Browsing by Author "Radwan, Rasha Ali"

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    Bioassay-guided isolation of anti-inflammatory and antinociceptive metabolites among three Moroccan Juniperus leaves extract supported with in vitro enzyme inhibitory assays
    (Elsevier Ireland Ltd, 2024-05) El Jemli, Meryem; Ezzat, Shahira M; Kharbach, Mourad; Mostafa, Eman Sherien; Radwan, Rasha Ali; El Jemli, Yousra; El-Guourrami, Otman; Ahid, Samir; Cherrah, Yahia; Zayed, Ahmed; Alaoui, Katim
    Ethnopharmacological relevance: Herbs of the genus Juniperus (family Cupressaceae) have been commonly used in ancestral folk medicine known as “Al’Araar” for treatment of rheumatism, diabetes, inflammation, pain, and fever. Bioassay-guided isolation of bioactives from medicinal plants is recognized as a potential approach for the discovery of novel drug candidates. In particular, non-addictive painkillers are of special interest among herbal phytochemicals. Aim of the study: The current study aimed to assess the safety of J. thurifera, J. phoenicea, and J. oxycedrus aqueous extracts in oral treatments; validating the traditionally reported anti-inflammatory and analgesic effects. Further phytochemical investigations, especially for the most bioactive species, may lead to isolation of bioactive metabolites responsible for such bioactivities supported with in vitro enzyme inhibition assays. Materials and methods: Firstly, the acute toxicity study was investigated following the OECD Guidelines. Then, the antinociceptive, and anti-inflammatory bioactivities were evaluated based on chemical and mechanical trauma assays and investigated their underlying mechanisms. The most active J. thurifera n-butanol fraction was subjected to chromatographic studies for isolating the major anti-inflammatory metabolites. Moreover, several enzymatic inhibition assays (e.g., 5-lipoxygenase, protease, elastase, collagenase, and tyrosinase) were assessed for the crude extracts and isolated compounds. Results: The results showed that acute oral administration of the extracts (300–500 mg/kg, p. o.) inhibited both mechanically and chemically triggered inflammatory edema in mice (up to 70% in case of J. thurifera) with a dose-dependent antinociceptive (tail flick) and anti-inflammatory pain (formalin assay) activities. This effect was partially mediated by naloxone inhibition of the opioid receptor (2 mg/kg, i. p.). In addition, 3-methoxy gallic acid (1), quercetin (2), kaempferol (3), and ellagic acid (4) were successfully identified being involved most likely in J. thurifera extract bioactivities. Nevertheless, quercetin was found to be the most potent against 5-LOX, tyrosinase, and protease with IC50 of 1.52 ± 0.01, 192.90 ± 6.20, and 399 ± 9.05 μM, respectively. Conclusion: J. thurifera extract with its major metabolites are prospective drug candidates for inflammatory pain supported with inhibition of inflammatory enzymes. Interestingly, antagonism of opioid and non-opioid receptors is potentially involved.
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    Using an UPLC/MS-based untargeted metabolomics approach for assessing the antioxidant capacity and anti-aging potential of selected herbs
    (Creative Commons Attribution, 2020) Salem, Mohamed A.; Radwan, Rasha Ali; Mostafa, Eman Sherien; Alseekh, Saleh; Fernie, Alisdair R.
    Aging is an unavoidable fate that afflicts all life, during this process in mammals reactive oxygen species (ROS) are generated which stimulate tyrosinase, elastase and collagenase activities that actively participate in skin aging. Therefore, the maintenance of antioxidant homeostasis is an important anti- aging strategy for skin. Nature has excellent anti-aging remedies that act externally as well as internally to delay the visual signs of aging. In view of this fact, the present study investigates the in vitro anti-aging activity of five medicinal plants belonging to phenolic rich families namely Rosmarinus officinalis, Lavandula officinalis, Matricaria chamomilla, Camellia sinensis and Pelargonium graveolens. The selected plants are those most frequently used in the preparation of ethnomedicinal recipes for the prevention or treatment of aging. The inhibitory effects of the ethanolic and aqueous extracts of the five selected plants on the activity of tyrosinase, elastase, and collagenase enzymes were investigated. Furthermore, the chemical composition of the plants and the antioxidant capacity of their extracts were assessed. The results showed that R. officinalis had the highest total phenolics content which was correlated with its potent antioxidant and anti-aging activities. To pinpoint the active metabolites in the tested extracts, we evaluated the metabolite variations using ultra-performance liquid chromatography coupled with high resolution electrospray ionization-tandem mass spectrometry (UPLC-HR-ESI-MS/MS). Multivariate data analysis (MVDA) revealed that R. officinalis significantly accumulated metabolites from the aromatic diterpenoid, flavonoid and phenolic acid classes. These results indicate that rosemary can be used for further development of topical preparations with anti-aging properties.