Punica granatum flower extract, a potent alpha-glucosidase inhibitor, improves postprandial hyperglycemia in Zucker diabetic fatty rats

Evaluation of destruction of bacterial membrane structure associated with anti-quorum sensing and ant-diabetic activity of Cyperus esculentus extract

Recently, there has been an increasing demand for medicinal plants to control diseases for good health and well-being, as primary health facilities are inadequate in certain populations to cure infections. Since synthetic medicines are toxic to humans and other animals, the present research is thus focused on using traditional medicine for treating various ailments as they are harmless. Based on the above facts, the current study was conducted to assay the antimicrobial, anti-diabetic, anti-cholinesterase, anti-oxidant, anti-quorum sensing, and anti-antibiotic resistance modifying effect of extracts of Cyperus esculentus. This study found 37 and 30 chemicals in butanol and dichloromethane (DCM) extracts using a gas chromatograph mass spectrophotometer (GC-MS). Most active compounds identified were benzofuran, 2,3-dihydro-, 1,2,3-benzenetriol, 3-bornanone, oxime and oleic acid by extracts of butanol whereas dichloromethane extracted three major active compounds (2,3-dihydro-3,5-dihydroxy-, 4H-pyran-4-one 3-deoxy-d-mannoic lactone and 5-hydroxymethylfurfural). Both dichloromethane and butanol extracts showed the highest antimicrobial activity. Compared to aqueous extracts, dichloromethane, and butanol showed excellent anti-diabetic anti-cholinesterase activities and inhibited virulence factors regulated by quorum sensing (QS). Anti-oxidants increased in solvent extracts (DCM and butanol) compared to aqueous extracts. Results of scanning electron microscope (SEM) and Fourier Transmission Infrared (FTIR) indicated damage to the cell membrane of S. aureus by the formation of pits and breakage in functional groups exposed to the extracts of butanol and dichloromethane compared to aqueous extracts. The above results confirmed that C. esculentus can be an alternative medicine for treating diseases.

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

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

The effects of pomegranate (Punica granatum) on nonalcoholic fatty liver disease: A systematic review of in vivo interventional studies

Nonalcoholic fatty liver disease (NAFLD) is a disorder in which excess fat accumulates in hepatocytes and can lead to serious complications. Oxidative stress is one of the leading causes of NAFLD. Pomegranates are considered antioxidant-rich fruit. This systematic review study was aimed to investigate the impact of pomegranate on NAFLD. PubMed, Scopus, and Google Scholar databases/search engines (from inception up to July 2023) were searched for interventional studies (human and animal) that examined the effects of supplementation with different parts of pomegranate including fruits, peels, seeds, or flower on NAFLD outcomes. A total of 222 articles were retrieved following the initial search. After excluding duplicates, the title and abstract of 114 articles were screened. Afterward, irrelevant articles were removed and the full texts of the remaining 27 articles were reviewed. Eventually, 19 articles (16 animal and three human interventional studies) that met the inclusion criteria, published between 2009 and 2023, were included in this systematic review. Our study indicates the potential beneficial effects of different parts of pomegranate on the improvement of NAFLD. However, given that the majority of the included articles were animal studies, further investigations in the form of human clinical trials are warranted to suggest a clinical indication of such interventions.

Variation of the essential oil components of Citrus aurantium leaves upon using different distillation techniques and evaluation of their antioxidant, antidiabetic, and neuroprotective effect against Alzheimer's disease

Citrus fruit essential oil is considered one of the widely studied essential oils while its leaves attract less attention although being rich in nearly the same composition as the peel and flowers. The leaves of bitter orange or sour orange (Citrus aurantium L.) were extracted using three different techniques namely; hydrodistillation (HD), steam distillation (SD), and microwave-assisted distillation (MV) to compare their chemical composition. The three essential oil samples were analyzed through GC/FID and GC/MS analyses. The samples were tested in vitro using different antioxidant techniques (DPPH, ABTS, CUPRAC, FRAP, PBD, and MCA), neuroprotective enzyme inhibitory activities (acetylcholine and butyl choline enzymes), and antidiabetic activities (α-amylase and α-glucosidase). The results showed that thirty-five volatile ingredients were detected and quantified. Monoterpenes represented the most abundant class in the three essential oils followed by sesquiterpenes. C. aurantium essential oil carried potential antioxidant activity where SD exhibited the highest antioxidant activity, with values arranged in the following order: FRAP (200.43 mg TE/g), CUPRAC (138.69 mg TE/g), ABTS (129.49 mg TE/g), and DPPH (51.67 mg TE/g). SD essential oil also presented the most potent α-amylase (0.32) inhibition while the MV essential oil showed the highest α-glucosidase inhibition (2.73 mmol ACAE/g), followed by HD (2.53 mmol ACAE/g), and SD (2.46 mmol ACAE/g). The SD essential oil exhibited the highest BChE and AChE inhibitory activities (3.73 and 2.06 mg GALAE/g), respectively). Thus, bitter orange essential oil can act as a potential source of potent antioxidant, antidiabetic, and neuroprotective activities for future drug leads.

Can Polyherbal Medicine be used for the Treatment of Diabetes? - A Review of Historical Classics, Research Evidence and Current Prevention Programs

Diabetes mellitus (DM), a chronic medical condition, has attained a global pandemic status over the last few decades affecting millions of people. Despite a variety of synthetic drugs available in the market, the use of herbal medicines for managing diabetes is gaining importance because of being comparatively safer. This article reviews the result of a substantial literature search on polyherbal formulations (PHFs) developed and evaluated with potential for DM. The accumulated data in the literature allowed us to enlist 76PHFs consisting of different parts of 147 plant species belonging to 58 botanical families. The documented plant species are laden with bioactive components with anti-diabetic properties and thus draw attention. The most favoured ingredient for PHFs was leaves of Gymnema sylvestre and seeds of Trigonella foenum-graecum used in 27 and 22 formulations, respectively. Apart from herbs, shilajit (exudates from high mountain rocks) formed an important component of 9 PHFs, whereas calcined Mytilus margaritiferus and goat pancreas were used in Dolabi, the most commonly used tablet form of PHF in Indian markets. The healing properties of PHFs against diabetes have been examined in both pre-clinical studies and clinical trials. However, the mechanism(s) of action of PHFs are still unclear and considered the pitfalls inherent in understanding the benefits of PHFs. From the information available based on experimental systems, it could be concluded that plant-derived medicines will have a considerable role to play in the control of diabetes provided the challenges related to their bioavailability, bioefficacy, optimal dose, lack of characterization, ambiguous mechanism of action, and clinical efficiency are addressed.

The Modulatory Bioeffects of Pomegranate (Punica granatum L.) Polyphenols on Metabolic Disorders: Understanding Their Preventive Role against Metabolic Syndrome

Modern research achievements support the health-promoting effects of natural products and diets rich in polyphenols. Pomegranate (PG) (Punica granatum L.) contains a considerable number of bioactive compounds that exert a broad spectrum of beneficial biological activities, including antimicrobial, antidiabetic, antiobesity, and atheroprotective properties. In this context, the reviewed literature shows that PG intake might reduce insulin resistance, cytokine levels, redox gene expression, blood pressure elevation, vascular injuries, and lipoprotein oxidative modifications. The lipid parameter corrective capabilities of PG-ellagitannins have also been extensively reported to be significantly effective in reducing hyperlipidemia (TC, LDL-C, VLDL-C, and TAGs), while increasing plasma HDL-C concentrations and improving the TC/HDL-C and LDL-C/HDL-C ratios. The health benefits of pomegranate consumption seem to be acheived through the amelioration of adipose tissue endocrine function, fatty acid utilization, GLUT receptor expression, paraoxonase activity enhancement, and the modulation of PPAR and NF-κB. While the results from animal experiments are promising, human findings published in this field are inconsistent and are still limited in several aspects. The present review aims to discuss and provide a critical analysis of PG's bioeffects on the components of metabolic syndrome, type-2 diabetes, obesity, and dyslipidemia, as well as on certain cardiovascular-related diseases. Additionally, a brief overview of the pharmacokinetic properties, safety, and bioavailability of PG-ellagitannins is included.

GC-MS analysis of n-hexane extract of Fagonia indica Burm.f. with hypoglycaemic potential

The present study was aimed at gas chromatography-mass spectrometry (GC-MS) analytical investigation of n-hexane extract of the aerial parts of Fagonia indica to identify hypoglycaemic compounds. Also, to investigate this extract for lactase enzyme inhibition responsible for hypoglycaemic activity. Phytochemical screening, GC-MS analysis and lactase inhibition of n-hexane extract was performed by the standard methods. GC-MS analytical study identified 15 compounds in this extract. The maximum percentage of lactase enzyme inhibition of n-hexane extract was 26.21 ± 1.25% (IC50 value of 311.2 ± 16.09 μg/mL) at 100 μg/mL concentration. The standard acarbose showed lactase inhibition of 63.21 ± 0.92% (IC50 value of 32.51 ± 0.85 µg/mL) at the same concentration. n-Hexane extract can be a potential source in the management of diabetes due to the presence of biologically active hypoglycaemic compounds.

The α-glucosidase inhibitory activity of avicularin and 4-O-methyl gallic acid isolated from Syzygium myrtifolium leaves

Diabetes Mellitus is the main cause of death on a global scale. In 2019, there were 463 million people with diabetes, and WHO predicts that by 2030, there will be 578 million. As an antidiabetic agent, α-glucosidase inhibitors are one of the methods employed to reduce the prevalence of diabetes. Diabetes is traditionally treated with Syzygium as a primary material, medicine, fruit, ornamental plant, and source of carpentry. This investigation aimed to examine the inhibitory effect of seven species of Syzygium against α-glucosidase enzyme using an in vitro assay and isolate active substances and ascertain their concentrations in each sample. As a solvent, ethanol was used in maceration to extract the substance. Afterward, the extract underwent a series of fractionation techniques, including liquid-liquid extraction, vacuum liquid chromatography, column chromatography, and preparative Thin Layer Chromatography (TLC) for purification and isolation. The compound's structures were elucidated using TLC, UV-Visible spectrophotometry, and nuclear magnetic resonance (NMR) spectroscopy. Based on concentrations of 100 and 200 µg/mL, Syzygium myrtifolium exhibited the most significant inhibitory effect, followed by other species of Syzygium. The proportion of ethyl acetate had the strongest activity (IC₅₀ 0.40 ± 0.02 µg/mL) contrasted to positive control acarbose (IC₅₀ 55.39 ± 0.67 g/mL) and quercitrin (IC₅₀ 6.47 ± 0.40 µg/mL). Avicularin and 4-O-methyl gallic acid were discovered in the ethyl acetate fraction of Syzygium myrtifolium with IC₅₀ values of 17.05 ± 0.75 µg/mL and 25.19 ± 0.21 µg/mL, respectively. As α-glucosidase inhibitory, the results of this study indicate Syzygium myrtifolium can be used as a dietary supplement to manage hyperglycemia.

Anthraquinone metabolites isolated from the rhizosphere soil Streptomyces of Panax notoginseng (Burk.) F. H. Chen target MMP2 to inhibit cancer cell migration

ETHNOPHARMACOLOGICAL RELEVANCE

Panax notoginseng (Burk.) F. H. Chen belongs to the Araliaceae family. It has been used by traditional Chinese people in Northeast Asia for centuries as an antidiabetic, antioxidant, antitumor agent, etc. Endophytic or rhizospheric microorganisms play key roles in plant defense mechanisms, and they are essential in the discovery of pharmaceuticals and valuable new secondary metabolites. In particular, endophytic or rhizospheric microorganisms of traditional medicinal plants.

AIM OF THE STUDY

To discover valuable new secondary metabolites from rhizosphere soil Streptomyces sp. SYP-A7185 of P. notoginseng, and to explore potential bioactivities and targets of metabolites protrusive function.

MATERIALS AND METHODS

The metabolites were obtained via column chromatography and identified by multiple spectroscopic analyses. The antitumor, antioxidant, antibacterial, and antiglycosidases effects of isolated metabolites were tested using 3-[4,5-dimethythiazol-2-yl]-2,5-diphenyltetazolium bromide (MTT), 2,2-diphenyl-1-picrylhydrazyl (DPPH), 96-well turbidimetric, and α-glucosidase inhibitory assays. The potential antitumor targets were predicted through network pharmacological approaches. The interactions between metabolites and target were verified by molecular docking and biolayer interferometry (BLI) assay. The effects of cancer cells migration were detected through wound healing assays in A549 and MCF-7. Other cellular validation experiments including reverse transcription-quantitative PCR (RT‒qPCR) and western blotting (WB) were used to confirm the hypothesis of network pharmacology.

RESULTS

Five different chemotypes of anthraquinone derivatives (1-10), including six new compounds (3, 6-10), were identified from Streptomyces sp. SYP-A7185. Compounds 1-6 and 9 displayed moderate to strong cytotoxicity on five human cancer cell lines (A549, HepG2, MCF-7, MDA-MD-231, and MGC-803). Moreover, matrix metalloproteinase-2 (MMP2) were predicted as a potential antitumor target of metabolites 1-6 and 9 by comprehensive network pharmacology analysis. Later, BLI assays revealed strong intermolecular interactions between MMP2 and antitumor metabolites, and molecular docking results showed the interaction of metabolites 1-6 and 9 with MMP2 was dependent on the crucial amino acid residues of LEU-83, ALA-84, LEU-117, HIS-131, PRO-135, GLY-136, ALA-140, PRO-141, TYR-143, and THR-144. These results implied that metabolites (1-6 and 9) might inhibit cancer cell migration besides cancer cell proliferation. After that, the cell wound healing assay showed that the cell migration processes were also inhibited after the treatments of compounds 1 and 3 in A549 and MCF-7 cells. In addition, the RT‒qPCR and WB results demonstrated that the gene expression levels of MMP2 were decreased after the treatment with compounds 1 and 3 in A549 and MCF-7 cells. Besides, compound 2 displayed moderate antioxidant activity (EC₅₀, 27.43 μM), compounds 3 and 6 exhibited moderate antibacterial activity, and compound 3 inhibited α-glucosidase with an IC₅₀ value of 13.10 μM.

CONCLUSIONS

Anthraquinone metabolites, from rhizosphere soil Streptomyces sp. of P. notoginseng, possess antitumor, antioxidant, antibacterial, and antiglycosidase activities. Moreover, metabolites 1 and 3 inhibit cancer cells migration through downregulating MMP2.

Characterization of a thermostable, protease-tolerant inhibitor of α-glycosidase from carrot: A potential oral additive for treatment of diabetes

Inhibiting α-glucosidase activity is important in controlling postprandial hyperglycemia and, thus, helping to manage type-2 diabetes mellitus (T2DM). In the present study, we purified a hypothetical protein of carrots called DCHP (Daucus Carrot hypoglycemic peptide), and their inhibitory effects on α-glucosidase, as well as related mechanisms, were investigated. The recombinant DCHP protein with a molecular weight of 8 kDa showed strong inhibitory activity against α-glycosidase and maintained good stability in solution. DCHP exhibited no inhibitory activity but was tolerant to trypsin and chymotrypsin. Cellular experiments demonstrated that glucose consumption and lactic acid production increased rapidly when treated with DCHP in Caco-2 and HepG2 cells. DCHP crystal was generated, and the crystal structure, which was similar to that of rBTI and consisted of a central α-helix and a two-stranded β-sheet with a unique loop region. The interaction between DCHP and α-glycosidase was investigated by molecular docking and site-directed mutation, which revealed that Glu43, Pro46, Thr47 Thr48 and Gln49 are the key residues in DCHP that inhibit α-glycosidase activity. This work provides potential bioactive peptides as functional foods or nutraceutical supplements in preventing and managing T2DM.

A Comparative Study between Conventional and Advanced Extraction Techniques: Pharmaceutical and Cosmetic Properties of Plant Extracts

This study aimed to compare the influence of extraction methods on the pharmaceutical and cosmetic properties of medicinal and aromatic plants (MAPs). For this purpose, the dried plant materials were extracted using advanced (microwave (MAE), ultrasonic (UAE), and homogenizer (HAE) assisted extractions) and conventional techniques (maceration, percolation, decoction, infusion, and Soxhlet). The tyrosinase, elastase, α-amylase, butyryl, and acetylcholinesterase inhibition were tested by using L-3,4 dihydroxy-phenylalanine, N-Succinyl-Ala-Ala-p-nitroanilide, butyryl, and acetylcholine as respective substrates. Antioxidant activities were studied by ABTS, DPPH, and FRAP. In terms of extraction yield, advanced extraction techniques showed the highest values (MAE > UAE > HAE). Chemical profiles were dependent on the phenolic compounds tested, whereas the antioxidant activities were always higher, mainly in infusion and decoction as a conventional technique. In relation to the pharmaceutical and cosmetic properties, the highest inhibitory activities against α-amylase and acetylcholinesterase were observed for Soxhlet and macerated extracts, whereas the highest activity against tyrosinase was obtained with MAE > maceration > Soxhlet. Elastase and butyrylcholinesterase inhibitory activities were in the order of Soxhlet > maceration > percolation, with no activities recorded for the other tested methods. In conclusion, advanced methods afford an extract with high yield, while conventional methods might be an adequate approach for minimal changes in the biological properties of the extract.

Structure based virtual screening of natural product molecules as glycosidase inhibitors

Objective of the present investigation comprised of the application of in silico methods to discover novel natural product (NP) based potential inhibitors for carbohydrate mediated diseases. Structure based drug design studies (molecular docking and structure based pharmacophore analysis)  were carried out on a series of natural product compounds to identify significant bioactive molecules to inhibit α-mannosidase (I and II) and β-galactosidase enzymes. Furthermore, protein ligand interaction fingerprint analysis, molecular dynamics simulations and molecular access system (MACCS) fingerprint analysis were performed to understand the binding behaviors of the studied molecules. The results derived from these analyses showed that the identified compounds exhibit significant binding interactions with the active site residues. The compounds, NP-51, NP-81 and NP-165 have shown significant docking score against the studied enzymes (α-mannosidases-I, α-mannosidases-II and β-galactosidases). The fingerprint studies showed that the presence of rings (aromatic or aliphatic) with sulfur atoms, nitrogen atoms, methyl groups, etc. have favorable effects on the α-mannosidase II inhibitory activity. However, the presence of halogen atoms substituted in the molecules have reduced inhibitory ability against α-mannosidase II. The compound, NP-165 has significant activity against both enzymes (α-mannosidases and β-galactosidases). These studies accomplished that the compounds identified through in silico methodologies can be used to develop semisynthetic derivatives of the glycosidase inhibitors and can be screened for the treatment of different carbohydrate mediated diseases.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40203-021-00115-9.

A Review on Antidiabetic Activity of Centaurea spp.: A New Approach for Developing Herbal Remedies

Objective

Diabetes mellitus (DM) is a long-life metabolic disorder, characterized by high blood glucose levels. The hyperglycemic condition generally leads to irreversible nerve injury and vascular damage. Among different types of diabetes, type 2 is more common and has spread all over the world. Although various therapeutic approaches have been developed to control type 2 DM, regulating blood glucose levels has still remained a controversial challenge for patients. Also, most prescription drugs cause different side effects, such as gastrointestinal disorders. Thus, developing novel and efficient antidiabetic agents possessing fewer adverse effects is in high demand.

Method

The literature was comprehensively surveyed via search engines such as Google Scholar, PubMed, and Scopus using appropriate keywords.

Results

Medicinal plants, both extracts and isolated active components, have played a significant role in controlling the blood glucose levels. Good-to-excellent results documented in the literature have made them a precious origin for developing and designing drugs and supplements against DM. Centaurea spp. have been traditionally used for controlling high blood glucose levels. Also, the antidiabetic properties of different species of Centaurea have been confirmed in recent studies through in vitro assays as well as in vivo experiments.

Conclusion

Potent results encouraged us to review their efficacy to open a new horizon for development of herbal antidiabetic agents.

A unique understanding of traditional medicine of pomegranate, Punica granatum L. and its current research status

ETHNOPHARMACOLOGICAL RELEVANCE

Pomegranate, Punica granatum L., has been used in traditional medicine in China and several regions of the world including Ayurveda, Islamic, and Persian for the treatment of atherosclerosis, diabetes, hypertension, hyperlipidemia, and several types of cancer, as well as for peptic ulcer and oral diseases for hundreds of years. Presently, pomegranate is treated as both a "medicine food homology" herbal medicine and a healthy food supplemental product.

AIM OF THE STUDY

The aim of this work is to develop an overview of pomegranate in the context of the status of its traditional medicine theories, the spread along the Silk Road, ethnopharmacological uses, chemical compositions, pharmacological activities, toxicology, and the involved pathways.

MATERIALS AND METHODS

Information on P. granatum L. was acquired from published materials, including monographs on medicinal plants, ancient and modern recorded classical texts; and pharmacopoeias and electronic databases (PubMed, Science Direct, Web of Science, Google Scholar, CNKI, and Wanfang Data).

RESULTS

Pomegranate has been used in many traditional medical systems throughout history. It is widely cultivated in Central Asia and spread throughout China along the Silk Road. Many phytochemicals, such as tannins, organic acids, flavonoids, alkaloids, and volatile oils have been identified from different parts of pomegranate, these compounds have a wide range of activities, including antioxidant, antimicrobial, and anti-oncogenic properties, as well as conferring resistance to cerebrovascular disease. Furthermore, A summary of the four promising pharmacological pathways is provided.

CONCLUSIONS

The traditional uses, chemical compositions, pharmacological activities, and signaling pathways of pomegranate are summarized comprehensively in the review. It can be treated as a guidance for the future clinical and basic research. The information provided in this review will be very useful for further studies to develop novel therapeutic directions for application of pomegranate.

Isolation of an acidic polysaccharide from the flowers of Leucosceptrum canum Smith and its immunomodulatory activity evaluation

A water-soluble polysaccharide (LCP-05) was isolated from the flowers of Leucosceptrum canum Smith. LCP-05 was an acidic polysaccharide with a molecular weight of approximately 8.9 kDa. Monosaccharide composition analysis indicated that LCP-05 was composed of Man, Rha, GlcA, GalA, Glc, Gal and Ara in a molar ratio of 0.83:1.68:0.33:2.15:1.00:1.45:1.22. The framework of LCP-05 was speculated to be a branched rhamnogalacturonan with the backbone consisting of α-1,2,4-linked Rhap and α-1,4-linked GalAp, and bearing branches at the O-4 position of the Rha residues. The side chains are terminated primarily with the Araf and Glcp residues. LCP-05 was found to be able to significantly induce the production of NO, IL-6, and TNF-α in RAW 264.7 cells, and to induce RAW 264.7 cell's suppressive effect on both cell growth and cell migration of 4 T1 mammary breast cancer cells.

Efficacy of Pomegranate Seed Powder on Glucose and Lipid Metabolism in Patients with Type 2 Diabetes: A Prospective Randomized Double-Blind Placebo-Controlled Clinical Trial

INTRODUCTION

Pomegranate is known as a functional food which has multiple health-promoting activities. It has been assessed for patients with metabolic syndrome. Specifically, an antidiabetic activity of its juice and plausible mechanisms for its action have been shown in multitudinous studies. The aim of this study was assessing the effects of complementary treatment with pomegranate seed powder (PSP) oral supplementation on patients with type 2 diabetes mellitus (T2DM).

METHODS

Sixty patients were treated for 8 weeks by 5 g PSP or placebo, twice daily. Fasting blood glucose (FBG), glycated hemoglobin (HbA1c), total cholesterol, and triglyceride (TG) were recorded as the outcome measures at the beginning and after the intervention. The findings were analyzed using the independent t test and Mann-Whitney U test.

RESULTS

After 8 weeks, the mean differences of FBG, HbA1c, cholesterol, and TG were significantly decreased in the PSP group when compared with the placebo group (p value <0.05). In addition, post-intervention values of FBG and HbA1c were significantly lower in patients treated with PSP compared to the placebo group (p values = 0.02 and 0.01, respectively). However, the latter comparison regarding cholesterol and TG showed no significant differences (p values = 0.51 and 0.26, respectively).

CONCLUSION

It seems that complementary treatment with PSP may have beneficial effects on FBG and HbA1c of patients with T2DM. However, its effect on TG and cholesterol was equivocal.

Ellagic Acid as a Tool to Limit the Diabetes Burden: Updated Evidence

Oxidative stress contributes not only to the pathogenesis of type 2 diabetes (T2D) but also to diabetic vascular complications. It follows that antioxidants might contribute to limiting the diabetes burden. In this review we focus on ellagic acid (EA), a compound that can be obtained upon intestinal hydrolysis of dietary ellagitannins, a family of polyphenols naturally found in several fruits and seeds. There is increasing research on cardiometabolic effects of ellagitannins, EA, and urolithins (EA metabolites). We updated research conducted on these compounds and (I) glucose metabolism; (II) inflammation, oxidation, and glycation; and (III) diabetic complications. We included studies testing EA in isolation, extracts or preparations enriched in EA, or EA-rich foods (mostly pomegranate juice). Animal research on the topic, entirely conducted in murine models, mostly reported glucose-lowering, antioxidant, anti-inflammatory, and anti-glycation effects, along with prevention of micro- and macrovascular diabetic complications. Clinical research is incipient and mostly involved non-randomized and low-powered studies, which confirmed the antioxidant and anti-inflammatory properties of EA-rich foods, but without conclusive results on glucose control. Overall, EA-related compounds might be potential agents to limit the diabetes burden, but well-designed human randomized controlled trials are needed to fill the existing gap between experimental and clinical research.

Pomegranate: Nutraceutical with Promising Benefits on Human Health

Pomegranate is an old plant made up by flowers, roots, fruits and leaves, native to Central Asia and principally cultivated in the Mediterranean and California (although now widespread almost all over the globe). The current use of this precious plant regards not only the exteriority of the fruit (employed also for ornamental purpose) but especially the nutritional and, still potential, health benefits that come out from the various parts composing this one (carpellary membranes, arils, seeds and bark). Indeed, the phytochemical composition of the fruit abounds in compounds (flavonoids, ellagitannins, proanthocyanidins, mineral salts, vitamins, lipids, organic acids) presenting a significant biological and nutraceutical value. For these reasons, pomegranate interest is increased over the years as the object of study for many research groups, particularly in the pharmaceutical sector. Specifically, in-depth studies of its biological and functional properties and the research of new formulations could be applied to a wide spectrum of diseases including neoplastic, cardiovascular, viral, inflammatory, metabolic, microbial, intestinal, reproductive and skin diseases. In this review, considering the increasing scientific and commercial interest of nutraceuticals, we reported an update of the investigations concerning the health-promoting properties of pomegranate and its bioactive compounds against principal human pathologies.

In vitro antioxidant, anticholinesterases, anti-α-amylase, and anti-α-glucosidase effects of Algerian Salvia aegyptiaca and Salvia verbenaca

In this study, Salvia aegyptiaca and Salvia verbenaca aerial part decoction and methanol extracts (SAE DE, SAE ME, SVR DE, and SVR ME) were screened for their in vitro antioxidant, anti-Alzheimer, and antidiabetic enzymes inhibition activities. The antioxidant properties of Salvia extracts were determined using DPPH radical scavenging, ABTS radical scavenging, Alkaline DMSO superoxide radical scavenging, β-carotene bleaching, reducing power, and metal chelating activity assays. All extracts showed high antioxidant capacity and the antioxidant properties with the best performance were detected in the SAE ME and SVR ME. The extracts of S. aegyptiaca and S. verbenaca showed a low inhibitory activity of acetylcholinesterase (AChE), whereas, the methanol extract of S. aegyptiaca had the highest inhibitory activity on butyrylcholinesterase (BChE) (71.60 ± 4.33% for 100 µg/ml) compared to the other extracts. In vitro inhibitory effect on diabetic enzymes showed that the ME inhibited α-amylase enzyme with an IC₅₀ 86 and 101 µg/ml for SAE and SVR, respectively. Similarly, both extracts inhibited α-glucosidase with (IC₅₀ 97 and 150 µg/ml, respectively). The decoction extracts exhibited lower activity on both enzymes. PRACTICAL APPLICATIONS: It is becoming evident that oxidative stress is involved in several acute and chronic diseases. Counteracting free radical generation has become one of the widest fields of research worldwide. This study deals with the in vitro antioxidant activity of two plants from the Salvia genus as well as the assessment of their in vitro inhibitory properties of four key enzymes implicated in diabetes and Alzheimer's disease. Concerning the practical applications of our work, it can be explored in its antioxidant part as a food supplement to prevent the excess of free radicals in the body and also in other industrial practices. Another potential use is in the prevention and amelioration of both diabetes and Alzheimer's disease symptoms for the extracts that had enzyme inhibitory activity, but this deserves further toxicological and in vivo studies.

Structural characterization and stability study of green synthesized starch stabilized silver nanoparticles loaded with isoorientin

Isoorientin (Iso) is a natural flavonoid, the effect of metal nanoparticles loaded with it was unknown. In this study, silver nanoparticles (AgNPs) were synthesized by corn starch and sodium citrate with the green synthesis method, and the structural characterization and stability of AgNPs loaded with Iso (AgNPs-Iso) were examined by UV-vis spectroscopy and zetasizer. Results showed that AgNPs (65 ± 0.87 nm, spheres) successfully loaded with Iso (117 ± 2.13 nm, loading efficiency: 76.60%). There are no significant changes of the stability of AgNPs and AgNPs-Iso in pH 5-9 and 0-0.30 M of NaCl solution. AgNPs-Iso was more stable than AgNPs in the simulated gastrointestinal digestion in vitro. Furthermore, AgNPs-Iso showed the lower erythrocytes hemolysis ratio and cytotoxicity, and exhibited a notably inhibitive effect on α-glucosidase and pancreatic lipase. Therefore, this study could provide the basic support for the further development of highly stable and lowly cytotoxic AgNPs-Iso on Type II diabetes and obesity.

An Insight into Unani Hypoglycemic Drugs and Their Mechanism of Action

BACKGROUND

Diabetes mellitus type-II is a major health problem characterized by hypoinsulinemia and insulin resistance, leading to hyperglycemia and its complications. In Unani medicine, it is known as ziyābetus. Several drugs are prescribed in Unani medicine as single and compound formulations for this disease. Most of these drugs have been studied on scientific parameters and shown significant activity in reducing the symptoms and complications of diabetes.

OBJECTIVES

Critical evaluation of Unani medicines for treating diabetes patients have been conducted. The aim of the study is to provide complete information on this subject with the action of the mechanism so that proper treatment should be done with prospective research.

METHODS

Unani literature was reviewed extensively via various search engines for the herbs, shrubs used for diabetes treatment. Ten drugs were selected for the present review.

RESULTS AND CONCLUSION

There is convincing evidence to suggest that the selected drugs have promising actions against diabetes and its complications. In addition, none of the studies has reported any adverse effects with the drugs. Also, there is evidence to suggest that the method of usage described in Unani medicine may reduce or eliminate adverse events, if any. Further, there is a great need to do more research on making medicine more effective. Besides, the review article is useful for treating patients effectively by advancing the research.

Efficacy of Qurs-e-Gulnar in Ziabetus (type 2 Diabetes Mellitus): a single blind randomized controlled trial

BACKGROUND AND OBJECTIVES

Diabetes is a serious threat to global health that respects neither socioeconomic status nor national boundaries. Globally, diabetes is among the top 10 causes of death. Unani system argued the effectiveness of several anti-hyperglycemic drugs, and all such drugs looked-for to be validated on scientifically. Hence a clinical trial was contemplated to evaluate the clinical efficacy of Qurs-e-Gulnar in the management of Diabetes Mellitus.

METHODS

This study was conducted as single blind randomized control, on 40 patients of type 2 diabetes with the test (n=20) and control (n=20) groups for 45 days. Test group received Qurs-e-Gulnar at the dose of three Qurs twice a day, and control group received two capsules Diabeat^® twice a day before meal. Subjective (at 0, 15th, 30th, and 45th) and objective parameters were assessed as pre-post treatment respectively.

RESULTS

After treatment with test compound significant reduction was observed in all the subjective parameters viz. polyuria, polydipsia, polyphagia and tiredness in comparison of control group. The objective parameters FBS and PPBS was found to be significantly reduced (p<0.001) in both the groups where as HbA1c was found unchanged in test group but control drug showed highly significant reduction in HbA1c (p<0.001).The results were assessed statistically using two tailed Student's t-test, and Fischer exact test.

CONCLUSION

On the basis of above observation it is concluded that the test compound Qurs-e-Gulnar has significant anti-diabetic effect which is evidentially observed both in subjective and objective parameters in test group in comparison of control group (CTRI/2017/07/009060).

Protective Effects of Pomegranate in Endothelial Dysfunction

BACKGROUND

Punica granatum L. is an infructescence native of occidental Asia and Mediterranean Europe, popularly referred to as pomegranate. It has been used in ethnomedicine for several applications, including the treatment of obesity, inflammation, diabetes, and the regulation of blood lipid parameters. Thus, pomegranate has been linked to the treatment of cardiovascular diseases that have endothelial dysfunction as a common factor acting mainly against oxidative stress due to its high polyphenol content. Its biocomponents have antihypertensive, antiatherogenic, antihyperglycemic, and anti-inflammatory properties, which promote cardiovascular protection through the improvement of endothelial function.

METHODS

Different electronic databases were searched in a non-systematic way to uncover the literature of interest.

CONCLUSION

This review article presents updated information on the role of pomegranate in the context of endothelial dysfunction and cardiovascular diseases. We have shown that pomegranate, or rather its components (e.g., tannins, flavonoids, phytoestrogens, anthocyanins, alkaloids, etc.), have beneficial effects on the cardiovascular system, improving parameters such as oxidative stress and the enzymatic antioxidant system, reducing reactive oxygen species formation and acting in an anti-inflammatory way. Thus, this review may contribute to a better understanding of pomegranate's beneficial actions on endothelial function and possibly to the development of strategies associated with conventional treatments of cardiovascular diseases.

Toxicological, anticholinesterase, antilipidemic, antidiabetic and antioxidant potentials of Grewia optiva Drummond ex Burret extracts

Background In this study, Grewia optiva Drummond ex Burret root extracts were assessed for use as a remedy for oxidative stress, diabetes mellitus and neurological disorders. Methods The antioxidative potentials of the extracts were determined using DPPH and ABTS assays, whereas their enzyme inhibitory potentials were determined against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-glucosidase and α-amylase. In the in vivo experiments, methanol extract was orally administered to mice (n = 5) at four doses of 200, 300, 400 and 500 mg kg-1 for 30 days and its effect on glucose, triglycerides, total cholesterol, etc. were investigated. Results The highest free radical scavenging activities against DPPH and ABTS radicals were recorded for the methanol and ethyl acetate extracts, and their respective IC50 values were 75 and 88 μg/mL. In addition, these two fractions were highly active in inhibiting AChE and BChE, with IC50 values of 120 and 185 μg/mL, respectively. Moderate inhibition (μg/mL) was recorded against α-glucosidase (69.02 ± 1.02 and 64.29 ± 2.41) and α-amylase (65.12 ± 2.02 and 63.29 ± 1.41) and these were comparable to the inhibitory activities exhibited by the standard, acarbose. All the extracts showed high phenolic and flavonoid contents, which correlated with their antioxidant, anticholinesterase, α-glucosidase and α-amylase activities. The phenolic compounds in the crude extract and fractions were determined using the standard HPLC method and bioactive compounds, namely, morin, ellagic acid, kaempferol-3-(p-coumaroyl-diglucoside)-7-glucoside, apigenin-7-O-rutinoside, quercetin-3-(caffeoyl-diglucoside)-7-glucoside, etc., which were detected at various retention times. Significant decrease in cholesterol, triglyceride and blood glucose levels were observed. Conclusion G. optiva is a good source of antioxidants and other phytochemicals, some of which possess anticholinesterase, anti-glucosidase, and anti-amylase activities, and can be used to treat different health conditions such as oxidative stress, neurological disorders, and diabetes mellitus.

Triterpene derivative improves the renal function of streptozotocin-induced diabetic rats: a follow-up study on maslinic acid

Introduction: Reports indicate that oral administration of plant-derived maslinic acid (MA) exhibits hypoglycemic and renoprotective effects in streptozotocin (STZ)-induced diabetic rats. Challenges with triterpenes such as MA include low bioavailabilty which affects treatment efficacy in experimental animals. The goal of this study was to synthesize the MA derivative phenylhydrazine (PH-MA) in an effort to improve the efficacy of MA.

Methods: Separate groups of non-diabetic and STZ-induced diabetic rats (n = 6) were anesthetized and the jugular vein cannulated for the infusion of 0.077 M NaCl at 9 mL/h. The bladder was catheterized for collection the urine samples every 30 min. After 30.5 h equilibration period, consecutive 30 min urine collections were made over the subsequent 4 h of 1 h control, 1.5 h treatment, and 1.5 h recovery periods. PH-MA (22 µg/h) and MA (90 µg/h) were added during the treatment periods for analysis of proximal tubular Na⁺ handling, plasma aldosterone and arginine vasopressin in male Sprague-Dawley rats.

Results: Intravenous infusion of PH-MA (22 µg/h) and MA (90 µg/h) significantly (p ˂ .05) increased Na⁺ output, fractional excretion of Na⁺ (FENa) and lithium (FELi). Interestingly, like MA, PH-MA significantly (p ˂ .05) increased glomerular filtration rate (GFR) over the treatment period and decreased plasma aldosterone levels. Our findings indicate that PH-MA inhibited sodium reabsorption in the proximal and distal tubule as shown by increased FENa and low plasma aldosterone levels, respectively.

Conclusions: PH-MA is, therefore, a promising multitarget antidiabetic agent that may ameliorate kidney function of diabetic patients at a dose four times lower than the parent compound (MA).

Carbon Nanoparticles Inhibit Α-Glucosidase Activity and Induce a Hypoglycemic Effect in Diabetic Mice

New, improved therapies to reduce blood glucose are required for treating diabetes mellitus (DM). Here, we investigated the use of a new nanomaterial candidate for DM treatment, carbon nanoparticles (CNPs). CNPs were prepared by carbonization using a polysaccharide from Arctium lappa L. root as the carbon source. The chemical structure and morphology of the CNPs were characterized using Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, elemental analysis, and transmission electron microscopy. CNPs were spherical, 10-20 nm in size, consisting of C, H, O, and N, and featuring various functional groups, including C=O, C=C, C–O, and C–N. In vitro, the as-prepared CNPs could inhibit α-glucosidase with an IC₅₀ value of 0.5677 mg/mL, which is close to that of the reference drug acarbose. Moreover, in vivo hypoglycemic assays revealed that the CNPs significantly reduced fasting blood-glucose levels in mice with diabetes induced by high-fat diet and streptozocin, lowering blood glucose after intragastric administration for 42 days. To the best of our knowledge, this is the first report of CNPs exhibiting α-glucosidase inhibition and a hypoglycemic effect in diabetic mice. These findings suggest the therapeutic potential of CNPs for diabetes.

Variation in the metabolites and α-glucosidase inhibitory activity of Cosmos caudatus at different growth stages

BACKGROUND

Cosmos caudatus is an annual plant known for its medicinal value in treating several health conditions, such as high blood pressure, arthritis, and diabetes mellitus. The α-glucosidase inhibitory activity and total phenolic content of the leaf aqueous ethanolic extracts of the plant at different growth stages (6, 8. 10, 12 and 14 weeks) were determined in an effort to ascertain the best time to harvest the plant for maximum medicinal quality with respect to its glucose-lowering effects.

METHODS

The aqueous ethanolic leaf extracts of C. caudatus were characterized by NMR and LC-MS/MS. The total phenolic content and α-glucosidase inhibitory activity were evaluated by the Folin-Ciocalteu method and α-glucosidase inhibitory assay, respectively. The statistical significance of the results was evaluated using one-way ANOVA with Duncan's post hoc test, and correlation among the different activities was performed by Pearson's correlation test. NMR spectroscopy along with multivariate data analysis was used to identify the metabolites correlated with total phenolic content and α-glucosidase inhibitory activity of the C. caudatus leaf extracts.

RESULTS

It was found that the α-glucosidase inhibitory activity and total phenolic content of the optimized ethanol:water (80:20) leaf extract of the plant increased significantly as the plant matured, reaching a maximum at the 10th week. The IC50 value for α-glucosidase inhibitory activity (39.18 μg mL- 1) at the 10th week showed greater potency than the positive standard, quercetin (110.50 μg mL- 1). Through an 1H NMR-based metabolomics approach, the 10-week-old samples were shown to be correlated with a high total phenolic content and α-glucosidase inhibitory activity. From the partial least squares biplot, rutin and flavonoid glycosides, consisting of quercetin 3-O-arabinofuranoside, quercetin 3-O-rhamnoside, quercetin 3-O-glucoside, and quercetin 3-O-xyloside, were identified as the major bioactive metabolites. The metabolites were identified by NMR spectroscopy (J-resolve, HSQC and HMBC experiments) and further supported by dereplication via LC-MS/MS.

CONCLUSION

For high phytomedicinal quality, the 10th week is recommended as the best time to harvest C. caudatus leaves with respect to its glucose lowering potential.

A new method for the in situ assay of α-glucosidase activity and inhibitor screening through an enzyme substrate-mediated DNA hybridization chain reaction

The strategy is based on small molecule-mediated hybridization chain reaction.

A Multi-Mode Bioactive Agent Isolated From Ficus microcarpa L. Fill. With Therapeutic Potential for Type 2 Diabetes Mellitus

Type 2 diabetes is a metabolic disorder, characterized by hyperglycemia and glucose intolerance. Natural products and its derived active compounds may be achievable alternatives for the treatment of type 2 diabetes. In present study we investigated the antidiabetic potential of Ficus microcarpa and isolated bioactive compounds i.e., Plectranthoic acid A (PA-A) and 3,4,5,7-Flavantetrol (FL). Anti-hyperglycemic potential was evaluated via α-glucosidase, α-amylase and dipeptidyl peptidase 4 (DPP-4) assays. 5'AMP-activated kinase (AMPK) activation potential was assessed by using primary hepatocytes. Distribution of PA-A in different parts of Ficus microcarpa was evaluated by using rapid high-performance liquid chromatography (HPLC). Ethyl acetate fraction (FME) exhibited significant inhibition of α-glucosidase, α-amylase, and DPP-4, therefore, was selected for isolation of bioactive compounds. Among isolated compounds PA-A was more potent and possessed pleotropic inhibitory activity with IC50 values of 39.5, 55.5, and 51.4 μM against α-glucosidase, α-amylase, and DPP-4, respectively. Our results showed that PA-A is also a potent activator of AMPK which is a central hub of metabolic regulation. Molecular docking studies confirmed the activity of PA-A against α-glucosidase, α-amylase, and DPP-4. Rapid HPLC method revealed that maximum concentration of PA-A is present in the stem (2.25 μg/mg dry weight) of Ficus microcarpa. Both in vitro and in silico studies proposed that Ficus microcarpa and its isolated compound PA-A could be an important natural source for alleviating the symptoms of type 2 diabetes mellitus and we suggest that PA-A should be explored further for its ultimate use for the treatment of type 2 diabetes.

Cassia grandis Lf nanodispersion is a hypoglycemic product with a potent α-glucosidase and pancreatic lipase inhibitor effect

Purpose

This study aimed to evaluate the hypoglycemic effect, antioxidant, α-glucosidase and lipase inhibitory activity, and the cytotoxicity of the Cassia grandis nanodispersion (CgND).

Methods

The hypoglycemic effect was evaluated in alloxan-induced diabetic mice. The particle size, polydispersion index, ζ-potential, and conductivity, as well as the drug-loaded content, were monitored in shelf-live, along a year. The delivery profile was evaluated in simulated intestinal fluids at pH 6.5 and 7.4. The antioxidant effect was evaluated as DPPH and ABTS inhibition. The murine α-glucosidase inhibitory activity and the lipase-inhibitory effect were evaluated in vitro. Cytotoxicity was evaluated by the Alamar blue test.

Results

CgND remained stable for a year in shelf conditions. The hypoglycemic effect in a dose of 10 mg/kg was not statistically different from glibenclamide 25 mg/kg. Nanoparticles released 100% of extract in 120 min at pH 6.5 and 7.4. Nanodispersion exhibited a potent α-glucosidase and lipase-inhibitory effect with IC₅₀ of 3.96 and 0.58 µg/mL, respectively. A strong antioxidant activity against DPPH (IC₅₀ 0.65 µg/mL) and ABTS (0.48 µg/mL) was also observed. The hypoglycemic effect could occur, at least in part, via antioxidant and α-glucosidase inhibition. CgND is non-cytotoxic in MRC-5 line cell. This nanodispersion is a promising nanotechnological product that could be used in pharmaceuticals for the treatment of Type II diabetes and related complications as obesity.

Vasculoprotective Effects of Pomegranate (Punica granatum L.)

Pomegranate (Punica granatum L.), one of the oldest known edible fruits, is nowadays broadly consumed throughout the world. Its fruits and seeds as well as other anatomical compartments (e.g., flowers and leaves) are rich in numerous bioactive compounds and therefore, the scientific interest in this plant has been constantly growing in recent years. It has been shown that pomegranate and its extracts exhibit potent antioxidative, antimicrobial, and anticarcinogenic properties. The present review summarizes some recent studies on pomegranate, highlighting mainly its vasculoprotective role attributed to the presence of hydrolyzable tannins ellagitannins and ellagic acid, as well as other compounds (e.g., anthocyanins and flavonoids). These in vitro and in vivo studies showed that substances derived from pomegranate reduce oxidative stress and platelet aggregation, diminish lipid uptake by macrophages, positively influence endothelial cell function, and are involved in blood pressure regulation. Clinical studies demonstrated that daily intake of pomegranate juice lessens hypertension and attenuates atherosclerosis in humans. Altogether, the reviewed studies point out the potential benefits of a broader use of pomegranate and its constituents as dietary supplements or as adjuvants in therapy of vascular diseases, such as hypertension, coronary artery disease, and peripheral artery disease.

In vitro bioaccessibility and functional properties of polyphenols from pomegranate peels and pomegranate peels-enriched cookies

Obesity is an urgent social problem and new functional foods providing polyphenols and dietary fibers (DF) may be promising tools to modulate oxidative stress, inflammation and energy homeostasis. Pomegranate peels (PPe) are an agro-industrial by-product containing polyphenols such as ellagitannins (ETs), gallic acid (GA), ellagic acid (EA) and its derivatives (EAs), as well as DF. In this study, PPe enriched cookies (PPeC) were developed, and the bioaccessibility as well as the ability of their polyphenols to exert antioxidant activity along the Gastro-intestinal Tract (GiT) and to modulate digestive enzymes were evaluated in vitro. Data showed that the potential bioaccessibility of ETs was 40% lower from PPeC than PPe whereas EAs' and GA bioaccessibility increased by 93% and 52% for PPeC compared to PPe. The concentration of the polyphenols at each digestion step was associated with the total antioxidant capacity of the potentially bioaccessible material. Moreover the polyphenols released in the simulated duodenal phase upon PPeC digestion exhibited inhibitory activity towards α-glucosidase, α-amylase and lipase, being α-glucosidase > α-amylase > lipase. In conclusion, the data demonstrated that the inclusion of PPe at 7.5% in a bakery product potentially led to a high bioaccessibility of ETs' degradation products (mainly EA and EAs) in the duodenum, with a consequent antioxidant protection along the GiT and modulation of glucose metabolism. Further human studies are warranted to evaluate whether these effects also occur in vivo.

HPLC-DAD finger printing, antioxidant, cholinesterase, and α-glucosidase inhibitory potentials of a novel plant Olax nana

BACKGROUND

The medicinal importance of a novel plant Olax nana Wall. ex Benth. (family: Olacaceae) was revealed for the first time via HPLC-DAD finger printing, qualitative phytochemical analysis, antioxidant, cholinesterase, and α-glucosidase inhibitory assays.

METHODS

The crude methanolic extract of O. nana (ON-Cr) was subjected to qualitative phytochemical analysis and HPLC-DAD finger printing. The antioxidant potential of ON-Cr was assessed via 1,1-diphenyl,2-picrylhydrazyl (DPPH), 2,2-azinobis[3-ethylbenzthiazoline]-6-sulfonic acid (ABTS) and hydrogen peroxide (H2O2) free radical scavenging assays. Furthermore, acetylcholinesterase (AChE) & butyrylcholinesterase (BChE) inhibitory activities were performed using Ellman's assay, while α- glucosidase inhibitory assay was carried out using a standard protocol.

RESULTS

The qualitative phytochemical analysis of ON-Cr revealed the presence of secondary metabolites like alkaloids, flavonoids, tannins, sterols, saponins and terpenoids. The HPLC-DAD finger printing revealed the presence of 40 potential compounds in ON-Cr. Considerable anti-radical activities was revealed by ON-Cr in the DPPH, ABTS and H2O2 free radical scavenging assays with IC50 values of 71.46, 72.55 and 92.33 μg/mL, respectively. Furthermore, ON-Cr showed potent AChE and BChE inhibitory potentials as indicated by their IC50 values of 33.2 and 55.36 μg/mL, respectively. In the α-glucosidase inhibition assay, ON-Cr exhibited moderate inhibitory propensity with an IC50 value of 639.89 μg/mL.

CONCLUSIONS

This study investigated Olax nana for the first time for detailed qualitative phytochemical tests, HPLC-DAD finger printing analysis, antioxidant, anticholinesterase and α-glucosidase inhibition assays. The antioxidant and cholinesterase inhibitory results were considerable and can provide scientific basis for further studies on the neuroprotective and anti-Alzheimer's potentials of this plant. ON-Cr may further be subjected to fractionation and polarity guided fractionation to narrow down the search for isolation of bioactive compounds.

Anti-diabetic Effect of Punica granatum Flower Polyphenols Extract in Type 2 Diabetic Rats: Activation of Akt/GSK-3β and Inhibition of IRE1α-XBP1 Pathways

Type 2 diabetes mellitus (T2DM) is the most common type of diabetes with more than hundreds of millions of patients worldwide. However, the medicines for treatment of T2DM are very limited. In China, Punica granatum L. flower (PGF) has been used as an anti-diabetic herb in the herbal medicine. The activity involves in improvement of insulin sensitivity. However, the underlying mechanism of action is elusive. The current study was designed to address this issue by investigating the effect of polyphenols extract of PGF in diabetic rats. A rat model was orally administrated with PGF polyphenols extract at doses of 50 and 100 mg/kg for 4 weeks. Insulin sensitivity was improved as indicated by oral glucose tolerance test (OGTT), insulin tolerance test (ITT) and homeostasis model assessment of insulin resistance (HOMA-IR). At the molecular level, insulin signaling activity was improved with an elevation in insulin-stimulated phosphorylation of insulin receptor substrate (IRS-1), Akt and GSK-3β. Endoplasmic reticulum (ER) stress signals including phosphorylation of inositol-requiring kinase1 (IRE1) and activation of X box binding protein (XBP-1) splicing were decreased by the PGF treatment. Expressions of IRE1α, XBPs, and CHOP were all decreased by PGF. Blood lipid profile, liver glycogen content and antioxidant status were improved by PGF in the rats. The observations suggest that PGF is able to lower glucose levels in T2DM rats by improving the insulin resistance. The mechanism is likely related to the activation of Akt-GSK3β signaling pathway and inhibition of ER stress.

Anti-inflammatory effect of pomegranate flower in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages

CONTEXT

Punica granatum L (Punicaceae) flower is an important diabetes treatment in oriental herbal medicine.

OBJECTIVE

This study investigates the inflammation effects of pomegranate flower (PFE) ethanol extract in LPS-induced RAW264.7 cells.

MATERIALS AND METHODS

PFE (10, 25, 50, 100 μg/mL) was applied to 1 μg/mL LPS-induced RAW 264.7 macrophages in vitro. Levels of nitric oxide (NO), prostaglandin E₂ (PGE₂) and pro-inflammatory cytokines interleukin (IL)-1β (IL-1β), interleukin (IL)-6 (IL-6) and tumor necrosis factor (TNF-α) in the supernatant fraction were determined using enzyme-linked immunosorbent assay (ELISA). Expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), phosphorylation of mitogen-activated protein kinase (MAPK) subgroups extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and P38, as well as nuclear factor-κB (NF-κB) activation in extracts were detected via Western blot.

RESULTS

10-100 μg/mL PFE decreased the production of NO (IC₅₀ value = 31.8 μg/mL), PGE₂ (IC₅₀ value = 54.5 μg/mL), IL-6 (IC₅₀ value = 48.7 μg/mL), IL-1β (IC₅₀ value = 71.3 μg/mL) and TNF-α (IC₅₀ value = 62.5 μg/mL) in LPS-stimulated RAW 264.7 cells significantly. A mechanism-based study showed that phosphorylation of ERK1/2, p38, JNK and translocation of the NF-B p65 subunit into nuclei were inhibited by the PFE treatment.

DISCUSSION AND CONCLUSION

These results show that PFE produced potential anti-inflammatory effect through modulating the synthesis of several mediators and cytokines involved in the inflammatory process.

Benzisoxazole: a privileged scaffold for medicinal chemistry

The benzisoxazole analogs represent one of the privileged structures in medicinal chemistry and there has been an increasing number of studies on benzisoxazole-containing compounds. The unique benzisoxazole scaffold also exhibits an impressive potential as antimicrobial, anticancer, anti-inflammatory, anti-glycation agents and so on. This review examines the state of the art in medicinal chemistry as it relates to the comprehensive and general summary of the different benzisoxazole analogs, their use as starting building blocks of multifarious architectures on scales sufficient to drive human drug trials. The number of reports describing benzisoxazole-containing highly active compounds leads to the expectation that this scaffold will further emerge as a potential candidate in the field of drug discovery.

Dietary Anthocyanins and Insulin Resistance: When Food Becomes a Medicine

Insulin resistance is an abnormal physiological state that occurs when insulin from pancreatic β-cells is unable to trigger a signal transduction pathway in target organs such as the liver, muscles and adipose tissues. The loss of insulin sensitivity is generally associated with persistent hyperglycemia (diabetes), hyperinsulinemia, fatty acids and/or lipid dysregulation which are often prevalent under obesity conditions. Hence, insulin sensitizers are one class of drugs currently employed to treat diabetes and associated metabolic disorders. A number of natural products that act through multiple mechanisms have also been identified to enhance insulin sensitivity in target organs. One group of such compounds that gained interest in recent years are the dietary anthocyanins. Data from their in vitro, in vivo and clinical studies are scrutinized in this communication to show their potential health benefit through ameliorating insulin resistance. Specific mechanism of action ranging from targeting specific signal transduction receptors/enzymes to the general antioxidant and anti-inflammatory mechanisms of insulin resistance are presented.