Nigerian medicinal plants with potential anticancer activity-a review

Abstract

Despite the fact that life expectancies are increasing and the burden of infectious diseases is decreasing, global cancer incidence rates are on the rise. Cancer outcome metrics are dismal for low- and middle-income countries (LMICs), including sub-Saharan Africa, where adequate resources and infrastructure for cancer care and control are lacking. Nigeria, the most populous country in Africa, exemplifies the miserable situation. However, the investigation of medicinal plants for better and safer anti-cancer drugs has now increased tremendously. While scientific evidence is emerging of the potential of some constituents of medicinal plants used in traditional medicine in Nigeria to have anti-cancer effects, there is now a critical need for platforms that integrate ethnomedicinal information on such plants with emerging scientific data on them, to support and accelerate the discovery and development of more efficacious and safer anti-cancer drugs and recipes. Thus, this review highlights the scientific evidence to date for the anti-cancer potential of plants commonly used in traditional medicine to treat cancers in Nigeria. Scientific databases such as PubMed, Science Direct, Scopus, Google Scholar, and Web of Science, as well as related sources, were searched to retrieve relevant information on anti-cancer medicinal plants. Ethnobotanical/ethnomedicinal details of the identified plants were then linked with the available scientific data on their anti-cancer potential, including the cytotoxicity to cancer and normal cells of the extracts and constituent compounds responsible for the activity. This annotated chronicle of Nigerian medicinal plants with potential anticancer activity is a great resource for all stakeholders in the prevention and management of cancers.

Keywords: Cancer; Nigeria; chemotherapy; cytotoxicity; ethnomedicine; medicinal plants.

Figure 1

Chemical structures of Table 1 compounds 1–33

Figure 2

Chemical structures of Table 1 compounds 34–67

Figure 3

Chemical structures of Table 1 compounds 68–98

Figure 4

Images of some plants/plant parts. A. Acanthospermum hispidum; B. Ageratum conyzoides; C. Annona muricata tree; D. Calliandra portoricensis; E. Citrus aurantium L.; F. Clausena anisata showing inflorescence Note. (A) Adapted from “File: Acanthospermum hispidum W IMG 2208.jpg” by Garg JM (https://commons.wikimedia.org/wiki/File:Acanthospermum_hispidum_W_IMG_2208.jpg). CC BY 3.0; (B) reprinted with permission from “Australian Plant Image Index (APII) Photo No. dig 12854” by Richardson RG, Richardson FJ (https://www.anbg.gov.au/cgi-bin/photo?photo_class=dig&photo_no=12854). © R.G. & F.J. Richardson 2006; (C) Photograph taken in June, 2021 at Ibadan, Oyo State, Nigeria; (D) reprinted with permission from “Calliandra” by Goosen N (https://ngoosen.fotki.com/fabaceae/calliandra/calliandraportoricensis.html#media). © Nora Goosen. (E) adapted with permission from “Rind fruit bitter oranges-93679” by Hans (https://pixabay.com/photos/rind-fruit-bitter-oranges-93679/). CC0; (F) reprinted with permission from “Brunken, U., Schmidt, M., Dressler, S., Janssen, T., Thiombiano, A. & Zizka, G. 2008. West African plants - A Photo Guide. www.westafricanplants.senckenberg.de - Forschungsinstitut Senckenberg, Frankfurt/Main, Germany” by Porembski S (http://www.westafricanplants.senckenberg.de/root/index.php?page_id=14&id=369#image=24952). BY-NC.

Figure 5

Flavonoids 99–110 isolated from Citrus aurantium

Figure 6

Images of some plants/plant parts. A. Erythrophleum suaveolens; B. Kigelia pinnata (or Kigelia africana) flowering and fruiting; C. Fagara zanthoxyloides (Zanthoxylum zanthoxyloides); D. fruiting branches of Lecaniodiscus cupanioides; E. Macaranga barteri tree; F. a stalked flowering head of Mimosa púdica Note. (A) Reprinted with permission from “ERYTHROPHLEUM SUAVEOLENS” by Olubodun O (https://forestcenter.iita.org/index.php/2019/06/21/erythrophleum-suaveolens/). CC BY-NC 2.0.; (B) adapted with permission from “KIGELIA AFRICANA” by Bown D (https://forestcenter.iita.org/index.php/2019/07/23/kigelia-africana/). CC BY-NC 2.0.; (C) adapted with permission from “Brunken, U., Schmidt, M., Dressler, S., Janssen, T., Thiombiano, A. & Zizka, G. 2008. West African plants - A Photo Guide. www.westafricanplants.senckenberg.de - Forschungsinstitut Senckenberg, Frankfurt/Main, Germany” by Ouédraogo O (http://www.westafricanplants.senckenberg.de/root/index.php?page_id=14&id=1681#image=7870). CC BY-NC. (D). reprinted with permission from “LECANIODISCUS CUPANIOIDES” by Bown D (https://www.flickr.com/photos/iita-media-library/6240362196/in/photostream/). CC BY-NC 2.0; (E) reprinted with permission from “Brunken, U., Schmidt, M., Dressler, S., Janssen, T., Thiombiano, A. & Zizka, G. 2008. West African plants - A Photo Guide. www.westafricanplants.senckenberg.de - Forschungsinstitut Senckenberg, Frankfurt/Main, Germany” by Schmidt M (http://www.westafricanplants.senckenberg.de/root/index.php?page_id=14&id=2476#image=7380). CC BY-NC. (F) reprinted with permission from “Brunken, U., Schmidt, M., Dressler, S., Janssen, T., Thiombiano, A. & Zizka, G. 2008. West African plants - A Photo Guide. www.westafricanplants.senckenberg.de - Forschungsinstitut Senckenberg, Frankfurt/Main, Germany” by Latham P. (http://www.westafricanplants.senckenberg.de/root/index.php?page_id=14&id=2528#image=41752). CC BY-NC.

Figure 7

Flavones 111–116 isolated from Mimosa pudica

Figure 8

Images of plants/plant parts. A. Tree and leaves of Moringa oleifera; B. Parkia biglobosa leaves and inflorescences. C. shrubs of Peristrophe bicalyculata; D. the leaves of Vitex doniana Note. (A) Photograph taken in June 2021 at Rijiyan Zaki Area, Kano State, Nigeria; (B) Reprinted with permission from “Parkia biglobosa” by iNaturalist (https://www.inaturalist.org/taxa/133528-Parkia-biglobosa). CC-BY; (C) Photograph taken in June 2021 at Ibadan, Oyo State, Nigeria; (D) adapted with permission from “West African plants—A Photo Guide” by Latham P (http://www.westafricanplants.senckenberg.de/root/index.php?page_id=14&id=1661#image=56072). CC BY-NC.

Figure 9

Compounds 117–119 isolated from Olax mannii Oliv.

Figure 10

Isolated compounds 120–124 from Parkia biglobosa

Figure 11

Compounds 125–141 isolated from Peristrophe bicalyculata