Cannabidiol Finds Dihydrocannabidiol as Its Twin in Anti-Inflammatory Activities and the Mechanism

Ethnopharmacological relevance: The hemp (cataloged at the “Medicinal Plant Names Services” as Cannabis sativa L.) extracts, cannabinoids have been used for centuries in Southeast Asia as folk medicines and now authorized by about 50 countries for application in medicine, health care products and cosmetics. As the most consumed cannabinoid, cannabidiol (CBD) has been recognized due to its various bioactivities, including anti-inflammatory and antibacterial properties.

Aims of the study: The utilization of CBD is limited due to its potential conversion to psychoactive Δ9-tetrahydrocannabinol in strong acidic environment, demanding to excavate safer alternatives with clarified bioactivities. Yet the anti-inflammatory and antibacterial properties of CBD still remain unknown, in both of the performances and the corresponding mechanisms. Previously, a synthetic CBD analogue, H2CBD (Dihydrocannabidiol) was found to be effective as CBD does towards some antioxidantive activities and mouse seizure mitigation. Therefore, it is wondering if H2CBD also acted similarly as CBD does in the aspect of anti-inflammatory performance and mechanism, and the safety.

Material and methods: The anti-inflammatory properties of CBD and H2CBD were revealed with enzymatic assays, proteins denaturation and lipopolysaccharide (LPS) stimulated RAW264.7 cells model, with epigallocatechin gallate (EGCG) as the positive control. Their anti-inflammatory mechanism was revealed with ELISA and Western blot assay. The antibacterial properties of CBD and H2CBD were also investigated towards E. faecalis and B. cereus along with their synergistic effect with commercial antibiotics.

Results: CBD and H2CBD exhibited almost same (P> 0.05) performance in all the assayed anti-inflammatory properties, yet their anti-inflammatory efficiencies positively correlated to their antioxidantive activity. Moreover, both of CBD and H2CBD presented anti-inflammation to LPS stimulated RAW264.7 cells through NF-κB and AKT pathway. Furthermore, CBD and H2CBD also supplied strong and very similar (P>0.05) antibacterial activities, comparable to tetracycline in same dose and strength. The erythrocyte hemolytic assay indicates CBD and H2CBD possessing the same safety. All the combinations of H2CBD with other cannabinoids or antibiotics present no antagonism against the bacteria, but nice synergistic or additive effect in some cases.

Conclusion: CBD and H2CBD presented very similarly in all the assayed anti-inflammatory performances, undergoing same inflammatory mechanism with NF-κB and AKT pathway; they also expressed similar antibacterial activity, like twins. These findings will supply CBD a sustainable, safer and economic alternative with same excellent performances.