Antibacterial, Antioxidant Activity of Ethanolic Plant Extracts of Some Convolvulus Species and Their DART-ToF-MS Profiling.

Convolvulus austroaegyptiacus Abdallah & Sa'ad (CA) and Convolvulus pilosellifolius Desr. (CP) are commonly used in the Saudi Arabia folk medicine. They are potent in treating the ulcers and skin diseases. The lack of information about their biological activities led us to investigate the possible biological activities by determination of antibacterial and antioxidant activities of total ethanolic extracts and various fractions. Total flavonoid contents of the plants were determined by colorimetric method while total phenols were determined by using Folin-Ciocalteu method. In vitro antibacterial activity was studied against E. coli, P. aeruginosa, and B. subtilis, and the total antioxidant capacity was evaluated by radical scavenging method. IC50 were found to be 21.81, 17.62, and 3.31 µg/mL for CA, CP, and vitamin C, respectively, while the lowest MIC value of 0.25 mg/mL was recorded with CP extract against B. subtilis. Around 21 compounds are tentatively elucidated from both plants using rapid, simple, and high-resolution analytical technique for chemical profiling of natural compounds by direct analysis in real-time of flight-mass spectrometry, of which 17 were not isolated or reported previously.

Evaluation of trace metals in tea samples from Jeddah and Jazan, Saudi Arabia by atomic absorption spectrometry.

The Cd, Pb, Mn, Zn, Ni, Co, Fe, Cr and Cu content were determined in various teas available in local markets of Jeddah and Jazan, Saudi Arabia. Concentrations of the trace metals were measured after acid digestion using a flame atomic absorption spectrometer. Validation of the digestion procedure was performed by the analysis of a certified reference material. The cadmium, lead, manganese, zinc, nickel, cobalt, iron, chromium and copper concentrations were found in the range of below the detection limit (BDL)--0.7 µg/g, BDL--8.7 µg/g, 48-859 µg/g, 6.6-120 µg/g, BDL--16.9 µg/g, BDL--3.1 µg/g, 46-348 µg/g, BDL--4.9 µg/g and 5.2-21.6 µg/g respectively. The values found in this study were compared with literature values.

Daily intake of selenium and concentrations in blood of residents of Riyadh City, Saudi Arabia.

Concentrations of selenium (Se) in food from local markets of Riyadh, Kingdom of Saudi Arabia (KSA) were measured and daily intake calculated based on information from a questionnaire of foods eaten by healthy Saudis. The daily intake of Se was then compared to concentrations of Se in blood serum. Primary sources of Se in the diet of Saudis were as follows: meat and meat products (31%), egg (20.4%), cereals and cereal products (16%), legumes (8.7%), fruits (6.8%), milk and dairy products (2.0%), beverages (2%), sweets (1.8%), pickles (0.2%), and oil (0.02%). Daily intake of Se, estimated to be 93 µg Se/person/day, was slightly greater than that calculated from the Food and Agriculture Organization (FAO) food balance sheet for KSA, which was approximately 90 µg Se/person/day. The daily intake of Se by Saudis in Riyadh was greater than that of Australians or Dutch but less that of Canadians and Americans. There was a statistically significant correlation (R = +0.38, P < 0.05) between daily intake of Se and concentrations of Se in blood serum of Saudis in Riyadh. The mean concentration of Se in serum was 1.0 × 10(2) ± 30.5 µg Se/l. Taken together, the results suggest that the average Se intake and Se serum concentrations are within the known limits and recommendations, making it unlikely that Saudis are on average at risk of deficiency or toxicity.

Three new cycloartane triterpenoids from Astragalus bicuspis.

Three new cycloartane triterpenoids have been isolated from Astragalus bicUSPIS Fisch. Their structures were elucidated as 23(R),24(S),25( R),26(S)-16 ß/23,23/26,24/25-triepoxy-26-hydroxy-9,19-cyclolanosta-3,6-dione (1), 6 α,23,24,25-tetraol-16 ß-acetoxy-23(R),24(R)-9,19-cyclanosta-3-one (2), and 6 α,23,24,25-tetraol-16 ß-acetoxy-23(R),24(R)-9,19-cyclolanosta-3 ß- O-xyloside (3), based on their spectroscopic analysis. All cycloartane tritepenoids exhibited weak cytotoxicities against 3T3 fibroblast cells as compared to the standard drug cycloheximide. Compounds 3 and 4 were also tested for their antileishmanial potential, and a weak activity was observed against promastigotes of Leishmania major.

Hepatoprotective effects of vitamin E/selenium against malathion-induced injuries on the antioxidant status and apoptosis-related gene expression in rats.

The present study is undertaken to evaluate the protective effect of vitamin E (α-tocopherol) and selenium (Se) against malathion (MTN)-induced oxidative stress and hepatic injuries in experimental rats. Male rats were randomly divided into eight groups comprised of 10 rats each. The 1(st) group served as a negative control (C(N)), whereas the 2(nd) was supplemented with a combination of α-tocopherol (100 mg kg(-1) body weight, b.w.)/Se (0.1 mg kg(-1) bw). The 3(rd), 4(th) and 5(th) groups were respectively administered with increasing doses of MTN equivalent to (1/50 )LD(50) (M(1/50)), (1/25) LD(50) (M(1/25)) and (1/10) LD(50) (M(1/10)), respectively. The 6(th), 7(th) and 8(th) groups were administered the same doses of MTN as in the 3(rd), 4(th) and 5(th) groups with a concomitant supplementation with α-tocopherol/Se. Subchronic exposure of rats to MTN for 45 days resulted in statistical dose-dependent decrease in acetylcholinestrase (AChE) activity, increase in oxidative stress marker lipid peroxidation (LPO) and reduction in reduced glutathione (GSH) level. Moreover, the levels of glutathione persoxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) were significantly decline in response to MTN exposure in a dose-dependent fashion. Furthermore, histopathological studies of liver in the rats which received MTN exhibited, moderate to severe degenerative and necrotic changes in the hepatocytes. Notably, the administration of α-tocopherol/Se protected the liver of rats exposed to MTN as evidenced by the appearance of normal histological structures, significant attenuation of the decline in all antioxidant enzymes tested (i.e. GPx, SOD and CAT), significant recovery in the GSH level and statistical reduction in LPO, as compared to the experimental rat. The effect of α-tocopherol/Se supplementation on transcriptional activity of three key stress and apoptosis-related genes (i.e., Tp53, CASP3 and CASP9), in response to MTN exposure in rats, was investigated. Results revealed a significant concentration-dependent up-regulation in the level of expression for the three genes examined, in response to MTN exposure, compared with the control. Interestingly, the supplementation of MTN-treated rats with α-tocopherol/Se modulates the observed significant dose-dependent up-regulation in the level of expression for three selected genes, indicative of an interfering role in the signaling transduction process of MTN-mediated poisoning. Taken together, these data suggest that the administration of α-tocopherol/Se may partially protect against MTN-induced hepatic oxidative stress and injuries.