Consumption of Raw Herbal Medicines Is Associated with Major Public Health Risks amongst Ugandans.

Background: Community consumption of herbal plants in developing countries is a common practice, however, scarcity of information on their physiochemical composition is a major public health concern. In Uganda, Vernonia amygdalina is of interest in rural communities due to its therapeutical action on both bacterial and protozoal parasites, however no studies have been conducted to assess the heavy metal concentrations in traditional plants used in alternative medicine. The aim of the study was to establish concentrations of heavy metals in Vernonia amygdalina, model the estimated daily intake (EDI), and assess both the non-cancer-related health risk using the target hazard quotient (THQ), and the risk related to cancer through the incremental lifetime cancer risk (ILCR) for the Ugandan population. Methods: Leaves of Vernonia amygdalina were collected from 20 georeferenced villages and processed into powder in the laboratory using standard methods. These were then analyzed in the laboratory using an atomic absorption spectrometer for lead (Pb), chromium (Cr), copper (Cu), zinc (Zn), cobalt (Co), iron (Fe), cadmium (Cd), and nickel (Ni). Concentrations were compared against the World Health Organization (WHO) limits. The EDI, THQ, and ILCR were modelled and significance was measured at 95% confidence. Results: The study showed that mean ± SEM concentrations of heavy metals were highest in the order of Cr, 121.8 ± 4.291 ppm > Ni, 84.09 ± 2.725 ppm > Zn, 53.87 ± 2.277 ppm > Pb, 40.61 ± 3.891 ppm > Cu, 28.75 ± 2.202 ppm > Fe, 14.15 ± 0.7271 ppm > Co, 7.923 ± 0.7674 ppm > Cd, 0.1163 ± 0.005714 ppm. Concentrations of Pb, Cr, Zn, Co, and Ni were significantly higher than the WHO limits. The EDI was significantly higher in children than in adults, demonstrating an increased risk of toxicity in children. The THQ and ILCR were over 1000 times higher in all Ugandans, demonstrating the undesirable health risks following oral consumption of Vernonia amygdalina due to very high Cr and Ni toxicities, respectively. Conclusion: Consumption of raw Vernonia amygdalina was associated with a high carcinogenic risk, demonstrating a need to enact policies to promote physiochemical screening of herbal medicines used in developing countries against toxic compounds.

The histo-morphometric evidences of vernonia amygdalina leaf extract-induced testicular toxicity / Evidencias histomorfométricas de la toxicidad testicular inducida por el extracto de la hoja de vernonia amygdalina

Vernonia amygdalina (bitter-leaf) is native to West Africa but occurs mostly in its cultivated form in various parts of central and southern Nigeria. It is a dark-green leafy vegetable commonly used in cooking and as folkloric medicine for the management of several diseases in Nigeria. In the present study, the effects of varying doses of ethanolic leaf extract of Vernonia amygdalina on the rat testis histo-morphometry were investigated. Forty male wistar rats were divided into groups of four. Group A, as the control was given 10 ml/kg/day/oral distilled water while Group B, C and D subsequently treated with 100, 300 and 600 mg/kg/day/oral route Vernonia amygdalina leaves extract respectively for 56 days. Results showed that Group B rats had normal testis histology comparable to the control group. However, rats in Group C and D exhibited dose-dependent poor testes histo-morphometric profiles, with the higher dosage-group (D) providing a worse feature. Thus, there was a statistically significant (p < 0.05) reduction in the tubular diameter, cross-sectional area of the tubules, number of tubular profiles per unit area and the mean numerical density of seminiferous tubules of Group C and Group D animals compared to the control group. Our results therefore indicated that, while the lower dose (100 mg/kg) of Vernonia amygdalina leaves extract can be accommodated by rat testis, the higher doses (300 mg/kg and 600 mg/kg) demonstrate testicular toxicity in the rat.

La Vernonia amygdalina (hoja amarga) es originaria de África Occidental, pero se produce mediante cultivo en varias partes del Centro y Sur de Nigeria. Es una verdura, una hoja color verde oscuro, común en la cocina y como medicina alternativa en el manejo de varias enfermedades en Nigeria. Se investigaron los efectos de diferentes dosis de extracto etanólico de la hoja de Vernonia amygdalina para estudiar los efectos sobre la histomorfometría testicular en la rata. Cuarenta ratas Wistar macho se dividieron en 4 grupos. Grupo A, como control con el suministro de 10 ml/kg/día/agua destilada vía oral, y los Grupos B, C y D tratados con 100, 300 y 600 mg/kg/día/ vía oral del extracto de Vernonia amygdalina, durante 56 días. Los resultados mostraron que las ratas del grupo B tenían una histología testicular normal y comparable con el grupo control. Sin embargo, las ratas del grupo C y D mostraron bajos perfiles histomorfométricos testiculares, dependientes de la dosis, y con la dosis más elevada, grupo (D) se observaron característica aún menores. Hubo una reducción estadísticamente significativa (p<0,05) en el diámetro tubular, área de sección transversal de los túbulos, número túbulos por unidad de superficie y densidad numérica media de los túbulos seminíferos del Grupo C y D en comparación con el grupo de control. Nuestros resultados indicaron que dosis bajas (100 mg/kg) del extracto de Vernonia amygdalina pueden ser aceptables y no alteran el testículo de rata, pero con dosis altas (300 mg/kg y 600 mg/kg) se observa toxicidad testicular.

A review of the medicinal potentials of plants of the genus Vernonia (Asteraceae).

ETHNOPHARMACOLOGICAL RELEVANCE: The Vernonia genus has about one thousand species and members of the genus are widely used as food and medicine. The aim of this review is to analyze published data on the ethnomedicinal, ethnoveterinary and zoopharmacognostic uses of plants of the Vernonia genus. This will help to identify the state of ethnopharmacological knowledge in regard to this genus and to propose future research priorities. MATERIALS AND METHODS: The major scientific databases including SciFinder, Sciencedirect, Medline and Google Scholar were queried for information on Vernonia genus using various keyword combinations. The International Plant Name Index was also used to verify the names of species and authors. RESULTS: A total of 109 Vernonia species were reported in the literature to have medicinal properties. One hundred and five (105) plants were linked to the treatment or management of 44 human diseases or health conditions. Plants of the genus also feature in ethnoveterinary and zoopharmacognostic practices. A total of 12 vernonia species were identified to be used in ethnoveterinary medicine while 2 species are used in self medication practices by chimpanzees and gorillas. In vitro and in vivo research studies reporting the validation of the medicinal properties of some species were also reviewed. One hundred and three bioactive compounds isolated from various Vernonia species were also identified. Vernonia amygdalina was identified as the most frequently used member of the Vernonia genus. The Vernolides, a class of sesquiterpene lactone were identified as the most studied compounds from the genus and show interesting bioactivity in antiplasmodial, antileishmanial, antischistosomial, cytotoxicity, antimicrobial and anti-inflammatory assays. CONCLUSION: On the basis of results from a combination of in vitro and in vivo efficacy and toxicity studies reported, Vernonia amygdalina holds the most promise for development into a nutraceutical against diabetes and malaria while Vernonia cinerea has potential against cancer and inflammatory conditions. Vernolide A is so far the most promising single agent from a Vernonia species that has potential for development into an anticancer agent. The other Vernonia species and isolated compounds require further studies to ascertain their medicinal potentials.