By Ryan Scheiderer, Saud Abdul Aziz

Faculty Mentor: Dr. Laura Sipe

Abstract

Serotonin (5-HT) is a neurotransmitter and hormone involved in immune regulation. This study examines inflammatory modulation by exposure of RAW264.7 macrophages. At 10-5 M, serotonin significantly reduced inflammatory markers. An MTT assay revealed reduced cell viability across all conditions, thus necessitating the normalization to cell number. Using the Griess assay normalized through Hoechst staining, serotonin treatment significantly decreased nitric oxide production in LPS treated cells, suggesting reduced iNOS activity in RAW264.7 macrophages. Additionally, an ELISA for quantitative detection of TNF-α showed that serotonin treatment much lowered TNF-α concentrations in the LPS treated culture supernatant compared to the control group. When exposed to LPS, serotonin treatment significantly reduced nitric oxide production and TNF-α concentrations in RAW264.7 macrophages, suggesting its potential to inhibit inflammatory pathways relevant to immune responses and cancer progression.