Nurten Ozsoy

Flavonoids and antioxidant activity of Rosa agrestis leaves.

In this work we report the isolation and characterisation of seven flavonoids, the levels of total phenolics, flavonoids and proanthocyanidins, and the antioxidant activity of the leaf extract of Rosa agrestis Savi (Rosaceae). The results showed that the R. agrestis leaf extract exhibited significant antioxidative activity as measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) (EC50 = 47.4 µg mL−1), inhibited both β-carotene bleaching and deoxyribose degradation, quenched a chemically generated superoxide anion in vitro and showed high ferrous ion chelating activity. Reactivity towards 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical cation and ferric-reducing antioxidant power (FRAP) values were equivalent to 2.30 mM L−1 Trolox, the water soluble α-tocopherol analogue, and 1.91 mM L−1 Fe2+, respectively. The high antioxidant activity of the extract appeared to be attributed to its high content of total phenolics, flavonoids and proanthocyanidins. The flavonoids isolated from R. agrestis leaves were diosmetin, kaempherol, quercetin, kaempherol 3-glucoside (astragalin), quercetin 3-rhamnoside (quercitrin), quercetin 3-xyloside and quercetin 3-galactoside (hyperoside). Diosmetin (5,7,3′-trihydroxy-4′-methoxyflavone) was isolated for the first time from Rosa species.

The immune system as a chronotoxicity target of the anticancer mTOR inhibitor everolimus

ABSTRACT The circadian timing system controls many biological functions in mammals including xenobiotic metabolism, detoxification, cell proliferation, apoptosis and immune functions. Everolimus is a mammalian target of rapamycin inhibitor, whose immunosuppressant properties are both desired in transplant patients and unwanted in cancer patients, where it is indicated for its antiproliferative efficacy. Here we sought whether everolimus circadian timing would predictably modify its immunosuppressive effects so as to optimize this drug through timing. C57BL/6J mice were synchronized with light-dark 12h:12h, with L onset at Zeitgeber Time (ZT) 0. Everolimus was administered orally to male (5 mg/kg/day) and female mice (15 mg/kg/day) at ZT1, during early rest span or at ZT13, during early activity span for 4 weeks. Body weight loss, as well as hematological, immunological and biochemical toxicities, were determined. Spleen and thymus were examined histologically. Everolimus toxicity was less severe following dosing at ZT13, as compared to ZT1, as shown with least body weight inhibition in both genders; least reductions in thymus weight both in males (p < 0.01) and females (p < 0.001), least reduction in female spleen weight (p < 0.05), and less severe thymic medullar atrophy both in males (p < 0.001) and females (p < 0.001). The mean circulating counts in total leukocytes, total lymphocytes, T-helper and B lymphocytes displayed minor and non-significant changes following dosing at ZT13, while they were decreased by 56.9% (p < 0.01), 45.5% (p < 0.01), 43.1% (p < 0.05) and 48.7% (p < 0.01) after everolimus at ZT1, respectively, in only male mice. Chronotherapy of everolimus is an effective way to increase the general tolerability and decrease toxicity on the immune system.

The protective effect of an aqueous extract from Smilax excelsa l. against carbon tetrachloride-induced liver injury in rats

Background: Because reactive oxygen species (ros) contribute to the pathogenesis of various acute and chronic liver diseases, dietary antioxidants and drugs from herbal origins have been proved to be beneficial as therapeutic agents in reversing hepatotoxicity and oxidative stress. The objective of this study was to investigate the protective effect of an aqueous extract from smilax excelsa l. Shoots and leaves against acute ccl4-induced liver injury as well as the changes in antioxidative defense system in female wistar albino rats. Materials and Methods: S. Excelsa extract was administered orally in doses of 100, 200 and 400 mg/kg body weight, once daily for 9 days. Acute hepatic toxicity was induced by intraperitoneal injection of ccl4 (1 ml/kg) on the 10 day. 24 h after ccl4 intoxication, biochemical and histopathological analyses were undertaken on sera and liver tissues. Results: Ccl4 challenge caused significant increases in the activities of liver enzymes as well as the levels of bilirubin, malondialdehyde and nitric oxide, while total serum protein levels and antioxidant defense system parameters were reduced significantly compared to the normal group. Administration of s. Excelsa extract at a dose of 400 mg/kg resulted in a suppression of ccl4-induced lipid peroxidation and altered oxidative stress parameters to nearly normal values in comparison to ccl4-treated rats. Nevertheless the extract did not reduce the extent of ccl4-induced mild liver injury, as seen by the histopathology of liver damage. Conclusion: The results of this study suggest that s. Excelsa could protect the liver tissues against ccl4-induced oxidative stress probably by increasing antioxidative defense activities.

New spiroindolinones bearing 5-chlorobenzothiazole moiety

Abstract In this study, 5-chloro-3H-spiro-[1,3-benzothiazole-2,3′-indole]-2′(1′H)-one derivatives 3a–l were synthesized by the reaction of 1H-indole-2,3-diones 1a–l with 2-amino-4-chlorothiophenol 2 in ethanol. 3a–l were tested for their abilities to inhibit lipid peroxidation (LP), scavenge DPPH• and ABTS•+ radicals, and to reduce Fe3+ to Fe2+. Most of the tested compounds exhibited potent scavenging activities against ABTS•+ radical, reducing powers and strong inhibitory capacity on LP. 3 a, 3 d, 3e, 3h, 3j and 3 k chosen as prototypes were evaluated in the National Cancer Institute’s in vitro primary anticancer assay. The greatest growth inhibitions were observed against a non-small cell lung cancer cell line HOP-92 for R1-fluoro substituted 3 d and a renal cancer cell line RXF-393 for R-chloro substituted 3 e in the primary screen.

Antioxidant and cytotoxic properties of novel spirocyclic benzothiazolines

In this work, we report the synthesis, structural characterization and evaluation of in vitro antioxidant and cytotoxic properties of novel spirobenzothiazolines (1a-e, 2a-e). 5-nonsubstituted spirobenzothiazolines (1a-e) demonstrated notable inhibitory capacity on lipid peroxidation (LPO), reducing power and scavinging effects on diphenylpicryl hydrazine (DPPH˙) and 2,2’-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid (ABTS˙+) radicals, that were similar to that of α-tocopherol. The most potent antioxidant was compound 1a (incorporating an ethyl group on the cyclohexane ring) with an anti-LPO activity 2-fold higher than that of α-tocopherol. Compound 1a exhibited anti-LPO and DPPH˙ scavenging activities at concentrations lower than those cytotoxic for mouse normal fibroblast (NIH/3T3) cells and was also found to be slightly more selective for cancer cells (human prostat adenocarcinoma cell/PC-3) than normal mammalian cells.