This study was done on thirty mature male rabbits of 1500 gm mean body weight, those rabbits were randomly divided into three equal experimental  groups of ten animals each .The first group was regarded as control group and drenched 3 ml normal saline daily for one month. The second group animals were drenched 3ml of licorice root water extract daily for one month also. While the third group animals were drenched 3ml of water extract of oregano daily for one month also. At the end of the drenching period blood samples were drawn from all animals by heart puncture and blood was analyzed for total RBC count; Hb %; pcv%; total leukocytic  count and blood indices of MCH; MCV, and MCHC were calculated in addition to doing blood smears from each animal to estimate percentages of differential leukocytic count. Results revealed that drenching licorice water extract had a significant increase  (p<0.05) on total RBC count;  total WBC count and neutrophils also, significant decrease in MCHC and eosinophil, whereas results of drenching water extract of Oreganum vulgari caused  significant increase on total leukocytic count , MCV and  neutrophil  while RBC had no significant effect so, PCV, Hb, had no effect in the two experimental.

The aim of this study was to evaluate the antimicrobial activity and determine the minimum bactericidal concentration (MBC) of the essential oils derived from Origanum vulgare (oregano), Melaleuca alternifolia (tea tree), Cinnamomum cassia (cassia), and Thymus vulgaris (white thyme) against Salmonella Typhimurium, Salmonella Enteritidis, Escherichia coli, Staphylococcus aureus and Enterococcus faecalis. The study also investigated the ability of these different bacterial strains to develop adaptation after repetitive exposure to sub-lethal concentrations of these essential oils. The MBC of the essential oils studied was determined by disc diffusion and broth dilution methods. All essential oils showed antimicrobial effect against all bacterial strains. In general, the development of adaptation varied according to the bacterial strain and the essential oil (tea tree > white thyme > oregano). Therefore, it is important to use essential oils at efficient bactericidal doses in animal feed, food, and sanitizers, since bacteria can rapidly develop adaptation when exposed to sub-lethal concentrations of these oils.

Invegstigation of antibacterial activity of water,ethanolic and methanolic extracts of Oregano(Origanum vulgare)and compared with Vancomycin, Erythromycin, cloxacillin ciprofloxacin and Streptomycin antibiotics was carried out on gram positive and Gram microorganisms for different extracts. The zone of inhibition varies depending on bac-terial ranges from 12 to 26, 14 to 20 and 18 to 22 for water,ethanolic and methanolic With anMICs of(0.167 0.1033) mg/ml against Bacillus subtilis and against Staphylococ-cus aureus was(0.21±0.102) μg/ml. when comparing the extracts MICs with those of antibiotics. All extracts showed pronounced antibacterial effects against both Gram posi-tive and Gram negative bacteria with a significant differences between the effect of extracts & antibiotics ( p < 0.05 )

Oregano is an aromatic plant native to the Mediterranean region of Europe and Asia which is rich in plant chemical compounds including carvacrol and thymol, as well as phenolic compounds with antioxidant properties. In this study, the effects of using oregano essential oil niosomal nanocarriers on the lipid peroxidation and the plasma antioxidant defense of Cyprinus fingerlings were investigated. A total of 240 common carp fingerling were fed in four groups, i.e., basic diet (control group), basic diet+0.05 (T1),+0.1 (T2),+1.5 g/Kg (T3) nano-niosomal oregano powder. On day 30 and day 60, the amount of plasma malondialdehyde (MDA) was significantly reduced in the treatments that had oregano added to their diet compared to the control group (p<0.0001). By ferric reducing antioxidant power (FRAP) method, a significant increase in the antioxidant capacity of plasma was observed on day 60 in the T2 (p=0.0003) and T3 (p<0.0001) compared to the control group.