Surface Chemistry Study of the Interactions of Sesame Oil with Meibomian Films.

Petar Eftimov,Georgi As. Georgiev,Norihiko Yokoi

doi:10.3390/molecules27020464

Petar Eftimov, Georgi As. Georgiev + Show 1 more

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https://doi.org/10.3390/molecules27020464

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Abstract

A possible approach for the treatment of meibomian gland disease (MGD) can be the supplementation of meibomian gland secretion (MGS) with nonpolar lipids (NPL) rich plant oils. Sesame oil (SO), approximately equal in monounsaturated fat (oleic acid, 40% of total) and polyunsaturated fat (linoleic acid, 42% of total), has shown multiple health benefits due to its anti-inflammatory and antioxidant effects. Thus, the interactions between SO and MGS in surface layers deserve further study. Therefore, pseudobinary films were formed with controlled MGS/SO molar ratios (0%, 10%, 30%, 50%, and 100% SO) at the air/water surface of the Langmuir trough over phosphate buffered saline (pH 7.4) subphase. Surface pressure (π)-area (A) isotherms and Brewster angle microscopy observations showed nonideal interactions where SO aggregates with MGS and complements the NPL stratum of the meibomian layers. The analysis of stress relaxation transients with Kohlrausch–Williams–Watts equation revealed that the supplementation of fixed amount of MGS with excess lipids via SO altered the dilatational elasticity of the films as reflected by the increase of the exponent β. Thus, SO with its unique combination of high oxidative stability and abundance of long polyunsaturated acyl chains might be a useful supplement to MGS layers.

Highlights

The tear film lipid layer (TFLL) that stabilizes the air/aqueous tear (AT) interface of the tear film (TF) in an open eye, is built primarily (>95%) by the meibomian gland secretion (MGS, or meibum) with the putative minor contribution of phospholipids from the lacrimal glands [1,2,3]
The first set of experiments was performed with pseudobinary MGS/sesame oil (SO) layers where the decrease of MGS content is compensated with a proportional supplementation of SO in the film-forming solutions
It can be seen that for pure meibum the onset of the surface pressure took place at apparent molecular area of 45 Å2 and at further compression, the surface pressure increased smoothly to 38 mN/m at 10 Å2

Summary

Introduction

The tear film lipid layer (TFLL) that stabilizes the air/aqueous tear (AT) interface of the tear film (TF) in an open eye, is built primarily (>95%) by the meibomian gland secretion (MGS, or meibum) with the putative minor contribution of phospholipids from the lacrimal glands [1,2,3]. An alternative approach has gained traction: to utilize GRASE (generally recognized as safe and efficient) plant oils as source of diverse natural NPL. Such strategy was successfully implemented into the Cationorm nanoemulsion where castor oil is used for the purpose. SO is approximately equal in monounsaturated fat (oleic acid, 40% of total) and polyunsaturated fat (linoleic acid, 42% of total), and the remaining oil content is saturated fat (~8% palmitic acid and 4% stearic acid) This diverse fatty acid composition yields promise that SO can supplement the composite acyl chains profile of human meibum. A unique advantage of SO compared to other vegetable oils is that due to its high antioxidant content it combines high oxidative stability with nearly 85% content of unsaturated fatty acid chains [14]

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