As the “mother” cannabinoid, CBGA (cannabigerolic acid) is converted to THCA, CBDA, and several other cannabinoids, and exists as a minor cannabinoid in live cannabis plants. CBG (cannabigerol) is the neutral form of CBGA by decarboxylation at high temperature. Besides the three widely adopted chemotypes, which are chemotype I (THC dominant), chemotype II (THC ≈ CBD), and chemotype II (CBD dominant), a fourth chemotype has been descripted for plants with CBG as the major cannabinoid. Without psychoactive effects, CBG dominant plants have the potential for both textile and pharmaceutical purposes.
CBG has analgesic, antifungal, antidepressant, and antihypertensive properties in basic research models and animal models. CBG also has remarkable anticancer properties. CBG was reported to reduce cell proliferation in several cancer cell lines, including human breast, prostate, and colorectal carcinoma, gastric adenocarcinoma, C6-rat glioma, rat basophilic leukaemia, and transformed thyroid cells.
Glioblastoma is the most aggressive cancer among primary brain tumours and the overall mean survival of patients' post-diagnosis averages around 16 months despite modern therapies. One recent study compared the cytotoxic, apoptotic, and anti-invasive effects of the CBG alone and together with CBD and THC on glioblastoma tumour cells. The results showed that CBG could kill glioblastoma cells, with comparable killing effects to THC, and in addition could inhibit glioblastoma cell invasion. Moreover, CBG can destroy therapy-resistant glioblastoma stem cells, which are extremely resistant to various cancer treatments. This study also showed that THC has little added value in glioblastoma treatment when compared to CBD and CBG in combination. Without the potential cognitive impairment of THC, CBG is considered as a new yet unexplored adjuvant treatment strategy of glioblastoma.
References:
Russo, E. B. & Marcu, J. Cannabis Pharmacology: The Usual Suspects and a Few Promising Leads. in Cannabinoid Pharmacology 67–134 (Elsevier, 2017). doi:10.1016/bs.apha.2017.03.004. https://pubmed.ncbi.nlm.nih.gov/28826544/
Ligresti, A., De Petrocellis, L. & Di Marzo, V. From Phytocannabinoids to Cannabinoid Receptors and Endocannabinoids: Pleiotropic Physiological and Pathological Roles Through Complex Pharmacology. Physiol Rev 96, 1593–1659 (2016). https://pubmed.ncbi.nlm.nih.gov/27630175/
Lah, T. T. et al. Cannabigerol Is a Potential Therapeutic Agent in a Novel Combined Therapy for Glioblastoma. Cells (2073-4409) 10, 340 (2021). https://pubmed.ncbi.nlm.nih.gov/33562819/
