Mahmoud E Balbaa

Biochemistry, Chemistry

Professor
25.81

Publications

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    Full-text · Dataset · Oct 2015
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    Mahmoud E Balbaa · Reem Waheb · Riham Hosna
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    ABSTRACT: Aims: It is to screen many natural product extracts for their in vitro and in vivo effects on the activities of hepatic α-amylase and α-glucosidase to validate their biological importance. Study Design: Different groups of non-diabetic and diabetic rats were treated by different plants for the in vivo study of glycosidases. In vitro effect of the plants on the tested enzymes was studied in presence and absence of their aqueous extract. Place and Duration of Study: Department of Biological & Environmental Sciences, Faculty of Science, Beirut Arab University, Beirut, Lebanon, between March 2013 and February 2014. Methodology: Enzymes were extracted from the livers of normal rats, also the natural products extracts were prepared for the in vitro studies. α-Amylase and α-glucosidase assays were done in the presence and absence of each plant extract. For the in vivo studies, normal non-diabetic rats were divided into groups, whereas the first group is a control that includes rats fed on normal food diet. The other groups include rats fed on normal food diet mixed with the tested plant leaves (20 mg/g body weight/day) Diabetes was induced in diabetic rats by single intraperitonial injection of streptozotocin. Diabetic rats were divided into groups and treated like the non-diabetic rats. Results: Only Thymus vulgaris and Origanum vulgare extracts showed a significant in vitro dosedependent inhibition on α-amylase with IC50 values of 0.2±0.01 and 0.37±0.03mg/ml, respectively. However, the in vivo effect was not detected for four weeks treatment for the two enzymes. The in vitro treatment of α-amylase by Thymus vulgaris and Origanum vulgare extracts exhibited a mixedtype inhibition. Moreover, the in vivo inhibition of both extracts on the tested hepatic enzymes was not detected in streptozotocin-induced diabetic rats fed on Thymus vulgaris and Origanum vulgare for four weeks. Blood sugar level was non-significantly decreased with respect to that of nontreated rats. Conclusion: some non anti-diabetic plant extracts possess an in vitro inhibition of glycosidases.
    Full-text · Article · Oct 2015
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    Mahmoud E Balbaa

    Full-text · Article · Oct 2015
  • Amin Al-awar · Zouhair Attieh · Mahmoud Balbaa
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    ABSTRACT: Diabetes mellitus is a metabolic defect characterized by an enzymatic alteration that reflects the change of the structure and function. Many enzymes of carbohydrate metabolism are modified during diabetes and it was found that arylsulfatase B (ASB) is one of these modified enzymes. In this article, we investigated the catalytic characters and gene expression of hepatic ASB in streptozotocin - induced diabetic rats supplemented daily with a black mulberry as an anti-diabetic material. Diabetes was induced experimentally in rats by one high dose of streptozotocin and different groups of the diabetic rats were supplemented with a black mulberry (Morus nigra) leaves and the juice. The results demonstrated that the black mulberry leaves suppressed the blood sugar levels in diabetic rats. Moreover, the administration of leaves decreased significantly the activity of hepatic ASB and its V-max value returned to normal. However, mulberry juice failed to lower significantly the activity of that enzyme or its V-max value. Furthermore, the study of the gene expression of the enzyme showed the same tendency. These data suggest that the daily treatment of mulberry leaves has a potent effect to correct the diabetes - stimulated ASB alteration.
    No preview · Article · Sep 2015 · Current Topics in Nutraceutical Research
  • Mahmoud E Balbaa
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    ABSTRACT: Growth factors and their receptors are important signaling molecules, which are involved in the regulation of cell growth. There are different types of growth factors causing different responses and there are many overlapping responses from some types. Epidermal growth factor (EGF) stimulates the phosphorylation of the ribosomal protein S6, whereas the activation of its receptor (EGFR) is associated with metastasis, poor prognosis and chemotherapy resistance. This receptor is overexpressed in epithelial malignancies. Transforming growth factor beta (TGFβ-1) is a multifunctional type involved in the regulation of growth and differentiation of both normal and transformed cells and overexpressed in hepatocellular carcinoma tissues. A significant higher serum level of EGF and TGF-β1was recently found in patients with hepatocellular carcinoma compared to their level in patients with chronic hepatitis C infection and control subjects. The levels of phosphorylated EGFR in hepatocellular carcinoma and chronic hepatitis C patients showed a highly significant difference between patients. Taken together, EGF and its receptor phosphorylated form can be used as sensitive biomarkers for the diagnosis and prognosis of these diseases. In conclusion, various growth factors are involved in different biological processes, some of which have a clinical importance in disease.
    No preview · Conference Paper · Aug 2015
  • Mahmoud Balbaa · Razan Hammoud · Hoda Yusef

    No preview · Article · Aug 2015 · Letters in Drug Design & Discovery
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    ABSTRACT: The inhibition of glycosidases from bacteria and the liver of normal and diabetic rats by 2-(tetra-O-acetyl-β-Dglucopyranosylsulfanyl)- 5-(1-benzyl-1H-indol-2-yl)-1,3,4-oxadiazole BnM-3B; 3-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)- 5-(1H-indol-2-yl)-1,3,4-oxadiazole- 2(3H)-thione MTB-4A; 3-(2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-β-Dglucopyranosyl)- 5-(1-benzyl-1H-indol-2-yl)-1,3,4-oxadiazole-2(3H)-thione BnN-5A has been investigated. In vitro treatment of hepatic α-amylase and β-glucuronidase from control and streptozotocin-induced diabetic rats by S- and Nglycosyl analogues from oxadiazolinethione derivatives exhibited a significant dose-dependent decrease on the specific activity of both α-amylase and β-glucuronidase. Moreover, these compounds also exhibited a significant decrease on the specific activity of α-amylase and α-glucosidase produced by Bacillus subtilis AH. The observed IC50 values of these compounds are much lower than that of ethanolamines, higher for α-glucosidase than α-amylase from bacteria and significantly lower for hepatic α-amylase and β-glucuronidase from diabetic rats. The obtained results suggest that these compounds are good inhibitors that act on glycosidases from bacteria and normal / diabetic rats in different mechanisms.
    No preview · Article · Mar 2015 · Letters in Drug Design & Discovery
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    Mahmoud Balbaa

    Full-text · Article · Jan 2015
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    Mahmoud E Balbaa

    Full-text · Article · Jan 2015
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    Rima Samarji · Mahmoud Balbaa
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    ABSTRACT: Background: Diabetes mellitus (DM) is characterized by the overproduction of the reactive oxygen species which affects the integrity of the lysosomal membrane affecting lysosomal enzymes. The effect of these species is blocked by some natural products as antioxidants. In the current study, groups of normal and streptozotocin (STZ)-induced diabetic rats were treated by Nigella sativa (NS), olive and canola oils and subjected to the study of arylsulfatases as a model of lysosomal enzymes. The aim of the present study is to investigate the effect of STZ-induced diabetes on arylsulfatases in presence and absence of NS, olive and canola oils. Methods: Different groups of rats were induced by STZ, treated with different oils and compared to their corresponding control group. All groups were subjected for the assays of blood glucose, insulin, catalase and arylsulfatases. A comparative kinetic study of arylsulfatses was performed to detect the alteration of catalytic characterization. Results: The results demonstrated that diabetes causes a significant elevation in the level of hepatic arylsulfatase B and a significant reduction of hepatic catalase as an antioxidant enzyme. NS and olive oils returned catalase and arylsulfatase B activities back near to normal by fixing their catalytic properties. Furthermore, the maximum velocity of arylsulfatases A and B was significantly elevated in the induced diabetes, whereas their Km values were significantly changed. The treatment of diabetic rats by NS and olive oils reduced the degree of significance. Conclusion: Diabetes induces significant alterations of the catalytic characters of arylsulfatases and some oils decrease this alteration through an antioxidant-mediated effect.
    Full-text · Article · Dec 2014 · Journal of Diabetes and Metabolic Disorders
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    ABSTRACT: This study included 20 selected female patients with breast cancer, 30 of their female relatives (sisters and daughters), and 10 healthy females as a control group. Genomic DNA was extracted from peripheral blood lymphocytes of all the subjects, and the polymerase chain reaction was carried out using specific primers for BRCA1 (exons 2 and 8) and BRCA2 (exons 9, 11, and 21). The mutations were detected using a single-strand conformation polymorphism assay and heteroduplex analysis. Finally, the sample variants and their controls were sequenced. Mutations were detected in 44% of the study population, with 18% found in the BRCA1 gene and 26% attributed to BRCA2. Five sequence variants were identified, including two frameshift mutations, one nonsense mutation, and two missense mutations. Therefore, we conclude that germline mutations in two major genes, BRCA1 and BRCA2, may have an important influence on the predisposition and development of familial breast cancer.
    Full-text · Article · Feb 2014 · Biochemical Genetics
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    Mahmoud Balbaa

    Full-text · Article · Jan 2014
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    ABSTRACT: In this article, we present a study on the levels of epidermal growth factor (EGF), its phosphorylated receptor (p-EGFR) and transforming growth factor-β1 (TGF-β1) in the sera of patients with hepatocellular carcinoma (HCC) and chronic hepatitis C (CHC) infection. The results reveal significant higher serum levels of EGF and TGF-β1 in patients with HCC compared to their level in patients with CHC infection and control subjects. The levels of p-EGFR in HCC and CHC patients show a highly significant difference between patients. Based on the best cutoff value of 914 pg/ml, EGF shows 63.3 % sensitivity and 87.5 % specificity for HCC patients where the area under the curve is 0.81. The p-EGFR shows sensitivity of 63.3 % and specificity of 100 % where the area under the curve is 0.87 for HCC patients based on the best cutoff value of 39 U/mg protein. The best cutoff value (370 pg/ml) for serum TGF-β1 displays sensitivity of 86.7 % and specificity of 100 %, where the area under the curve is 0.97 for HCC patients.
    Full-text · Article · Sep 2013 · Medical Oncology
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    Mahmoud Balbaa

    Full-text · Article · Jan 2013
  • Mahmoud E Balbaa
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    ABSTRACT: Background: Several drugs have been implicated as having various respiratory and cardiac effects. For example, phenobarbitone is a central nervous system sedative and is also an anticonvulsant. Neostigmine, which is a stimulant of the parasympathetic nervous system, acts as a reversible anti-cholinesterase for the treatment myasthenia gravis and certain types of glaucoma. Aminophylline is a vasodilator, which improves the cardiac index and pulmonary vascular resistance. Gallamine is considered as a muscle relaxant that has a cardiovascular effect [1]. On the other hand, the main respiratory chain in mitochondria consists of dehydrogenases, including succinate-cytochrome c reductase (SCR), linked to flavoproteins and the cytochrome system. This enzyme catalyzes the oxidation of succinate by cytochrome c (cyt c) or 2,6-dichlorophenolindophenol (DCIP) under optimal conditions. The reduction of DCIP by succinate was found to be highly dependent upon DCIP concentration [2]. Aims: In clinical applications, different types of enzymes were investigated in an attempt to reflect changes occurring in the different tissues. SCR was subjected for the current study to reveal the effect of the above mentioned drugs on the biological oxidation because of their clinical application without enough knowledge of their specific action on the enzymes of the respiratory chain. Methods: The mice were treated with different doses of the above mentioned drugs in saline by i.m. or s.e. injections. At the end of each infection period, the infected group and the corresponding control one were sacrificed. The livers were immediately removed, homogenized and centrifuged. The obtained supernatant was subjected to enzyme assay and the corresponding enzyme purification of the kinetic study. Results: SCR was inhibited in vitro and in vivo by phenobarbitone, aminopbylline and neostigmine using both DCIP and cyt c as substrates. The enzyme was also activated by gallamine towards both substrates. In vitro, phenobarbitone and aminophylline inhibited the enzyme with respect to the reduction of DCIP and cyt c in a non-competitive manner with Kj values of 1.5 X 10-5 and 5.7 x 10-5 M, respectively. Moreover, neostigmine competitively inhibited the enzyme towards both substrates with Kj values of 1.36 x 10-5 and 1.50 x 10-5 M, respectively. Conclusions: completely different mechanisms are operative through the effect of these drugs on the enzyme. References: [1] Balbaa, M., Al-Meer, J. and Al-Khal, A. (2004): Effect of some cardiac and respiratory drugs on succinate-cytochrome c reductase. J. Enzym. Inhib. Med. Chem., 19: 343. [2] Takemori, S. and King, T.E. {1964) J. Biol. Chem. 239, 3456.
    No preview · Conference Paper · Nov 2012
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    ABSTRACT: Coccidiosis is one of the most common parasitic diseases affecting many species of domestic animals. This disease has a major economic significance and the search for new compounds having anticoccidial activity is of great importance. In this article, different levels of protection from coccidian infection by Eimeria stiedae were developed in rabbits by treatment with compounds incorporating the skeleton of thiourea. These compounds include 4,5-diphenylimidazole-2-thione (1), 4,5-Diphenyl-1,2,4-triazole-3-thiol (2) and 5-(2-Hydroxyphenyl)-4-phenyl-1,2,4-triazole-3-thiol (3) compared to the anticoccidial drug toltrazuril as a reference compound. Compounds 1-3 inhibit coccidiosis-induced activity of α-glucosidase. The protection from coccidial infection by compound 1 was higher than that shown for compounds 2 and 3. These data suggest that diazole and triazole thione derivatives have a mimetic effect for anticoccidial drugs through their inhibition of glycosidases.
    Full-text · Article · Oct 2012 · Acta biochimica Polonica
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    MAHMOUD BALBAA and EL SAYED H. EL ASHRY
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    ABSTRACT: The enzyme inhibition is valuable in the regulation of the enzyme activity. It has many applications, which include the drug design to target an enzyme. In the present review, we focus on the inhibition of different enzymes such as glycosidases, arylsulfatases and others by synthetic inhibitors or drugs. This provides the strategy that combines the inhibitory and therapeutic mode of action of the confirmed inhibitors.
    Full-text · Article · Jan 2012
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    Natalia El-Merhie · Ismail Sabry · Mahmoud Balbaa
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    ABSTRACT: Calcium is an essential nutrient required for critical biological functions. Calcium supplementation is to be evaluated using immature female rats. The present study focused on some blood parameters, gonadal development and bone structure. Forty immature female Sprague-Dawley rats were randomly divided into four equal-sized groups (80 g average body weight) to receive calcium chloride dihydrate (group I: control; groups II, III and IV: received 20 mg, 40 mg and 60 mg per kg body weight, respectively) for 5 weeks. Rats were decapitated, and their trunk blood was sampled for biochemical assays. Cholesterol, triglycerides, glucose and calcium were measured. Gonadal and bone structure were histologically evaluated. Results revealed that treatment of developing female rats with three calcium doses used have no marked effect on the serum calcium and cholesterol levels. However, serum triglyceride level and body weight gain are significantly decreased in rats treated with all of the three calcium doses. Serum glucose level showed a marked increase in animals treated with the higher calcium doses. Moreover, observable histological alterations are recognized in the ovaries. Bones of the experimental animals also showed morphological alterations. These results suggest that increasing calcium supplementation decreases triglycerides and percentage body weight gain and positively affects the bone and gonadal development.
    Full-text · Article · Dec 2011 · Journal of physiology and biochemistry
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    ABSTRACT: Mutations in the genes encoding enzymes involved in the metabolism of chemical carcinogens can significantly affect the risk of cell transformation and cancer development. The resident Lebanese population has experienced a sharp increase in cancer incidence within the last few years. The relationship between gene polymorphisms of metabolic enzymes and gastrointestinal (GI) cancer incidence was not previously investigated. The aim of this study was to investigate the relationship between CYP1A1, CYP2E1, and GSTM1 gene polymorphisms and GI cancer incidence among Lebanese. Blood and/or paraffin-embedded biopsy samples were collected from patients and healthy controls. The genotypes were determined by polymerase chain reaction and polymerase chain reaction-restriction fragment length polymorphism. The results of the present case-control study show that the studied Lebanese population generally resembles Caucasian populations with respect to the considered polymorphisms. Further, the GSTM1*0/*0 genotype is a significant risk factor for gastric (odds ratio = 4.1; 95% confidence interval: 1.2-14.5) and colorectal cancers (odds ratio = 3.8; 95% confidence interval: 1.7-8.5); on the other hand, CYP1A1*2A and CYP2E1*6 alone are not significantly associated with GI cancer development, although CYP1A1*2A was more frequent among patients. A remarkable and statistically significant 36.5-fold increase in the risk of gastric cancer was observed among patients with CYP1A1*2A/*2A combined with GSTM1*0/*0. The investigation of genetic risk factors and susceptibility gene polymorphisms in Lebanese is helpful for better understanding of GI cancer etiology.
    No preview · Article · Jun 2011 · Genetic Testing and Molecular Biomarkers
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    ABSTRACT: The in vivo and in vitro effects of 4,5-diphenylimidazole-2-thione (1), 4,5-diphenyl-1,2,4-triazole-3-thiol (2) and 5-(2-hydroxyphenyl)-4-phenyl-1,2,4-triazole-3-thiol (3) on α-glucosidase and α-amylase were investigated. The in vivo inhibition has been found to be dose-dependent and to occur at a value less than LD50. The in vitro treatment of the enzymes by 4,5-diphenylimidazole-2-thione exhibited a reversible inhibition of the non-competitive type with Ki value of 3.5 and 6.5×10(-5) M for α-glucosidase and α-amylase, respectively. 4,5-diphenyl-1,2,4-triazole-3-thione showed a reversible inhibition of the competitive and non-competitive types, with Ki value of 10(-5) M magnitude, for α-glucosidase and α-amylase. On the other hand, 5-(o-hydroxyphenyl)-4-phenyl-1,2,4-triazole-3-thione did not display an inhibitory effect towards α-amylase but showed a potent inhibition of the competitive type for hepatic α-glucosidase with 10(-5) M magnitude of Ki value.
    No preview · Article · Jun 2011 · European Journal of Medicinal Chemistry

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