Mohamed M. Sayed-Ahmed

Design, synthesis and biological evaluation of novel quinazoline derivatives as potential antitumor agents: Molecular docking study

Novel derivatives of quinazoline (1-27) have been synthesized and tested for their antitumor activity against three tumor cell lines among these cell lines the human breast carcinoma cell line (MCF-7) in which EGFR is highly expressed. All tested compounds showed potent and selective activity against breast cancer (MCF-7) with IC(50) range of 3.35-6.81 microg/ml. With regarding broad-spectrum activity compounds 5, 9, 15, 18 and 20 exploited potent antitumor against human liver cell line (HEPG2), human breast cell line (MCF-7) and human cervix cell line (HELA) with IC(50) range of 3.35-5.59 microg/ml. Virtual screening was carried out through docking the designed compounds into the ATP binding site of epidermal growth factor receptor (EGFR) to predict if these compounds have analogous binding mode to the EGFR inhibitors.

THYMOQUINONE SUPPLEMENTATION PREVENTS THE DEVELOPMENT OF GENTAMICIN‐INDUCED ACUTE RENAL TOXICITY IN RATS

1 The present study investigated the possible protective effects of thymoquinone (TQ), a compound derived from Nigella sativa with strong anti‐oxidant properties, against gentamicin (GM)‐induced nephrotoxicity. 2 A total of 40 adult male Wistar albino rats was divided into four groups. Rats in the first group were injected daily with normal saline (2.5 mL/kg, i.p.) for 8 consecutive days, whereas rats in the second group received TQ (50 mg/L in drinking water) for 8 consecutive days. Animals in the third group were injected daily with GM (80 mg/kg, i.p.) for 8 consecutive days, whereas animals in the fourth group received a combination of GM (80 mg/kg, i.p.) and TQ (50 mg/L in drinking water) for 8 consecutive days. 3 Gentamicin resulted in a significant increase in serum creatinine, blood urea nitrogen (BUN), thiobarbituric acid‐reactive substances (TBARS) and total nitrate/nitrite (NOx) and a significant decrease in reduced glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT) and ATP levels in kidney tissues. 4 Interestingly, TQ supplementation resulted in a complete reversal of the GM‐induced increase in BUN, creatinine, TBARS and NOx and decrease in GSH, GPx, CAT and ATP to control values. Moreover, histopathological examination of kidney tissues confirmed the biochemical data, wherein TQ supplementation prevents GM‐induced degenerative changes in kidney tissues. 5 Data from the present study suggest that TQ supplementation prevents the development of GM‐induced acute renal failure by a mechanism related, at least in part, to its ability to decrease oxidative stress and to preserve the activity of the anti‐oxidant enzymes, as well as it ability to prevent the energy decline in kidney tissues.

Metformin attenuates streptozotocin-induced diabetic nephropathy in rats through modulation of oxidative stress genes expression

Diabetes mellitus is a group of metabolic diseases characterized by hyperglycemia resulting from defects in insulin secretion and/or action. One of the most important complications of this metabolic disease is diabetic nephropathy. Hyperglycemia promotes oxidative stress and hence generation of reactive oxygen species (ROS), which is known to play a crucial role in the pathogenesis of diabetic nephropathy. Recent studies have established that metformin, an oral hypoglycemic drug, possesses antioxidant effects. However, whether metformin can protect against diabetic nephropathy has not been reported before. The overall objectives of the present study are to elucidate the potential nephroprotective effect of metformin in a rat diabetic nephropathy model and explore the exact underlying mechanism(s) involved. The effect of metformin on the biochemical changes associated with hyperglycemia induced by streptozotocin was investigated in rat kidney tissues. In addition, energy nucleotides (AMP and ATP), and Acetyl-CoA in the kidney homogenates and mitochondria, and the mRNA expression of oxidative stress and pro-inflammatory mediators were assessed. Our results showed that treatment of normoglycemic rats with metformin caused significant increase in ATP, Acetyl-CoA, and CoA-SH contents in kidney homogenates and mitochondria along with profound decrease in AMP level. On the other hand, treatment of diabetic nephropathy rats with metformin normalized all biochemical changes and the energy status in kidney tissues. At the transcriptional levels, metformin treatment caused significant restoration in diabetic nephropathy-induced oxidative stress mRNA levels, particularly GSTα, NQO1, and CAT genes, whereas inhibited TNF-α and IL-6 pro-inflammatory genes. Our data lend further credence for the contribution of metformin in the nephroprotective effect in addition to its well known hypoglycemic action.

Thymoquinone Attenuates Diethylnitrosamine Induction of Hepatic Carcinogenesis Through Antioxidant Signaling

Hepatocellular carcinoma accounts for about 80–90% of all liver cancer and is the fourth most common cause of cancer mortality. Although there are many strategies for the treatment of liver cancer, chemoprevention seems to be the best strategy for lowering the incidence of this disease. Therefore, this study has been initiated to investigate whether thymoquinone (TQ), Nigella sativa derived-compound with strong antioxidant properties, supplementation could prevent initiation of hepatocarcinogenesis-induced by diethylnitrosamine (DENA), a potent initiator and hepatocarcinogen, in rats. Male Wistar albino rats were divided into four groups. Rats of Group 1 received a single intraperitoneal (I.P.) injection of normal saline. Animals in Group 2 were given TQ (4 mg/kg/day) in drinking water for 7 consecutive days. Rats of Group 3 were injected with a single dose of DENA (200 mg/kg, I.P.). Animals in Group 4 were received TQ and DENA. DENA significantly increased alanine transaminase (ALT), alkaline phosphatase (ALP), total bilirubin, thiobarbituric acid reactive substances (TBARS) and total nitrate/nitrite (NOx) and decreased reduced glutathione (GSH), glutathione peroxidase (GSHPx), glutathione-s-transferase (GST) and catalase (CAT) activity in liver tissues. Moreover, DENA decreased gene expression of GSHPx, GST and CAT and caused severe histopathological lesions in liver tissue. Interestingly, TQ supplementation completely reversed the biochemical and histopathological changes induced by DENA to the control values. In conclusion, data from this study suggest that: (1) decreased mRNA expression of GSHPx, CAT and GST during DENA-induced initiation of hepatic carcinogenesis, (2) TQ supplementation prevents the development of DENA-induced initiation of liver cancer by decreasing oxidative stress and preserving both the activity and mRNA expression of antioxidant enzymes.

Thymoquinone supplementation reverses acetaminophen-induced oxidative stress, nitric oxide production and energy decline in mice liver

This study was undertaken to evaluate the protective effect of thymoquinone (TQ) against acetaminophen-induced hepatotoxicity. Mice were given TQ orally at three different doses (0.5, 1 and 2mg/kg/day) for 5 days before a single hepatotoxic dose of acetaminophen (500 mg/kg i.p.). TQ supplementation dramatically reduced acetaminophen-induced hepatotoxicity, in a dose-dependent manner, as evidenced by decreased serum alanine aminotransferase (ALT) activities. Acetaminophen (500 mg/kg i.p.) resulted in a significant increase in serum ALT and total nitrate/nitrite, hepatic lipid peroxides and a significant decrease in hepatic reduced glutathione (GSH) and ATP in a time-dependent manner. Interestingly, supplementation of TQ (2mg/kg/day) for 5 days before acetaminophen administration resulted in reversal of acetaminophen-induced increase in ALT, total nitrate/nitrite, lipid peroxide and a decrease in GSH and ATP. Moreover, TQ did not affect acetaminophen-induced early decrease in hepatic GSH indicating lack of the effect on the metabolic activation of acetaminophen. In conclusion, TQ is effective in protecting mice against acetaminophen-induced hepatotoxicity possibly via increased resistance to oxidative and nitrosative stress as well as its ability to improve the mitochondrial energy production.

THYMOQUINONE SUPPLEMENTATION ATTENUATES CYCLOPHOSPHAMIDE INDUCED CARDIOTOXICITY IN RATS

This study examined the possible protective effects of thymoquinone (TQ), the main constituent of the volatile oil of black seed (Nigella sativa), against cyclophosphamide (CP)‐induced cardiotoxicity. Adult male Wistar albino rats were divided into four treatment groups. Rats in the first group were served as control. Rats in the second group received TQ (50 mg/L in drinking water) for 12 days. Animals in the third group were injected with a single dose of CP (200 mg/kg, IP) at day 5. Rats in the fourth group received TQ (50 mg/L in drinking water) for 5 days before a single dose of CP (200 mg/kg, IP) and continued thereafter throughout the experiment. On day 13, animals were sacrificed; serum and hearts were isolated and analyzed. Cyclophosphamide resulted in a significant increase in serum creatine kinase, lactate dehydrogenase, cholesterol, triglycerides, creatinine, urea, and tumor necrosis factor‐α. In heart tissues, CP resulted in a significant increase in thiobarbituric acid reactive substances and total nitrate/nitrite and a significant decrease in reduced glutathione, glutathione peroxidase, catalase, and adenosine triphosphate levels. Interestingly, TQ supplementation resulted in a complete reversal of all the biochemical changes induced by CP to their control values. Data from this study suggest that TQ supplementation attenuates CP‐induced cardiotoxicity by a mechanism related, at least in part, to its ability to decrease oxidative and nitrosative stress and to preserve the activity of antioxidant enzymes as well as its ability to improve the mitochondrial function and energy production.

Doxorubicin Toxicity can be Ameliorated during Antioxidant L-Carnitine Supplementation

Doxorubicin is an antibiotic broadly used in treatment of different types of solid tumors. The present study investigates whether L-carnitine, antioxidant agent, can reduce the hepatic damage induced by doxorubicin. Male Wistar albino rats were divided into six groups: group 1 was intraperitoneal injected with normal saline for 10 consecutive days; group 2, 3 and 4 were injected every other day with doxorubicin (3 mg/kg, i.p.), to obtain treatments with cumulative doses of 6, 12 and 18 mg/kg. The fifth group was injected with L-carnitine (200 mg/kg, i.p.) for 10 consecutive days and the sixth group was received doxorubicin (18 mg/kg) and L-carnitine (200 mg/kg). High cumulative dose of doxorubicin (18 mg/kg) significantly increases the biochemical levels of alanine transaminase, alkaline phosphatase, total bilirubin, thiobarbituric acid reactive substances (TBARs), total nitrate/nitrite (NOx) p < 0.05 and decrease in glutathione (GSH ), superoxide dismutase (SOD), glutathione peroxidase (GSHP x), glutathione-s-transferase (GST), glutathione reductase (GR) and catalase (CAT) activity p < 0.05. The effect of doxorubicin on the activity of antioxidant genes was confirmed by real time PCR in which the expression levels of these genes in liver tissue were significantly decrease compared to control p < 0.05. Interestingly, L-carnitine supplementation completely reversed the biochemical and gene expression levels induced by doxorubicin to the control values. In conclusion, data from this study suggest that the reduction of antioxidant defense during doxorubicin administration resulted in hepatic injury could be prevented by L-carnitine supplementation by decreasing the oxidative stress and preserving both the activity and gene expression level of antioxidant enzymes.

Metformin Rescues the Myocardium from Doxorubicin-Induced Energy Starvation and Mitochondrial Damage in Rats

Clinical use of doxorubicin (DOX) is limited by its cardiotoxic side effects. Recent studies established that metformin (MET), an oral antidiabetic drug, possesses an antioxidant activity. However, whether it can protect against DOX-induced energy starvation and mitochondrial damage has not been reported. Our results, in a rat model of DOX-induced cardiotoxicity, show that DOX treatment significantly increased serum levels of LDH and CK-MB, indicators of cardiac injury, and induced expression of hypertrophic gene markers. DOX also caused marked decreases in the cardiac levels of glutathione, CoA-SH and ATP, and mRNA expression of catalase and NQO-1. These biochemical changes were associated with myocardial histopathological and ultrastructural deteriorations, as observed by light and electron microscopy, respectively. Cotreatment with MET (500 mg/kg) eliminated all DOX-induced biochemical, histopathological, and ultrastructural changes. These findings demonstrate that MET successfully prevents DOX-induced cardiotoxicity in vivo by inhibiting DOX-induced oxidative stress, energy starvation, and depletion of intramitochondrial CoA-SH.

Carnitine esters prevent oxidative stress damage and energy depletion following transient forebrain ischaemia in the rat hippocampus.

1 The present study investigated whether propionyl‐l‐carnitine (PLC) has neuroprotective effects, similar to those reported for acetyl‐l‐carnitine (AC), against transient forebrain ischaemia‐induced neuronal damage and biochemical derangement in the rat hippocampal CA1 region. 2 In total, 105 adult male Wistar albino rats were divided into seven groups of 15 animals each. The first three groups were injected i.p. with normal saline, AC (300 mg/kg) or PLC (300 mg/kg) for 7 successive days. The next three groups were injected i.p. with the same doses of normal saline, AC or PLC immediately after the induction of 10 min forebrain ischaemia and i.p. injections were continued for 7 successive days. Rats in the seventh group were subjected to sham‐operated ischaemia and injected with normal saline for 7 successive days. 3 Seven days after treatment, animals were killed and their brains isolated for histopathological examination and biochemical studies. 4 Forebrain ischaemia resulted in a significant decrease in the number of intact neurons (77%), ATP concentration (51%) and glutathione content (32%), whereas there was a significant increase in the production of thiobarbituric acid‐reactive substances (TBARS; 71%) and total nitrate/nitrite (NOx; 260%) in hippocampal tissues. 5 Administration of either AC or PLC attenuated forebrain ischaemia‐induced neuronal damage, manifested by a greater number of intact neurons, ATP and glutathione, as well as a decrease in TBARS and NOx in hippocampal tissues. 6 Results from the present study suggest, for the first time, that PLC attenuates forebrain ischaemia‐induced neuronal injury, oxidative stress and energy depletion in the hippocampal CA1 region. Propionyl‐l‐carnitine has neuroprotective effects similar to AC and could have a potential use in the treatment of neurodegenerative diseases. 7 The results of the present study will open up new perspectives for the use of PLC in the treatment of neurodegenerative diseases associated with, or secondary to, myocardial ischaemia–reperfusion injury and chronic circulatory failure.

MicroRNAs and Metastasis-related Gene Expression in Egyptian Breast Cancer Patients

AIM AND BACKGROUND MicroRNAs (miRNAs) are a class of naturally occurring small noncoding RNAs that regulate gene expression, cell growth, differentiation and apoptosis by targeting mRNAs for translational repression or cleavage. The present study was conducted to study miRNAs in Egyptian breast cancer (BC) and their relation to metastasis, tumor invasion and apoptosis in addition to their association with the ER and PR statuses. METHODS Real Time RT-PCR was performed to identify the miRNA expression level of eight miRNAs and eight metastatic-related genes in 40 breast cancer samples and their adjacent non-neoplastic tissues. The expression levels of each miRNA relative to U6 RNA were determined. Also, miRNA expression profiles of the BC and their corresponding ANT were evaluated. RESULTS The BC patients showed an up-regulation in miRNAs (mir-155, mir-10, mir-21 and mir-373) with an upregulation in MMP2, MMp9 and VEGF genes. We found down regulation in mir-17p, mir-126, mir-335, mir-30b and also TIMP3, TMP1 and PDCD4 genes in the cancer tissue compared to the adjacent non-neoplastic tissues. Mir -10b, mir -21, mir-155 and mir373 and the metastatic genes MMP2, MMP9 and VEGF were significantly associated with an increase in tumor size (P<0.05). No significant difference was observed between any of the studied miRNAs regarding lymph node metastasis. Mir-21 was significantly over-expressed in ER-/PR- cases. CONCLUSION Specific miRNAs (mir-10, mir-21, mir-155, mir-373, mir-30b, mir-126, mir-17p, mir-335) are associated with tumor metastasis and other clinical characteristics for BC, facilitating identification of individuals who are at risk.