Possible role of pomegranate fruit in reversing renal damage in rats exposed to Phenylhydrazine.

Background: Pomegranate granatum (molasses and peels) and its constituents showed protective effects against natural toxins such as phenylhydrazine (PHZ) as well as chemical toxicants such as arsenic, diazinon, and carbon tetrachloride. Aim: The current study aimed to assess the effect of pomegranate molasses (PM), white peel extract, and red peel extract on nephrotoxicity induced by PHZ. Methods: 80 male rats were divided into eight equal groups; a control group, PM pure group, white peel pomegranate pure group, red peel pomegranate pure group, PHZ group, PM + PHZ group, white peel pomegranate + PHZ group and red peel pomegranate + PHZ group. Kidney function, inflammation markers, antioxidant activities, and renal tissue histopathology were investigated. Results: The results revealed that PHZ group showed a significant increase in lactate Dehydrogenase (LDH), malondialdehyde (MDA), creatinine, uric acid, BUNBUN, C - reactive protein (CRP), tumor necrosis factor, thiobarbituric acid reactive substances (TBARSs), and total antioxidant capacity (TAC) with a significant decrease of catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD) as compared with a control group. Other pomegranate-treated and PHZ co-treated groups with pomegranate showed a significant decrease of LDH, MDA, creatinine, uric acid, BUN, tumor necrosis factor, TBARSs, and TAC with a significant increase of CAT, GPx, and SOD as compared with PHZ group. Conclusion: Collectively, our data suggest that red, white peels, and molasses have anti-toxic and anti-inflammatory effects on renal function and tissues.

Formation pathways of gamma-butyrolactone from the furan ring of tegafur during its conversion to 5-fluorouracil.

Tegafur (FT) is a 5-fluorouracil (5-FU) prodrug that has been clinically used for various cancer chemotherapies. The following metabolites of FT were identified in patients: 5-FU, fluoro-beta-alanine, and gamma-butyrolactone (GBL) and its acidic form, gamma-hydroxybutyrate (GHB). GBL/GHB, which is probably generated from the furan ring of FT, inhibits tumor cell angiogenesis, contributing to the antitumor effect of FT-based therapies. In the present study, we identified the metabolites formed from the furan ring of FT by CYP2A6 and thymidine phosphorylase (TPase) using 2,4-dinitrophenylhydrazine derivatization procedures and clarified the metabolic pathway of FT to GBL/GHB. Succinaldehyde (SA) and 4-hydroxybutanal (4-OH-BTL) were produced as the metabolites because of the cleavage of the furan ring of FT during its conversion to 5-FU in cDNA-expressed CYP2A6 and purified TPase, respectively; however, GBL/GHB was hardly detected in cDNA-expressed CYP2A6 and purified TPase. GBL/GHB was formed after human hepatic microsomes or cDNA-expressed CYP2A6 mixed with cytosol were incubated with FT. Furthermore, 4-OH-BTL was converted to GBL/GHB in the microsomes and cytosol. These results suggest that GBL/GHB is generated from FT through the formation of SA and 4-OH-BTL but not directly from FT. Furthermore, the amount of 5-FU and GBL/GHB formed in the hepatic S9 was markedly decreased in the presence of a CYP2A6 inhibitor, suggesting that GBL/GHB may be mainly generated through the CYP2A6-mediated formation of SA.

Characterisation of hydrazides and hydrazine derivatives as novel aspartic protease inhibitors.

Virtual screening of an in-house virtual library of synthetic compounds using FlexX, followed by enzyme inhibition, identified hydrazide and hydrazine derivatives as novel aspartic protease inhibitors. These compounds inhibited human cathepsin D and Plasmodium falciparum plasmepsin-II with low micromolar concentrations (IC(50) = 1-2.5 microM). Modelling studies with plasmepsin-II predicted binding of ligands at the centre of the extended substrate-binding cleft, where hydrazide/hydrazine parts of the inhibitors acted as the transition state mimic by forming electrostatic interactions with catalytic aspartates.

[An in vitro study of the mechanism by which captopril attenuates myocardial reperfusion damage]. / Estudio in vitro del mecanismo por el cual el captopril atenúa el daño miocárdico por reperfusión.

The purpose of this study was to establish the molecular mechanism whereby captopril prevents the formation of active oxygen species, since many studies have provided evidence that postischemic myocardial dysfunction is mediated, at least in part, by the generation of these agents. Results indicate that captopril is a potent inhibitor of certain reactions mediated by O2-. However, this interference of captopril was not understood as an scavenging activity against the free radicals generated. The data could be explained by considering a direct interaction of captopril with the metal ions present that catalyse the formation of O2-. This mechanism could be of biological relevance.

Agaritine does not mediate the mutagenicity of the edible mushroom Agaricus bisporus.

Ethanolic extracts of the edible mushroom Agaricus bisporus displayed a direct-acting mutagenic response in various Salmonella typhimurium strains, TA104 being clearly the most sensitive. Incorporation of an activation system derived from the liver of mice, hamsters or Aroclor 1254-induced rats failed to increase the mutagenic response. The mutagenic response of ethanolic extracts from various types of mushroom, containing different levels of agaritine (range 0.3-6.5 g/kg fresh weight), was very similar and did not correlate with the agaritine levels. Moreover, use of gamma-glutamyl transpeptidase, the enzyme catalysing the activation of agaritine, as an activation system did not enhance the mutagenicity of the mushroom ethanolic extracts. It is concluded that agaritine is not responsible for the mutagenicity of mushroom extracts.