Inhibitory potential of traditional herbs on α-amylase activity

Natural Compounds of Lasia spinosa (L.) Stem Potentiate Antidiabetic Actions by Regulating Diabetes and Diabetes-Related Biochemical and Cellular Indexes

Natural biometabolites of plants have been reported to be useful in chronic diseases including diabetes and associated complications. This research is aimed to investigate how the biometabolites of Lasia spinosa methanol stem (MEXLS) extract ameliorative diabetes and diabetes-related complications. MEXLS was examined for in vitro antioxidant and in vivo antidiabetic effects in a streptozotocin-induced diabetes model, and its chemical profiling was done by gas chromatography-mass spectrometry analysis. The results were verified by histopathological examination and in silico ligand-receptor interaction of characterized natural biometabolites with antidiabetic receptor proteins AMPK (PDB ID: 4CFH); PPARγ (PDB ID: 3G9E); and mammalian α-amylase center (PDB ID: 1PPI). The MEXLS was found to show a remarkable α-amylase inhibition (47.45%), strong antioxidant action, and significant (p < 0.05) decrease in blood glucose level, serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), low-density lipoprotein (LDL), urea, uric acid, creatinine, total cholesterol, triglyceride (TG), liver glycogen, creatinine kinase (CK-MB), and lactate dehydrogenase (LDH) and increase in serum insulin, glucose tolerance, and high-density lipoprotein (HDL). Rat’s pancreas and kidney tissues were found to be partially recovered in histopathological analyses. Methyl α-d-galactopyranoside displayed the highest binding affinity with AMPK (docking score, −5.764), PPARγ (docking score, −5.218), and 1PPI (docking score, −5.615) receptors. Data suggest that the MEXLS may be an exciting source to potentiate antidiabetic activities affirming a cell-line study.

HPLC-DAD phenolics screening and in vitro investigation of haemostatic, antidiabetic, antioxidant and photoprotective properties of Centaurea tougourensis Boiss. & Reut

Introduction

Traditional medicine has an important place in human history and this since antiquity. Indeed, during Egyptian and Chinese civilization era, many detailed manuscripts, describing the therapeutic effect of plants, were found which suggest that folk medicine is the basis of the actual medicine.

Objective

To investigate the phytochemical and pharmacological properties of the n-butanol (n-BuOH) and ethyl acetate (EA) extracts of the aerial part of Centaurea tougourensis.

Methods

The phytochemical evaluation was done based on HPLC-DAD approach. The antioxidant activity was determined by DPPH and cupric ion reducing antioxidant capacity (CUPRAC), while the hemostatic effect was performed using plasma recalcification time (PRT) method. The antidiabetic capacity was investigated by alpha-amylase inhibition assay and the photoprotective test was evaluated by the measurement of sun protection factor (SPF).

Results

13 phenolic compounds were identified in both extracts of C. tougourensis. These extracts showed antioxidant, haemostatic, antidiabetic and photoprotective properties with a dose-dependent manner. Amounts of n-BuOH activities were found higher, with a respective IC50 value of 0.72±0.07 μg/ml in DPPH assay, an A0.50 value lower than 3.125 μg/ml in CUPRAC assay besides a shortening rate percentage of coagulation (86.71%) in haemostatic assay, a moderate inhibition effect on alpha amylase activity with an IC50 value of (711.5±0.03 μg/ml) and a maximum sun protection factor of (56.035). These results were mostly found highly significant (p<0.001) when compared to respective standards.

Conclusion

This study demonstrated some pharmacological effects of C. tougourensis which suggests that our plant could be a good candidate to treat some illnesses related to oxidative stress, bleeding or skin cancer.

The Glycemic Control Potential of Some Amaranthaceae Plants, with Particular Reference to In Vivo Antidiabetic Potential of Agathophora alopecuroides

Natural products continue to provide inspiring moieties for the treatment of various diseases. In this regard, investigation of wild plants, which have not been previously explored, is a promising strategy for reaching medicinally useful drugs. The present study aims to investigate the antidiabetic potential of nine Amaranthaceae plants: Agathophora alopecuroides, Anabasis lachnantha, Atriplex leucoclada, Cornulaca aucheri, Halothamnus bottae, Halothamnus iraqensis, Salicornia persia, Salsola arabica, and Salsola villosa, growing in the Qassim area, the Kingdom of Saudi Arabia. The antidiabetic activity of the hydroalcoholic extracts was assessed using in vitro testing of α-glucosidase and α-amylase inhibitory effects. Among the nine tested extracts, A. alopecuroides extract (AAE) displayed potent inhibitory activity against α-glucosidase enzyme with IC₅₀ 117.9 µg/mL noting better activity than Acarbose (IC₅₀ 191.4 µg/mL). Furthermore, AAE displayed the highest α- amylase inhibitory activity among the nine tested extracts, with IC₅₀ 90.9 µg/mL. Based upon in vitro testing results, the antidiabetic activity of the two doses (100 and 200 mg/kg) of AAE was studied in normoglycemic and streptozotocin (STZ)-induced diabetic mice. The effects of the extract on body weight, food and water intakes, random blood glucose level (RBGL), fasting blood glucose level (FBGL), insulin, total cholesterol, and triglycerides levels were investigated. Results indicated that oral administration of the two doses of AAE showed a significant dose-dependent increase (p < 0.05) in the body weight and serum insulin level, as well as a significant decrease in food and water intake, RBGL, FBGL, total cholesterol, and triglyceride levels, in STZ-induced diabetic mice, compared with the diabetic control group. Meanwhile, no significant differences of both extract doses were observed in normoglycemic mice when compared with normal control animals. This study revealed a promising antidiabetic activity of the wild plant A. alopecuroides.

Inhibitory Potential of Acroptilon repens against Key Enzymes involved in Alzheimer and Diabetes, Phytochemical Profile, Radical Scavenging, and Antibacterial Activity

Background:

This study was devoted to assessing the inhibitory potential of acetone, methanol, and ethanol extracts of Acroptilon repens against disease-associated enzymes, as well as their antioxidant/antibacterial activity and phytochemical composition.

Methods:

Comparative assessment using various antioxidant evaluation methods, including FRAP, scavenging ability on DPPH radical and hydrogen peroxide, and RP, indicated that the acetone extract presented the highest antioxidant activity, due to its highest total antioxidant content.

Results:

The TPC and TFC of these extracts were 3.44 ± 0.32 mg GAE/g DW and 2.09 ± 0.2 mg QE/g DW, respectively. The hydrodistillation essential oil from A. repens was analyzed by GC/MS, and 17 compounds were identified. All extracts showed good inhibitory activities against disease-related enzyme acetylcholinesterase and α-amylase, with the lowest IC₅₀ for acetonic extract. Extracts of A. repens exhibited inhibiting activities against the Gram-positive bacteria, with the most effect of acetone extract.

Conclusion:

Our findings suggest A. repens as a promising source of natural antioxidant, antimicrobial, anti-cholinesterase and anti-amylase agents for the management of oxidative damage, and pharmaceutical, food, and cosmeceutical purposes.

Antioxidant, Antidiabetic, and Anti-obesity Potential of Ipomoea reptans Poir Leaves

Ipomoea reptans Poir or kangkung is a popular leafy vegetable, a favorite to people in Asian countries. However, limited information is available on their bioactivities. In the present study, the antioxidant, antidiabetic, and anti-obesity potential of I. reptans leaves were investigated. Different fractions (ethanol, ethyl acetate, and hexane) of I. reptans leaves were evaluated for their scavenging activity on DPPH radicals, whereas their reducing potential was investigated by cupric reducing antioxidant capacity (CuPRAC), total antioxidant, and reducing power assays. The antidiabetic potential was investigated by their inhibition effect on a-glucosidase. Total phenolic and flavonoid contents of I. reptans leaves were solvent dependent. Ethyl acetate contained the highest phenolic content, followed by ethanol and hexane fractions. However, for flavonoid content, the order was ethanol > ethyl acetate > hexane. All fractions showed DPPH scavenging activity in a concentration-dependent manner, with activities weaker than standards ascorbic acid and BHT, in the order of ethanol > ethyl acetate > hexane. All fractions showed reducing capacity, but only hexane and ethanol fractions of I. reptans leaves showed inhibition on a-glucosidase, with hexane showed more potent inhibition compared to acarbose. The study also found that fractions of I. reptans inhibit lipase and trypsin, enzymes related to lipid metabolism. Findings in this study offer a prospect for I. reptans leaves as a functional food source for antioxidant, antidiabetic, and anti-obesity purposes.

Chemical Composition, Antioxidant Potential and Enzymes Inhibitory Properties of Globe Artichoke By-Products

In this study, chemical composition and in vitro biological activities of artichoke by-products (leaves, floral stems and bracts) issued from two Tunisian varieties were evaluated. Analysis was performed by means of high-performance liquid chromatography with diode array detection coupled to electrospray ionization mass spectrometric (LC/DAD/ESI-MS). Total phenolic (TPC) and flavonoid (TFC) contents as well as the antioxidant activity conducted by three complementary methods, DPPH, ABTS and FRAP tests, were performed for each sample. Enzyme inhibitory effects against acetylcholinesterase, butyrylcholinesterase and α-amylase were also studied. Results showed that TPC and TFC varied according to variety as well as the plant part. Bracts presented the highest TPC values (10-15 mg GAE/g DW), while leaves were distinguished by the highest TFC values (52-58 mg EQ/g DW). In vitro assays showed that Violet d'Hyères bracts and Blanc d'Oran leaves present the most antioxidant activities (30.040 and 20.428 mgET/gDW, respectively, by the DPPH method). Leaves demonstrated the highest acetylcholinesterase and butyrylcholinesterase inhibitory effects. Moreover, all organs displayed a noticeable inhibition towards α-amylase. LC/DAD/MS analysis revealed that artichoke by-products are a potential source of biopharmaceuticals such as luteolin derivatives from leaves and mono/dicaffeoylquinic acids in the other parts. This research demonstrates that globe artichoke by-products, unexploited in our country, are a promising source of natural health promoting compounds with potential applications in the food and pharmaceutical industries.

Molecular dynamics simulation for screening phytochemicals as α-amylase inhibitors from medicinal plants

Diabetes mellitus (DM) is a complicated metabolic disorder with several enzymes, including α-amylase and α-glycosidase. The α-amylase is responsible for postprandial glucose levels; therefore, inhibiting its activity is helpful in diabetes management. Hence, to find natural inhibitors of α-amylase, we have prepared a 257 phytochemical library from selected medicinal plants with antidiabetic activity and conducted a virtual screening and molecular dynamics study. Seventy-nine phytochemicals were screened out of 257 phytochemicals based on binding energy, ranged from -10.1 kcal mol^-1 to -7.6 kcal mol^-1. The binding energies of screened compounds were lower or equal to the reference molecule (-7.6 kcal mol^-1). The binding affinity of six screened phytochemicals was re-scored by X-SCORE. These phytochemicals were subjected to ADMET and Drug-likeness analysis. After screening docking and drug-likeness analysis, six phytochemicals viz., Shahidine, Epicatechin, Quercetin, Isocolumbin, Ellagic acid, Luteolin and a reference molecule (Acarbose) were subjected to Molecular dynamics (MD) simulation to analyze the stability of the docked protein-ligand complex. The values of root mean square deviation, RMSF, RG, SASA, H-Bond, the interaction energy of all protein-ligand complexes were calculated after 30 ns of MD simulation. The results of screened complexes revealed good stability as compared to reference Acarbose. Pharmacophore features of the screened phytochemicals and α-amylase inhibitors showed many common pharmacophore features. Based on finding the screened phytochemicals, e.g. Shahidine, Epicatechin, Quercetin, Isocolumbin, Ellagic acid, and Luteolin, may be used as a potential inhibitors against α-amylase. These phytochemicals could be optimized and synthesized to develop potential drugs to manage and treat diabetes, targeting α-amylase.Communicated by Ramaswamy H. Sarma.

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

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

Effect of aqueous extract of Aegle marmelos fruit and leaf on glycemic, insulinemic and lipidemic status of type 2 diabetic model rats

BackgroundAegle marmelos is a popular fruit plant in the Indian subcontinent, various parts of which are traditionally used against various illnesses including diabetes mellitus (DM). However, the underlying mechanisms of the antidiabetic effects of the plant are not clear, especially in type 2 DM. The present study was undertaken to investigate the effect of aqueous extracts of A. marmelos fruits (AMFE) and leaves (AMLE) on glycemic, lipidemic, insulinemic, insulin resistance and β-cell functional status of type 2 diabetic model rats. Methods An interventional study was designed using 20 type 2 diabetic rats. Type 2 DM was induced in Long Evans rats by a single intra-peritoneal injection of streptozotocin (90 mg/kg body weight) to 48 h old pups. Three months after induction of diabetes, the rats were divided into three independent groups: water-treated control group (n=6), AMLE-treated group (n=7) and AMFE-treated group (n=7). The rats were fed with extracts or water for 21 consecutive days and blood samples were collected at days 0 and 21 after an overnight fast. Data were expressed as mean±SD and analyzed by paired t-test or ANOVA as appropriate. Results There were significantly lower blood glucose values in AMLE and AMFE groups at Endpoint compared to Baseline (mmol/l, mean±SD, Baseline vs. Endpoint, 7.04±1.0 vs. 6.06±0.92; p=0.032 and 7.04±0.97 vs. 5.87±0.93; p=0.047). There were also significantly lower serum insulin levels in AMLE and AMFE groups at Endpoint compared to Baseline (µIU/mL, mean±SD, Baseline vs. Endpoint, 14.02±5.48 vs. 7.57±2.90; p=0.026 and 11.54±4.83 vs. 6.58±4.36; p=0.008). Insulin resistance (HOMA-IR) was significantly improved both in AMLE and AMFE groups at Endpoint compared to Baseline (mean±SD, Baseline vs. Endpoint, 4.22±1.68 vs. 2.05±0.90; p=0.021 and 3.69±1.79 vs. 1.69±1.61; p=0.013). However, β-cell function or lipid profile did not show any significant alteration at Endpoint compared to Baseline in AMLE and AMFE groups. Conclusions Aqueous extracts of A. marmelos leaf and fruit have hypoglycemic property which seem to be mediated by lowering of insulin resistance. These findings highlight the therapeutic potential of the extracts of A. marmelos in human type 2 DM and provides strong impetus for further studies.

GC-MS analysis and in vitro antioxidant and enzyme inhibitory activities of essential oil from aerial parts of endemic Thymus spathulifolius Hausskn. et Velen

We investigated the antioxidant and enzyme inhibitory activities and chemical composition of the hydro-distilled essential oil (0.35% yield) from aerial parts of Thymus spathulifolius. Antioxidant capacity of the oil was assessed by different methods including free radical scavenging (DPPH and ABTS), reducing power (FRAP and CUPRAC) and phosphomolybdenum assay. Inhibitory activities were analyzed against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-amylase, α-glucosidase, and tyrosinase. Twenty-one constituents were identified representing 97.2% of the total oil with thymol (50.5%), borneol (16.7%) and carvacrol (7.7%) as the major components. The essential oil exhibited good antioxidant activity with IC50 values of 3.82 and 0.22 mg/mL determined by free radical scavenging DPPH and ABTS, respectively. EC50 values of FRAP and CUPRAC were found to be 0.12 and 0.34 mg/mL, respectively. The results of the present study support the uses of T. spathulifolius essential oil as a source of natural antioxidants and bioactivities for functional foods and phytomedicines.

In vivo and in vitro antimalarial activity of bergenin

Malaria is a potentially life-threatening protozoal parasitic disease transmitted by female Anopheles mosquitoes. Drug therapy is currently the most widely used method for the control and treatment of this disease. Several plants were found to contain substances possessing antimalarial properties. In this study, we investigated the antimalarial activity of bergenin, a sesquiterpene lactone compound derived from Rodgersia aesculifolia Batal. The results indicated that bergenin effectively inhibited Plasmodium falciparum growth in vitro (IC50, 14.1 μg/ml, with ~100% inhibition at 50 μg/ml), without apparent cytotoxicity to erythrocytes or to mammalian HeLa and HepG2 cells. Bergenin exhibited less cytotoxic activity and the selectivity index (SI) was 887 and 1,355 for HeLa and HepG2 cells, respectively. The administration of bergenin to Plasmodium berghei-infected mice for 6 days significantly inhibited the growth of the parasites. Taken together, these findings provide evidence that bergenin may be a promising novel drug for antimalarial treatment.

Tropical plant extracts as potential antihyperglycemic agents

Preliminary investigations on 14 plant extracts (obtained by ethanolic and aqueous extraction) identified those having high antioxidant and a significant total phenolic content. Antihyperglycemic, α-amylase and α-glucosidase inhibition activities were also observed. A correlation between the antihyperglycemic activity, total phenolic content and antioxidant (DPPH scavenging) activity was established. To further substantiate these findings, the possibility of tannins binding non-specifically to enzymes and thus contributing to the antihyperglycemic activity was also investigated. Our study clearly indicated that the antihyperglycemic activity observed in the plant extracts was indeed not due to non-specific tannin absorption.