Inflammation: Anti-Inflammatory Effect of CBD on Canine Models of Inflammation
by Candid Tails on May 10, 2022
Gugliandolo, P. Licata, A. F. Peritore, R. Siracusa, R. D’Amico, M. Cordaro, R.Fusco, D. Impellizzeri, R. Di Paola, S. Cuzzocrea, R. Crupi and C. D. Interlandi
- TNF-α is a proinflammatory molecule with increased expression and present in high pathological levels in canine atopic dermatitis
- IL-6 (proinflammatory molecule) production is boosted in atopic dermatitis and its blockage can help improving this disease
- Both TNF-α and IL-6 are associated with the pathogenesis of arthritis in dogs
- CBD reduced the secretion of TNF-α and IL-6 (molecules that drive the inflammatory response) in an ex vivo model of inflammation in canine blood cells
- The TNF-α to IL-10 (pro-inflammatory molecule) ratio is a marker of the balance between key pro- and anti-inflammatory levels
- Treatment with CBD restored the TNF-α to IL-10 ratio to a healthy balance
- CBD also reduced NF-κB activation (NF-κB is a regulator of the inflammatory response and of many pro-inflammatory cytokines)
- Finally, administration of CBD to the inflamed cells resulted in a lower COX-2 (which is upregulated in inflammation) expression
OBJECTIVES & HYPOTHESIS → The aim of the study was to investigate the anti-inflammatory and immunomodulatory properties of CBD directly in dogs.
METHODS → The study used an ex vivo model where whole blood from healthy dogs was stimulated with LPS (evokes a pro-inflammatory environment, thus allowing the characterization of the effect of CBD on canine inflammatory response). Whole blood samples were obtained from 6 healthy dogs and added directly to different medias:
- Control: whole blood + vehicle (DMSO 0.1%)
- LPS: whole blood + LPS 100 ng/mL + vehicle (DMSO 0.1%)
- CBD 50 μg: whole blood + LPS 100 ng/mL + CBD (kanarescue 5% in DMSO 0.1%) 50 μg/mL
- CBD 100 μg: whole blood + LPS 100 ng/mL CBD (kanarescue 5% in DMSO 0.1%) 100 μg/mL
The study then focused on the levels of the major regulating molecules. IL-6 and TNF-α are the major pro-inflammatory cytokines (molecules/factors) driving inflammatory response and immune cell activation; they play a key role in the physiological inflammatory response such as during infection, but also in several diseases where elevated levels of these cytokines are associated with a poor clinical outcome. IL-10 is an anti-inflammatory cytokine and immune-regulating mediator. The balance between TNF-α and IL-10 is important for immune homeostasis maintenance; commonly, an increase in TNF-α is counterbalanced by a simultaneous increase in the anti-inflammatory cytokine IL-10, which suppresses the production of many activating and regulatory mediators. Furthermore, the study evaluated the effect of CBD on Nf-κB (key regulator of inflammatory response that regulates the expression of several pro-inflammatory mediators) and COX-2 expression. COX-2 plays a fundamental role in the inflammatory cascade, and thus in acute and chronic inflammation.
RESULTS → When stimulation with LPS was performed in the presence of CBD (50 and 100 μg/mL) there was a significant reduction in cytokines secretion. The study observed a dose dependence effect of CBD; when compared to CBD 50 μg/mL, the dose of CBD 100 μg/mL produced a bigger inhibitory effect on IL-6 and TNFα release in whole blood supernatant.
Graphic 1: IL-6 and TNF-α levels after LPS 100ng/mL stimulation and with concomitant use of CBD at different doses (50 and 100 ng/mL)
When evaluating the TNF-α to IL-10 ratio as a cytokine marker of the balance between key pro and anti-inflammatory levels, the results show that LPS stimulation produces a significant increase in the TNF-α to IL-10 ratio in whole dog blood, while treatment with CBD is able to restore the TNF-α to IL-10 ratio compared to the control groups. Finally, the LPS stimuli induced an increase in Nf-κB p-65 activation, while there was a reduction in Nf-κB expression for the groups incubated with LPS and CBD. Moreover, levels for COX-2, known to be upregulated during inflammation, were increased in the LPS group. The CBD treatment (50 and 100 μg/mL) group showed significantly lower COX-2 expression compared to LPS.