Effects of Croton menyharthii and Uvariodendron kirkii extracts on ovarian corpora lutea and reproductive hormones.

Uvariodendron kirkii and Croton menyharthii are traditionally used as fertility regulators in Kenya. The rapidly increasing population has put a strain on the limited resources and poses serious challenge to national planning. The aim of the study was to validate the traditional claims by investigating the effect of root bark extract of both plants on reproductive hormones and ovarian structures. Twenty five mature normocyclic female winstar rats were used. Group 1 consisted of 5 animals that acted as control. Group 2 and 3 with 5 animals each; received 500 and 800mg/Kg Croton menyharthii respectively on alternative days for 28 days through intra- abdominal gavage. Group 4 and 5 were treated in a similar manner but received Uvariodendron kirkii aqueous extract. Serum was harvested from all animals on 28th day and hormone levels determined. Left ovaries were harvested and processed for histomorphology. Both Croton menyharthii and Uvariodendron kirkii caused a significant increase of progesterone in a dose dependent manner. Croton menyharthii extracts caused a degeneration of corpora lutea. At 800mg/kg Croton menyharthii caused a significant increase in corpora lutea numbers but a decline in size. Uvariodendron kirkii caused hypertrophy and a significant increase in corpora lutea numbers. Enhanced/ hypertrophied corpora lutea possibly led to high levels of progesterone seen, interfered with the implantation window due to disrupted hormonal milieu thereby leading to compromised fertility and implantation index. The study validates the traditional use of the plant in fertility regulation. We suggest further investigation on these potential plants to address the call for novel contraceptive drugs

Molecular pilot study on peripheral populations of Kenyan greenbul in an afromontane fragmented forest

We provide a molecular study on peripheral populations of three closely related species of African forest-dependent greenbuls: the generalist Eurillas latirostris and the specialists Phyllastrephus cabanisi and Arizelocichla nigriceps. These species co-occur within their range limits in the Kenyan Afromontane forest, Cherangani Hills. This forest has experienced drastic deforestation, which began about 50years ago, that is causing habitat fragmentation. The aims of this study, using the analyses of molecular tools, are twofold: (i) to provide evidence that functional traits (i.e., ecological attributes) may shape different genetic structure in peripheral populations and (ii) to identify the possible effects of forest fragmentation. Blood and plucked feathers were sampled from a total of 124 birds analysed using two molecular approaches: (i) sequencing of cytochrome b mtDNA and (ii) genotyping nuclear DNA at eight microsatellite loci. Molecular diversity indices, minimum spanning network and mismatch distribution analysis of mtDNA results indicated that the peripheral populations showed different demographic trends: a highly variable and bimodal pattern in forest specialist P.cabanisi, a less variable and unimodal pattern in forest generalist E.latirostris and in the montane specialist A.nigriceps. Although this is a pilot study on the Cherangani forest fragmentation, the nuclear results may not exclude the hypothesis of reduced connectivity in all forest-dependent greenbuls.Resume Nous apportons une etude moleculaire des populations peripheriques de trois especes de bulbuls etroitement liees, dependantes de la foret africaine: l'espece generaliste Eurillas latirostris et les especes specialistes Phyllastrephus cabanisi et Arizelocichla nigriceps. Ces especes coexistent, au sein de leur aire de repartition, dans la foret afromontagnarde kenyane des Cherangani Hills. Cette foret subit une deforestation dramatique, qui a commence il y a quelque 50ans et qui provoque une fragmentation de l'habitat. Le but de cette etude, qui utilise une analyse d'outils moleculaires, est double: i) apporter la preuve que des caracteristiques fonctionnelles (c. a d. ecologiques) peuvent modeler differentes structures genetiques dans des populations peripheriques et ii) identifier les effets possibles de la fragmentation forestiere. Du sang et des plumes ont ete preleves sur un total de 124 oiseaux analyses suivant deux approches moleculaires: 1) le sequencage de l'ADN mitochondrial (cytochromeb) et 2) le dechiffrage du genotype de l'ADN nucleaire de huit loci microsatellites. Les resultats des Indices de diversite moleculaire, du Reseau de recouvrement minimum, et de l'Analyse des ecarts de la distribution de l'ADNmt ont montre que les populations peripheriques presentaient des tendances demographiques differentes: un schema tres variable et bimodal chez l'espece specialiste de la foret P. cabanisi, un schema moins variable et unimodal chez la generaliste de la foret E.latirostris et chez la specialiste de montagne A. nigriceps. Bien que ceci soit une etude pilote de la fragmentation de la foret de Cherangani, les resultats nucleaires ne permettent pas d'exclure l'hypothese d'une connectivite reduite entre tous les bulbuls dependant de la foret