Ameliorative effects of Tagetes erecta Linn. flower against desiccation stress-induced dry eye symptoms in the mice model

Tagetes erecta Linn, popularly known as Marigold, has various pharmacological effects. It is used as a natural food colorant, poultry feed additive, and nutritional supplement, especially for the posterior segment of the eye. However, the effect of T. erecta Linn on ocular disorders is still unknown. To investigate the effect of oral administration of ethanol extract of T. erecta Linn flower (TE) in a murine model of dry eye syndrome (DED), desiccation stress (DS) was performed, and subcutaneous injection of scopolamine hydrobromide was administered four times a day for 21 days. TE and cyclosporine A (CsA) were administered for an additional 14 days under DS conditions. Changes in tear production and corneal fluorescein staining were measured at baseline, after 7 days of DS, and after treatment for 7 and 14 days. DS significantly decreased tear production and increased corneal fluorescein score; the parameters were significantly reversed in the TE400 (oral administration of 400 mg TE/kg body weight) group. TE markedly improved DS-induced changes including corneal epithelial detachment and lacrimal gland inflammation. The anti-inflammatory effect of TE 400 supplementation was similar to that of CsA. Our findings suggest that oral administration of TE may protect against DS-induced DED via stabilization of the tear film and suppression of inflammation. This study provides an experimental basis for further studies on the potential clinical use of TE in preventing DED.