Metabolome-Based Analysis of Herbal Cough Preparations Via Headspace Solid-Phase Microextraction GC/MS and Multivariate Data Analyses: A Prospect for Its Essential Oil Equivalency

ACS Omega. 2020 Nov 27;5(48):31370-31380. doi: 10.1021/acsomega.0c04923. eCollection 2020 Dec 8.

Abstract

Liquid cough preparations containing essential oils pose a challenge for isolating and quantifying their volatile components from such a complex matrix enriched with nonvolatile constituents and excipients. This study aims to develop a strategy integrating QC analysis of seven natural cough preparations in the Egyptian market and to assess volatile variation among the preparations using multivariate data analyses. Cough preparations were subjected to headspace solid-phase microextraction (HS-SPME) for determination of their essential oil composition mediating for their actions and to assess volatile differences among them. HS-SPME is a suitable technique for sample preparation that allows for extraction and enrichment of volatiles from complex nonvolatile matrices and their direct desorption into the gas chromatography analytical system. A total of 88 volatile components were identified belonging to seven classes, viz. aromatics, aliphatic hydrocarbons, mono/sesquiterpene hydrocarbons, and oxygenated mono/sesquiterpenes. Oxygenated monoterpenes, viz., menthol, cineole, thymol, and (E)-anethole, were the major volatiles identified in five cough preparations (79.5-98.6%), whereas aromatics, chiefly cinnamate derivatives, constituted the second class amounting for 50.5 and 27.4% in the other two cough preparations. Meaningful results regarding the products' efficacy and safety were extrapolated from this analytical procedure, where artificial preservatives (parabens) were detected in five cough preparations. This study established an efficient strategy for exploring volatile profiling and defining different markers among the different cough preparations. Additionally, authenticity of listed herbal ingredients in the cough preparations was also confirmed in certain preparations, while other formulations failed to show representative volatile components. Volatile variation among preparations was assessed using multivariate data analyses in an attempt to prioritize cough preparations for usage, suggesting the preference of Bronchicum and Babetone among examined cough products.