TY  - CONF
AU  - Ntungwe, Epole
AU  - Jovanović Stojanov, Sofija
AU  - Duarte, Noélia
AU  - R. Candeias, Nuno
AU  - Díaz-Lanza, Ana María
AU  - Pešić, Milica
AU  - Rijo, Patrícia
PY  - 2022
UR  - http://radar.ibiss.bg.ac.rs/handle/123456789/5610
UR  - https://sciforum.net/paper/view/13460
AB  - The development of multidrug resistance (MDR) is one of the major challenges in the successful treatment of cancer. MDR is often associated with the P-glycoprotein efflux pump. Natural products are a source of promising lead compounds to overcome MDR and, among them, diterpenoids from Plectranthus spp. are known as P-gp modulators. Bioguided fractionation of P. mutabilis acetone extract led to the isolation of one new nor-abietane diterpene, mutabilol (1), and three coleon compounds (coleon-U-quinone (2), 8α,9α-epoxycoleon-U-quinone (3), and coleon U (4)). Moreover, an additional acetoxy derivative of an abietane diterpenoid was tentatively identified using HPLC-MS/MS. The compounds were quantified using HPLC-DAD and coleon U was found to be the major compound in the extract. Using computational studies, a biosynthetic relationship between compounds 2 - 4 revealed that both compounds 2 and 3 were formed directly from compound 4. Compounds 2 - 4 were found to be selective towards the cancer cell lines and their anticancer effect was not compromised by the P-gp activity in resistant NCI-H460/R cells. Importantly 2, 3, and 4 were able to inhibit P-gp activity in NCI-H460/R cells at longer exposure (72 h) and revert doxorubicin (DOX) resistance in combined treatment. None of the compounds influenced the P-gp expression in NCI-H460/R cells, while the extract significantly increased it. Our study identified abietane diterpenoids from P. mutabilis that can evade MDR in cancer cells and inhibit the P-gp activity in prolonged treatment.
PB  - SCIForum
C3  - The 8th International Electronic Conference on Medicinal Chemistry; 2022 Nov 1-30; Virtual Event
T1  - P-gp modulation and biosynthetic relationship of isolated compounds from Plectranthus mutabilis Codd.
DO  - 10.3390/ECMC2022-13460
ER  - 

@conference{
author = "Ntungwe, Epole and Jovanović Stojanov, Sofija and Duarte, Noélia and R. Candeias, Nuno and Díaz-Lanza, Ana María and Pešić, Milica and Rijo, Patrícia",
year = "2022",
abstract = "The development of multidrug resistance (MDR) is one of the major challenges in the successful treatment of cancer. MDR is often associated with the P-glycoprotein efflux pump. Natural products are a source of promising lead compounds to overcome MDR and, among them, diterpenoids from Plectranthus spp. are known as P-gp modulators. Bioguided fractionation of P. mutabilis acetone extract led to the isolation of one new nor-abietane diterpene, mutabilol (1), and three coleon compounds (coleon-U-quinone (2), 8α,9α-epoxycoleon-U-quinone (3), and coleon U (4)). Moreover, an additional acetoxy derivative of an abietane diterpenoid was tentatively identified using HPLC-MS/MS. The compounds were quantified using HPLC-DAD and coleon U was found to be the major compound in the extract. Using computational studies, a biosynthetic relationship between compounds 2 - 4 revealed that both compounds 2 and 3 were formed directly from compound 4. Compounds 2 - 4 were found to be selective towards the cancer cell lines and their anticancer effect was not compromised by the P-gp activity in resistant NCI-H460/R cells. Importantly 2, 3, and 4 were able to inhibit P-gp activity in NCI-H460/R cells at longer exposure (72 h) and revert doxorubicin (DOX) resistance in combined treatment. None of the compounds influenced the P-gp expression in NCI-H460/R cells, while the extract significantly increased it. Our study identified abietane diterpenoids from P. mutabilis that can evade MDR in cancer cells and inhibit the P-gp activity in prolonged treatment.",
publisher = "SCIForum",
journal = "The 8th International Electronic Conference on Medicinal Chemistry; 2022 Nov 1-30; Virtual Event",
title = "P-gp modulation and biosynthetic relationship of isolated compounds from Plectranthus mutabilis Codd.",
doi = "10.3390/ECMC2022-13460"
}

Ntungwe, E., Jovanović Stojanov, S., Duarte, N., R. Candeias, N., Díaz-Lanza, A. M., Pešić, M.,& Rijo, P.. (2022). P-gp modulation and biosynthetic relationship of isolated compounds from Plectranthus mutabilis Codd.. in The 8th International Electronic Conference on Medicinal Chemistry; 2022 Nov 1-30; Virtual Event
SCIForum..
https://doi.org/10.3390/ECMC2022-13460

Ntungwe E, Jovanović Stojanov S, Duarte N, R. Candeias N, Díaz-Lanza AM, Pešić M, Rijo P. P-gp modulation and biosynthetic relationship of isolated compounds from Plectranthus mutabilis Codd.. in The 8th International Electronic Conference on Medicinal Chemistry; 2022 Nov 1-30; Virtual Event. 2022;.
doi:10.3390/ECMC2022-13460 .

Ntungwe, Epole, Jovanović Stojanov, Sofija, Duarte, Noélia, R. Candeias, Nuno, Díaz-Lanza, Ana María, Pešić, Milica, Rijo, Patrícia, "P-gp modulation and biosynthetic relationship of isolated compounds from Plectranthus mutabilis Codd." in The 8th International Electronic Conference on Medicinal Chemistry; 2022 Nov 1-30; Virtual Event (2022),
https://doi.org/10.3390/ECMC2022-13460 . .

TY  - JOUR
AU  - Garcia, Catarina
AU  - Isca, Vera
AU  - Pereira, Filipe
AU  - Monteiro, Carlos
AU  - Ntungwe, Epole
AU  - Sousa, Francisco
AU  - Dinić, Jelena
AU  - Holmstedt, Suvi
AU  - Roberto, Amílcar
AU  - Díaz-Lanza, Ana
AU  - Reis, Catarina
AU  - Pešić, Milica
AU  - Candeias, Nuno
AU  - Ferreira, Ricardo
AU  - Duarte, Noélia
AU  - Afonso, Carlos
AU  - Rijo, Patrícia
PY  - 2020
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/4261
AB  - Cancer is among the leading causes of death worldwide. One of the most challenging obstacles in cancer treatment is multidrug resistance (MDR). Overexpression of P-glycoprotein (P-gp) is associated with MDR. The growing incidence of cancer and the development of MDR drive the search for novel and more effective anticancer drugs to overcome the MDR problem. Royleanones are natural bioactive compounds frequently found in Plectranthus spp. The cytotoxic diterpene 6,7-dehydroroyleanone (1) is the main component of the P. madagascariensis (Pers.) Benth. essential oil, while 7α-acetoxy-6β-hydroxyroyleanone (2) can be isolated from acetonic extracts of P. grandidentatus Gürke. The reactivity of the natural royleanones 1 and 2 was explored to obtain a small library of new P-gp inhibitors. Four new derivatives (6,7-dehydro-12-O-tert-butyl-carbonate-royleanone (20), 6,7-dehydro-12-O-methylroyleanone (21), 6,7-dehydro-12-O-benzoylroyleanone (22), and 7α-acetoxy-6β-hydroxy-12-O-benzoylroyleanone (23) were obtained as pure with overall modest to excellent yields (21-97%). P-gp inhibition potential of the derivatives 20-23 was evaluated in human non-small cell lung carcinoma NCI-H460 and its MDR counterpart NCI-H460/R with the P-gp overexpression, through MTT assay. Previously prepared diterpene 7α-acetoxy-6β-benzoyloxy-12-O-(4-chloro)benzoylroyleanone (4), has also been tested. The P-gp inhibiting effects of compounds 1-4 were also assessed through a Rhodamine 123 accumulation assay. Derivatives 4 and 23 have significant P-gp inhibitory potential. Regarding stability and P-gp inhibition potential, results suggest that the formation of benzoyl esters is a more convenient approach for future derivatives with enhanced effect on the cell viability decrease. Compound 4 presented higher anti-P-gp potential than the natural diterpenes 1, 2, and 3, with comparable inhibitory potential to Dexverapamil. Moreover, derivative 4 showed the ability to sensitize the resistant NCI-H460/R cells to doxorubicin.
PB  - Lausanne : Frontiers
T2  - Frontiers in Pharmacology
T1  - Royleanone Derivatives From Plectranthus spp. as a Novel Class of P-Glycoprotein Inhibitors
VL  - 11
DO  - 10.3389/fphar.2020.557789
SP  - 557789
ER  - 

@article{
author = "Garcia, Catarina and Isca, Vera and Pereira, Filipe and Monteiro, Carlos and Ntungwe, Epole and Sousa, Francisco and Dinić, Jelena and Holmstedt, Suvi and Roberto, Amílcar and Díaz-Lanza, Ana and Reis, Catarina and Pešić, Milica and Candeias, Nuno and Ferreira, Ricardo and Duarte, Noélia and Afonso, Carlos and Rijo, Patrícia",
year = "2020",
abstract = "Cancer is among the leading causes of death worldwide. One of the most challenging obstacles in cancer treatment is multidrug resistance (MDR). Overexpression of P-glycoprotein (P-gp) is associated with MDR. The growing incidence of cancer and the development of MDR drive the search for novel and more effective anticancer drugs to overcome the MDR problem. Royleanones are natural bioactive compounds frequently found in Plectranthus spp. The cytotoxic diterpene 6,7-dehydroroyleanone (1) is the main component of the P. madagascariensis (Pers.) Benth. essential oil, while 7α-acetoxy-6β-hydroxyroyleanone (2) can be isolated from acetonic extracts of P. grandidentatus Gürke. The reactivity of the natural royleanones 1 and 2 was explored to obtain a small library of new P-gp inhibitors. Four new derivatives (6,7-dehydro-12-O-tert-butyl-carbonate-royleanone (20), 6,7-dehydro-12-O-methylroyleanone (21), 6,7-dehydro-12-O-benzoylroyleanone (22), and 7α-acetoxy-6β-hydroxy-12-O-benzoylroyleanone (23) were obtained as pure with overall modest to excellent yields (21-97%). P-gp inhibition potential of the derivatives 20-23 was evaluated in human non-small cell lung carcinoma NCI-H460 and its MDR counterpart NCI-H460/R with the P-gp overexpression, through MTT assay. Previously prepared diterpene 7α-acetoxy-6β-benzoyloxy-12-O-(4-chloro)benzoylroyleanone (4), has also been tested. The P-gp inhibiting effects of compounds 1-4 were also assessed through a Rhodamine 123 accumulation assay. Derivatives 4 and 23 have significant P-gp inhibitory potential. Regarding stability and P-gp inhibition potential, results suggest that the formation of benzoyl esters is a more convenient approach for future derivatives with enhanced effect on the cell viability decrease. Compound 4 presented higher anti-P-gp potential than the natural diterpenes 1, 2, and 3, with comparable inhibitory potential to Dexverapamil. Moreover, derivative 4 showed the ability to sensitize the resistant NCI-H460/R cells to doxorubicin.",
publisher = "Lausanne : Frontiers",
journal = "Frontiers in Pharmacology",
title = "Royleanone Derivatives From Plectranthus spp. as a Novel Class of P-Glycoprotein Inhibitors",
volume = "11",
doi = "10.3389/fphar.2020.557789",
pages = "557789"
}

Garcia, C., Isca, V., Pereira, F., Monteiro, C., Ntungwe, E., Sousa, F., Dinić, J., Holmstedt, S., Roberto, A., Díaz-Lanza, A., Reis, C., Pešić, M., Candeias, N., Ferreira, R., Duarte, N., Afonso, C.,& Rijo, P.. (2020). Royleanone Derivatives From Plectranthus spp. as a Novel Class of P-Glycoprotein Inhibitors. in Frontiers in Pharmacology
Lausanne : Frontiers., 11, 557789.
https://doi.org/10.3389/fphar.2020.557789

Garcia C, Isca V, Pereira F, Monteiro C, Ntungwe E, Sousa F, Dinić J, Holmstedt S, Roberto A, Díaz-Lanza A, Reis C, Pešić M, Candeias N, Ferreira R, Duarte N, Afonso C, Rijo P. Royleanone Derivatives From Plectranthus spp. as a Novel Class of P-Glycoprotein Inhibitors. in Frontiers in Pharmacology. 2020;11:557789.
doi:10.3389/fphar.2020.557789 .

Garcia, Catarina, Isca, Vera, Pereira, Filipe, Monteiro, Carlos, Ntungwe, Epole, Sousa, Francisco, Dinić, Jelena, Holmstedt, Suvi, Roberto, Amílcar, Díaz-Lanza, Ana, Reis, Catarina, Pešić, Milica, Candeias, Nuno, Ferreira, Ricardo, Duarte, Noélia, Afonso, Carlos, Rijo, Patrícia, "Royleanone Derivatives From Plectranthus spp. as a Novel Class of P-Glycoprotein Inhibitors" in Frontiers in Pharmacology, 11 (2020):557789,
https://doi.org/10.3389/fphar.2020.557789 . .

TY  - JOUR
AU  - Garcia, Catarina
AU  - Ntungwe, Epole
AU  - Rebelo, Ana
AU  - Bessa, Cláudia
AU  - Stanković, Tijana
AU  - Dinić, Jelena
AU  - Díaz-Lanza, Ana
AU  - P Reis, Catarina
AU  - Roberto, Amílcar
AU  - Pereira, Paula
AU  - Cebola, Maria-João
AU  - Saraiva, Lucília
AU  - Pešić, Milica
AU  - Duarte, Noélia
AU  - Rijo, Patrícia
PY  - 2019
UR  - https://www.mdpi.com/2218-273X/9/10/616
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/3492
AB  - The Plectranthus genus is commonly used in traditional medicine due to its potential to treat several illnesses, including bacterial infections and cancer. As such, aiming to screen the antibacterial and cytotoxic activities of extracts, sixteen selected Plectranthus species with medicinal potential were studied. In total, 31 extracts obtained from 16 Plectranthus spp. were tested for their antibacterial and anticancer properties. Well diffusion method was used for preliminary antibacterial screening. The minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values of the five most active acetonic extracts (P. aliciae, P. japonicus, P. madagascariensis var. "Lynne", P. stylesii, and P. strigosus) were determined. After preliminary toxicity evaluation on Artemia salina L., their cytotoxic properties were assessed on three human cancer cell lines (HCT116, MCF-7, and H460). These were also selected for mechanism of resistance studies (on NCI-H460/R and DLD1-TxR cells). An identified compound-parvifloron D-was tested in a pair of sensitive and MDR-Multidrug resistance cancer cells (NCI-H460 and NCI-H460/R) and in normal bronchial fibroblasts MRC-5. The chemical composition of the most active extract was studied through high performance liquid chromatography with a diode array detector (HPLC-DAD/UV) and liquid chromatography-mass spectrometry (LC-MS). Overall, P. strigosus acetonic extract showed the strongest antimicrobial and cytotoxic potential that could be explained by the presence of parvifloron D, a highly cytotoxic diterpene. This study provides valuable information on the use of the Plectranthus genus as a source of bioactive compounds, namely P. strigosus with the potential active ingredient the parvifloron D.
T2  - Biomolecules
T1  - Parvifloron D from Plectranthusstrigosus: Cytotoxicity Screening of Plectranthus spp. Extracts.
IS  - 10
VL  - 9
DO  - 10.3390/biom9100616
SP  - 616
ER  - 

@article{
author = "Garcia, Catarina and Ntungwe, Epole and Rebelo, Ana and Bessa, Cláudia and Stanković, Tijana and Dinić, Jelena and Díaz-Lanza, Ana and P Reis, Catarina and Roberto, Amílcar and Pereira, Paula and Cebola, Maria-João and Saraiva, Lucília and Pešić, Milica and Duarte, Noélia and Rijo, Patrícia",
year = "2019",
abstract = "The Plectranthus genus is commonly used in traditional medicine due to its potential to treat several illnesses, including bacterial infections and cancer. As such, aiming to screen the antibacterial and cytotoxic activities of extracts, sixteen selected Plectranthus species with medicinal potential were studied. In total, 31 extracts obtained from 16 Plectranthus spp. were tested for their antibacterial and anticancer properties. Well diffusion method was used for preliminary antibacterial screening. The minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values of the five most active acetonic extracts (P. aliciae, P. japonicus, P. madagascariensis var. "Lynne", P. stylesii, and P. strigosus) were determined. After preliminary toxicity evaluation on Artemia salina L., their cytotoxic properties were assessed on three human cancer cell lines (HCT116, MCF-7, and H460). These were also selected for mechanism of resistance studies (on NCI-H460/R and DLD1-TxR cells). An identified compound-parvifloron D-was tested in a pair of sensitive and MDR-Multidrug resistance cancer cells (NCI-H460 and NCI-H460/R) and in normal bronchial fibroblasts MRC-5. The chemical composition of the most active extract was studied through high performance liquid chromatography with a diode array detector (HPLC-DAD/UV) and liquid chromatography-mass spectrometry (LC-MS). Overall, P. strigosus acetonic extract showed the strongest antimicrobial and cytotoxic potential that could be explained by the presence of parvifloron D, a highly cytotoxic diterpene. This study provides valuable information on the use of the Plectranthus genus as a source of bioactive compounds, namely P. strigosus with the potential active ingredient the parvifloron D.",
journal = "Biomolecules",
title = "Parvifloron D from Plectranthusstrigosus: Cytotoxicity Screening of Plectranthus spp. Extracts.",
number = "10",
volume = "9",
doi = "10.3390/biom9100616",
pages = "616"
}

Garcia, C., Ntungwe, E., Rebelo, A., Bessa, C., Stanković, T., Dinić, J., Díaz-Lanza, A., P Reis, C., Roberto, A., Pereira, P., Cebola, M., Saraiva, L., Pešić, M., Duarte, N.,& Rijo, P.. (2019). Parvifloron D from Plectranthusstrigosus: Cytotoxicity Screening of Plectranthus spp. Extracts.. in Biomolecules, 9(10), 616.
https://doi.org/10.3390/biom9100616

Garcia C, Ntungwe E, Rebelo A, Bessa C, Stanković T, Dinić J, Díaz-Lanza A, P Reis C, Roberto A, Pereira P, Cebola M, Saraiva L, Pešić M, Duarte N, Rijo P. Parvifloron D from Plectranthusstrigosus: Cytotoxicity Screening of Plectranthus spp. Extracts.. in Biomolecules. 2019;9(10):616.
doi:10.3390/biom9100616 .

Garcia, Catarina, Ntungwe, Epole, Rebelo, Ana, Bessa, Cláudia, Stanković, Tijana, Dinić, Jelena, Díaz-Lanza, Ana, P Reis, Catarina, Roberto, Amílcar, Pereira, Paula, Cebola, Maria-João, Saraiva, Lucília, Pešić, Milica, Duarte, Noélia, Rijo, Patrícia, "Parvifloron D from Plectranthusstrigosus: Cytotoxicity Screening of Plectranthus spp. Extracts." in Biomolecules, 9, no. 10 (2019):616,
https://doi.org/10.3390/biom9100616 . .