The ameliorative effect of bergamot oil nano-emulsion in stressed rabbit bucks: Influence on blood biochemical parameters, redox status, immunity indices, inflammation markers, semen quality, testicular changes and the expression of HSPs genes

Abstract

This work explored the activities of bergamot oil nano-emulsion (NBG) in modulating blood biochemical parameters, redox status, immunity indices, inflammation markers, semen quality, testicular changes and the expression of HSPs genes in stressed rabbit bucks. Twenty-four mature rabbit bucks (5 months) were randomly divided into three groups; control group (NBG0) received 1 ml of distilled water, while the other two groups received NBG orally at doses of 50 and 100 mg/kg (bw) twice a week. The present study's findings revealed that treated groups had lower values of total and direct bilirubin, triglyceride, lactate dehydrogenase, and creatinine compared with NBG0 group (p < 0.05). NBG100 group recorded the greatest of total protein, albumin, GPx, T3 and T4 values as well as the lowest values of uric acid, MDA, and indirect bilirubin. Both treated groups showed significantly reduced 8-OhDG, Amyloid A, TLR 4, while significantly increased nitric oxide, IgA, IgM, TAC, and SOD levels. Semen characteristics such as volume, sperm count, sperm motility, normal sperm, and vitality were significantly higher in the NBG100 group compared to the NBG50 and NBG0 groups, whereas sperm abnormalities and dead sperm were significantly reduced. HSP70, HSP72, and HSPA9 gene overexpression showed that testicular integrity was maintained after buck received oral doses of 50 or 100 mg/kg of NBG. Existing findings indicate that oral administration of NBG improves heat tolerance in rabbit bucks primarily as e result of its antioxidant and anti-inflammatory effects.

Keywords: Bergamot oil nano-emulsion; Citrus bergamia; Heat stress; Inflammation; Oxidative stress; Rabbit bucks; Semen quality.

Fig. 1

A TEM image of NBG reveals spherical particles of various sizes and few aggregations.

Fig. 2

Calculated temperature-humidity index (THI) throughout the experimental period in Sharkia Province, Egypt.

Fig. 3

Effects of orally administration of nano-emulsion of bergamot oil (NBG) on liver biomarkers of rabbit bucks during thermal stress. Data presented as mean ± SEM, *P < 0.05, **P < 0.01, ***P < 0.001 compared to control. Rabbits received bergamot essential oil nano-emulsion at different concentrations: 0 (Control), 50 (NBG50) and 100 mg/kg (NBG100).

Fig. 4

Effects of orally administration of nano-emulsion of bergamot oil (NBG) on total protein, albumin and globulin levels of rabbit bucks during thermal stress. Data presented as mean ± SEM, *P < 0.05, compared to control. Rabbits received bergamot essential oil nano-emulsion at different concentrations: 0 (Control), 50 (NBG50) and 100 mg/kg (NBG100).

Fig. 5

Effects of orally administration of nano-emulsion of bergamot oil (NBG) on kidney biomarkers of rabbit bucks during thermal stress. Data presented as mean ± SEM, *P < 0.05, **P < 0.01 compared to control. Rabbits received bergamot essential oil nano-emulsion at different concentrations: 0 (Control), 50 (NBG50) and 100 mg/kg (NBG100).

Fig. 6

Effects of orally administration of nano-emulsion of bergamot essential oil (NBG) on DNA damage, inflammatory and immunity indices of rabbit bucks during thermal stress. Data presented as mean ± SEM, *P < 0.05, **P < 0.01, ***P < 0.001 compared to control. Rabbits received bergamot essential oil nano-emulsion at different concentrations: 0 (Control), 50 (NBG50) and 100 mg/kg (NBG100).

Fig. 7

Effects of orally administration of nano-emulsion of bergamot oil (NBG) on antioxidative and oxidative biomarkers of rabbit bucks during thermal stress. Data presented as mean ± SEM, **P < 0.01, ***P < 0.001 compared to control. TAC; total antioxidant capacity, Gpx; Glutathione peroxidase, SOD; Superoxide dismutase, MDA; Malondialdehyde. Rabbits received bergamot essential oil nano-emulsion at different concentrations: 0 (Control), 50 (NBG50) and 100 mg/kg (NBG100).

Fig. 8

Effects of orally administration of nano-emulsion of bergamot oil (NBG) on antioxidative and oxidative biomarkers of rabbit bucks during thermal stress. Data presented as mean ± SEM, **P < 0.01, ***P < 0.001 compared to control. T3; Triiodothyronine and T4; Thyroxine. Rabbits received bergamot essential oil nano-emulsion at different concentrations: 0 (Control), 50 (NBG50) and 100 mg/kg (NBG100).

Fig. 9

The lesions score of the severity extent within testicular tissues as affected by dietary supplement of NBG in rabbit buck diets. The represented scores are the mean lesion score. Histologic lesions were scored for severity (0 = No altrerations, 1 = Mild altrerations, 2 = Moderate altrerations, 3 = Severe altrerations).

Fig. 10

(A-F). Photomicrograph of H&E-stained sections from testicular tissues of bucks. (A&B) Bucks reared under HS conditions (NBG), showing some atrophied seminepherous tubules (curved arrow) with necrotic germinal epithelial lining (arrowhead), in addition to interstitial edema (arrow). (C&D) Bucks received 50 mg/kg of NBG under hot conditions showing normal architectures of the majority of seminepherous tubules (thick arrow), less edema (arrow) and depleted few numbers of germ cells (arrowhead). (E&F) Bucks received 100 mg/kg of NBG showing regular histology of seminepherous tubules (thick arrow), spermatogonia (arrow), spermatocytes (arrowhead), central impacted sperms (star) and lyding cells (curved arrow).

Fig. 11

Effect of nano-emulsion bergamot oil (NBG) on heat shock proteins (HSP72, HSP70, and HSPA9) related expressions in testicular tissues. Results are presented as mean ± SEM, **P < 0.01 ***P < 0.001 compared to control.