Phytomedicine Plus (May 2024)
Formulation and evaluation of the effects of ophthalmic nanoemulsion of Nigella sativa seed extract on atropine-induced dry eye in mice
Abstract
Background: Nigella sativa L. seed from the Ranunculaceae family, whose many therapeutic effects have been stated in recent research, is one of the herbs with known anti-inflammatory effects. Nigella sativa L. seed may have therapeutic effects on dry eye, a disease that manifests with symptoms of redness, burning, foreign body sensation, and sensitivity to light. Aim of the study: To evaluate the effects of Nigella sativa L. seed extract nanoemulsion on atropine-induced dry eye in mice. Material and methods: The hydro-alcoholic extract of the Nigella sativa seed was prepared using the maceration method (10% w/w). Subsequently, by using Tween 20 and Tween 80 surfactants with different ratios, the desired nanoemulsion was achieved. DLS, Zeta potential, TEM, and FT-IR tests were used to determine the size and morphology of nanoparticles.A total number of 36 adult male mice were used in this study divided equally into six groups, each receiving a different compound according to the protocol with three groups receiving therapeutic nanoemulsion eye drops daily. Tear production was evaluated by Schirmer's test and reported as a ratio to the first-day tear production on days 1, 7, and 14. Results: According to the investigations by the DLS method, the Nanoparticles' size was reported 10.4 nm. The TEM image revealed that the nanoparticle of Nigella sativa seed extract emulsion has a spherical shape with an approximate size of 10 nm. Zeta test results in -37.6 mv, which was evaluated as sufficient quality. The final composition of nanoemulsion was chosen as 5 % of Nigella sativa seed extract, 75 % of water, and 20 % of surfactant with a ratio of 1:4.Schirmer's test results indicated that the highest dose of nanoemulsion (1 %) resulted in the most significant amount of tear production, compared to lower doses (0.5 % and 0.1 %) and the control group. Conclusion: This study showed that Nigella sativa seed extract nanoemulsion has a potentially positive effect on the amount of tear production in atropine-induced dry eyes. Thus, the employment of this nanoemulsion should be considered in the treatment of dry eye.
