Document Type
Oral Presentation
Location
Oxford Conference Center
Event Website
https://oxfordicsb.org/
Start Date
23-4-2026 8:30 AM
End Date
23-4-2026 10:00 AM
Description
Cancer remains a major global health challenge, with multidrug resistance (MDR)—frequently driven by P-glycoprotein (P-gp) overexpression—significantly limiting the effectiveness of chemotherapy. Within a One Health perspective, Africa, home to five major medicinal biodiversity hotspots, represents an underexplored reservoir for natural products–based drug discovery. Among this rich flora, the genus Plectranthus (Lamiaceae) emerges as a particularly promising source of bioactive abietane diterpenes. In this work, the abietane diterpene 7α-acetoxy-6β-hydroxyroyleanone (Roy), isolated from Plectranthus grandidentatus Gürke, exhibited pronounced cytotoxic activity against several cancer cell lines. To enhance its pharmacological profile, a series of Roy ester derivatives was synthesized and evaluated for their ability to inhibit P-glycoprotein (P-gp). Ligand-based pharmacophore modeling and structure–activity relationship (SAR) analysis were employed to support the identification of structural features relevant to P-gp modulation. A library of Roy derivatives was screened for cytotoxic activity and P-glycoprotein (P-gp) inhibition in multidrug-resistant (MDR) cancer cell lines. Several compounds significantly enhanced intracellular doxorubicin (DOXO) accumulation, with the 12-p-chlorobenzoyl Roy derivative exhibiting the strongest P-gp inhibitory effect and selective cytotoxicity, particularly in lung cancer models. To overcome limitations related to solubility and bioavailability, Roy and a phenylpropanoate derivative were incorporated into gold nanoparticle (AuNP)-based nanosystems. These Roy-functionalized AuNPs were physicochemically characterized and evaluated in vitro in breast cancer cell lines (MDA-MB-231, 4T1, and MCF-7), where they demonstrated enhanced cytotoxicity and improved selectivity compared with free Roy. Overall, this work highlights the value of medicinal plants as sources of bioactive scaffolds for addressing multidrug resistance, reinforcing the role of botanical science in innovative and sustainable drug discovery.
The work was supported by FCT through the projects UID/04567/2025 (DOI: 10.54499/UID/04567/2025).
Recommended Citation
Rijo, Patricia, "Medicinal Plants and One Health Drug Discovery: Plectranthus Abietanes as P-Glycoprotein Modulators" (2026). Oxford ICSB. 40.
https://egrove.olemiss.edu/icsb/2026_ICSB/Schedule/40
Publication Date
April 2026
Accessibility Status
Screen reader accessible, Searchable text
Included in
Medicinal Plants and One Health Drug Discovery: Plectranthus Abietanes as P-Glycoprotein Modulators
Oxford Conference Center
Cancer remains a major global health challenge, with multidrug resistance (MDR)—frequently driven by P-glycoprotein (P-gp) overexpression—significantly limiting the effectiveness of chemotherapy. Within a One Health perspective, Africa, home to five major medicinal biodiversity hotspots, represents an underexplored reservoir for natural products–based drug discovery. Among this rich flora, the genus Plectranthus (Lamiaceae) emerges as a particularly promising source of bioactive abietane diterpenes. In this work, the abietane diterpene 7α-acetoxy-6β-hydroxyroyleanone (Roy), isolated from Plectranthus grandidentatus Gürke, exhibited pronounced cytotoxic activity against several cancer cell lines. To enhance its pharmacological profile, a series of Roy ester derivatives was synthesized and evaluated for their ability to inhibit P-glycoprotein (P-gp). Ligand-based pharmacophore modeling and structure–activity relationship (SAR) analysis were employed to support the identification of structural features relevant to P-gp modulation. A library of Roy derivatives was screened for cytotoxic activity and P-glycoprotein (P-gp) inhibition in multidrug-resistant (MDR) cancer cell lines. Several compounds significantly enhanced intracellular doxorubicin (DOXO) accumulation, with the 12-p-chlorobenzoyl Roy derivative exhibiting the strongest P-gp inhibitory effect and selective cytotoxicity, particularly in lung cancer models. To overcome limitations related to solubility and bioavailability, Roy and a phenylpropanoate derivative were incorporated into gold nanoparticle (AuNP)-based nanosystems. These Roy-functionalized AuNPs were physicochemically characterized and evaluated in vitro in breast cancer cell lines (MDA-MB-231, 4T1, and MCF-7), where they demonstrated enhanced cytotoxicity and improved selectivity compared with free Roy. Overall, this work highlights the value of medicinal plants as sources of bioactive scaffolds for addressing multidrug resistance, reinforcing the role of botanical science in innovative and sustainable drug discovery.
The work was supported by FCT through the projects UID/04567/2025 (DOI: 10.54499/UID/04567/2025).
https://egrove.olemiss.edu/icsb/2026_ICSB/Schedule/40
Comments
Patrícia Rijo holds a degree in Chemistry from the Faculty of Sciences of the University of Lisbon (FCUL) and a Master’s degree, Ph.D., and Habilitation in Pharmaceutical and Therapeutic Chemistry from the Faculty of Pharmacy of the University of Lisbon (FFUL). She is currently an Associate Professor with Habilitation at the School of Health Sciences and Technologies (ECTS), Universidade Lusófona (ULHT), Lisbon, Portugal, where she teaches Organic Medicinal Chemistry and Pharmacognosy. She coordinates the Master’s programme in Chemistry of Natural Bioactives and serves as International Coordinator. Her main research areas encompass medicinal chemistry, phytochemistry, and pharmacognosy, with a strong focus on natural products chemistry and their translation into bioactive and therapeutic applications. She is Vice-Director for Internationalisation and Strategic Networks at CBIOS – Research Center for Biosciences and Health Technologies (ULHT), where she leads the Laboratory of Natural Bioactives (Bio.Natural). Her research integrates the sustainable exploration of medicinal plants with semisynthetic derivatization, biological evaluation, and innovative delivery strategies, contributing to drug discovery within a One Health framework. Since 2015, Dr. Rijo has been actively involved in international scientific networking, having participated in seven international research networks, including COST Actions and CYTED programmes. She currently serves as Vice-Chair of the COST Action CA21145. In parallel, she has contributed as an expert evaluator to international research and innovation funding panels in several countries, including Serbia, Argentina, Poland, Chile, France (ANR), and at the European Union level. Dr. Rijo maintains a strong commitment to science communication, outreach, and academic leadership. She has coordinated 14 science outreach projects and organized 23 national and international scientific events. Her engagement includes participation in initiatives such as the New European Bauhaus, CiênciaVitae–CBIOS, the Talent Bootcamp (FCT NOVA and FCUL), and the Global Women’s Breakfast (IUPAC). She has been a member of the Scientific Committee of ESCOP since 2025 and, since 2019, has presided over the Bio.Natural – Bioactive Natural Products Research Meeting. She serves as Associate Editor of Phytomedicine (Elsevier) and Frontiers in Pharmacology (Ethnopharmacology and Drug Discovery section), and is a member of the Editorial Boards of hLife (Elsevier) and Pharmaceuticals (MDPI, Natural Products section). Dr. Rijo has authored more than 170 peer-reviewed scientific publications, delivered over 300 communications at national and international scientific meetings—including numerous invited lectures—and is the inventor of three registered patents.