Rodent

Resumen Context: Pavetta crassipes (K. Schum) is used in ethnomedicine for the management of various ailments and food without scientific report of its toxicity profile. Aims: To evaluate the toxicological effects of Pavetta crassipes leaves in rodents. Methods: The leaves of Pavetta crassipes were collected from the suburbs of Abuja, Nigeria, dried and powdered using an electric mill. Hot aqueous extraction was done using 250 g of the powdered leaf in 1000 mL distilled water. Lethal dose 50 (LD50) determination was done in mice (intraperitoneally) and rats (orally), twenty-eight-day toxicity testing in rats at doses of 400, 800 and 1600 mg/kg was also done using the aqueous extract. Biochemical, hematological and histological effects were evaluated using standard procedures. Results: The aqueous leaf extract of Pavetta crassipes (AE) appears safe as the LD50 for intraperitoneal route in mice and oral route in rats was greater than 5000 mg/kg. The results of the 28-day repeated exposure test produced no mortality or adverse effects on the body weights and organ/body weight ratio of rats. Histological changes occurred in the kidneys at 800 and 1600 mg/kg. There was a significant (p<0.01) reduction in AST, ALT, ALP and urea. Lymphocyte (%) and platelet count increased (p<0.01) but neutrophil (%) reduced (p<0.01). Conclusions: The LD50 of AE was greater than 5000 mg/kg but prolonged use at high doses may produce some adverse effects.

The evolutionary relationships between Peromyscus, Habromys, Isthmomys, Megadontomys, Neotomodon, Osgoodomys, and Podomys are poorly understood. In order to further explore the evolutionary boundaries of Peromyscus and compare potential taxonomic solutions for this diverse group and its relatives, we conducted phylogenetic analyses of DNA sequence data from alcohol dehydrogenase (Adh1-I2), beta fibrinogen (Fgb-I7), interphotoreceptor retinoid-binding protein (Rbp3), and cytochrome-b (Cytb). Phylogenetic analyses of mitochondrial and nuclear genes produced similar topologies although levels of nodal support varied. The best-supported topology was obtained by combining nuclear and mitochondrial sequences. No monophyletic Peromyscus clade was supported. Instead, support was found for a clade containing Habromys, Megadontomys, Neotomodon, Osgoodomys, Podomys, and Peromyscus suggesting paraphyly of Peromyscus and confirming previous observations. Our analyses indicated an early divergence of Isthmomys from Peromyscus (approximately 8 million years ago), whereas most other peromyscine taxa emerged within the last 6 million years. To recover a monophyletic taxonomy from Peromyscus and affiliated lineages, we detail 3 taxonomic options in which Habromys, Megadontomys, Neotomodon, Osgoodomys, and Podomys are retained as genera, subsumed as subgenera, or subsumed as species groups within Peromyscus. Each option presents distinct taxonomic challenges, and the appropriate taxonomy must reflect the substantial levels of morphological divergence that characterize this group while maintaining the monophyletic relationships obtained from genetic data.