The effect of a sublethal concentration of Solanum nigrum on some antioxidants in Biomphalaria arabica

Schistosomisis is endemic in many rural areas of developing countries. The life cycle of schistosomes is complex with two hosts, an intermediate snail host and a definitive human host. Biomphalaria arabica is the intermediate host for Schistosoma mansoni in Saudi Arabia. One method of controlling the disease is to break the life cycle at the intermediate host snail stage using molluscicides. Snails kill schistosomes by a mechanism involving production of reactive oxygen species. In this study malondialdehyde (MDA), and the antioxidants glutathione (GSH), catalase (CAT) and glutathione peroxidase (GP(x)) were determined in tissue homogenates of B. arabica treated with sublethal concentration (LC25) of the plant molluscicide Solanum nigrum. MDA, GSH and CAT were significantly increased in molluscicide-treated snails compared to controls (p < 0.000). GP(x) was decreased in treated snails. It therefore appears that a sublethal concentration of S. nigrum increases both ability of snail tissue to generate cytotoxic ROS and antioxidants for protection of the tissue against the cytotoxicity. The increase in the level of ROS would decrease snail- schistosome compatibility.King Saud Universit

TP53 genetic alterations in Arab breast cancer patients: Novel mutations, pattern and distribution

Breast cancer remains a worldwide public health concern. The incidence and mortality of breast cancer varies significantly in ethnically and geographically distinct popula-tions. In the Kingdom of Saudi Arabia (KSA) breast cancer has shown an increase in incidence and is characterized by early onset and aggressiveness. The tumor suppressor TP53 gene is a crucial genetic factor that plays a significant role in breast carcinogenesis. Furthermore, studies have shown a correla¬tion between certain p53 mutations and response to therapy in breast cancer. In the present study, TP53 mutations were identified by direct sequencing of the gene (exons 4-9) from 119 breast cancer tissues. The prevalence of TP53 mutations in Arab breast cancer patients living in the KSA is among the highest in the world (40%). Notably, 73% of the patients whose tumors harbored p53 mutations were less than 50 years of age. Furthermore, for the first time, we identified 7 novel mutations and 16 mutations in breast cancer tissues. Notably, all the novel point mutations were found in exon 4, wherein 29% of the mutations were localized. Furthermore, an excess of G:C→A:T transitions (49%) at non-CpG sites was noted, suggesting exposure to particular environmental carcinogens such as N-nitroso compounds. The results indicate that the TP53 gene plays a significant role in breast carcinogenesis and the early onset of the disease among Arab female individuals.King Saud Universit

Assessment of selected Saudi and Yemeni plants for mosquitocidal activities against the yellow fever mosquito Aedes aegypti

© 2019 by the authors. Marine organisms are recognized as a source of compounds with interesting biological activities. Vibrio neocaledonicus has been reported on for its high effectiveness against corrosion in metals but it has been little studied for its chemical and biological activities. In this study, four compounds were isolated from V. neocaledonicus: indole (1); 1H-indole-3-carboxaldehyde (2); 4-hydroxybenzaldehyde (3) and Cyclo (-Pro-Tyr) (4); using a bioassay-guided method, since in a previous study it was found that the ethyl acetate extract was active on the enzymes acetylcholinesterase (AChE), alpha-glucosidase (AG) and xanthine oxidase (XO). The inhibitory activities of the three compounds against AChE, AG and XO was also evaluated. In addition, the enzymatic inhibitory activity of indole to the toxins from the venom of Bothrops asper was tested. Results showed that indole exhibited strong inhibitory activity to AG (IC50 = 18.65 ± 1.1 µM), to AChE, and XO (51.3% and 44.3% at 50 µg/mL, respectively). 1H-indole-3-carboxaldehyde displayed strong activity to XO (IC50 = 13.36 ± 0.39 µM). 4-hydroxybenzaldehyde showed moderate activity to XO (50.75% at 50 µg/mL) and weak activity to AChE (25.7% at 50 µg/mL). Furthermore, indole showed a significant in vitro inhibition to the coagulant effect induced by 1.0 µg of venom. The findings were supported by molecular docking. This is the first comprehensive report on the chemistry of V. neocaledonicus and the bioactivity of its metabolites