Medicinal Plants Used by the Indigenous People of the Philippines: A Systematic Review of Ethnobotanical Surveys and Bioactive compounds

Abstract

Cancer is one of the leading public health concerns worldwide. In the Philippines, 189 out of 100,000 Filipinos are adversely affected by cancer, with mortality of ninety-six (96) Filipinos every day. Influenced by their cultural beliefs, practices, and socio-demographic factors, Filipinos, especially the indigenous peoples, tend to lean more towards alternative and complementary medicine when it comes to treating illnesses and diseases such as cancer. Efforts had been made to record plants utilized by these people; however, there is still no existing comprehensive list of anticancer medicinal plants used by the Philippines' indigenous peoples, thus the motivation of this study. This study also aims to record reported compounds responsible for the identified plants' anticancer activity in the light of bioprospecting. Various published and unpublished ethnobotanical and ethnopharmacological studies from three (3) databases and university repository was screened and subjected to a set of defined inclusion and exclusion criteria. This resulted in the corpus of two hundred twenty-seven (227) articles, which narrowed down to fifty-eight (58) after the intervention from which one hundred fifty-two (152) anticancer plants were identified. Amongst these, medicinal plants that lack research to prove anticancer efficacy was identified thus merit further studies. The study also recorded the alarming percentage of medicinal plants that are yet evaluated per conservation status, thus urging for appraisal amidst the threat of climate crisis. Interestingly, novel compounds for cancer therapeutics had been isolated from some of the plants identified, reiterating the importance of indigenous knowledge in pharmaceutical bioprospecting. The current study allows the description of a large number of anticancer medicinal plants used by the indigenous people of the Philippines with the discussions of its anticancer activity.