A simple LC-MS/MS method for the simultaneous quantification of endocannabinoids in biological samples

Area of Science:

• Biochemistry
• Analytical Chemistry
• Neuroscience

Background:

• The endocannabinoid (EC) system plays crucial roles in various physiological and pathophysiological processes.
• Accurate quantification of ECs, including anandamide (AEA), 2-arachidonoylglycerol (2-AG), N-arachidonoyldopamine (NADA), 2-arachidonoylglycerol ether (2-AGE), and O-arachidonoylethanolamine (VA), is essential for understanding their effects.

Purpose of the Study:

• To develop and validate a robust analytical method for quantifying multiple ECs in cellular samples.
• To establish a reliable tool for researchers investigating the EC system's involvement in health and disease.

Main Methods:

• Liquid chromatography coupled with positive electrospray ionization tandem mass spectrometry (LC-MS/MS) was employed.
• Sample preparation involved two liquid extractions using ethyl acetate.
• Method validation followed FDA bioanalytical guidelines, assessing parameters like linearity, precision, accuracy, and matrix effects.

Main Results:

• The validated LC-MS/MS method demonstrated good sensitivity with low limits of quantification for AEA, 2-AG, NADA, 2-AGE, and VA.
• Linearity was established up to 10 ng/mL or 50 ng/mL depending on the analyte.
• The method showed acceptable precision, accuracy, and low matrix effects for most ECs, with minor challenges for NADA and VA.

Conclusions:

• A validated LC-MS/MS method is available for the accurate quantification of major endocannabinoids in cellular matrices.
• This method facilitates in-depth research into the physiological and pathophysiological roles of the endocannabinoid system.
• The developed assay has been successfully applied to measure ECs in various cell lines and mouse brain tissues.