Lippia citriodora (verbascoside) extract supplementation: Effect on rabbit semen quality in vivo and in vitro

Verbascoside, the main component of Lippia citriodora extract, is one of the most powerful free radical scavengers exhibiting a wide biological activity. In in vivo study 20 adult New Zealand white rabbit bucks were divided into two homogeneous groups, one control (CON) and one verbascoside-supplemented (0.1%) in feed mixture (EXP) and later in vitro effects of verbascoside on the motility aspects of rabbit spermatozoa were analysed. The spermatozoa concentration, ejaculate volume, spermatozoa motility, progressive motility, distance parameters, velocity parameters and type of spermatozoa movement were negatively affected by Lippia citriodora leaves extract after the first 4 weeks of dietary treatment, till the end of experiment (8 weeks). Four weeks after the suspension of feed additive supplementation, all spermatozoa traits values returned to the normality, and in line with CON group. For in vitro findings, ejaculates from 10 male New Zealand white bucks were collected using an artificial vagina. Then it was diluted in physiological saline solution containing different concentrations of verbascoside at the concentration of 0, 0.0024, 0.0219, 0.157, 120.0 mg/ml (Ctrl, VB1, VB2, VB3, VB4 groups, respectively), using a dilution ratio of 1: 4. The obtained data proved that verbascoside at the concentration of 0.0024 and 0.0219 mg/ml had no adverse effect on spermatozoa. Additionally, we found that verbascoside at higher concentrations (0.157 and 120.0 mg/ml) significantly altered all the motility parameters analysed in the experiment. In conclusion a possible negative effect of verbascoside supplementation into feed mixture (0.1%) on semen quality parameters in rabbit bucks as well as in vitro can be stated, obviously considering that target organs of antioxidant activities of phenylpropanoid glycosides are various. In addition it has to be emphasized that the extract showed a reversible action, since the semen traits of treated animals returned to the normality after the dietary administration period

Influence of electron injection on the temporal response of ZnO homojunction photodiodes

The effects of solid-state electron injection on the peak amplitude and decay time of photosignal in a ZnO-based homojunction UV photodiode were studied using temporal photoresponse measurements under femtosecond pulses of 355 nm radiation. The injection of about 50 C of charge, carried out by applying forward bias to the junction, resulted in a nearly twofold increase of the peak photoresponse and a corresponding increase of the decay constant. Both observations are shown to be a consequence of electron trapping. The long-term stability of the induced changes is also discussed