The Effects of Apricot Kernels and Pure Amygdalin on the Structural, Oxidative, and Inflammatory Characteristics of Rabbit Testicular Tissue.

BACKGROUND: Apricot kernels containing amygdalin (AMG) as the major cyanogenic glycoside are potentially useful as a complementary therapy for the management of several ailments including cancer. Nevertheless, little is known regarding the toxic and therapeutic doses of AMG, particularly in terms of male reproduction. Hence, this study evaluates selected qualitative characteristics of rabbit testicular tissue following in vivo administration of AMG or apricot kernels for 28 days. METHODS: The rabbits were randomly divided into five groups (Control, P1, P2, P3, P4). The Control received no AMG/apricot kernels while the experimental groups P1 and P2 received a daily intramuscular injection of amygdalin at a dose of 0.6 and 3.0 mg/kg of body weight (b.w.) for 28 days, respectively. P3 and P4 received a daily dose of 60 and 300 mg/kg b.w. of crushed apricot kernels mixed with feed for 28 days, respectively. Changes to the testicular structure were quantified morphometrically, while tissue lysates were subjected to the evaluation of reactive oxygen species (ROS) production, total antioxidant capacity, activities of antioxidant enzymes, and glutathione concentration. The extent of damage to the proteins and lipids was quantified as well. Levels of selected cytokines were determined by the enzyme-linked immunosorbent assay while a luminometric approach was used to assess the activity of caspases. RESULTS: Rabbits treated with 3.0 mg/kg b.w. AMG presented a significantly increased protein oxidation (p = 0.0118) accompanied by a depletion of superoxide dismutase (p = 0.0464), catalase (p = 0.0317), and glutathione peroxidase (p = 0.0002). Significantly increased levels of interleukin-1 beta (p = 0.0012), tumor necrosis factors alpha (p = 0.0159), caspase-3/7 (p = 0.0014), and caspase-9 (p = 0.0243) were also recorded in the experimental group P2 when compared to the Control. No effects were observed in the rabbits treated with apricot kernels at the oxidative, inflammatory, and histopathological levels. CONCLUSIONS: Apricot kernels did not induce toxicity in the testicular tissues of male rabbits, unlike pure AMG, which had a negative effect on male reproductive structures carried out through oxidative, inflammatory, and pro-apoptotic mechanisms.

The effect of enterocin A/P dipeptide on growth performance, glutathione-peroxidase activity, IgA secretion and jejunal morphology in rabbits after experimental methicillin-resistant Staphylococcus epidermidis P3Tr2a Infection.

The increasing frequency of methicillin-resistant (MR) staphylococci in humans and animals need special attention for their difficult treatment and zoonotic character, therefore novel antimicrobial compounds on a natural base against antibiotic-resistant bacteria are requested. Currently, bacteriocins/enterocins present a new promising way to overcome this problem, both in prevention and treatment. Therefore, the preventive and medicinal effect of dipeptide enterocin EntA/P was evaluated against MR Staphylococcus epidermidis SEP3/Tr2a strain in a rabbit model, testing their influence on growth performance, glutathione-peroxidase (GPx) enzyme activity, phagocytic activity (PA), secretory (s)IgA, and jejunal morphometry (JM). Eighty-eight rabbits (aged 35 days, meat line M91, both sexes) were divided into experimental groups S (SEP3/Tr2a strain; 1.0 × 105 CFU/mL; dose 500µL/animal/day for 7 days, between days 14 and 21 to simulate the pathogen attack), E (EntA/P; 50 µL/animal/day, 25,600 AU/mL in two intervals, for preventive effect between days 0 and 14; for medicinal effect between days 28 and 42), E + S (EntA/P + SEP3/Tr2a; preventive effect; SEP3/Tr2a + EntA/P; medicinal effect) and control group (C; without additives). Higher body weight was recorded in all experimental groups (p < 0.001) compared to control data. The negative influence/attack of the SEP3Tra2 strain on the intestinal immunity and environment was reflected as decreased GPx activity, worse JM parameters and higher sIgA concentration in infected rabbits. These results suggest the promising preventive use of EntA/P to improve the immunity and growth of rabbits, as well as its therapeutic potential and protective role against staphylococcal infections in rabbit breeding.

Potential toxicity of cyanogenic glycoside amygdalin and bitter apricot seed in rabbits-Health status evaluation.

Amygdalin is one of the most studied secondary metabolites of Prunus genus. It is a cyanogenic glycoside which was initially obtained from the bitter almonds seeds and is a major component of the seeds of plants, such as apricots, almonds, peaches, apples and other rosaceous plants. The views of scientists on the use of amygdalin have been contradictory for many years, partly because toxicokinetics and metabolism of amygdalin still have not been adequately explored. The present in vivo study was designed to reveal whether pure amygdalin intramuscularly injected or apricot seeds oral consumption induce changes in overall health status of rabbit as a biological model. A total of 60 adult rabbits were randomly divided into five groups. The control group received no amygdalin while the two experimental groups E1 and E2 received a daily intramuscular injection of amygdalin at doses 0.6 and 3.0 mg/kg bw. The experimental groups E3 and E4 were fed crushed bitter apricot seeds (Prunus armeniaca L.), at doses 60 and 300 mg/kg bw, mixed with commercial feed for rabbits. Blood collection was carried out after 14 days. Biochemical, haematological and antioxidant enzymes activity analysis were performed and statistically evaluated. A short-term amygdalin administration had negligible impact on biochemical parameters-mainly level of urea, bilirubin, cholesterol. Haematological profile of rabbits was influenced very slightly-non-significant platelet count and platelet percentage increase, erythrocytes count and haemoglobin decrease. SOD activity of rabbits decreased significantly (p > 0.05) after apricot seeds consumption (102.3 U/ml) in comparison to control (117.4 U/ml). Differences might be connected to diverse metabolism by different administration routes and at the same time by the presence of other substances in apricot seeds (phytosterols, polyphenols, fatty acids). However, a short-term consumption had only slight effect on health status of rabbits and at recommended doses did not represent risk for their health.

Green tea can supress rabbit ovarian functions in vitro and in vivo.

The aim of present study was to evaluate the action of green tea and its constituents on rabbit ovarian functions and some non-reproductive indexes. In in vitro experiments, rabbit ovarian fragments were cultured with green tea constituents - epigallocatechin-3-gallate (EGCG), green tea polyphenols (GTPP) and resveratrol (RSV) (at 0, 1, 10 or 100 µg/mL medium). The accumulation of an apoptosis marker - caspase 3 and the release of progesterone (P4) and testosterone (T) were measured. In in vivo experiments, does were fed a standard diet or a diet enriched with green tea powder. The weight gain, mortality, ovarian length and weight, conception and kindling rate, number of liveborn, stillborn, and weaned pups, diameter of ovarian follicles and some blood haematological and biochemical parameters were analysed. Culture of ovarian fragments with EGCG increased accumulation of caspase 3, whilst both GTTP and RSV decreased it. EGCG inhibited both P4 and T output, GTPP stimulated P4 and inhibited T, whilst RSV promoted release of both P4 and T. Feeding with green tea increased ovarian length and diameter of ovarian non-ovulated peri-ovulatory haemorrhagic but not of primary and secondary growing follicles. Furthermore, green tea reduced conception and kindling rate, the number of liveborn and weaned pups, increased female mortality but not their weight gain. It reduced platelet distribution width, but it did not affect other haematological and biochemical indexes. These observations suggest that dietary green tea can reduce rabbit doe's viability, ovarian functions and fecundity, perhaps due to changes in ovarian cell apoptosis, steroid hormones release and blockade of the ovulation of large ovarian follicles. The anti-reproductive action of green tea could be due to its constituent - EGCG with pro-apoptotic and anti-steroid hormone properties.

Yucca schidigera can promote rabbit growth, fecundity, affect the release of hormones in vivo and in vitro, induce pathological changes in liver, and reduce ovarian resistance to benzene.

This study evaluated the effect of Yucca schidigera (YS) extract on the physiological, reproductive, and endocrine indexes of New Zealand White rabbit does. Six-week-old rabbit does were fed a standard diet (control group) or a diet enriched with 5 or 20g of Y powder extract per 100-kg feed mixture for 350days. The does were artificially inseminated after induction of superovulation. Weight gain; conception and kindling rate; viability of pups and mothers; histopathological state of liver and muscle; plasma levels of progesterone (P4), oxytocin (OT), and prostaglandin F (PGF); and the release of P4, insulin-like growth factor I (IGF-I), OT, and PGF by isolated ovarian fragments and their response to the addition of benzene were analyzed. YS extract supplementation promoted weight gain and induced histopathological changes in the liver (creased vacuolization and occurrence of fuchsinophile inclusions in hepatocytes, liver fibrosis, hyperemia, occurrence of Kupffer cells, signs of necrosis and inflammation). YS consumption was not associated with changes in muscle (occurrence of fuchsinophile inclusions and signs of atrophy, interstitial edema, and inflammation), although Y2 increased muscle vascularization. YS supplementation increased conception and kindling rates but did not affect viability of pups or adult animals. Moreover, it enhanced plasma OT and PGF levels; plasma P4 concentration was increased by low-dose YS, but decreased by high-dose YS. Cultured ovarian fragments isolated from YS-fed does released more P4 and PGF and less IGF-I than ovarian fragments of control animals. However, YS supplementation did not affect ovarian OT release. Benzene alone did not influence the release of hormones by ovaries of control does. YS supplementation induced the inhibitory effect of benzene on the release of PGF, but not on other ovarian hormones. Collectively, these results suggest that dietary supplementation of YS extract can stimulate rabbit performance (growth and fecundity), which may be due to the promotion of P4, OT, and PGF release. It could, however, induce some pathological changes in the liver and reduce resistance of ovaries to the environmental contaminant benzene.

Effect of thyme oil on small intestine integrity and antioxidant status, phagocytic activity and gastrointestinal microbiota in rabbits.

The effects of 0.5 g thyme oil per kg dry matter (DM) of diet on duodenal tissue integrity, antioxidant status, phagocytic activity and selected microbiota in the caecum and faeces of rabbits were studied. Twenty-four rabbits were divided into two groups and were fed a commercial granulated diet for growing rabbits (CD) with access to water ad libitum. The first group was fed the CD, while to the CD of the second group thyme oil was added. Intestinal integrity was tested by measuring the transepithelial electrical resistance (TEER). Thyme oil significantly increased the value of total antioxidant status (TAS) in the blood plasma and glutathione peroxidase (GPx) activity in the liver, and it decreased malondialdehyde (MDA) concentration in the duodenal tissue. Thyme oil resulted in strengthened intestinal integrity, as the essential oil supplementation significantly increased TEER values in the experiment. The faecal microbiota of rabbits was almost completely balanced in both groups, and only a slight decrease was found in the microbial population at day 42 of the trial. In both groups, the bacterial counts were generally lower in the caecum than in the faecal samples. In conclusion, dietary supplementation with 0.5 g/kg DM thyme oil may improve intestinal integrity, and it may have an antioxidant effect. A tendency was also found for thyme oil to stimulate the abundance of some microbes beneficial in the rabbit gut.