Morphological evaluation of the protective role of dark soy sauce against acrylamide induced neurotoxicity in albino rats

Abstract

Background: Acrylamide (ACR) exposure is associated with neurotoxicity, carcinogenicity, and reproductive toxicity. The use of soy sauce as a condiment is common and it has been found that it possesses high antioxidant activity. The objective of the current study is to evaluate the protective role of dark soy sauce (DSS) against ACR-induced neurotoxicity in rats.

Materials and methods: Thirty-five adult male rats were divided into four groups: control, ACR given for 4 weeks, DSS given for 4 weeks before ACR, and DSS given with ACR for 4 weeks. The trigeminal ganglia and cerebellum were dissected and processed for histological staining with haematoxylin and eosin and immunohistochemistry for synaptophysin (SYP) and morphometric analysis.

Results: In the trigeminal ganglia, ACR group showed central chromatolysis, degeneration and cell loss. DSS before ACR group had less marked changes in the neuronal architecture, while in ACR with DSS group, better preservation was observed. In the cerebellum, ACR group showed shrunken Purkinje cells and nuclear pyknosis. Spacing and dissociation between Purkinje layer and other layers was seen. DSS before ACR group showed few degenerated Purkinje cells with normal pattern of the other layers of cerebellar cortex. ACR with DSS group showed less disturbed cerebellar layers architecture. Cerebellar SYP immunoexpression and its area per cent were decreased in ACR group compared with the control. It increased in both DSS treated groups, specifically DSS concomitantly given with ACR.

Conclusions: ACR exerted marked cellular degenerative effects and administration of DSS and ACR at the same time had neuroprotective effect. DSS treatment before ACR exposure gave only marginal improvement.