Wafaa Gh. Shousha

Structural features, kinetics and SAR study of radical scavenging and antioxidant activities of phenolic and anilinic compounds

BackgroundPhenolic compounds are widely distributed in plant kingdom and constitute one of the most important classes of natural and synthetic antioxidants. In the present study fifty one natural and synthetic structurally variant phenolic, enolic and anilinic compounds were examined as antioxidants and radical scavengers against DPPH, hydroxyl and peroxyl radicals. The structural diversity of the used phenolic compounds includes monophenols with substituents frequently present in natural phenols e.g. alkyl, alkoxy, ester and carboxyl groups, besides many other electron donating and withdrawing groups, in addition to polyphenols with 1–3 hydroxyl groups and aminophenols. Some common groups e.g. alkyl, carboxyl, amino and second OH groups were incorporated in ortho, meta and para positions.ResultsSAR study indicates that the most important structural feature of phenolic compounds required to possess good antiradical and antioxidant activities is the presence of a second hydroxyl or an amino group in o- or p-position because of their strong electron donating effect in these positions and the formation of a stable quinone-like products upon two hydrogen-atom transfer process; otherwise, the presence of a number of alkoxy (in o or p-position) and /or alkyl groups (in o, m or p-position) should be present to stabilize the resulted phenoxyl radical and reach good activity. Anilines showed also similar structural feature requirements as phenols to achieve good activities, except o-diamines which gave low activity because of the high energy of the resulted 1,2-dimine product upon the 2H-transfer process. Enols with ene-1,2-diol structure undergo the same process and give good activity. Good correlations were obtained between DPPH inhibition and inhibition of both OH and peroxyl radicals. In addition, good correlations were obtained between DPPH inhibition and antioxidant activities in sunflower oil and liver homogenate systems.ConclusionsIn conclusion, the structures of good anti radical and antioxidant phenols and anilines are defined. The obtained good correlations imply that measuring anti DPPH activity can be used as a simple predictive test for the anti hydroxyl and peroxyl radical, and antioxidant activities. Kinetic measurements showed that strong antioxidants with high activity have also high reaction rates indicating that factors stabilizing the phenoxyl radicals lower also the activation energy of the hydrogen transfer process.

Potent neuroprotective role of novel melatonin derivatives for management of central neuropathy induced by acrylamide in rats

Acrylamide (ACR) has been shown to be a neurotoxic agent for both laboratory animals and human. The present study aimed at synthesizing new functionalized melatonin derivatives bearing promising heterocyclic moiety that could be expected to have protective effect against ACR-induced neurotoxicity in adult female rats. The novel melatonin derivatives 4, 6, 7 and 11 were synthesized and their chemical structures were confirmed by studying their analytical and spectral data. The administration of ACR [i.p., 50 mg kg(-1) body weight (b. wt.)] alone resulted in significant increase in brain malondialdehyde level (MDA) and lactate dehydrogenase (LDH) activity whereas it caused significant decrease in brain monoamines levels and antioxidant enzymes activity. Treatment with melatonin derivatives 4, 6, 7 and 11 (i.p., 50 mg kg(-1) b. wt) prior to ACR produced significant decrease in brain MDA level and LDH activity with concomitant significant increase in brain monoamines and antioxidant enzymes activity. It could be concluded that the new synthesized melatonin derivatives exhibited promising protective activity against ACR-induced neurotoxicity.

A New Class of Antimetabolites: Pyridine Thioglycosides as Potential Anticancer Agents

The present study was designed for highlighting and focusing on the cytotoxic activity of a new class of antimetabolites both on human cell lines, namely liver carcinoma cell line (Hepg2), lung carcinoma cell line (H460), breast carcinoma cell line (MCF7), brain carcinoma cell line (U251), and animal cell line EAC (Ehrlich ascites carcinoma cells). The results revealed that some of these modified deazapyrimidine thioglycosides have significant cytotoxic activity against EAC cells with growth inhibition percentage ranged between 80% to 90%. The possible inhibitory mechanism of the pyridine thioglycosides was explored by studying the cell cycle perturbation of thioglycosides against human cell lines (in vitro) as well as the most suitable time for maximum compound cytotoxic activity after 6, 18, and 24 h of incubation. To confirm the cytotoxic activity of these compounds, they have been tested for their apoptotic and antiproliferative activity in vivo against solid Ehrlich tumours using five groups of Swiss albino mice for 37 days from inoculation and three treatments, 250, 500 and 1,000 μg/kg body weight. There was signifi cant reduction in Ehrlich tumour size in case of the 500 and 1,000 μg/kg body weight group but mild significant tumour reduction in the 250 μg/kg body weight group. Histograms of DNA per cell for each treatment group indicated that there was a dose-dependent increase in the preG1 phase with a corresponding complete arrest of cells from entering the G2/M phase compared to the untreated EAC group. In conclusion, pyridine thioglycosides have proven good cytotoxic effects against EAC cells and also significant cytotoxic activity against the four tested human cell lines. Flow cytometric DNA ploidy analysis of pyridine thioglcyosides against the Hepg2 and U251 cell lines revealed that the postulated mechanism of action of pyridine thioglcyosides is cell cycle arrest in the S phase. This is similar to antimetabolites and cell cycle arrest in the G2/M phase (M phase) in the same way as microtubule inhibitors like pyridine thioglycosides are cell-cycle-specific in the S phase and the M phase (in case of human cell lines) and have apoptotic effects (in case of animal cell line).

Curcumin: a unique antioxidant offers a multimechanistic approach for management of hepatocellular carcinoma in rat model.

This study was designed to investigate the role of curcumin against hepatocellular carcinoma (HCC) induced in rats. Forty rats were divided into five groups. Group (1) was negative control. Groups (2), (4), and (5) were orally administrated N-nitrosodiethylamine for HCC induction, then group (2) was left untreated, and group (4) was treated orally with curcumin, while group (5) was intraperitoneally injected with doxorubicin. Group (3) was served as curcumin control group. Serum alpha-fetoprotein, alpha l-fucosidase and vascular endothelial growth factor levels were analyzed. Gamma glutamyl transferase (GGT) and heat shock protein gp96 (HSPgp96) gene expressions were detected by RT-PCR. The immunohistochemical analysis of proliferating cell nuclear antigen (PCNA) and Ki-67 expressions was performed. Apoptosis was detected using DNA fragmentation assay. Also, histological investigation of liver tissue was achieved. Untreated HCC group showed significant elevation in the studied biochemical markers and significant upregulation in GGT and HSPgp96 gene expression as well as marked increase in PCNA and Ki-67 expression. Furthermore, this group revealed no DNA fragmentation. Histological investigation of liver tissue sections in HCC group revealed a typical anaplasia. On the other hand, the curcumin-treated group showed a significant depletion in the studied tumor markers and a significant downregulation in GGT and HSPgp96 gene expression. Also, this group displayed remarkable decrease in PCNA and Ki-67 expression. Moreover, this group revealed an obvious DNA fragmentation. Interestingly, treatment with curcumin showed remarkable improvement in the histological features of liver tissue. This study revealed the promising therapeutic role of curcumin against hepatocellular carcinoma owing to its antiangiogenic, antiproliferative, and apoptotic effects.

Biochemical and molecular evidences for the antitumor potential of Ginkgo biloba leaves extract in rodents.

Hepatocellular carcinoma (HCC) is one of the deadliest primary cancers, with a 5-year survival rate of 10% or less. This study was undertaken to elucidate the underlying biochemical and molecular mechanisms in favor of N-nitrosodiethylamine-induced hepatocellular carcinoma. Furthermore, the aim of this work was extended to explore the efficacy of Ginkgo biloba leaves extract in deterioration of HCC in rats. In the current study, HCC group experienced significant downregulation of ING-3 gene expression and upregulation of Foxp-1 gene expression in liver. Treatment of HCC groups with Ginkgo biloba leaves extract resulted in upregulation of ING-3 and downregulation of Foxp-1 gene expression in liver. In addition, there was significant increase in serum alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA) and glypican-3 (GPC-3) levels in HCC group versus the negative control group. In contrast, the groups with HCC subjected to either high or low dose of Ginkgo biloba leaves extract elicited significant reduction (P<0.05) of AFP, CEA and GPC-3 in serum compared to the untreated HCC rats. Besides, histological examination of liver tissue sections of rats in HCC group revealed typical anaplasia. Interestingly, treatment with Ginkgo biloba leaves extract elicited marked improvement in the histological feature of liver tissue in HCC groups. In conclusion, this research indicated that the carcinogenic potency of N-nitrosodiethylamine targeted multiple systems on the cellular and molecular levels. In addition, the results of the current study shed light on the promising anticancer activity of Ginkgo biloba leaves extract in treatment of hepatocellular carcinoma induced chemically in the experimental model through its apoptotic and antiproliferative properties.

Implications of Sex Hormone Receptor Gene Expression in the Predominance of Hepatocellular Carcinoma in Males: Role of Natural Products

The present study was planned to investigate the role of sex hormone receptor gene expression in the pathogenesis of hepatocellular carcinoma (HCC). Adult male Wistar rats were divided into seven groups. Group (1) was negative control. Groups (2), (5), (6), and (7) were orally administered with N-nitrosodiethylamine for the induction of HCC, then group (2) was left untreated, group (5) was orally treated with curcumin, group (6) was orally treated with carvacrol, and group (7) was intraperitoneally injected with doxorubicin, whereas groups (3) and (4) were orally administered only curcumin and carvacrol, respectively. The HCC group showed significant upregulation in the androgen receptor (AR) and the estrogen receptor-alpha (ERα) gene expression levels in the liver tissue. On the contrary, HCC groups treated with either curcumin or carvacrol showed significant downregulation in AR and ERα gene expression levels in the liver tissue. In conclusion, the obtained data highlight that both AR and ERα but not estrogen receptor-beta (ERβ) gene expression may contribute to the male prevalence of HCC induced in male rats. Interestingly, both curcumin and carvacrol were found to have a promising potency in alleviating the male predominating HCC.

Expanding the mutation and clinical spectrum of Roberts syndrome

Roberts syndrome and SC phocomelia syndrome are rare autosomal recessive genetic disorders representing the extremes of the spectrum of severity of the same condition, caused by mutations in ESCO2 gene. We report three new patients with Roberts syndrome from three unrelated consanguineous Egyptian families. All patients presented with growth retardation, mesomelic shortening of the limbs more in the upper than in the lower limbs and microcephaly. Patients were subjected to clinical, cytogenetic and radiologic examinations. Cytogenetic analysis showed the characteristic premature separation of centromeres and puffing of heterochromatic regions. Further, sequencing of the ESCO2 gene identified a novel mutation c.244_245dupCT (p.T83Pfs*20) in one family besides two previously reported mutations c.760_761insA (p.T254Nfs*27) and c.764_765delTT (p.F255Cfs*25). All mutations were in homozygous state, in exon 3. The severity of the mesomelic shortening of the limbs and craniofacial anomalies showed variability among patients. Interestingly, patient 1 had abnormal skin hypopigmentation. Serial fetal ultrasound examinations and measurements of long bones diagnosed two affected fetuses in two of the studied families. A literature review and case comparison was performed. In conclusion, we report a novel ESCO2 mutation and expand the clinical spectrum of Roberts syndrome.

Role of Serum Adiponectin, IL-6 and Hs CRP in Nonalcoholic Fatty Liver Egyptian Patients.

Scientific Background: Non alcoholic fatty liver (NAFLD) is accumulation of fat in the liver cells of peoples who drink little or no alcohol causing mild steatosis with mostly no signs, symptoms or complication but this may progress to steatohepatitis (NASH) and may liver cirrhosis then failure. NAFLD is recognized as the most common type of chronic liver disease in Western countries and the leading cause of cryptogenic cirrhosis. Insulin resistance (IR) is a key factor in the pathogenesis of NAFLD, the latter being considered as the hepatic component of IR or metabolic syndrome (MetS). Although the pathogenesis of NAFLD is not fully elucidated, a complex interaction between adipokines and cytokines produced by adipocytes and/or inflammatory cells infiltrating adipose tissue appears to play a crucial role in MetS and NAFLD and its progress. A number of factors are linked with NAFLD such as obesity, type 2 diabetis mellitus (T2DM), hyperlipidemia, gastric Original Research Article International Journal of Biochemistry Research & Review, 4(6): 493-504, 2014 494 bypass, and its progress to NASH correlate with certain cytokines secreted like adiponectin, interlukin-6 (IL-6), and Creactive protein CRP. Adiponectin is a novel adipocyte-specific protein, which, it has been suggested, plays a role in the development of insulin resistance and atherosclerosis. The role of (IL-6) in liver pathology is very complex, and its participation in the development of NAFLD remains unclear. IL-6 is a key element in the acute phase response, mediating the synthesis of several acute phase proteins (such as CRP and serum amyloid A). Thus, we cannot exclude the possibility that IL-6 might also play an indirect deleterious role in NAFLD pathogenesis. In diet-induced obese mice, treatment with IL-6 antibodies improved sensitivity to insulin. Objective: This study aim is to evaluate the level of adiponectin, IL-6 and CRP in Egyptian patients with NAFLD. Methods: This study was conducted on 2 groups 104 NAFLD as diagnosed by ultrasound examination and 21 healthy participants as control group. All the subjects were subjected to an abdominal ultrasonography, liver enzymes ALT & AST, lipid profile (triglycerides, HDL, LDL, cholesterol, CRP, IL-6 & Adiponectin). Results: Plasma adiponectin levels were significantly lower in NAFLD patients than control gp (3.05±2.65μg/ml vs 10.52±3.35 (μg/ml). IL-6 level was higher in NAFLD than control gp but not significant (114.24±22.32pg/ml vs 104.9±19.98pg/ml). CRP was significantly higher in NAFLD than control gp (17.86±11.59mg/L vs 5.4±3.81mg/L). Adiponectin ROC curve showed an AUROC curve in NAFLD gp (0.918 p=0.0001). IL-6 ROC curve showed an AUROC curve in NAFLD gp (0.703 p=0.0003). CRP ROC curve showed an AUROC curve in NAFLD gp (0.853 p=0.0001). Conclusion: Patients with NAFLD have lower adiponectin levels and higher IL-6 and CRP levels compared with their control group.

Optimization of the production and characterization of milk-clotting enzyme from Bacillus subtilis isolated from marine sponge

Background and objectives Milk-clotting enzyme (MCE) has important applications in the dairy industry and in the cheese-manufacturing process. Because of the increase in cheese consumption and the low supply of calf rennets, there is a need for a suitable rennet substitute from an appropriate source. The present investigation aims at microbial production of MCE and medium optimization for maximal enzyme production by the most potent strain. Partial purification and the properties of the partially purified enzyme are also studied. Materials and methods In the present study several microorganisms were tested for production of the MCE. MCE/caseinase ratio was investigated and was used as the key parameter for selection of the most potent strain and for medium optimization. Medium optimization experiments were carried out in an attempt to increase the enzyme productivity by the most potent strain. The produced enzyme was partially purified using ammonium sulfate at 50% concentration and the properties of the partially purified enzyme were investigated. Results and conclusion Among all the tested bacteria the marine sponge Pseudoceratina arabica isolated bacterium (isolate I) showed the highest milk-clotting activity. This isolate was used for MCE production throughout this study and it was identified as Bacillus subtilis KU710517. Maximum enzyme productivity (581.8 U/ml) and maximum MCE/caseinase ratio were obtained using a medium containing 50 g/l wheat bran with xylose and yeast extract as carbon and nitrogen sources. For the partially purified enzyme, the optimal temperature and pH were 85°C and 5.0, respectively. The enzyme was thermally stable at 45°C and retained 100% activity after 90 min. At 50°C for the same period of time it retained about 82% activity. However, at 60°C, the enzyme lost about 70% of its original activity after 30 min. The activation energy (Ea) of the enzyme was calculated as 6.95 kcal/mol. Km and Vmax values were 4.6 mg/ml and 2933 U/mg protein, respectively.

Oxidative Role of Aflatoxin B1 on the Liver of Wheat Milling Workers

Abstract Aim: The study aimed to estimate oxidative role of aflatoxin B1 (AFB1) on the liver in wheat milling workers. Materials and Methods: Case-control study was conducted to compare between the levels of AFB1/albumin (AFB1/alb), liver enzymes (ALT, AST, GGT, and ALP), P53, MDA, GST, SOD, zinc and vitamin C in 35 wheat milling workers and 40 control subjects. Results: Statistical analysis revealed that ALT, AST, GGT, ALP, P53, MDA, GST and SOD in workers were significantly elevated compared to their controls. In the milling workers, there were significant correlations between MDA levels and the levels of AST, GGT, and P53, while, P53 was inversely correlated with GST and SOD activities. There were significant correlations between Zn levels and GGT, GST and SOD activities, between vitamin C and GST activities, and vitamin C inversely correlated with MDA. Conclusion: The present study concluded that the oxidative stress of AFB1 elevated the MDA and the liver enzymes in wheat milling workers. GST has a crucial role in the detoxification of aflatoxin and SOD as a scavenger antioxidant increased in the workers to overcome the oxidative toxic effects of AFB1 on the liver of the workers, and roles of Zn and vitamin C were significant in activation of these processes.