title: Insights into the antioxidative potentials of plants and skin
title: Einblicke in der antioxidativen Potenziale von Pflanzen und Haut
titleType: AlternativeTitle
Creators: name: Alnemari, Reem Mohamed
Publisher: name: Philipps-Universität Marburg
Year: 2023
Subjects: Life sciences
Biowissenschaften, Biologie

description: This thesis has been started by the characterisation of specific plants formulation ‘’PlantsCrystals’’ regarding the antioxidant capacity and size analysis. After that, and using the same principle along with skin analysing techniques, the research is concluded by presenting a novel ex-vivo model to assess the skin's oxidative state using ORAC assay and tape striping method. The developed model has been validated,standardised and then utilised for multiple applications. The employed methodology included multiple antioxidant estimation assays, such as flavonoid and carotenoid content determination, Folin Ciocalteu, DPPH and ORAC assays. Furthermore, ORAC assay, tape stripping and the multi-probe adapter MPA 10 device were the main protocols that were used to develop and assess the porcine ex-vivo skin model.Validation was done by the employment of the preliminary skin samples, afterwards, it was tested on a larger sample size using fresh porcine skin in a controlled lab climate. The numerical values of the antioxidant skin barrier were determined and expressed as the intrinsic AOC. Later, several treatments were applied and significant findings were obtained, as our model was able to detect the changes accurately in a good agreement with the reported data. The most common antioxidative agentsin the cosmetics market were included as treatment agents: ascorbic acid, vitamin E, CoQ10 and ascorbyl palmitate, and their impact on the skin was investigated. In addition to the studies using the main pro-oxidative agent: UV radiation. Moreover, combined treatments were applied aiming to explore the potentials and the limits of this model, and interestingly, it proved its capability to reflect the net effect of multiple factors on the skin antioxidant barrier. Unlimited practice can be applied using the model suggested in this thesis, in order to predict the impact of any kind of single or combined treatment on the skin, without the need to analyse the individual oxidative markers or the use of sophisticated devices. Other relevant investigations have also been demonstrated in the current work, including the study on the novel PlantCrystals which was acting as the backbone of the later studies, mainly through the optimization and the validation of the AOC assays. In addition to the determination of the biophysical properties of intact and impaired porcine skin which was an important knowledge about the porcine ex-vivo model. Therefore, this thesis is presenting a rapid, sustained, non-invasive, versatile, time- and cost-effective model to investigate the skin’s oxidative state. Furthermore, it is revealing, for the first time, the mean values of the intrinsic AOC and the biophysical properties of the ex-vivoporcine skin. Enormous research ideas can be recommended to be done based on the studies of the current work, initially on the impaired skin, including the utilising of the impaired skin model, the investigation of its iAOC and the treatment impact by applying anti- and pro-oxidative agents. Moreover, the model at this point is ready to be applied to living animals and/or human volunteers, to be part of the safety and efficacy pre-marking studies of the cosmeceutical formulations. This step is highly applicable, as we implied a simple and non-invasive procedure that has been used extensively with good acceptability.