Effects of pyridine inhalation exposure on olfactory epithelium in mice

Ameliorative effect of Koflet formulations against pyridine-induced pharyngitis in rats

In present study two formulations of Koflet (syrup and lozenges) were evaluated against pyridine-induced pharyngitis in rats. Topical application of 10% pyridine showed extravasation of Evans blue stain as a characteristic feature of on-going inflammation. In addition, the levels of TNF-α (p < 0.01) and IL-6 (p < 0.01) were significantly increased compared to control. Further, histopathology of the pharyngeal tissue showed submucosal gland hypertrophy, severe mucosal inflammation characterized by presence of mononuclear cells and neutrophils along with haemorrhages and congestion; however, saline applied animals (normal control) showed normal cytoarchitecture of the pharynx. Interestingly, pre-treatment with dexamethasone (1 mg/kg, p.o.), Koflet lozenges (KL) (500 and 1000 mg/kg, p.o.) and Koflet syrup (KS) (2 and 4 ml/kg, p.o.) for 7 days showed significant and dose dependent protection by decreasing the EB dye extravasation, and serum levels of TNF-α and IL-6. In addition, histopathological findings have further supported the protective effect of Koflet formulations. These findings suggest that, both Koflet syrup and Koflet lozenges are highly effective in treating non-infectious type of pharyngitis. Among the two formulations KS was found to be more potent than KL, and possible mechanism of action thought to be mediating through inhibition of TNF-α and/or phospholipids–arachidonic acid pathway.