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.

Anatomical characters of the medicinal leaf and stem of Gymnanthemum amygdalinum (Delile) Sch.Bip. ex Walp. (Asteraceae)

Gymnanthemum amygdalinum (Delile) Sch.Bip. ex Walp. (Asteraceae), better known by its former name Vernonia amygdalina Delile, is a small shrub used in folk medicine as an antipyretic, laxative, antimalarial and anthelmintic. Studies have demonstrated that different vegetal extracts possess antioxidant, antimicrobial and antiparasitic activities. Among the bioactive metabolites, there are sesquiterpene lactones, saponins, polyphenols and flavonoids. This study investigated the leaf and stem microscopic characters of G. amygdalinum, aiming to expand the knowledge on this medicinal species and indicate anatomical structures. Plant material was fixed and sectioned by freehand and using a microtome. The sections were either stained or underwent standard histochemical tests. Scanning electron microscopy was performed to investigate epidermal relief. The leaf is amphistomatic with anomocytic stomata. There are striate cuticle, glandular and non-glandular trichomes and dorsiventral mesophyll. In transverse section, the midrib and the petiole have a plano-convex shape. Both show several collateral vascular bundles and few crystals of calcium oxalate. In the stem, the epidermis persists and the phellogen has a peripheral origin. It presents typical endodermis and sclerenchymatic caps adjoining the phloem. The aspects that contribute to characterizing the species are stomata on both leaf surfaces, midrib and petiole features, the endodermis and sclerenchymatic caps in the stem, as well as the different types of trichome on both aerial organs.

Gymnanthemum amygdalinum (Delile) Sch.Bip. ex Walp. (Asteraceae), espécie mais conhecida pela sinonímia Vernonia amygdalina Delile, é um pequeno arbusto empregado na medicina popular como antipirético, laxativo, antimalárico e anti-helmíntico. Estudos demonstraram que diferentes extratos do vegetal possuem atividades antioxidante, antimicrobiana e antiparasitária. Entre os metabólitos bioativos presentes, citam-se lactonas sesquiterpenoides, saponinas, polifenóis e flavonoides. Este estudo investigou os caracteres microscópicos de folha e caule de G. amygdalinum, a fim de ampliar o conhecimento acerca dessa espécie medicinal e apontar estruturas anatômicas características. O material foi fixado e seccionado à mão livre e em micrótomo. Os cortes foram corados ou submetidos aos testes histoquímicos clássicos. Empregou-se microscopia eletrônica de varredura para investigar a ultraestrutura da superfície epidérmica. A folha é anfiestomática com estômatos anomocíticos. Há cutícula estriada, tricomas glandular e tector e mesofilo dorsiventral. Em secção transversal, a nervura central e o pecíolo têm contorno plano-convexo. Ambos mostram vários feixes vasculares colaterais e poucos cristais de oxalato de cálcio. No caule, a epiderme permanece e o felogênio tem instalação periférica. São observadas endoderme típica e calotas esclerenquimáticas apostas ao floema. Os aspectos que fornecem elementos para a identificação da espécie são a ocorrência de estômatos em ambas as superfícies foliares, a organização da nervura central e do pecíolo, a endoderme e as calotas esclerenquimáticas no caule, além dos diferentes tipos de tricoma nos órgãos aéreos estudados.