Abstract
Petiveria alliacea L. (Phytolaccaceae), commonly known as “Anamú” or “Guinea Hen Weed,” is a medicinal plant traditionally used in herbal medicine across Latin America, the Caribbean, and Africa. Preclinical investigations have attributed cytotoxic, antioxidant, immunomodulatory, and proapoptotic properties to its bioactive compounds, indicating potential antineoplastic activity. However, available evidence remains fragmented across different experimental models, cancer types, plant preparations, and study designs, and no systematic synthesis of the antineoplastic evidence base has been published to date. This protocol describes the methodology for a systematic review aiming at evaluating the antineoplastic effects of Petiveria alliacea in in vitro cell models, in vivo animal studies, and clinical trials involving cancer patients. Searches will be conducted in ten electronic databases (including MEDLINE, EMBASE, Scopus, LILACS, Web of Science, ScienceDirect, SciELO, Epistemonikos, ClinicalTrials.gov, and EudraCT) in English, Spanish, or Portuguese, covering studies published from January 2000 onwards. Eligible studies will include controlled in vitro, in vivo, and clinical investigations reporting antineoplastic outcomes. Study selection will be performed independently by two reviewers using Rayyan. Risk of bias will be assessed using validated tools for preclinical research. Subgroup and sensitivity analyses are planned by tumor type, extract type, plant part, and study model. This protocol was registered in PROSPERO on 26 March 2026 (registration number: CRD420251108791).
[1] Bray F. Global cancer statistics 2022: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries, CA Cancer Journal for Clinicians, 74 (3):229–263, 2024.
https://doi.org/10.3322/caac.21834
[2] Sung H. Global Cancer Statistics 2020: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries, CA Cancer Journal for Clinicians, 71 (3):209–249, 2021.
https://doi.org/10.3322/caac.21660
[3] Newman DJ, Cragg GM. Natural products as sources of new drugs over the nearly four decades from 01/1981 to 09/2019. Journal of Natural Products, 83 (3):770–803, 2020.
https://doi.org/10.1021/acs.jnatprod.9b01285
[4] Queiroz M. Cytokine profile and natural killer cell activity in Listeria monocytogenes infected mice treated orally with Petiveria alliacea extract, Immunopharmacology and Immunotoxicology, 22 (3):501–518, 2000.
https://doi.org/10.3109/08923970009026010
[5] Caro D. Anti-inflammatory and antinociceptive activities of Petiveria alliacea L. (Phytolaccaceae) in mice, Tropical Journal of Pharmaceutical Research, 14 (9):1649–1657, 2015.
https://doi.org/10.4314/tjpr.v14i9.16
[6] Williams L. An examination of the pharmacological and biochemical basis of action of thiol compounds isolated from Petiveria alliacea L., West Indian Medical Journal, 44 (Suppl 1):6–8, 1995.
[7] Urueña C. Petiveria alliacea extracts use multiple mechanisms to inhibit growth of human and mouse tumoral cells, BMC Complementary and Alternative Medicine, 8:60, 2008.
https://doi.org/10.1186/1472-6882-8-60
[8] Fiorentino S. Petiveria alliacea standardized extract induces direct antitumor effect and stimulates innate immune response, Journal of Ethnopharmacology, 227:82–89, 2018.
https://doi.org/10.1016/j.jep.2018.08.016
[9] Ballesteros-Ramírez R, Martínez-Ramos N, Fernández Deaza GP, Duque Grisales E, Murillo R. The antineoplastic effects of Petiveria alliacea (“Anamú” / “Guinea Hen Weed”): a systematic review. PROSPERO 2026 CRD420251108791.
[10] Ouzzani M. Rayyan—a web and mobile app for systematic reviews, Systematic Reviews, 5:210, 2016.
https://doi.org/10.1186/s13643-016-0384-4
[11] Hooijmans C. SYRCLE’s risk of bias tool for animal studies, BMC Medical Research Methodology, 14:43, 2014.
https://doi.org/10.1186/1471-2288-14-43
[12] Macleod M. Pooling of animal experimental data reveals influence of study design and publication bias, Stroke, 35 (5):1203–1208, 2004.
https://doi.org/10.1161/01.STR.0000125719.25853.20
[13] Sena E. Publication bias in reports of animal stroke studies leads to major overstatement of efficacy, PLoS Biology, 8 (3):e1000344, 2010.
https://doi.org/10.1371/journal.pbio.1000344
[14] Macleod M, Collings AM, Graf C, Kiermer V, Mellor D, Swaminathan S, Sweet D, Vinson V. The MDAR (Materials Design Analysis Reporting) Framework for transparent reporting in the life sciences. Proc Natl Acad Sci U S A, 118(17), 2021.
https://doi.org/10.1073/pnas.2103238118
[15] Campbell M, McKenzie JE, Sowden A, Katikireddi SV, Brennan SE, Ellis S, Hartmann-Boyce J, Ryan R, Shepperd S, Thomas J, Welch V, Thomson H. Synthesis without meta-analysis (SWiM) in systematic reviews: reporting guideline. BMJ, 368:l6890, 2020.

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
Copyright (c) 2026 Ricardo Ballesteros-Ramírez, Nicolás Martínez-Ramos, Ginna Paola Fernández Deaza, Eduardo Duque Grisales, Claudia Lorena Motta Robayo, Raúl Murillo

