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Background: Origanum majorana (O. majorana) is one of the most widely used herbs in Egypt due to its antioxidant, anti-inflammatory, anti-genotoxic, antimutagenic, anticoagulant and beneficial properties. Our study's main goal is to determine how well O. majorana leaf extract can reduce hepatotoxicity and oxidative stress produced by dexamethasone (DXM). Thirty female rats were divided into three groups of ten. Animals in group1 received distilled water daily for eight weeks and served as control. Those in group 2 exposed subcutaneously to 0.1 mg/kg body weight of DXM three times per week for eight weeks and served as the toxic group, while those in group 3 were treated daily and orally with 100 mg/kg of O. majorana aqueous extract + 0.1 mg/kg of DXM three times per week for eight weeks and served as treated group. Results: Due to DXM treatment, the activities of liver function markers were significantly elevated (P < 0.0001), whereas O. majorana pretreated animals improved or reduced the elevated liver function enzyme activities. Dexamethasone administration considerably enhancing oxidative stress which rose (P < 0.0001) MDA concentration and attenuated the antioxidant defense system by decreasing the activities of GST, GSP, GSR, and CAT significantly in liver homogenate when compared to control animals. The results further demonstrated that pretreatment with O. majorana boosted the antioxidant defenses against the damaging effects of DXM. Conclusion: It can be said that dexamethasone exposure induced- hepatotoxicity and oxidative stress in rats that repaired by O. majorana aqueous extract which had the ability to reduce the impact of hepatic damage. To evaluate the health benefits and safety of O. majorana in individuals, more clinical research is needed. [ABSTRACT FROM AUTHOR]

Mesembryanthemum crystallinum (Ice plant) is an annual halophytic plant species spread in the coastal areas of the Mediterranean Sea, Egypt. Information about the behaviour of halophytes under the future concentration of ozone (O3) is scanty. Therefore, we have assessed the effects of elevated O3 (ambient + 20 ppb), moderate salinity (200 mM NaCl), and their combined treatment (salinity + elevated O3) on various morphological, growth, physiological, biochemical and anatomical parameters of Egyptian ice plant. Under salinity stress, plant growth, percentage of pigmented leaf and its thickness, ROS levels, antioxidative enzymes, and ROS scavenging activities were increased, while photosynthetic pigments and efficiency were decreased compared to the control. Elevated O3 exposure led to reductions in most of the growth parameters and pigments, while ROS levels, histochemical localization of H2O2 and ·O2−, antioxidative enzymes and non-enzymatic antioxidants (betacyanin, phenolics, thiols and ascorbic acid) showed increases. Surprisingly, salinity alleviated the oxidative stress of elevated O3 due to the rise of SOD activity, antioxidant compounds, and a decrease of ·O2− production rate with concomitant increases of most of the growth parameters. Thick lower collenchyma and enhancement of xylem parenchyma under O3 and combined treatment suggested that anatomical acclimation also operated under O3 stress and salinity played a vital role in the growth of this plant under combined stress. Results showed that salt is essential for the optimum development of this species and its role is extended to alleviate the oxidative damage caused by elevated O3. The results further recommend the use of Egyptian M. crystallinum as a O3 tolerant crop for saline areas along the Mediterranean Sea coast. Highlights: Egyptian M. crystallinum showed the optimum growth under salinity condition. EO3 stimulated non enzymatic antioxidants as betacyanin, thiols and ascorbic acid. Antioxidant enzymes also induced such as CAT, POX and APX under O3 stress. Salinity alleviated O3 stress by increase of SOD, thiols, AsA and decrease of ·O2−. M. crystallinum is candidate in future restoration of high saline-EO3 areas. [ABSTRACT FROM AUTHOR]