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    In Vitro Tyrosinase and Collagenase Inhibitory and Antioxidant Potential of Smyrnium rotundifolium Mill. and Euphorbia virgata Waldst.&Kit. from Türkiye
    (Sivas Cumhuriyet Üniversitesi, 2024) Gürer, Eda Sönmez; Karadağ, Ayşe Esra; Baydar, Rengin; Demirel, Melek
    Antioxidants help prevent signs of aging and skin tone inequalities by protecting our skin from free radicals. High tyrosinase inhibition has a whitening effect on the skin, while collagenase inhibition has an anti-sagging effect on the skin. Antioxidant activity and tyrosinase/collagenase enzyme inhibition capacities have mutually supporting effects. The aim of this study was to determine the antioxidant activities, tyrosinase and collagenase inhibitory potentials of ethanol extracts of two medicinal plants from Turkey (Smyrnium rotundifolium and Euphorbia virgata). In the study, 6 different reference substances and their chemical contents were investigated. Myricetin, quercetin and kaempferol were observed in S. rotundifolium extract, and quercetin was observed in E. virgata extract. According to the antioxidant capacity results measured by both analyses; S. rotundifolium (IC50 DPPH•: 4.9±0.15 µg/mL, IC50 ABTS•+: 4.3±0.2 µg/mL) and E. virgata (IC50 DPPH•: 4.6±0.11 µg/mL, IC50 ABTS•+: 4.1±0.13 µg/mL) extracts were observed to have antioxidant capacities similar to each other. It was determined that S. rotundifolium had higher anti-collagenase (27.9±0.13% inhibition) and anti-tyrosinase (11.1±0.14% inhibition) activities compared to E. virgata extract. These results showed us that S. rotundifolium can be considered as a strong candidate for the management of epidermal hyperpigmentation and skin elasticity and deserves further study.
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    Investigation of the chemical composition, antioxidant and anticholinesterase activities of Consolida orientalis
    (2024) Sönmez Gürer, Eda; Karadağ, Ayşe Esra; Rengin, Baydar; Demirel, Melek
    Aims: It is known that a decrease in the amount of acetylcholine in the body, which is known to be responsible for learning and cholinergic activity in the nervous system, causes Alzheimer’s disease. Acetylcholine is destroyed by acetylcholinesterase (AChE) and Butyrylcholinesterase (BChE) enzymes in the nervous system. Consolida orientalis (C. orientalis) is a species that belongs to the Ranunculaceae family and grows naturally in many parts of the world. It is known that it plays a role in many biological activities thanks to its content of important phytochemical components such as phenolics and alkaloids. In this study; It was aimed to investigate the antioxidant activity, AChE and BChE enzyme inhibition activities of C. orientalis flower extracts. Methods: The chemical content of ethanol extracts obtained from the flowers of C. orientalis plant, which was collected and identified from Sivas İmaret village between June and July 2023, was examined with 6 different reference substances (gallic acid, rosmarinic acid, myrcetin, quercetin, apigenin and camphorol). Antioxidant activity was determined by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) tests. Ascorbic acid and trolox were used as positive controls. The inhibition capacity of the samples on AChE and BChE enzymes was determined by the Ellman method. Results: Chemical content analysis of the extract was performed by high pressure liquid chromatography (HPLC) and only gallic acid was detected among the standard compounds. When C. orientalis ethanol extracts were examined with DPPH and ABTS tests, they showed low-moderate antioxidant activity (IC50 (µg/ml) DPPH=4.8, IC50 (µg/ml) ABTS=4.4) compared to standard substances. C. orientalis ethanol extract was studied at a concentration of 20 µg/ml. The extract inhibited the AChE enzyme at 66.5% and the BChE enzyme at 53.2%. It was observed that the extract inhibited both enzymes at moderate to good levels, although not higher than galantamine used as positive control. Conclusion: This study shows us that C. orientalis flowers have therapeutic potential for the effective management of neurological disorders due to their antioxidant and anticholinesterase activity. It is thought that our data will contribute to the literature as a preliminary study for the development of a new phytotherapeutic agent in the treatment of Alzheimer’s disease.