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Beta cell regeneration and antidiabetic potential of Ficus sycomorus and Zanthoxylum chalybeum
Kimani, Clare Njoki. 2023. Beta cell regeneration and antidiabetic potential of Ficus sycomorus and Zanthoxylum chalybeum. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/550675c3-045c-41ab-84f1-29d1abb076b6
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Stellenbosch : Stellenbosch University
2023
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| access_status_str | Open Access |
| author | Kimani, Clare Njoki |
| author2 | Muller, Christo J. F. |
| author_browse | Kimani, Clare Njoki Muller, Christo J. F. |
| author_facet | Muller, Christo J. F. Kimani, Clare Njoki |
| author_sort | Kimani, Clare Njoki |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Kimani, Clare Njoki. 2023. Beta cell regeneration and antidiabetic potential of Ficus sycomorus and Zanthoxylum chalybeum. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/550675c3-045c-41ab-84f1-29d1abb076b6 |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/128414 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:43:13.574Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2023 |
| publishDateRange | 2023 |
| publishDateSort | 2023 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/128414 Beta cell regeneration and antidiabetic potential of Ficus sycomorus and Zanthoxylum chalybeum Kimani, Clare Njoki Muller, Christo J. F. Reuter, Helmuth Kotze, Sanet Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Medicine. Division of Clinical Pharmacology. Pancreatic beta cells -- Regeneration Type 2 diabetes -- Alternative treatment Medicinal plants -- Therapeutic use UCTD Kimani, Clare Njoki. 2023. Beta cell regeneration and antidiabetic potential of Ficus sycomorus and Zanthoxylum chalybeum. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/550675c3-045c-41ab-84f1-29d1abb076b6 Thesis (PhD)--Stellenbosch University, 2023. ENGLISH ABSTRACT: Background Type 2 diabetes (T2D) is characterized by pancreatic beta cell dysfunction and loss of beta cell mass despite current treatment. Consequently, there has been growing interest in developing beta cell-centered therapies. To this end, the discovery that the pancreas harbors an inherent regenerative capacity is of much therapeutic relevance. Several studies that propose mitogenic effects for phytochemicals, mediated by modulation of beta cell differentiation transcription factors and regulation of the cell cycle machinery are of particular interest. The use of Z. chalybeum and F. sycomorus to treat diabetes has previously been documented and corroborated experimentally. This study explored the effects of Z. chalybeum and F. sycomorus aqueous stem bark extracts on beta cell regeneration. Methods RIN-5F pancreatic beta cells were cultured under standard conditions or in the presence of diabetogenic stressors (palmitate or streptozotocin) before treating with varying concentrations of F. sycomorus or Z. chalybeum extract. Subsequently, the extracts were evaluated for their effects on cell viability, proliferation, apoptosis and oxidative status. Due to cytotoxicity of the F. sycomorus extract in RIN-5F beta cells, only the Z. chalybeum extract was evaluated in vivo. Streptozotocin (STZ)-induced diabetic male Wistar rats were treated with Z. chalybeum aqueous stem bark extract for 28 days. Body weights, food and water intake, fasting blood glucose, oral glucose tolerance and insulin concentrations were determined. Pancreas tissue was harvested for immunohistochemistry. To explore the effect of Z. chalybeum on beta cell regeneration, histological pancreas tissue sections were stained for the expression of key beta cell regeneration markers, neurogenin-3 (Ngn-3), V-maf musculoaponeurotic fibrosarcoma oncogene homolog A (MafA) and pancreatic duodenal homeobox protein 1 (Pdx-1), and the proliferation marker Ki-67. Moreover, islet morphometry was evaluated based on insulin/glucagon immunoreactivity. We performed a phytochemical profile of the F. sycomorus and Z. chalybeum extracts, using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Thereafter, the physiochemical, pharmacokinetic and toxicological profiles of the identified compounds were determined using computational tools and predictive molecular interactions of the compounds for beta cell regeneration targets were assessed via molecular docking. Results In RIN-5F cells, F. sycomorus extract increased cell viability and cell numbers at lower concentrations, but induced cytotoxicity and cell cycle arrest at higher concentrations. Conversely, Z. chalybeum increased cell viability, cell numbers and proliferation. In palmitate-pre-treated cells, Z. chalybeum extract significantly increased cell activity after 72 hours. However, in palmitate or streptozotocin pre-treated cells, neither F. sycomorus nor Z. chalybeum mitigated against reactive oxygen species generation or apoptosis. In vivo, Z. chalybeum extract did not ameliorate the glycemic indices of the diabetic rats. In the diabetic rats, morphometric analysis showed decreased islet/pancreas area, beta cell/ islet area, beta cell size, beta cell density and islet size, that were not attenuated by Z. chalybeum. We observed increased Pdx-1 and Ki-67 positivity in extract-treated islets, although these increases were not statistically significant. Using LC-MS/MS analysis, we tentatively identified 20 and 19 compounds from F. sycomorus and Z. chalybeum aqueous extracts, respectively. Based on ligand target and subsequent molecular docking interactions and binding affinity, we identified quercetin 3, 7-O-α-L-dirhamnoside, rutin, vanillic acid, and diosmin as potential dual specificity tyrosine-phosphorylation-regulated kinase 1A (Dyrk1A) inhibitors, while syringic acid was identified as a potential gamma-aminobutyric acid receptor B1 (GABARB1) agonist. Conclusion Z. chalybeum extract displayed mild beta cell regenerative potential that may be mediated by increased cell proliferation. However, the mitogenic effects observed in vitro, were not robust enough to elicit sufficient recovery of functional beta cell mass in our STZ-induced Wistar rat model, particularly in light of the sustained hyperglycemia, hypoinsulinemia and diminished beta cell area. The identification of diosmin, quercetin 3, 7-O-α-L-dirhamnoside, rutin and vanillic acid, as potential Dyrk1A inhibitors, and syringic acid as a potential GABARB1 agonist, merits further inquiry of their molecular interactions in the context of their therapeutic potential for beta cell regeneration. AFRIKAANSE OPSOMMING: Agtergrond: Tipe 2-diabetes (T2D) word gekenmerk deur pankreasbetasel wanfunksie en verlies van betasel massa ten spyte van huidige behandeling. Gevolglik is daar toenemend belangstelling in die ontwikkeling van betasel-gesentreerde terapieë, veral weens die ontdekking dat die pankreas 'n inherente betasel regeneratiewe vermoë het. Verskeie studies het mitogeniese effekte vir fitochemikalieë voorgestel wat bemiddel word deur die modulasie van seldifferensiasie, seltranskripsie asook deur die regulering van die selsiklus masjinerie kan plaasvind. Die gebruik van Z. chalybeum en F. sycomorus om diabetes te behandel is reeds gedokumenteer en eksperimenteel bevestig. Hierdie studie het gepoog om die uitwerking van Z. chalybeum en F. sycomorus waterekstrakte van die stambas op betaselregenerasie te ondersoek. Metodes RIN-5F pankreasbetaselle is onder normale selkultuur toestande, met of sonder diabetogeniese stressors (palmitaat of STZ) kultuur, waarna die selle met wisselende konsentrasies van F. sycomorus of Z. chalybeum ekstrak behandel is. Vervolgens is die ekstrakte vir hul effekte op sellewensvatbaarheid, proliferasie, apoptose asook oksidatiewe status, geëvalueer. As gevolg van die sitotoksiese effek van F. sycomorus in RIN-5F beta-selle, is slegs die Z. chalybeum-ekstrak in vivo geëvalueer. Manlike Wistar-rotte, met streptozotosien (STZ)-geïnduseerde diabetes, is met Z. chalybeum ekstrak vir 28 dae behandel. Liggaamsgewigte, voedsel- en waterinname, vastende bloedglukose, orale glukosetoleransie en insulienkonsentrasies is bepaal. Pankreasweefsel is vir immunohistochemie versamel. Om die effek van Z. chalybeum op betaselregenerasie te ondersoek, is histologiesnitte van die pankreasweefsel immunologies gekleur vir die uitdrukking van die sleutel betaselregenerasiemerkers, neurogenien-3 (Ngn-3), V-maf muskuloaponeurotiese fibrosarkoom onkogeen homoloog A (MafA) en pankreas duodenale homeobox proteïen 1 (Pdx-1), asook die proliferasiemerker Ki-67 ondersoek. Ook is pankreaseilande morfometries geëvalueer vir hul insulien/glukagon immunoreaktiwiteit. Fitochemiese profiele van die F. sycomorus en Z. chalybeum ekstrakte is bepaal deur LC-MS/MS. Daarna is die fisiochemiese, farmakokinetiese en toksikologiese eienskappe van die geïdentifiseerde verbindings bepaal deur middel van berekeningsinstrumente is voorspellende molekulêre interaksies van die verbindings vir betaselregenerasie teikens verder deur middel van molekulêre dok beoordeel. Resultate In RIN-5F-selle het die F. sycomorus ekstrak sellewensvatbaarheid en selgetalle teen laer konsentrasies verhoog, maar het by hoër konsentrasies sitotoksisiteit asook blokkering van die selsiklus geïnduseer. In teenstelling het Z. chalybeum sellewensvatbaarheid, selgetalle en proliferasie verhoog. In die palmitaat- behandelde selle het Z. chalybeum-ekstrak selaktiwiteit na 72 uur aansienlik verhoog. In palmitaat- of STZ-behandelde selle was beide F. sycomorus of Z. chalybeum ekstrakte oneffektief om die geïnduseerde oksidatiewe stress en apoptose, betekenisvol te verminder. In vivo het Z. chalybeum-ekstrak nie die glukemiese indekse van die diabetiese rotte verbeter nie. Morfometries het die diabetiese rotte verminderde eiland/pankreasweefsel area, betasel/eiland area, betaselgrootte, betaseldigtheid en eiland grootte getoon, wat nie deur Z. chalybeum verbeter is nie. Ons het verhoogde Pdx-1 en Ki-67 positiwiteit in die ekstrak-behandelde eilande waargeneem, maar die toenames was nie statisties betekenisvol nie. Met behulp van LC-MS/MS-analise het ons 20 en 19 verbindings, onderskeidelik van die F. sycomorus en Z. chalybeum ekstrakte, geïdentifiseer. Gebaseer op ligand-teiken en daarop volgende molekulêre koppelinteraksies en bindingsaffiniteite, het ons quercetien 3, 7-O-α-L-dirhamnosied, rutien, vanilliensuur en diosmien geïdentifiseer as potensiële Dyrk1A inhibeerders, terwyl siringiensuur as 'n potensiële GABARB1 agonis geïdentifiseer is. Gevolgtrekking Z. chalybeum-ekstrak het tekens van betaselregenerasie potensiaal getoon wat deur verhoogde selproliferasie bemiddel kon word. Die mitogeniese effekte wat in vitro waargeneem is, was egter nie kragtig genoeg om voldoende herstel van funksionele betaselmassa in ons STZ-geïnduseerde Wistar-ratmodel te bewerkstellig nie, veral in die lig van die volgehoue hiperglukemie, hipoinsulienemie en verminderde betasel area. Die identifikasie van diosmien, quercetien 3, 7-O-α-L-dirhamnosied, rutien en vanilliensuur, as potensiële Dyrk1A inhibeerders, en siringiensuur as 'n potensiële GABARB1 agonis, verdien verdere ondersoek na hul molekulêre interaksies in die konteks van hul terapeutiese potensiaal vir betaselregenerasie. Doctoral 2023-01-18T11:01:01Z 2023-08-30T13:05:24Z 2023-03 2023-01-18T11:01:01Z 2023-08-31T09:18:39Z 2023-01-18T11:01:01Z 2023-08-31T09:18:39Z 2023-03 Thesis https://scholar.sun.ac.za/handle/10019.1/128414 en Stellenbosch University application/pdf xxv, 257 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Pancreatic beta cells -- Regeneration Type 2 diabetes -- Alternative treatment Medicinal plants -- Therapeutic use UCTD Kimani, Clare Njoki Beta cell regeneration and antidiabetic potential of Ficus sycomorus and Zanthoxylum chalybeum |
| title | Beta cell regeneration and antidiabetic potential of Ficus sycomorus and Zanthoxylum chalybeum |
| title_full | Beta cell regeneration and antidiabetic potential of Ficus sycomorus and Zanthoxylum chalybeum |
| title_fullStr | Beta cell regeneration and antidiabetic potential of Ficus sycomorus and Zanthoxylum chalybeum |
| title_full_unstemmed | Beta cell regeneration and antidiabetic potential of Ficus sycomorus and Zanthoxylum chalybeum |
| title_short | Beta cell regeneration and antidiabetic potential of Ficus sycomorus and Zanthoxylum chalybeum |
| title_sort | beta cell regeneration and antidiabetic potential of ficus sycomorus and zanthoxylum chalybeum |
| topic | Pancreatic beta cells -- Regeneration Type 2 diabetes -- Alternative treatment Medicinal plants -- Therapeutic use UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/128414 |
| work_keys_str_mv | AT kimaniclarenjoki betacellregenerationandantidiabeticpotentialofficussycomorusandzanthoxylumchalybeum |