The role of edible bird's nest and mechanism of averting lead acetate toxicity effect on rat uterus

Abstract

Aim: This study aimed to evaluate the protective effect of edible bird's nest (EBN) supplement on the uteri of rats exposed to lead acetate (LA) toxicity.

Materials and methods: Five treatment groups were established as follows: Group 1 (C), which was given distilled water; Group 2 (T0), which was administered with LA (10 mg/kg body weight [BW]); and Groups 3 (T1), 4 (T2), and 5 (T3), which were given LA (10 mg/kg BW) plus graded concentrations of 30, 60, and 120 mg/kg BW of EBN, respectively. Rats were euthanized at week 5 to collect blood for superoxide dismutase (SOD) assay, and uterus for histomorphological study and expression analyses of epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), and proliferating cell nuclear antigen (PCNA).

Results: Results revealed that LA causes destruction of uterine lining cells and necrosis of uterine glands of exposed rats without EBN supplement while the degree of damage decreased among EBN treated groups; T3 showed the highest ameliorating effect against LA toxicity, as well as an increased number of uterine glands. Increased levels of SOD were also achieved in EBN supplemented groups than the controls. Results of immunohistochemistry showed significantly higher expressions of EGF, VEGF, and PCNA levels (p<0.05) in T3 compared to other treatments. EBN maintained upregulation of antioxidant - reactive oxygen species balance.

Conclusion: The findings showed that EBN could ameliorate the detrimental effects of LA toxicity on the uterus possibly by enhancing enzymatic antioxidant (SOD) activity as well as expressions of EGF, VEGF, and PCNA with cell proliferation roles.

Keywords: edible bird’s nest; growth factors; lead acetate; proliferating cell nuclear antigen; superoxide dismutase; uterus.

Figure-1

Effect of edible bird’s nest on body weight of rats exposed to lead acetate toxicity.

Figure-2

(a and b) Effect of edible bird’s nest on uterine-body weight ratio and uterine length of rats exposed to lead acetate toxicity.

Figure-3

Histologic sections from adult rat uteri exposed to lead acetate toxicity. Black arrows and yellow arrows indicate uterine epithelial lining and uterine glands, respectively. Noticed necrosis of uterine glands and destruction of uterine lining cells in positive control T0, T1 and T2.

Figure-4

(a-d) Histomorphometric parameters evaluated in the rat uterus, measured during the proestrus phase. Note the lesser thickness of the endometrium and decrease numbers of uterine glands in T0. While, T3 showed greater thickness of the endometrium and increased numbers of uterine glands compared to other treatment groups.

Figure-5

Photomicrograph sections of the uteri of rats of different experimental groups (C, T0, T1, T2, and T3) exposed to LA and treated with different doses of edible bird’s nest showing expression of epidermal growth factor (EGF) (200×). Notice low staining in T0 and T1 compared to other treatment groups. Photomicrographs labeled with NC represents control stains without antibody and immunity reaction for EGF groups. It shows higher EGF expression observed at T3 compared to other treatment groups.

Figure-6

Photomicrograph sections of the uteri of rats of the different experimental groups (C, T0, T1, T2, and T3) exposed to lead acetate toxicity and treated with different doses of edible bird’s nest showing expression of vascular endothelial growth factor (VEGF) (200×). T0 and T1 have not staining for VEGF and higher VEGF expressions were observed in stromal cells, uterine luminal epithelium, and uterine glandular epithelium in T2 and T4 compared to control. Photomicrographs labeled with NC represents control stains without antibody and immunity reaction for VEGF groups. It shows higher VEGF expression observed at T3 compared to other treatment groups.

Figure-7

Photomicrograph sections of the uteri of rats of the different experimental groups (C, T0, T1, T2, and T3) exposed to lead acetate toxicity and treated with different doses of edible bird’s nest showing expression of proliferating cell nuclear antigen (PCNA) (200×). T0 and T1 have not staining for PCNA and higher expressions were observed in stromal cells, uterine luminal epithelium, and uterine glandular epithelium in T2 and T3 compared to control. Photomicrographs labeled with NC represents control stains without antibody and immunity reaction for PCNA groups. It shows higher PCNA expression observed at T3 compared to other treatment groups.

Figure-8

Effect of edible bird’s nest on antioxidant enzyme (superoxide dismutase) activities in plasma of lead acetate exposed and EBN treated rats.