A wrinkle in time : the effect of Persicaria senegalensis (Meisn.) Soják on the maintenance of the dermal matrisome in photoageing skin

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dc.contributor.advisor Lall, Namrita
dc.contributor.coadvisor Chung-Ho, Lin
dc.contributor.postgraduate Payne, Bianca
dc.date.accessioned 2024-06-14T11:13:42Z
dc.date.available 2024-06-14T11:13:42Z
dc.date.created 2024-09
dc.date.issued 2024-02
dc.description Thesis (PhD (Medicinal Plant Science))--University of Pretoria, 2024. en_US
dc.description.abstract Ageing is characterised by oxidative stress, abnormal proteolysis, and inflammation. Identifying multiple potentially therapeutic mechanisms of action provides a multi-faceted and holistic approach to natural well-ageing strategies. Persicaria senegalensis (Meisn.) Soják is traditionally used for hemorrhoids, malaria, skin troubles, syphilis, and livestock ailments. Bioactivity includes anti-feedant, sub-clinical mastitis, larvicidal, molluscicidal, anticancer, antibacterial, and anti-diabetes activities. Fermentation and gold nanoparticles offer potential advantages including diminished toxicity, enhanced bioactivity, increased bioavailability, targeted delivery, and increased phytochemical load. This study investigated the anti-ageing bioactivity of the crude ethanolic (PS), Bifidobacterium bifidum fermented (PSF), and gold nanoparticle (PS-AuNP) extracts of P. senegalensis for the first time. PS exhibited noteworthy elastase inhibition (IC50 56.07 ± 0.85 μg/mL), significantly increased elastin production, and reduced the concentration of inflammatory cytokines in dermal fibroblasts. Liquid-liquid partitioning revealed the n-butanol partition to exhibit improved elastase inhibition (IC50 0.29 ± 0.36 μg/mL). 1-(2-Methoxyphenyl)-3-phenylprop-2-en-1-one was isolated for the first time from the n-butanol partition but exhibited no anti-elastase activity at 100 μg/mL. PSF displayed significantly improved elastase inhibition (IC50 14.56 ± 1.27 μg/mL) while PS-AuNPs displayed lower anti-elastase activity (IC50 139.73 ± 17.98 μg/mL) but noteworthy collagenase inhibition (95.64 ± 6.67% at 100 μg/mL). PS and PSF were weakly cytotoxic while PS-AuNPs were moderately cytotoxic on human keratinocytes and dermal fibroblasts in vitro. Notably, PS and PSF enhanced the binding affinity between MMP-9 and TIMP-1 as a novel mechanism of action. This is the first study to investigate the effect of a plant extract on the binding affinity of an enzyme and ligand. PS and PSF were subjected to human irritancy and efficacy studies. PS was classified as a mild irritant, while PSF was a non-irritant, suggesting that fermentation improved the skin compatibility properties of the extract. Both samples significantly reduced the appearance of fine lines and wrinkles after 28 days of application. This is the first report on the anti-ageing potential of P. senegalensis, reporting 1-(2-methoxyphenyl)-3-phenylprop-2-en-1-one isolated for the first time in this species, a novel mechanism of action (TIMP-1/MMP-9 biding modulation) and validated findings in a human study. en_US
dc.description.availability Unrestricted en_US
dc.description.degree PhD (Medicinal Plant Science) en_US
dc.description.department Plant Production and Soil Science en_US
dc.description.faculty Faculty of Natural and Agricultural Sciences en_US
dc.description.sdg SDG-03: Good health and well-being en_US
dc.description.sdg SDG-09: Industry, innovation and infrastructure en_US
dc.description.sdg SDG-15: Life on land en_US
dc.description.sponsorship Water Research Commission en_US
dc.description.sponsorship National Research Foundation en_US
dc.identifier.citation * en_US
dc.identifier.doi https://doi.org/10.25403/UPresearchdata.26014135 en_US
dc.identifier.other S2024 en_US
dc.identifier.uri http://hdl.handle.net/2263/96498
dc.identifier.uri DOI: https://doi.org/10.25403/UPresearchdata.26014135.v1
dc.language.iso en en_US
dc.publisher University of Pretoria
dc.rights © 2023 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.
dc.subject UCTD en_US
dc.subject Sustainable Development Goals (SDGs) en_US
dc.subject Bifidobacterium bifidum en_US
dc.subject Anti-aging en_US
dc.subject Cytokines en_US
dc.subject Persicaria senegalensis en_US
dc.subject Polygonaceae en_US
dc.subject MRHF en_US
dc.subject HaCat en_US
dc.subject Elastase inhibition en_US
dc.subject Elastin en_US
dc.subject Fermentation en_US
dc.subject Gold nanoparticles en_US
dc.subject Inflammation en_US
dc.subject TIMP-1 en_US
dc.subject MMP-9 en_US
dc.title A wrinkle in time : the effect of Persicaria senegalensis (Meisn.) Soják on the maintenance of the dermal matrisome in photoageing skin en_US
dc.type Thesis en_US


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