Cannabidiol-Driven Alterations to Inflammatory Protein Landscape of Lipopolysaccharide-Activated Macrophages In Vitro May Be Mediated by Autophagy and Oxidative Stress

Abstract

Background: The nonpsychotropic phytocannabinoid cannabidiol (CBD) presents itself as a potentially safe and effective anti-inflammatory treatment relative to clinical standards. In this present study, we compare the capacity of CBD to the corticosteroid dexamethasone (Dex) in altering the secreted protein landscape of activated macrophages and speculate upon the mechanism underpinning these alterations. Materials and Methods: Human THP-1 monocytes were differentiated into macrophages (THP-1 derived macrophages [tMACs]), activated with lipopolysaccharide (LPS), and then treated with 5, 10, 25, 50, or 100 lM CBD or 10 lM Dex for 24 h. Following treatment, cytotoxicity of CBD and protein expression levels from culture supernatants and from whole cell lysates were assessed for secreted and intracellular proteins, respectively. Results: High concentration (50 and 100 lM) CBD treatments exhibit a cytotoxic effect on LPS-activated tMACs following the 24-h treatment. Relative to the LPS-activated and untreated control (M[LPS]), both 25 lM CBD and 10 lM Dex reduced expression of pro-inflammatory markers-tumor necrosis factor alpha, interleukin 1 beta, and regulated on activation, normal T cell expressed and secreted (RANTES)-as well as the pleiotropic marker interleukin-6 (IL-6). A similar trend was observed for anti-inflammatory markers interleukin-10 and vascular endothelial growth factor (VEGF). Dex further reduced secreted levels of monocyte chemoattractant protein-1 in addition to suppressing IL-6 and VEGF beyond treatments with CBD. The anti-inflammatory capacity of 25 lM CBD was concurrent with reduction in levels of phosphorylated mammalian target of rapamycin Ser 2448, endothelial nitric oxide synthase, and induction of cyclooxygenase 2 relative to M(LPS). This could suggest that the observed effects on macrophage immune profile may be conferred through inhibition of mammalian target of rapamycin complex 1 and ensuing induction of autophagy. Conclusion: Cumulatively, these data demonstrate cytotoxicity of high concentration CBD treatment. The data reported herein largely agree with other literature demonstrating the anti-inflammatory effects of CBD. However, there is discrepancy within literature surrounding efficacious concentrations and effects of CBD on specific secreted proteins. These data expand upon previous work investigating the effects of CBD on inflammatory protein expression in macrophages, as well as provide insight into the mechanism by which these effects are conferred.

Oleanolic Acid-Enriched Olive Oil Alleviates the Interleukin-6 Overproduction Induced by Postprandial Triglyceride-Rich Lipoproteins in THP-1 Macrophages

“…LPS is widely used in experiments to induce an inflammatory response, and numerous studies have shown an overproduction of IL-1β, IL-6 and TNF-6 in THP-1 cells stimulated by LPS [34][35][36]. In our study, the activation of THP-1 macrophages with LPS produced an abundant release of IL-6, IL-1β and TNF-α in the cell culture supernatants.…”

The molecular activity of cannabidiol in the regulation of Nrf2 system interacting with NF-κB pathway under oxidative stress

“…Another work in colorectal cancer cells also demonstrates autophagy by increasing ROS overproduction-mediated mitochondrial dysfunction due to CBD application (4 μM) [ 8 ]. In addition, in human THP-1 monocytes, a higher concentration of CBD (25 μM) can also promote the expression of cyclooxygenase 2 [ 32 ], which generates nitric oxide responsible for oxidative stress and associated pro-inflammation and pathogenic stimulation [ 33 ]. Moreover, CBD used before and after irradiation of keratinocytes with UVB showed a significant reduction in the total formation of MDA- and 4-HNE-protein adducts [ 34 ].…”

Cannabidiol modulation of oxidative stress and signalling

“…Data from Gonzalez-Garcia et al, (2017) indicate that CBD induces apoptosis of encephalitogenic cells through oxidative stress induction (increase in ROS) in murine MS [210]. CBD has also been shown to increase the oxygen consumption rate and enhance mitochondrial bioenergetics [190], and at high concentrations can promote COX-2 expression in LPS-treated macrophages [216]. In further support of the pro-oxidant capacity of CBD, it is also important to note that CBD has been shown to increase the expression of the NOX4 and p22phox NAP(P)H oxidases [208], and also enhances the production of the p47 subunit of pro-oxidative NADPH oxidase in endotoxin-treated neutrophils from healthy subjects [217].…”