{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,4]],"date-time":"2026-06-04T05:30:31Z","timestamp":1780551031990,"version":"3.54.1"},"reference-count":49,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2025,5,1]],"date-time":"2025-05-01T00:00:00Z","timestamp":1746057600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"NRF, South Africa. National Research foundation","award":["TTK190403426633"],"award-info":[{"award-number":["TTK190403426633"]}]},{"name":"Rhodes University, Makhanda and 117898 (VJT)","award":["TTK190403426633"],"award-info":[{"award-number":["TTK190403426633"]}]},{"name":"Tshwane University of Technology, Pretoria, South Africa","award":["TTK190403426633"],"award-info":[{"award-number":["TTK190403426633"]}]}],"content-domain":{"domain":["www.mdpi.com"],"crossmark-restriction":true},"short-container-title":["Diseases"],"abstract":"<jats:p>Background: Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with limited therapeutic options. Leonotis ocymifolia is a shrub widely used in traditional medicine to alleviate cancer-related symptoms. In a search to find safe and efficacious therapeutic agents from medicinal plants, Leonotis ocymifolia was studied to find compounds with anticancer activity against TNBC. Methods: Compounds from Leonotis ocymifolia were characterized using spectroscopic data such as IR, 1D and 2D NMR, and MS spectrometry and evaluated for cytotoxic activity against triple-negative breast cancer (HCC70), hormone receptor-positive breast cancer (MCF-7), and non-tumorigenic mammary epithelial cell lines (MCF-12A). Results: A previously unreported bis-spirolabdane, 13S-nepetaefolin (1), together with five known labdane diterpenoids, namely nepetaefolin (2), dubiin (3), nepetaefuran (4), leonotin (5), and leonotinin (6), from the genus Leonotis were isolated. Overall, the labdane diterpenoids showed selective activity toward triple-negative breast cancer cells (HCC70). Of the compounds extracted, 13S-nepetaefolin demonstrated the greatest cytotoxic activity with an IC50 of 24.65 \u00b5M (SI = 1.08) against HCC70 cells; however, it was equally cytotoxic to non-tumorigenic MCF-12A breast cells (IC50 of 26.55 \u00b5M), whereas its isomer (2) showed no activity. This suggests that stereochemistry might have an effect on the cytotoxic activity of the bis-spirolabdane diterpenoids. All the compounds (1\u20136) demonstrated adsorption, distribution, metabolism, and excretion properties (ADME), while leonotin (5) and leonotinin (6) exhibited lead-like properties and high synthetic accessibility scores. Conclusions: The findings from this study warrant further investigation of L. ocymifolia for potential triple-negative breast cancer (TNBC) therapeutic agents, including potential chemical derivatization of bis-spiro labdane diterpenoid (1) to improve selectivity to TNBC over non-cancer cells.<\/jats:p>","DOI":"10.3390\/diseases13050140","type":"journal-article","created":{"date-parts":[[2025,5,1]],"date-time":"2025-05-01T05:10:32Z","timestamp":1746076232000},"page":"140","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Labdane Diterpenoids from Leonotis ocymifolia with Selective Cytotoxic Activity Against HCC70 Breast Cancer Cell Line"],"prefix":"10.3390","volume":"13","author":[{"given":"Jane","family":"Ncongwane","sequence":"first","affiliation":[{"name":"Department of Chemistry, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5232-1514","authenticated-orcid":false,"given":"Comfort","family":"Nkambule","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gerda","family":"Fouche","sequence":"additional","affiliation":[{"name":"Department of Chemistry, University of Pretoria, Pretoria 0001, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3771-128X","authenticated-orcid":false,"given":"Douglas","family":"Kemboi","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa"},{"name":"School of Science and Technology, University of Kabianga, Kericho 2030-20200, Kenya"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nyeleti","family":"Vukea","sequence":"additional","affiliation":[{"name":"Department of Biochemistry and Microbiology, Rhodes University, Grahamstown 6140, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Candace","family":"Davison","sequence":"additional","affiliation":[{"name":"Department of Biochemistry and Microbiology, Rhodes University, Grahamstown 6140, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jo-Anne","family":"de la Mare","sequence":"additional","affiliation":[{"name":"Department of Biochemistry and Microbiology, Rhodes University, Grahamstown 6140, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vuyelwa","family":"Tembu","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,5,1]]},"reference":[{"key":"ref_1","first-page":"229","article-title":"Global cancer statistics 2022: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries","volume":"74","author":"Bray","year":"2024","journal-title":"CA Cancer J. Clin."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1097\/PPO.0000000000000500","article-title":"Epidemiology of triple-negative breast cancer: A review","volume":"27","author":"Howard","year":"2021","journal-title":"Cancer J."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"288","DOI":"10.1001\/jama.2018.19323","article-title":"Breast cancer treatment: A review","volume":"321","author":"Waks","year":"2019","journal-title":"JAMA"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Basmadjian, R.B., Chow, K., Kim, D., Kenney, M., Lukmanji, A., O\u2019Sullivan, D.E., Xu, Y., Quan, M.L., Cheung, W.Y., and Lupichuk, S. (2023). The association between early-onset diagnosis and clinical outcomes in triple--negative breast cancer: A systematic review and meta-analysis. Cancers, 15.","DOI":"10.3390\/cancers15071923"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"14","DOI":"10.1016\/j.biopha.2018.06.066","article-title":"Clinical and molecular aspects of breast cancer: Targets and therapies","volume":"106","author":"Godone","year":"2018","journal-title":"Biomed. Pharmacother."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Iacopetta, D., Ceramella, J., Baldino, N., Sinicropi, M.S., and Catalano, A. (2023). Targeting breast cancer: An overlook on current strategies. Int. J. Mol. Sci., 24.","DOI":"10.3390\/ijms24043643"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Obidiro, O., Battogtokh, G., and Akala, E.O. (2023). Triple- negative breast cancer treatment options and limitations: Future outlook. Pharmaceutics, 15.","DOI":"10.20944\/preprints202306.0074.v1"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1570","DOI":"10.1021\/np50113a017","article-title":"Diterpenes from the leaves of Leonotis ocymifolia var","volume":"57","author":"Habtemariam","year":"1994","journal-title":"raineriana. J. Nat. Prod."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"8173543","DOI":"10.1155\/2023\/8173543","article-title":"Review of Medicinal Plants Traditionally Used to Treat Diarrhea by the People in the Amhara Region of Ethiopia","volume":"2023","author":"Damtie","year":"2023","journal-title":"Evid. Based Complement. Altern. Med."},{"key":"ref_10","unstructured":"Kigen, G., Some, F., Kibosia, J., Rono, H., Kiprop, E., Wanjohi, B., Kigen, P., and Kipkore, W. (2014). Ethnomedicinal plants traditionally used by the keiyo community in Elgeyo Marakwet County, Kenya. J. Biodivers. Biopros. Dev., 1."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"368","DOI":"10.1016\/S0975-3575(10)80017-3","article-title":"Ethnobotanical study of medicinal plants used as anti-obesity remedies in Nkonkobe Municipality of South Africa","volume":"2","author":"Afolayan","year":"2010","journal-title":"Phcog. J."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"186","DOI":"10.1080\/13880200490514032","article-title":"A pharmacognostical study of 26 South African plant species used as traditional medicines","volume":"42","author":"Scott","year":"2004","journal-title":"Pharm. Biol."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Mufti, A., Feriani, A., Ouchari, W., Mandour, Y.M., Tlili, N., Ibrahim, M.A., Mahmoud, M.F., and Sobeh, M. (2023). Leonotis ocymifolia (Burm. f.) Iwarsson aerial parts aqueous extract mitigates cisplatin-induced nephrotoxicity via attenuation of inflammation, and DNA damage. Front. Pharmacol., 14.","DOI":"10.3389\/fphar.2023.1221486"},{"key":"ref_14","first-page":"1614793","article-title":"Analgesic and anti-inflammatory effects of 80% methanol extract of Leonotis ocymifolia (burm. F.) Iwarsson leaves in rodent models","volume":"2018","author":"Alemu","year":"2018","journal-title":"eCAM"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"30","DOI":"10.4102\/satnt.v29i1.5","article-title":"The major differences in chemical composition and antibacterial activity of two closely related Leonotis species (Lamiaceae) may have taxonomic value","volume":"29","author":"Eloff","year":"2010","journal-title":"Suid-Afrik. Tydskr. Nat. Wet. Tegnol."},{"key":"ref_16","unstructured":"Mokoka, T.A. (2013). The Discovery and Characterization of Antiprotozoal Compounds from South African Medicinal Plants by a HPLC-Based Activity Profiling Technique. [Ph.D. Thesis, University of KwaZulu-Natal]."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"103","DOI":"10.4314\/ajtcam.v2i2.31108","article-title":"In vivo and in vitro anti-fertility and anti-implantation properties of Leonotis ocymifolia in rats","volume":"2","author":"Tafesse","year":"2005","journal-title":"Afr. J. Tradit. Complement. Altern. Med."},{"key":"ref_18","first-page":"5384804","article-title":"Evaluation of the antimalarial activity of the hydroalcoholic extract of leaf of Leonotis ocymifolia (Burm. f.) Iwarsson (Lamiaceae) against plasmodium berghei in mice","volume":"2020","author":"Teklu","year":"2020","journal-title":"eCAM"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"911","DOI":"10.1016\/j.phymed.2010.02.009","article-title":"Trypanocidal and antileukaemic effects of the essential oils of Hagenia abyssinica, Leonotis ocymifolia, Moringa stenopetala, and their main individual constituents","volume":"17","author":"Nibret","year":"2010","journal-title":"Phytomedicine"},{"key":"ref_20","first-page":"918","article-title":"Terpenoids from Kenyan Leonotis mollissima","volume":"7","author":"Kinuthia","year":"2018","journal-title":"J. Pharmacogn. Phytochem."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"147","DOI":"10.1002\/mrc.1136","article-title":"Complete 1H and 13C NMR assignments of three labdane diterpenoids isolated from Leonotis ocymifolia and six other related compounds","volume":"41","author":"Hussein","year":"2003","journal-title":"Magn. Reson. Chem."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"341","DOI":"10.1248\/cpb.51.341","article-title":"Studies on the Constituents of Leonurus sibiricus L","volume":"51","author":"Satoh","year":"2003","journal-title":"Chem. Pharm. Bull."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"111924","DOI":"10.1016\/j.ejmech.2019.111924","article-title":"Repurposing a polymer precursor: Synthesis and in vitro medicinal potential of ferrocenyl 1,3-benzoxazine derivatives","volume":"187","author":"Mbaba","year":"2020","journal-title":"Eur. J. Med. Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"3284","DOI":"10.1021\/ci500467k","article-title":"iLOGP: A simple, robust, and efficient description of n-octanol\/water partition coefficient for drug design using the GB\/SA approach","volume":"54","author":"Daina","year":"2014","journal-title":"J. Chem. Inf. Model."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Daina, A., Michielin, O., and Zoete, V. (2017). SwissADME: A free web tool to evaluate pharmacokinetics, drug-likeness and medicinal chemistry friendliness of small molecules. Sci. Rep., 7.","DOI":"10.1038\/srep42717"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"3345","DOI":"10.1021\/jm011027b","article-title":"Descriptors, physical properties, and drug-likeness","volume":"45","author":"Beck","year":"2002","journal-title":"J. Med. Chem."},{"key":"ref_27","first-page":"145","article-title":"The configuration of the diterpene spiroethers from Marrubium vulgare and from Leonotis leonurus","volume":"109","author":"Laonigro","year":"1979","journal-title":"Gazz. Chim. Ital."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1577","DOI":"10.1248\/cpb.53.1577","article-title":"New labdane diterpenoids from Hyptis fasciculata","volume":"53","author":"Ohsaki","year":"2005","journal-title":"Chem. Pharm. Bull."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"5527","DOI":"10.1021\/ja00721a046","article-title":"Structure of nepetaefolin, a prefuranoid diterpene","volume":"92","author":"White","year":"1970","journal-title":"J. Am. Chem. Soc."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"6236","DOI":"10.1021\/ja00854a049","article-title":"Crystal and molecular structure of the unusual spiro dihydrofuran diterpene nepetaefolin","volume":"97","author":"Pettit","year":"1975","journal-title":"J. Am. Chem. Soc."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1701","DOI":"10.1039\/p19730001701","article-title":"Diterpenoids of Leonotis species. Part IV. Dubiin, a furanoid labdane derivative from L. dubia E. Mey","volume":"1","author":"Eagle","year":"1973","journal-title":"J. Chem. Soc. Perkin Trans."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"720","DOI":"10.1021\/jo00944a023","article-title":"Structures of nepetaefolin, nepetaefuran, and nepetaefuranol","volume":"38","author":"White","year":"1973","journal-title":"J. Org. Chem."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"White, J., Manchand, P., and Whalley, W. (1969). The structure of leonotin, a novel furanoid diterpene. J. Chem. Soc. D Chem. Commun., 1315\u20131316.","DOI":"10.1039\/c29690001315"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"728","DOI":"10.1021\/np3000156","article-title":"Bis-spirolabdane diterpenoids from Leonotis nepetaefolia","volume":"75","author":"Li","year":"2012","journal-title":"J. Nat. Prod."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2661","DOI":"10.1039\/p19740002661","article-title":"Nepetaefolinol and two related diterpenoids from Leonotis nepetaefolia","volume":"1","author":"Purushothaman","year":"1974","journal-title":"J. Chem. Soc. Perkin Trans."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Mobbili, G., Romaldi, B., Sabbatini, G., Amici, A., Marcaccio, M., Galeazzi, R., Laudadio, E., Armeni, T., and Minnelli, C. (2023). Identification of Flavone Derivative Displaying a 4\u2032-Aminophenoxy Moiety as Potential Selective Anticancer Agent in NSCLC Tumor Cells. Molecules, 28.","DOI":"10.3390\/molecules28073239"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1794","DOI":"10.1021\/acs.jnatprod.9b01158","article-title":"Antineurodegenerative labdane diterpenoid glycosides from the twigs of Pinus koraiensis","volume":"83","author":"Park","year":"2020","journal-title":"J. Nat. Prod."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"967","DOI":"10.1016\/j.intimp.2015.08.015","article-title":"Nepetaefuran and leonotinin isolated from Leonotis nepetaefolia R. Br. potently inhibit the LPS signaling pathway by suppressing the transactivation of NF-\u03baB","volume":"28","author":"Ueda","year":"2015","journal-title":"Int. Immunopharmacol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1089\/omi.2017.0020","article-title":"NF-\u03baB is a potential molecular drug target in triple-negative breast cancers","volume":"21","author":"Poma","year":"2017","journal-title":"OMICS"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"308","DOI":"10.1016\/j.bcp.2019.02.028","article-title":"Andrographolide and its potent derivative exhibit anticancer effects against imatinib-resistant chronic myeloid leukemia cells by downregulating the Bcr-Abl oncoprotein","volume":"163","author":"Liao","year":"2019","journal-title":"Biochem. Pharmacol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1016\/j.phrs.2017.07.019","article-title":"Labdane diterpenoids as potential anti-inflammatory agents","volume":"124","author":"Tran","year":"2017","journal-title":"Pharmacol. Res."},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Franco, Y.E.M., Okubo, M.Y., Torre, A.M., Paiva, P., Rosa, P.N.M., Silva, V.A.O., Reis, R.M., Ruiz, T.G.A.L., Imamura, P.M., and de Carvalho, J.E. (2019). Coronarin D induces apoptotic cell death and cell cycle arrest in human glioblastoma cell line. Molecules, 24.","DOI":"10.3390\/molecules24244498"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"248","DOI":"10.1016\/j.drudis.2019.10.014","article-title":"A drug-likeness toolbox facilitates ADMET study in drug discovery","volume":"25","author":"Jia","year":"2020","journal-title":"Drug Discov. Today"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"16076","DOI":"10.1021\/acsomega.0c01581","article-title":"In Silico ADME\/Tox Profiling of Natural Products: A Focus on BIOFACQUIM","volume":"5","year":"2020","journal-title":"ACS Omega"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"962","DOI":"10.1007\/s11095-010-0303-7","article-title":"Lipophilicity and its relationship with passive drug permeation","volume":"28","author":"Liu","year":"2011","journal-title":"Pharm. Res."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"2844","DOI":"10.1016\/j.bmcl.2009.03.109","article-title":"Defining optimum lipophilicity and molecular weight ranges for drug candidates-molecular weight dependent lower logD limits based on permeability","volume":"19","author":"Waring","year":"2009","journal-title":"Bioorg Med. Chem. Lett."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"197","DOI":"10.1038\/nrd3367","article-title":"Probing the links between in vitro potency, ADMET and physicochemical parameters","volume":"10","author":"Gleeson","year":"2011","journal-title":"Nat. Rev. Drug Discov."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"817","DOI":"10.1021\/jm701122q","article-title":"Generation of a set of simple, interpretable ADMET rules of thumb","volume":"51","author":"Gleeson","year":"2008","journal-title":"J. Med. Chem."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/S0169-409X(00)00129-0","article-title":"Experimental and computational approaches to estimate solubility and permeability in drug discovery and development settings","volume":"46","author":"Lipinski","year":"2001","journal-title":"Adv. Drug Deliv. Rev."}],"updated-by":[{"DOI":"10.3390\/diseases14060197","type":"correction","label":"Correction","source":"publisher","updated":{"date-parts":[[2025,5,1]],"date-time":"2025-05-01T00:00:00Z","timestamp":1746057600000}}],"container-title":["Diseases"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2079-9721\/13\/5\/140\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,2]],"date-time":"2026-06-02T10:46:58Z","timestamp":1780397218000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2079-9721\/13\/5\/140"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,5,1]]},"references-count":49,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2025,5]]}},"alternative-id":["diseases13050140"],"URL":"https:\/\/doi.org\/10.3390\/diseases13050140","relation":{},"ISSN":["2079-9721"],"issn-type":[{"value":"2079-9721","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,5,1]]}}}