The Effect of Combined Treatment of Psilocybin and Eugenol on Lipopolysaccharide-Induced Brain Inflammation in Mice

Abstract

Inflammation is an organism’s biological defense mechanism. Acute and chronic inflammation of the body triggers the production of pro- and anti-inflammatory pathways that can affect the content of cytokines in the brain and thus cause brain inflammation. Disorders such as depression and posttraumatic stress disorder (PTSD) are often associated with elevated inflammation. Recently, positive and promising clinical results of psilocybin for the treatment of depression and PTSD were reported. Thus, we decided to test whether psilocybin alone or in combination with eugenol, an anti-inflammatory and antioxidant agent, would prevent the increase in or decrease the content of cytokines in the brain of C57BL/6J mice injected with lipopolysaccharides (LPS). Two experiments were performed, one with pre-treatment of mice through gavage with psilocybin (0.88 mg/kg), eugenol (17.6 mg/kg), or combinations of psilocybin and eugenol (1:10, 1:20, or 1:50), followed by intraperitoneal injection of LPS, and the second, post-treatment, with initial injection with LPS, followed by treatment with psilocybin, eugenol, or their combination. Brain tissues were collected, and cytokines were analyzed by qRT-PCR, Western blot, and ELISA. Data were analyzed with a one-way ANOVA followed by Tukey’s post hoc test or with multiple unpaired t-tests. LPS upregulated mRNA expression of COX-2, TNF-α, IL-1β, and IL-6. All pre-treatments decreased the expression of COX-2 and TNF-α, with psilocybin alone and in 1:50 combination, with eugenol being the most effective. In the post-treatment, all combinations of psilocybin and eugenol were effective in reducing inflammation, with the 1:50 ratio displaying the most prominent results in reducing the mRNA content of tested cytokines. Western blot analysis confirmed the effect on COX-2 and IL-1β proteins. Finally, the ELISA showed that post-treatment with psilocybin + eugenol (1:50) demonstrated the best results, decreasing the expression of multiple markers including IL-6 and IL-8. This demonstrates the anti-inflammatory effects of a combination of psilocybin and eugenol in the brain of animals with systemically induced inflammation.

Theophylline-based hybrids as acetylcholinesterase inhibitors endowed with anti-inflammatory activity: synthesis, bioevaluation,in silicoand preliminary kinetic studies

“… 46 In combination with psilocybin, it was able to protect against inflammation induced in mice brain by LPS where several cytokines levels such as TNF, IL-1β, IL-6 were reduced. 47 This was also reproducible in other experimental model based on aluminum chloride induced neurotoxicity. 48…”

Psilocybin and Eugenol Reduce Inflammation in Human 3D EpiIntestinal Tissue

“…Next, we tested the efficacy of psilocybin and eugenol to prevent the inflammatory response induced by TNF-α/IFN-γ. While our previous studies have demonstrated psilocybin and eugenol have synergistic effects on COX-2 and IL-6 within HSIEC in vitro [12], as well as synergistic effects on reducing COX-2 and IL-6 levels within the LPS-induced murine brain inflammation [22], in this study, we only saw synergistic effects at the highest dose of psilocybin (40 µM) combined with eugenol (25 µM) (Table 1). With the combined treatment of psilocybin (40 µM) and eugenol (25 µM), there was a fold change of −21.0× and −62.5× for TNF-α and IFN-γ, respectively, which was superior to both psilocybin's induced fold changes of −13.7× and −9.5×, or eugenol's induced fold changes of −8.8× and −17.0× for TNF-α and IFN-γ, respectively (Table 1).…”

“…Previously, we have shown eugenol has potent anti-inflammatory effects and shows synergy with psilocybin in vivo within the brain [22], as well as in vitro within small intestinal epithelial cells [12]; however, outside of cell models, the effects of eugenol on IBD still remains unknown. Although eugenol is still being studied, it is demonstrating potential as an IBD therapeutic and has been declared by World Health Organization (WHO) to be generally recognized as safe and non-mutagenic [23].…”

Anti-Inflammatory Effects of Serotonin Receptor and Transient Receptor Potential Channel Ligands in Human Small Intestinal Epithelial Cells

“…One study found that psilocybin reduced inflammation in the brains of rats by decreasing the activity of certain immune cells called microglia [ 8 ]. Recently, the oral administration of psilocybin and eugenol in vivo ameliorated LPS-induced inflammation within the brain [ 9 ]. While more research is needed to fully understand the anti-inflammatory effects of psilocybin, these findings suggest that it may have potential as a therapeutic agent for a range of conditions characterized by inflammation in the body or brain.…”