Therapeutic Potential of Clove Essential Oil in Diabetes: Modulation of Pro-Inflammatory Mediators, Oxidative Stress and Metabolic Enzyme Activities.

Type 1 diabetes is characterized by insulin deficiency due to the destruction of pancreatic ß cells, leading to hyperglycemia, which in turn induces vascular complications. In the current study, we investigated the effect of intraperitoneal administration of clove essential oil (CEO: 20 mg/kg body weight) on certain oxidative stress and glucose metabolism enzymes, as well as the expression of proinflammatory mediators. Administration of CEO to diabetic rats showed a significant decline in blood glucose levels, total cholesterol, and xanthine oxidase, compared to the streptozotocin group. Furthermore, these treated rats elicited a notable attenuation in the levels of lipid peroxides, and thiols groups in both liver and brain tissues. The activities of antioxidant and metabolic enzymes were reverted to normality in diabetic upon CEO administration. In addition to its protective effects on red blood cell hemolysis, CEO is a potent α-amylase inhibitor with an IC50 =298.0±2.75 µg/mL. Also, treatment of diabetic rats with CEO significantly reduced the iNOS expression in the spleen. Our data showed that CEO has potential beneficial effects on diabetes, which can possibly prevent the pathogenesis of diabetic micro- and macrovascular complications.

Capparis spinosa inhibits Leishmania major growth through nitric oxide production in vitro and arginase inhibition in silico.

Cutaneous leishmaniasis is an infectious disease, considered as a major public health problem in different regions of the world. The current treatments are limited due to their toxicity and treatment failures, which have increased the search for new substances of natural origin to control this infection. Capparis spinosa is an important medicinal plant, rich in biochemical compounds with a broad range of activities including antimicrobial effects. Nevertheless, more investigations are still needed to determine its effect on Leishmania parasites. This study aimed to evaluate the effect of C. spinosa' extracts on Leishmania major promastigotes and amastigotes growth as well as on L-arginine metabolic pathways, especially the production of leishmanicidal molecules such as nitric oxide. Our results showed that C. spinosa' methanolic and aqueous extracts contained polyphenols and flavonoids at different concentrations. The methanolic extract of C. spinosa, compared to the aqueous extract, showed significantly higher amounts of total polyphenols (21.23 ± 1.08) mg GAE/g of dw (P < 0.05), as well as a higher antioxidant activity evaluated respectively by Reducing Power and DPPH (EC50: 0.31 ± 0.02 and 7.69 ± 1.28) mg/ml. Both extracts significantly inhibited L. major promastigotes and intra-macrophagic amastigotes growth in vitro in a dose-dependent manner (P < 0.001) and induced NO production not only in Leishmania-infected macrophages but also in uninfected macrophages, without showing any cytotoxicity in vitro. Furthermore, in silico docking studies showed that C. spinosa compounds identified by RP-HPLC exhibited inhibitory activity against the arginase enzyme. The leishmanicidal effect of C. spinosa may be due to its phenolic content and its mechanism of action may be mediated by an increase in NO production and by the inhibition of arginase enzyme in silico. These findings support the hypothesis that C. spinosa might be a valuable source of new biomolecules for leishmaniasis treatment.

Syzygium aromaticum bud (clove) essential oil is a novel and safe aldose reductase inhibitor: in silico, in vitro, and in vivo evidence.

PURPOSE: This study aimed to evaluate the antioxidant and antidiabetic properties of clove essential oil (CEO) and to elucidate its mode of action, using selected biochemical targets, relevant to diabetes, and, specifically, its inhibitory effect on the polyol pathway. METHODS: In the current study, CEO was examined for its inhibitory effects on aldose reductase in silico, in vitro, and in vivo, as well as its antioxidative activity. RESULTS: In silico docking studies showed that all the selected major compounds of CEO have an energy change ranging between - 5.5 and - 8.8 kcal/mol and an inhibition constant ranging between 357.08 nM and 93.12 µM. CEO significantly inhibits aldose reductase with an IC50 value of 58.55 ± 5.84 µg/mL in a noncompetitive manner. The supplementation of CEO at 20 mg/kg BW decreases retinal sorbitol dehydrogenase activity via decreased aldose reductase activity in streptozotocin (STZ)-induced diabetic Sprague Dawley rats. Moreover, diabetic rats injected with CEO have exhibited improved levels of glycemia. The IC50 values for ABTS, hydroxyl, and hydrogen peroxide scavenging activities of CEO were found to be 34.42, 277.4, and 39.99 µg/mL, respectively. Reducing power assay and phosphomolybdate assay exhibited a reduction force with the A0.5 values of 50.25 and 140.16 µg/mL, respectively. CONCLUSION: CEO potentially exerts a beneficial effect on diabetes-related complications due to its antioxidant and inhibitory effect on aldose reductase activity.

Bioactive Compounds from Ephedra fragilis: Extraction Optimization, Chemical Characterization, Antioxidant and AntiGlycation Activities.

Response surface methodology (RSM) with a Box-Behnken design (BBD) was used to optimize the extraction of bioactive compounds from Ephedra fragilis. The results suggested that extraction with 61.93% ethanol at 44.43 °C for 15.84 h was the best solution for this combination of variables. The crude ethanol extract (CEE) obtained under optimum extraction conditions was sequentially fractionated with solvents of increasing polarity. The content of total phenolic (TP) and total flavonoid (TF) as well as the antioxidant and antiglycation activities were measured. The phytochemical fingerprint profile of the fraction with the highest activity was characterized by using RP-HPLC. The ethyl acetate fraction (EAF) had the highest TP and TF contents and exhibited the most potent antioxidant and antiglycation activities. The Pearson correlation analysis results showed that TP and TF contents were highly significantly correlated with the antioxidant and antiglycation activities. Totally, six compounds were identified in the EAF of E. fragilis, including four phenolic acids and two flavonoids. Additionally, molecular docking analysis also showed the possible connection between identified bioactive compounds and their mechanisms of action. Our results suggest new evidence on the antioxidant and antiglycation activities of E. fragilis bioactive compounds that may be applied in the treatment and prevention of aging and glycation-associated complications.

Purification and characterization of aldose reductase from jerboa (Jaculus orientalis) and evaluation of its inhibitory activity by Euphorbia regis-jubae (Webb & Berth) extracts.

This study aimed, for the first time, to assess the purification of aldose reductase (AR) in Jaculus orientalis (Dipodidae family) kidney and to evaluate the in vitro aldose reductase inhibitory (ARI) effects of Euphorbia regis-jubae (Euphorbiaceae family) aqueous and hydroethanolic extracts. Initial screening assay of the enzymatic AR activity in different jerboa states (euthermic, prehibernating and hibernating) and tissues (brain, brown adipose tissue, liver and kidneys) was assessed. Then, AR has been purified to homogeneity from the kidneys of prehibernating jerboas by a series of chromatographic technics. Furthermore, the in vitro and in silico ARI effects of E. regis-jubae (Webb & Berth) extracts, characterized by hight performance liquid chromatography (HPLC) on the purified enzyme were evaluated. Our results showed that the highest enzyme activity was detected in the kidneys, followed by white adipose tissue and the lungs of pre-hibernating jerboa. The enzyme was purified to homogeneity from jerboa kidneys during prehibernating state with a purification factor of 53.4-fold and a yield of about 6%. AR is monomeric, active in D(+)-glyceraldehyde substrate and in disodium phosphate buffer. The pH and temperature for AR were determined to be 6.5-7.5 and 35 °C, respectively. Results of the in vitro ARI activity was strongest with both the hydroethanolic extract (IC50 = 96.45 µg/mL) and aqueous extract (IC50 = 140 µg/mL). Molecular docking study indicated that catechin might be the main component in both aqueous and hydroethanolic extracts to inhibited AR. This study provides new evidence on the ARI effect of E. regis-jubae (Webb & Berth), which may be related to its phenolic constituents.

Cytoprotective effect of ethyl acetate fraction from Ephedra fragilis on H2O2-induced oxidative damage in Tetrahymena pyriformis.

The main purpose of the present study was to investigate the ability of ethyl acetate fraction (EAF) from Ephedra fragilis to function as a protective agent against hydrogen peroxide induced oxidative damage in Tetrahymena pyriformis. The cells were preincubated with EAF (50-200 µg/mL) or ascorbic acid (50 µg/mL) for 24 h, followed by incubation with 50% H2O2 inhibitory concentration for 48 h. Cell viability was assessed using trypan exclusion method. Cell morphology and mobility, antioxidant enzymes activities (catalase (CAT), superoxide dismutase (SOD) and glutathione reductase (GR)), malondialdehyde (MDA) and protein carbonyl (PCO) levels, DNA fragmentation and metabolic enzymes activities (succinate dehydrogenase (SDH) and NADPH-cytochrome c reductase (NCCR)) were investigated. Our results indicate that, pretreatment of T. pyriformis cells with EAF improved the cell viability, restored normal cell mobility and morphology, decreased the levels of both MDA and PCO level, prevent DNA fragmentation and enhanced the activity of antioxidant (CAT, SOD and GR) and metabolic (SDH and NCCR) enzymes in H2O2 damaged cells. In conclusion, these results suggest for the first time that E. fragilis is a promising source of natural antioxidants, that could offer protection against oxidative stress and should be further exploited for its use in clinical medicine.

Evaluation of Moroccan microalgae: Spirulina platensis as a potential source of natural antioxidants.

Background Ethanolic, aqueous and lipidic extracts of Spirulina platensis were evaluated for their bioactive substances (polyphenols and fatty acids) and antioxidant activities using two different assays diphenyl-1-picrylhydrazyl (DPPH) and azino-bis (ethylbenzthiazoline-6- sulfonicacid (ABTS)). Methods The phenolic compounds amounts were determined by colorimetric assays and were analyzed by high-performance and liquid chromatography (HPLC) method. The identification of phenolic compounds in the extract was accomplished by comparison of their retention times with those of pure standards. The chemical composition of fatty acids in lipidic extract was determined by GC/FIDs and GC/MS method. Results The obtained results revealed that using DPPH, the ethanolic extract recorded the highest activity with (IC50=449 µg/mL ± 83). It was characterized with a high levels of phenolic and flavonoid content 0.33 ± 0.01 mg GAE/g dw and 0.21 ± 0.01 mg quercetin/g dw, respectively. The ethanolic extract showed the presence of caffeic acid, syringic acid, ferulic acid, p-coumaric acid, chlorogenic acid, kaempferol, quercetin and apigenin. Those entire phenolic compounds seem participle synergistically to the pronounced higher activity. To the best of our knowledge, the apigenin (4', 5, 7,-trihydroxyflavone), a natural compound which is famously known by its potent antiradical activity, was identified for the first time in Moroccan S. platensis only in the ethanolic extract. A high positive correlation (r=0.895) between the antioxidant activity and the chemical composition of ethanolic extract was observed. For ABTS, lipidic extract showed the highest activity with (IC50=740 µg/mL ± 12). A total of 15 fatty acids compounds, amounting 89.73% of the extract were identified. γ-linolenic acid (GLA) (39.02%) and α-linolenic acid (ALA) (13.85%) were the major component and contribute greatly to the antioxidant activity observed. The lipidic extract has a high content of unsaturated fatty acids (70.95%) which are often exhibited very high antioxidant activity since they have two or more double bonds and chain lengths. The aqueous extract either with DPPH or ABTS methods, recorded low antioxidant activity. Its correlation was r=0.499, lower than found in the ethanolic extract. Conclusions These results showed that Spirulina platensis could be considered as a valuable source of fatty acids and phenolics with potent antioxidant activity. It may be employed in the manufacture of pharmaceutical drugs as an alternative source of natural antioxidants.

Assessment of metals bioaccumulation and bioavailability in mussels Mytilus galloprovincialis exposed to outfalls pollution in coastal areas of Casablanca.

The present work aims to study the metallic contamination of four sampling sites located nearby major sewage outfalls of the Casablanca coast (Morocco), using indigenous mussels Mytilus galloprovincialis as bioindicators of pollution. This research offered the opportunity to study trace metals bioaccumulation mechanisms, which represent a major factor in assessment processes of the pollution effects in coastal ecosystem health. The bioavailability and the bioaccumulation of trace metals (Cu, Zn, Ni, Pb) were evaluated in order to compare the metallic contamination in mussels' tissues and find a possible correlation with physiological parameters of this filter feeding species. Our results showed a significant spatiotemporal variation of bioaccumulation, compared to control. A significant correlation coefficient between metals (Zn and Pb) bioavailability and physiological index (CI) was revealed in mussels from the most polluted location. The seasonal variation of trace metal accumulation was also raised; the highest values recorded during the dry period.