Sawsan A. Omer
King Saud University
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Featured researches published by Sawsan A. Omer.
Oxidative Medicine and Cellular Longevity | 2012
Zeinab K. Hassan; Mai A Elobeid; Promy Virk; Sawsan A. Omer; Maha H. Elamin; Maha H. Daghestani; Ebtisam M. Al-Olayan
Reactive oxygen species (ROS) are cytotoxic agents that lead to significant oxidative damage. Bisphenol A (BPA) is a contaminant with increasing exposure to it and exerts both toxic and estrogenic effects on mammalian cells. Due to limited information concerning the effect of BPA on liver, this study investigates whether BPA causes hepatotoxicity by induction of oxidative stress in liver. Rats were divided into five groups: The first four groups, BPA (0.1, 1, 10, 50 mg/kg/day) were administrated orally to rats for four weeks. The fifth group was taken water with vehicle. The final body weights in the 0.1 mg group showed a significant decrease compared to control group. Significant decreased levels of reduced glutathione, superoxide dismutase, glutathione peroxidase, glutathione-S-transferase, glutathione reductase and catalase activity were found in the 50 mg BPA group compared to control groups. High dose of BPA (50 mg/kg) significantly increased the biochemical levels of ALT, ALP and total bilirubin. BPA effect 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. Data from this study demonstrate that BPA generate ROS and reduce the antioxidant gene expression that causes hepatotoxicity.
Food and Chemical Toxicology | 2013
Maha H. Elamin; Maha H. Daghestani; Sawsan A. Omer; Mai A Elobeid; Promy Virk; Ebtesam M. Al-Olayan; Zeinab K. Hassan; Osama B. Mohammed; Abdelilah Aboussekhra
Breast cancer constitutes a major health problem for women worldwide. However, its incidence varies between populations and geographical locations. These variations could be diet-related, since there are several carcinogenic compounds in the modern diet, while natural products contain various anti-cancer elements. Several lines of evidence indicate that, in addition to their clear preventive effect, these compounds could also be used as therapeutic agents. In the present report we have shown that oleuropein, a pharmacologically safe natural product of olive leaf, has potent anti-breast cancer properties. Indeed, oleuropein exhibits specific cytotoxicity against breast cancer cells, with higher effect on the basal-like MDA-MB-231 cells than on the luminal MCF-7 cells. This effect is mediated through the induction of apoptosis via the mitochondrial pathway. Moreover, oleuropein inhibits cell proliferation by delaying the cell cycle at S phase and up-regulated the cyclin-dependent inhibitor p21. Furthermore, oleuropein inhibited the anti-apoptosis and pro-proliferation protein NF-κB and its main oncogenic target cyclin D1. This inhibition could explain the great effect of oleuropein on cell proliferation and cell death of breast cancer cells. Therefore, oleuropein warrants further investigations to prove its utility in preventing/treating breast cancer, especially the less-responsive basal-like type.
Asian Pacific Journal of Cancer Prevention | 2013
Zeinab K. Hassan; Maha H. Elamin; Sawsan A. Omer; Maha Hassan Daghestani; Ebtesam Salah Al-Olayan; Mai A Elobeid; Promy Virk
BACKGROUND Breast cancer is a major health problem worldwide. Olive oil induces apoptosis in some cancer cells due to phenolic compounds like oleuropein. Although oleuropein has anticancer activity, the underlying mechanisms of action remain unknown. The study aimed to assess the mechanism of oleuropin-induced breast cancer cell apoptosis. MATERIALS AND METHODS p53, Bcl-2 and Bax gene expression was evaluated by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) in luminal MCF-7 cells. RESULTS Oleuropein-induced apoptosis was accompanied by up-regulation of both p53 and Bax gene expression levels and down-regulation in Bcl2. CONCLUSIONS Oleuropein induces apoptosis in breast tumour cells via a p53-dependent pathway mediated by Bax and Bcl2 genes. Therefore, oleuropein may have therapeutic potential in breast cancer patients by inducing apoptosis via activation of the p53 pathway.
Asian Pacific Journal of Cancer Prevention | 2012
Zeinab K. Hassan; Maha H. Elamin; Maha H. Daghestani; Sawsan A. Omer; Ebtesam M. Al-Olayan; Mai A Elobeid; Promy Virk; Osama B. Mohammed
Breast cancer causes death due to distant metastases in which tumor cells produce matrix metalloproteinase (MMP) enzymes which facilitate invasion. Oleuropein, the main olive oil polyphenol, has anti-proliferative effects. This study aimed to investigate the effect of oleuropein on the metastatic and anti-metastatic gene expression in the MDA human breast cancer cell line. We evaluated the MMPs and TIMPs gene expression by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) in treated and untreated cells. This study demonstrated that OL may induce anti-metastatic effects on human breast cancer cells. We found that TIMP1,-3, and -4 were over-expressed after all periods of incubation in treated cancer cells compared to untreated cells, while MMP2 and MMP9 genes were down-regulated, at least initially. Treatment of breast cancer cells with oleuropein could help in prevention of cancer metastasis by increasing the TIMPs and suppressing the MMPs gene expressions.
Conservation Genetics | 2011
T Wacher; Torsten Wronski; Robert L. Hammond; Bruce Winney; Mark J. Blacket; Kris J. Hundertmark; Osama B. Mohammed; Sawsan A. Omer; William Macasero; Hannes Lerp; Martin Plath; Christoph Bleidorn
Goitred gazelle (Gazella subgutturosa) rank among the most endangered mammals on the Arabian Peninsula and the Asian steppes. Past conservation efforts have been plagued by confusion about the phylogenetic relationship among various—phenotypically discernable—populations, and even the question of species boundaries was far from being certain. This lack of knowledge had a direct impact on conservation measures, especially ex situ breeding programmes, hampering the assignment of captive stocks to potential conservation units. Here, we provide a phylogenetic framework, based on the analysis of mtDNA sequences of a number of individuals collected from the wild and captivity throughout the species’ natural range. Our analyses revealed a polyphyly within the presumed species of G. subgutturosa resulting in two distinct clades: one on the Arabian Peninsula, Iraq, Jordan, Syria and Turkey (Gazella marica; sand gazelle) and one genetically diverse larger clade from the rest of its Asian range (G. subgutturosa; goitred gazelle). Additionally, we provide a quick method (PCR-RFLP) to analyse the taxonomic affiliation of captive gazelles that will be used for re-introductions into the wild.
Asian Pacific Journal of Tropical Medicine | 2014
Osama B. Mohammed; Abdulrahman A. Jarelnabi; Riyadh S. Aljumaah; Mohammed A. Alshaikh; Amel O. Bakhiet; Sawsan A. Omer; Abdulaziz N. Alagaili; Mansour F. Hussein
Abstract Objective To detect Coxiella burnetii ( C. burnetii ) DNA in clinical specimens from camel, goats, cattle and sheep in the Kingdom of Saudi Arabia. Methods A total of 367 clinical samples including blood, milk, faeces and urine were collected from different livestock and subjected to PCR amplification using primers which amplify transposon-like region and transposase gene. Results Positive amplification from both regions was obtained from camel, goats and cattle but not from sheep. A percentage of 10.8% samples yielded positive PCR amplification from both blood and milk, where 15 of 139 blood and 16 of 148 milk samples were positive. Faeces and urine showed higher percentages of positive samples reaching 40.8% and 23.8% respectively. Conclusions The preferred route of shedding in camel appeared to be the faeces followed by urine, while that of goats appeared to be the faeces and that of the cattle appeared to be the milk.
International Journal of Endocrinology | 2012
Maha H. Daghestani; Arjumand S. Warsy; Mazin H. Daghestani; Ali Al-Odaib; Abdelmoneim Eldali; Nadia A. Aleisa; Sawsan A. Omer; Zeinab K. Hassan
Background. Several studies have shown an association between codon 16 polymorphism of the β2AR gene and obesity. Methods. We studied the association between Arg16Gly polymorphism and obesity and its influence on anthropometric parameters, lipids, insulin resistance and leptin in Saudi individuals. The study group included 329 individuals (males: 109 and females: 220). Metabolic parameters, including glucose, lipids, insulin, and leptin were analyzed and anthropometric parameters including waist and hip circumference, waist/hip (W/H) ratio, and body mass index (BMI) were measured and HOMA-IR was calculated. Genotyping was conducted by DNA sequencing of 353 bp fragments, carrying the Arg16Gly polymorphic site. Results and Conclusion. Overweight and obese subjects had a significantly higher frequency of Gly16 (0.375 and 0.38, resp.) compared with normal-weight subjects (0.200). In addition, subjects carrying Gly16 allele regardless of their BMI had greater waist and hip circumference, W/H ratio, plasma lipids, leptin, glucose level, and insulin resistance as judged from the HOMA-IR, compared to those with the wild-type allele. The findings of this study show a significant association between the Arg16Gly polymorphism in β2AR gene and the development of insulin resistance, overweight, and obesity in Saudi populations with an influence on the levels of lipid and leptin.
Veterinary Parasitology | 2011
Abdulaziz N. Alagaili; Osama B. Mohammed; Sawsan A. Omer
The gastrointestinal parasites and prevalence of infestation in the Arabian red fox Vulpes vulpes arabica Thomas, were investigated at the King Khalid Wildlife Research Centre (KKWRC) in Thumamah, Riyadh Province, Saudi Arabia. Faecal samples were collected from 58 wild caught foxes while under anaesthesia and examined for gastrointestinal parasites stages. Male and female foxes were infected with three major groups of parasites; cestodes, nematodes, protozoa as well as an acanthocephalan. Faecal analyses revealed that 22 foxes (37.9%) were infected with two different Isospora spp. and three (5.2%) with an undescribed Eimeria sp., 12 (20.7%). Nine individuals (15.5%) harboured hookworms, (Trichosomoides sp.), two (3.5%) were infected with Trichuris sp. (probably Trichuris vulpes) and one individual (1.7%) with Taenia sp. (probably Taenia hydatigena). Carcasses of five male and three female foxes were necropsied. Four of the necropsied carcasses yielded Ancylostoma caninum, two each harboured Pterygodermatitis affinis, T. vulpes and Macracanthorhynchus catalinus, in six foxes Joyeuxiella echinorynchoides was found. Five and four foxes were infected with T. hydatigena and Diplopylidium nölleri, respectively. The possible role of the Arabian red fox as an intercalary host essential for the life cycle of Trichosomoides sp., common to the Libyan jird, Meriones libycus, in particular and the importance of this species as a vector for zoonotic infections and in the spread of other parasites to wild and domestic animals in general is discussed.
Journal of Wildlife Diseases | 2010
Mansour F. Hussein; Riyadh S. Aljumaah; Abdelgadir Homeida; Mohammed A. Alshaikh; A.R. Gar ElNabi; Osama B. Mohammed; Sawsan A. Omer; William Macasero
During March 2009, we evaluated the hemostatic profile and platelet indices of 18 Arabian sand gazelles (Gazella subgutturosa marica) and compared the results with those from humans and camels (Camelus dromedarius). Gazelles and camels had shorter activated partial thromboplastin times, lower proconvertin and higher antihemophilic factor coagulation activity, and plasma fibrinogen levels than humans. Prothrombin time was longer in sand gazelles and shorter in camels than it was in humans. Plasma thromboplastin component, Stuart factor, and plasma thromboplastin antecedent were similar in gazelles, humans, and camels, whereas the platelet count of the sand gazelle was significantly higher than it was for camels and humans.
Comparative Haematology International | 2012
Mansour F. Hussein; Ibrahim M. Al-Khalifa; Riyadh S. Aljumaah; Abdelrahman Gar Elnabi; Osama B. Mohammed; Sawsan A. Omer; William Macasero
Serum samples from sand gazelles (n = 227), mountain gazelles (n = 232), and Arabian oryx (n = 96) reared in captivity in Riyadh, Saudi Arabia were tested for the presence of Coxiella burnetii antibodies using an indirect enzyme immunoassay. C. burnetii antibodies were present in 18.3%, 7.3%, and 46.9% of these animals, respectively. The difference in serological prevalence between the three species was statistically significant. Age- and sex-related differences in prevalence were also observed. This study is the first record of C. burnetii antibodies in Arabian gazelles.