstanding mechanical, thermal, chemical, and optical properties were utilized as a base material and were coated with polydopamine (PDA) (PDA@CNT) via the simple self-polymerization of dopamine (DA). Then, PDA@CNT coatings of up to five layers were examined for potential biomedical applications. The success of multiple coating of CNTs with PDA was confirmed via increased weight loss values with the increased number of PDA coatings of CNTs at 500 °C by thermogravimetric analysis. The surface area of bare CNTs was measured as 263.9 m2/g and decreased to 197.0 m2/g after a 5th coating with PDA. Furthermore, the antioxidant activities of CNT and PDA@CNTs were determined via total flavonoid content (TFC), total phenol content (TPC), and Fe(III)-reducing antioxidant power (FRAP) tests, revealing the increased antioxidant ability of PDA@CNTs with the increasing numbers of PDA coatings. Moreover, a higher inhibition percentage of the activity of the alpha-glucosidase enzyme with 95.1 ± 2.9% inhibition at 6 mg/mL PDA-1st@CNTs concentration was found. The CNT and PDA@CNTs exhibited blood compatibility, less than a 2.5% hemolysis ratio, and more than 85% blood clotting indexes. The minimum inhibition concentration (MIC) of PDA-5th@CNTs against E. coli and S. aureus bacteria was determined as 10 mg/mL.

In Vivo and In Vitro Antidiabetic and Anti-Inflammatory Properties of Flax (Linum usitatissimum L.) Seed Polyphenols

Flaxseed is an oilseed (45-50% oil on a dry-weight basis) crop. Its oil has demonstrated multiple health benefits and industrial applications. The goal of this research was to evaluate the antidiabetic and anti-inflammatory potential of the free polyphenol fraction of flax (Linum usitatissimum L.) seeds (PLU), based on their use in traditional medicine. Mice with alloxan-induced diabetes were used to study the antidiabetic activity of PLU in vivo, with an oral administration of 25 and 50 mg/kg over 28 days. Measurements of body weight and fasting blood glucose (FBG) were carried out weekly, and biochemical parameters were evaluated. An oral glucose tolerance test was also performed. Inhibitory activities of PLU on α-amylase and α-glucosidase activities were evaluated in vitro. The anti-inflammatory was evaluated in vivo in Wistar rats using the paw edema induction Test by carrageenan, and in vitro using the hemolysis ratio test. PLU administration to diabetic mice during the study period improved their body weight and FBG levels remarkably. In vitro inhibitory activity of digestive enzymes indicated that they may be involved in the proposed mode of action of PLU extract. Qualitative results of PLU revealed the presence of 18 polyphenols. These findings support daily consumption of flaxseed for people with diabetes, and suggest that polyphenols in flaxseed may serve as dietary supplements or novel phytomedicines to treat diabetes and its complications.

Antioxidants Isolated from Elaeagnus umbellata (Thunb.) Protect against Bacterial Infections and Diabetes in Streptozotocin-Induced Diabetic Rat Model

The increase in resistance of microbes against conventional drugs is currently a hot issue, whereas diabetes is another main cause of mortalities encountered throughout the world after cancer and heart attacks. New drug sources in the form of plants are investigated to get effective drugs for the mentioned diseases with minimum side effects. Elaeagnus umbellata Thunb. is a medicinal plant used for the management of stress related disorders like diabetes and other health complications. The active constituents of the chloroform extract derived from E. umbellata berries was isolated by silica gel column chromatography which were identified as morin, phloroglucinol, and 1-hexyl benzene through various spectroscopic techniques (electron ionization mass spectrometry, 1H-NMR, and 13C-NMR spectroscopy). The possible protective effects (antioxidant, antibacterial, and antidiabetic activity) of isolated compounds were evaluated using reported methods. Morin exhibited strong in vitro antiradical potential against DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid) radicals along with prominent antibacterial activities against selected bacterial strains (Escherichia coli, Bacillus cereus, Salmonella typhi, Klebsiella pneumonia, Pseudomonas aeruginosa and Proteus mirabilis). Among the isolated compounds the more potent one (morin) was assessed for its in vivo antidiabetic potential in streptozotocin-induced diabetic rat model. The in vivo effects observed were further confirmed in ex vivo experiments where the effect of isolated compound on antioxidant enzyme like glutathione peroxidase (GPx), total content of reduced glutathione (GSH), % DPPH inhibition, and the lipid peroxidation MDA (Malondialdehyde) level in pancreatic tissues homogenates were evaluated. In vivo morin at tested doses (2, 10, 15, 30 and 50 mg/kg body weight) significantly restored the alterations in the levels of fasting blood glucose level and body weight loss along with significant decrease in levels of cholesterol, triglycerides, low density lipoprotein, HbA1c level, and significantly increased the high-density lipoprotein in diabetic rats. Morin also effectively ameliorated the hepatic enzymes, and renal functions like serum creatinine. Morin significantly increased the antioxidant enzyme like GPx activity, GSH content, and % DPPH inhibition activity, while reduced the lipid peroxidation MDA (malondialdehyde) level in pancreatic tissues homogenates, and modification of histopathological changes in diabetic rats. Morin exhibited high antioxidant, antibacterial, and antidiabetic potentials as compared to phloroglucinol and 1-hexyl benzene, that could, therefore, be considered as a promising therapeutic agent to treat diabetes mellitus and bacterial infections.

Development and Characterization of Novel Biopolymer Derived from Abelmoschus esculentus L. Extract and Its Antidiabetic Potential

Abelmoschus esculentus (Okra) is an important vegetable crop, widely cultivated around the world due to its high nutritional significance along with several health benefits. Different parts of okra including its mucilage have been currently studied for its role in various therapeutic applications. Therefore, we aimed to develop and characterize the okra mucilage biopolymer (OMB) for its physicochemical properties as well as to evaluate its in vitro antidiabetic activity. The characterization of OMB using Fourier-transform infrared spectroscopy (FT-IR) revealed that okra mucilage containing polysaccharides lies in the bandwidth of 3279 and 1030 cm^-1, which constitutes the fingerprint region of the spectrum. In addition, physicochemical parameters such as percentage yield, percentage solubility, and swelling index were found to be 2.66%, 96.9%, and 5, respectively. A mineral analysis of newly developed biopolymers showed a substantial amount of calcium (412 mg/100 g), potassium (418 mg/100 g), phosphorus (60 mg/100 g), iron (47 mg/100 g), zinc (16 mg/100 g), and sodium (9 mg/100 g). The significant antidiabetic potential of OMB was demonstrated using α-amylase and α-glucosidase enzyme inhibitory assay. Further investigations are required to explore the newly developed biopolymer for its toxicity, efficacy, and its possible utilization in food, nutraceutical, as well as pharmaceutical industries.

Enzymatic Synthesis, Structural Analysis, and Evaluation of Antibacterial Activity and α-Glucosidase Inhibition of Hesperidin Glycosides

This study was designed to investigate the structure of synthesized hesperidin glycosides (HGs) and evaluate their antibacterial and α-glucosidase inhibitory activities. The preliminary structure of HGs was confirmed by glucoamylase treatment and analyzed on thin layer chromatography (TLC). The LC-MS/MS profiles of HGs showed the important fragments at m/z ratios of 345.21 (added glucose to glucose of rutinose in HG1) and 687.28 (added maltose to glucose of rutinose in HG2), confirming that the structures of HG1 and HG2 were α-glucosyl hesperidin and α-maltosyl hesperidin, respectively. In addition, 1H and 13C-NMR of hesperidin derivatives were performed to identify their α-1,4-glycosidic bonds. The MIC and MBC studies showed that transglycosylated HG1 and HG2 had better antibacterial and bactericidal activities than hesperidin and diosmin, and were more active against Staphylococcus aureus than Escherichia coli. Hesperidin, HG1, HG2, and diosmin inhibited α-glucosidase with IC50 values of 2.75 ± 1.57, 2.48 ± 1.61, 2.36 ± 1.48, and 2.99 ± 1.23 mg/mL, respectively. The inhibition kinetics of HG2 shown by a Lineweaver–Burk plot confirmed HG2 was an α-glucosidase competitive inhibitor with an inhibitor constant, Ki, of 2.20 ± 0.10 mM. Thus, HGs have the potential to be developed into antibacterial drugs and treatments for treating α-glucosidase-associated type 2 diabetes.

Alotaibi A, Al-zharani M, Ziyyat A, Mekhfi H, Legssyer A, Aziz M, Bnouham M. Opuntia dillenii (Ker Gawl.) Haw., Seeds Oil Antidiabetic Potential Using In Vivo, In Vitro, In Situ, and Ex Vivo Approaches to Reveal Its Underlying Mechanism of Action

Opuntia dillenii Ker Gawl. is one of the medicinal plants used for the prevention and treatment of diabetes mellitus (DM) in Morocco. This study aims to investigate the antihyperglycemic effect of Opuntia dillenii seed oil (ODSO), its mechanism of action, and any hypoglycemic risk and toxic effects. The antihyperglycemic effect was assessed using the OGTT test in normal and streptozotocin (STZ)-diabetic rats. The mechanisms of action were explored by studying the effect of ODSO on the intestinal absorption of d-glucose using the intestinal in situ single-pass perfusion technique. An Ussing chamber was used to explore the effects of ODSO on intestinal sodium-glucose cotransporter 1 (SGLT1). Additionally, ODSO’s effect on carbohydrate degrading enzymes, pancreatic α-amylase, and intestinal α-glucosidase was evaluated in vitro and in vivo using STZ-diabetic rats. The acute toxicity test on mice was performed, along with a single-dose hypoglycemic effect test. The results showed that ODSO significantly attenuated the postprandial hyperglycemia in normal and STZ-diabetic rats. Indeed, ODSO significantly decreased the intestinal d-glucose absorption in situ. The ex vivo test (Ussing chamber) showed that the ODSO significantly blocks the SGLT1 (IC₅₀ = 60.24 µg/mL). Moreover, ODSO indu\ced a significant inhibition of intestinal α-glucosidase (IC₅₀ = 278 ± 0.01 µg/mL) and pancreatic α-amylase (IC₅₀ = 0.81 ± 0.09 mg/mL) in vitro. A significant decrease of postprandial hyperglycemia was observed in sucrose/starch-loaded normal and STZ-diabetic ODSO-treated rats. On the other hand, ODSO had no risk of hypoglycemia on the basal glucose levels in normal rats. Therefore, no toxic effect was observed in ODSO-treated mice up to 7 mL/kg. The results of this study suggest that ODSO could be suitable as an antidiabetic functional food.