Evaluation of the Toxic Effect of Silver Nanoparticles Versus Copper Oxide Nanoparticles and the Possible Protective Effect of Ascorbic Acid on the Parotid glands of Albino Rats

Abstract

I. Light microscopic results: a) Control Groups (C1&C2):

Examination of the PG of both control groups revealed normal histological features of the parenchymal element and connective tissue. The ducts were surrounded by fibrous C.T stroma containing cells, fibers and blood vessels (B.V) and their lumen were empty.

b) Group I (CuONPs): Examination of the H&E stained sections of this group revealed serous acini with ill-defined outline and cytoplasmic vacuolation varying in sizes. Nuclei of the acinar cells appeared

pyknotic and pleomorphic. Some cells showed binucleation and crescent shaped nuclei. Intercalated ducts showed loss of cell height, while striated and excretory ducts showed signs of degeneration and their lumen contained stagnated secretion. Hyalinization of the fibrous C.T surrounding the excretory ducts and presence of congested BVs filled with RBCs were also noted. The present study aimed to evaluate the toxic effect of copper oxide nanoparticles (CuONPs) and silver nanoparticles (AgNPs) and the possible protective effect of ascorbic acid on the parotid gland (PG) of Albino rats histologically and ultrastructurally.

Fifty four male Albino rats weighing between 150 - 200 mg were used in this study.

The animals were divided into the following groups:

I. Control groups (14 rats): Which were divided to:

a) Subgroup C1: seven Albino rats received IP injection with 2.5 mg/kg body weight (b.w) distilled water three times a week for 6 weeks up to 18 injections.

b) Subgroup C2: seven Albino rats received IP injection with aqueous nitrate buffer in a dose of 2 mg/kg body weight (b.w.) daily for 28 days. II. Experimental groups (40 rats):

Which were divided to:

a) Group I: ten Albino rats received IP injection with CuONPs suspended in distilled water in a dose of 2.5 mg/kg (b.w) three times a week for 6 weeks up to 18 injections. b) Group II: ten Albino rats received IP injection with CuONPs suspended in distilled water in a dose of 2.5 mg/kg (b.w) three

times a week for 6 weeks up to 18 injections, with oral administration of 100 mg/kg (b.w) of vitamin C in drinking water three times a week for 6 weeks. c) Group III: ten Albino rats received 2 mg/kg (b.w) of AgNPs

IP injection daily for 28 days.

d) Group IV: ten Albino rats received 2 mg/kg (b.w) of AgNPs IP injection daily for 28 days, with oral administration of 100 mg/kg (b.w) of vitamin C in drinking water daily for 28 days.

After the experimental period, rats were sacrificed by extra dose of anesthesia. The gland was excised and half the specimens were examined by LM and the other half were prepared and examined by TEM.