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Potential of selected South African plant extracts in reducing eczema associated symptoms

Dissertation (MSc (Medicinal Plant Sciences))--University of Pretoria, 2022

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Other Authors: Lall, Namrita
Format: Thesis
Language:English
Published: University of Pretoria 2022
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author2 Lall, Namrita
author_browse Lall, Namrita
author_facet Lall, Namrita
collection Thesis
dc_rights_str_mv © 2022 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.
description Dissertation (MSc (Medicinal Plant Sciences))--University of Pretoria, 2022
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institution University of Pretoria (South Africa)
language English
last_indexed 2026-06-10T12:39:10.429Z
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provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2022
publishDateRange 2022
publishDateSort 2022
publisher University of Pretoria
publisherStr University of Pretoria
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source_str UPSpace — University of Pretoria Institutional Repository
spelling oai:repository.up.ac.za:2263/86148 Potential of selected South African plant extracts in reducing eczema associated symptoms Lall, Namrita marizenel7@gmail.com Twilley, Danielle Nel, Marize Atopic dermatitis Antihistamine Anti-inflammatory Wound healing Anti-tyrosinase Anti-elastase UCTD Natural and agricultural sciences theses SDG-03 Natural and agricultural sciences theses SDG-09 Natural and agricultural sciences theses SDG-15 Dissertation (MSc (Medicinal Plant Sciences))--University of Pretoria, 2022 Two main hypotheses have been accepted as the potential cause of eczema. The inside-out hypothesis states that eczema is caused by an immunological defect involving the overproduction of tumor necrosis factor-alpha (TNF-α), which further causes post-inflammatory hyperpigmentation. The outside-in hypothesis states that eczema is due to a skin barrier disruption including the skin becoming cracked. This promotes histamine production which could lead to wrinkle formation when overproduced. The aim of this study was to determine whether three South African plants namely Juncus lomatophyllus (JL), Elegia tectorum (ET) and Bulbine frutescens (BF) reduce symptoms associated with eczema and inhibit the production of either TNF-α or histamine. Furthermore, this study evaluated whether synthesized gold nanoparticles (AuNPs) using JL, ET and BF or fermenting the ethanolic extracts (Et-OH) of JL (JLF) and ET (ETF), using Bifidobacterium bifidum, would enhance biological activity. Bioassay-guided fractionation was conducted due to the limited information found on JL’s compound composition. Gas chromatography-mass spectrometry (GC-MS) of two semi-pure fractions, pooled from the butanol partition (JLB), indicated volatile compounds with a peak area above 5%. Furthermore, JLAuNP (50% inhibitory concentration (IC50): 268.8 ± 5.64 μg/mL) displayed enhanced anti-tyrosinase activity when compared to JL-EtOH and JLF (IC50 > 400 μg/mL). JLB, JLAuNP and JL-EtOH effect on TNF-α production using lipopolysaccharide (LPS) stimulated peripheral blood mononuclear cells (PBMCs) was evaluated. None of the selected samples displayed antiproliferative activity against human keratinocytes (HaCaT) and PBMCs (IC50 > 400 μg/mL). JLAuNP (23.59 ± 1.95 pg/mL), compared to the untreated control (46.17 ± 9.51 pg/mL), significantly inhibited TNF-α production while JLB and JL-EtOH showed no effect at 200 μg/mL. ET-EtOH displayed anti-elastase activity (IC50: 28.27 ± 2.02 μg/mL), while ETF and ETAuNP displayed no inhibition (IC50 > 500 μg/mL). ET-EtOH was further evaluated on histamine production using phorbol 12-myristate 13-acetate (PMA) stimulated granulocytes. No antiproliferative activity was observed against HaCaT cells and granulocytes (IC50 > 400 μg/mL). Furthermore, ET-EtOH (0.10 ± 0.009 ng/mL) significantly inhibited histamine production at 6 μg/mL compared to the vehicle control (0.26 ± 0.02 ng/mL). BF samples (eight) were evaluated for their potential wound healing activity using HaCaT cells. The commercial spray (BFS) and BFSAuNP displayed antiproliferative activity (IC50 of 4.63 ± 0.05 and 3.50 ± 0.40%), while the ethanolic leaf juice (BFE), ethanolic whole leaf (BFE+), gel extract (BFG) and their AuNPs showed no activity (IC50 > 400 μg/mL and 10%). BFE (31.40 ± 0.88 %) and BFEAuNP (20.87 ± 0.69%) when compared to the controls showed significant closure at 100 μg/mL and were further evaluated. None of the samples displayed antiproliferative effects against granulocytes. Compared to the untreated control (0.30 ± 0.02 ng/mL), BFEAuNP at 100 μg/mL (0.12 ± 0.04 ng/mL) significantly inhibited histamine production. This study concluded that JLAuNP’s, ET-EtOH and BFEAuNPs potentially reduce eczema associated symptoms based on the in vitro results obtained. This is the first report of the synthesis of AuNPs from JL, ET and BF and their potential biological activity. Lastly, this study is the first to identify potential volatile compounds present in JL. National Research Foundation [grant number: 105169 and 98334] Water Research Commission [contract number: C2019/2020-00132] bs2026 Plant Science MSc (Medicinal Plant Sciences) Unrestricted SDG-03: Good health and well-being SDG-09: Industry, innovation and infrastructure SDG-15: Life on land 2022-07-13T13:39:11Z 2022-07-13T13:39:11Z 2022-09 2022 Dissertation Nel, M 2022, Potential of selected South African plant extracts in reducing eczema associated symptoms, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd https://repository.up.ac.za/handle/2263/86148 S2022 https://repository.up.ac.za/handle/2263/86148 https://doi.org/10.25403/UPresearchdata.20268048 en © 2022 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. application/pdf University of Pretoria
spellingShingle Atopic dermatitis
Antihistamine
Anti-inflammatory
Wound healing
Anti-tyrosinase
Anti-elastase
UCTD
Natural and agricultural sciences theses SDG-03
Natural and agricultural sciences theses SDG-09
Natural and agricultural sciences theses SDG-15
Potential of selected South African plant extracts in reducing eczema associated symptoms
title Potential of selected South African plant extracts in reducing eczema associated symptoms
title_full Potential of selected South African plant extracts in reducing eczema associated symptoms
title_fullStr Potential of selected South African plant extracts in reducing eczema associated symptoms
title_full_unstemmed Potential of selected South African plant extracts in reducing eczema associated symptoms
title_short Potential of selected South African plant extracts in reducing eczema associated symptoms
title_sort potential of selected south african plant extracts in reducing eczema associated symptoms
topic Atopic dermatitis
Antihistamine
Anti-inflammatory
Wound healing
Anti-tyrosinase
Anti-elastase
UCTD
Natural and agricultural sciences theses SDG-03
Natural and agricultural sciences theses SDG-09
Natural and agricultural sciences theses SDG-15
url https://repository.up.ac.za/handle/2263/86148
https://doi.org/10.25403/UPresearchdata.20268048