Medicinal Plants from North and Central America and the Caribbean Considered Toxic for Humans: The Other Side of the Coin

Abstract

The consumption of medicinal plants has notably increased over the past two decades. People consider herbal products as safe because of their natural origin, without taking into consideration whether these plants contain a toxic principle. This represents a serious health problem. A bibliographic search was carried out using published scientific material on native plants from Mexico, Central America, and the Caribbean, which describe the ethnobotanical and toxicological information of medicinal plants empirically considered to be toxic. A total of 216 medicinal plants belonging to 77 families have been reported as toxic. Of these plants, 76 had been studied, and 140 plants lacked studies regarding their toxicological effects. The toxicity of 16 plants species has been reported in clinical cases, particularly in children. From these plants, deaths have been reported with the consumption of Chenopodium ambrosioides, Argemone mexicana, and Thevetia peruviana. In most of the cases, the principle of the plant responsible for the toxicity is unknown. There is limited information about the toxicity of medicinal plants used in Mexico, Central America, and the Caribbean. More toxicological studies are necessary to contribute information about the safe use of the medicinal plants cited in this review.

Traditional Herbal Medicine in Mesoamerica: Toward Its Evidence Base for Improving Universal Health Coverage

“…For several important medicinal species there is very limited evidence for either safety or efficacy or altogether, including but not limited to Tagetes erecta , Piper auritum , Byrsonima crassifolia , Bursera simaruba , Artemisia ludoviciana , Hyptis verticillata , Spondias purpurea Tradescantia zebrina Crescentia cujete, Parmentiera aculeata, Piper amalago, Baccharis inamoena, Bougainvillea glabra, Lepidium virginicum, Malvaviscus arboreus, Mimosa albida, Solanum lycopersicum, Cornutia pyramidata, Dorstenia contrajerva, Tagetes filifolia and Jatropha curcas ( Table 3 ). This situation emphasizes the lacking knowledge base and the concerns regarding toxicity of native botanical drug species widely used in traditional medicine throughout MA ( Caceres Guido et al., 2015 ; Valdivia-Correa et al., 2016 ; Alonso-Castro et al., 2017b ).…”

“…Several reviews point out the whole plant, especially the seeds, as toxic. Effects reported include dermatitis, abortifacient and neurotoxicity, mainly related with the presence of alkaloids such as berberine and saguinarine Alonso-Castro et al, 2017b). Acute toxicity of the plant extracts in mice (LD 50 400 mg/kg, IP); hepatotoxicity of sanguinarine in mice (10 mg/kg, IP); neuroparalysis and death of several people, were reviewed (Brahmachari et al, 2013;Rubio-Piña and Vaźquez-Flota, 2013).…”

“…The emphasis on introduced taxa in formal phytotherapy in Latin America is due to an often lacking evidence base for native botanical drugs ( Caceres Guido et al., 2015 ; Valdivia-Correa et al., 2016 ; Alonso-Castro et al., 2017b ) and the relative good documentation of effectiveness and safety issues of herbal drugs present in the European and the US Pharmacopoeia ( Lozoya and Zolla, 1984 ; Caceres Guido et al., 2015 ; Martins et al., 2019 ).…”

Inhibition of Key Enzymes Linked to Obesity and Cytotoxic Activities of Whole Plant Extracts of Vernonia mesplilfolia Less

“…In addition, it is noteworthy that cytotoxicity noticed in vitro is not always greeted in vivo. This could be owed to the fact that within a biological system, a number of toxic compounds are capable of undergoing biotransformation, thus bringing about the formation of end products with minute toxic levels [42,43].The toxic character of plant extracts are mostly a pointer to factors like the season of harvest of the plant material, the presence of heavy metals in the soil, the growth stage of the plant, and a host of other factors [44].…”

Toxicidade e atividade antibacteriana de plantas medicinais utilizadas no tratamento de doenças respiratórias: revisão integrativa

“…Os fatores que predispõem a toxicidade das plantas medicinais em humanos são a idade do paciente, o estado nutricional e a presença de doenças crônicas. As pessoas acreditam que excedendo a dose diária necessária a eficácia do tratamento é aumentada, porém, o que ocorre é a maior probabilidade da manifestação de efeitos tóxicos (Castro et al, 2017).…”