A newly synthetic chromium complex – chromium(phenylalanine)3 improves insulin responsiveness and reduces whole body glucose tolerance

AbstractLow-molecular-weight organic chromium complexes such as chromium picolinate are often used as dietary supplements to improve insulin sensitivity and to correct dyslipidemia. However, toxicity associated with such chromium compounds has compromised their therapeutic value. The aim of this study was to evaluate the impact of a newly synthesized complex of chromium with phenylalanine, Cr(pa)3 on insulin-signaling and glucose tolerance. Cr(pa)3 was synthesized by chelating chromium(III) with d-phenylalanine ligand in aqueous solution. In mouse 3T3-adipocytes, Cr(pa)3 augmented insulin-stimulated glucose-uptake as assessed by a radioactive-glucose uptake assay. At the molecular level, Cr(pa)3 enhanced insulin-stimulated phosphorylation of Akt in a time- and concentration-dependent manner without altering the phosphorylation of insulin receptor. Oral treatment with Cr(pa)3 (150μg/kg/d, for six weeks) in ob/ob(+/+) obese mice significantly alleviated glucose tolerance compared with untreated obese mice. Unlike chromium picolinate, Cr(pa)3 does not cleave DNA under physiological reducing conditions. Collectively, these data suggest that Cr(pa)3 may represent a novel, less-toxic chromium supplement with potential therapeutic value to improve insulin sensitivity and glycemic control in type II diabetes

Antioxidant Properties of the Methanol Extract of the Wood and Pericarp of Caesalpinia decapetala

The antioxidant activities of the methanol extracts from the wood and pericarp of Caesalpinia decapetala (Roth) Alston (Caesalpiniaceae) were assessed in efforts to validate the herb. The antioxidant activity of the plant has been studied using its ability to scavenger DPPH, superoxide radicals, and nitric oxide radical along with its ability to inhibit lipid peroxidation. The antioxidant activity and phenolic content of the pericarp as determined by the DPPH, superoxide radical, nitric oxide radical, total phenols, the flavonoids, and total flavonols were higher than that of the wood. Analysis of plant extracts revealed a high amount of polyphenols and flavonoids suggesting a possible role of these phytoconstituents in the antioxidant property. Moreover, the results were observed in a concentration and dose dependent manner. Studies clearly indicate that the C. decapetala has significant antioxidant activity

Antioxidant and Cytotoxic Activities of Centella asiatica (L) Urb.

In the present study, the phenolic (Folin-Dennis) and flavonoid (colorimetric assay) constituents, antioxidant [2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) assay] and cytotoxic activities of an aqueous extract (AE) of Centella asiatica leaves were investigated. The aqueous extract (50 g/L) was obtained by infusion followed by cold maceration for 24 h. The levels of phenolic and flavonoid compounds were 2.86 g/100 g and 0.361 g/100 g, respectively. The AE showed elevated DPPH scavenging activity, with an IC50 value of 31.25 μg/mL. The AE had a promising activity against mouse melanoma (B16F1), human breast cancer (MDA MB-231) and rat glioma (C6) cell lines, with IC50 values of 698.0, 648.0 and 1000.0 μg/mL, respectively. A positive correlation was established between the level of flavonoids, antioxidant and antitumor activities

Free Radical Scavenging and Analgesic Activities of Cucumis sativus L. Fruit Extract

The aqueous fruit extract of Cucumis sativus L. was screened for free radical scavenging and analgesic activities. The extract was subjected to in vitro antioxidant studies at 250 and 500 μg/ml and analgesic study at the doses 250 and 500 mg/kg, respectively. The free radical scavenging was compared with ascorbic acid, BHA (Butylated hydroxyl anisole), whereas, the analgesic effect was compared with Diclofenac sodium (50 mg/kg). The C. sativus fruit extract showed maximum antioxidant and analgesic effect at 500 μg/ml and 500 mg/kg, respectively. The presence of flavonoids and tannins in the extract as evidenced by preliminary phytochemical screening suggests that these compounds might be responsible for free radical scavenging and analgesic effects

Cytisus scoparius link - A natural antioxidant

BACKGROUND: Recent investigations have shown that the antioxidant properties of plants could be correlated with oxidative stress defense and different human diseases. In this respect flavonoids and other polyphenolic compounds have gained the greatest attention. The plant Cytisus scoparius contains the main constituent of flavone and flavonals. The present study was undertaken to evaluate the in vitro antioxidant activities of extract of aerial part of Cytisus scoparius. METHODS: The plant extract was tested for DPPH (1, 1-diphenyl, 2-picryl hydrazyl) radical scavenging, nitric oxide radical scavenging, superoxide anion radical scavenging, hydroxyl radical scavenging, antilipid peroxidation assay, reducing power and total phenol content. RESULTS: The extract exhibited scavenging potential with IC(50 )value of 1.5 μg/ml, 116.0 μg/ml and 4.7 μg/ml for DPPH, nitric oxide and superoxide anion radicals. The values were found to lesser than those of vitamin C, rutin, and curcumin, as standards. The extract showed 50% protection at the dose of 104.0 μg/ml in lipid peroxidation induced by Fe(2+)/ ascorbate system in rat liver microsomal preparation. There is decrease in hydroxyl radical generation with IC(50 )value of 27.0 μg/ml when compared with standard vitamin E. The reducing power of the extract depends on the amount of extract. A significant amount of polyphenols could be detected by the equivalent to 0.0589 μg of pyrocatechol from 1 mg of extract. CONCLUSION: The results obtained in the present study indicate that hydro alcoholic extract of aerial part of Cytisus scoparius is a potential source of natural antioxidants

Antioksidativni potencijal i sposobnost hvatanja slobodnih radikala metanolnog ekstrakta plodova Citrullus colocynthis (L.) Schrad.

Citrullus colocynthis (L.) Schrad. (Cucurbitaceae) is a medicinal plant traditionally used as an abortifacient and to treat constipation, oedema, bacterial infections, cancer and diabetes. Preliminary phytochemical screening of the plant showed the presence of large amounts of phenolics and flavonoids. Subsequent quantification showed the presence of 0.74% phenolics (calculated as gallic acid) and 0.13% flavonoids calculated as catechin equivalents per 100 g of fresh mass. The presence of phenolic compounds prompted us to evaluate its antioxidant activity. In the present study, methanolic fruit extract of C. colocynthis was screened to evaluate its free-radical scavenging ability. The highest antioxidant and free radical scavenging effect of the fruit extract was observed at a concentration of 2500 µg mL1.Citrullus colocynthis (L.) Schrad. (Cucurbitaceae) je ljekovita biljka koja se tradicionalno upotrebljava kao abortiv i za liječenje konstipacije, edema, bakterijskih infekcija, karcinoma i dijabetesa. Preliminarno fitokemijsko pretraživanje ukazalo je na prisutnost velikih količina fenola i flavonoida. Udio fenola bio je 0,74% (preračunato na galnu kiselinu), a flavonoida 0,13% preračunato na ekvivalente katehina na 100 g svježe mase. Zbog prisutnosti fenolnih spojeva ispitivano je antioksidativno djelovanje i sposobnost hvatanja slobodnih radikala metanolnog ekstrakta plodova. Koncentracija 2500 µg mL1 imala je najjači učinak

Trace elements in glucometabolic disorders: an update

Many trace elements, among which metals, are indispensable for proper functioning of a myriad of biochemical reactions, more particularly as enzyme cofactors. This is particularly true for the vast set of processes involved in regulation of glucose homeostasis, being it in glucose metabolism itself or in hormonal control, especially insulin. The role and importance of trace elements such as chromium, zinc, selenium, lithium and vanadium are much less evident and subjected to chronic debate. This review updates our actual knowledge concerning these five trace elements. A careful survey of the literature shows that while theoretical postulates from some key roles of these elements had led to real hopes for therapy of insulin resistance and diabetes, the limited experience based on available data indicates that beneficial effects and use of most of them are subjected to caution, given the narrow window between safe and unsafe doses. Clear therapeutic benefit in these pathologies is presently doubtful but some data indicate that these metals may have a clinical interest in patients presenting deficiencies in individual metal levels. The same holds true for an association of some trace elements such as chromium or zinc with oral antidiabetics. However, this area is essentially unexplored in adequate clinical trials, which are worth being performed