Protective Effects of Two Halophilic Crude Extracts from Pseudomonas zhaodongensis and Bacillus stratosphericus against Memory Deficits and Anxiety- and Depression-Like Behaviors in Methionine-Induced Schizophrenia in Mice Focusing on Oxidative Stress Status.

Recently, the implication of oxidative stress in behavioral-like disorders has received a lot of attention. Many studies were interested in searching for new natural compounds with protective effects on behavioral-like disorders by focusing on oxidative stress as the main causal factor. Here, we assess the potential effect of cell-free extracts from halophilic bacteria on memory, anxiety, and depression-related behaviors in mice, as well as on cognitive deficits, negative symptoms, and some oxidative stress biomarkers in methionine-induced mice models of schizophrenia. Firstly, crude extracts of bacteria isolated from the Dead Sea were screened for their effects on memory and anxiety- and depression-like behaviors through Y-maze, elevated plus maze, and forced swimming test, respectively, using two doses 60 mg/kg and 120 mg/kg. Then, 120 mg/kg of two bacterial crude extracts, from two strains designated SL22 and BM20 and identified as Bacillus stratosphericus and Pseudomonas zhaodongensis, respectively, with significant contents of phenolic and flavonoid-like compounds, were selected for the assessment of cognitive and negative symptom improvement, as well as for their effects on oxidative stress status in methionine-induced mice models of schizophrenia using six groups (controls, methionine, crude extracts solely, and combinations of crude extracts and methionine). Results showed that the administration of the crude extracts caused a significant increase in the spontaneous alternations in the Y-maze task, the time spent in open arms of the elevated plus maze, and a decrease in immobility time in the forced swimming test in comparison with the control group. Furthermore, the administration of bacterial extracts seemed to diminish disorders related to cognitive and negative symptoms of schizophrenia and to improve the oxidative state in the temporal lobes, in comparison with the methionine group. Our findings suggest substantial antioxidant and anti-neuropsychiatric effects of the crude extracts prepared from Pseudomonas zhaodongensis strain BM20 and Bacillus stratosphericus strain SL22 and that further studies are needed to purify and to determine the active fraction from the extracts.

Phenolic profile (HPLC-UV) of olive leaves according to extraction procedure and assessment of antibacterial activity.

The aim of the present study is to firstly study the effect of the extraction solvents (ethanol, acetonitrile, distilled water), pH, temperature, and the extraction method (maceration, sonication, maceration in two steps) on the flavonoid and phenolic contents of olive leaves. Furthermore, qualitative and quantitative analyzes of phenolic compounds by (HPLC) were performed. Results showed that the extract macerated in two steps by ethanol followed by distilled water of dried leaves showed high contents of phenolic compounds and flavonoids compared to the extracts obtained by the other studied techniques and solvents. On the other hand, the macerated extracts were studied for their antibacterial activity against five pathogenic bacteria (Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Listeria monocytogenes). The results showed a strong antibacterial activity of the same macerated extract in two steps for dried leaves, which could be attributed to its richness in bioactive compounds such as oleuropein.