Gallstone and Gallbladder Disease: Biliary Tract and Cholangiopathies.

Cholestatic liver diseases are named primarily due to the blockage of bile flow and buildup of bile acids in the liver. Cholestasis can occur in cholangiopathies, fatty liver diseases, and during COVID-19 infection. Most literature evaluates damage occurring to the intrahepatic biliary tree during cholestasis; however, there may be associations between liver damage and gallbladder damage. Gallbladder damage can manifest as acute or chronic inflammation, perforation, polyps, cancer, and most commonly gallstones. Considering the gallbladder is an extension of the intrahepatic biliary network, and both tissues are lined by biliary epithelial cells that share common mechanisms and properties, it is worth further evaluation to understand the association between bile duct and gallbladder damage. In this comprehensive article, we discuss background information of the biliary tree and gallbladder, from function, damage, and therapeutic approaches. We then discuss published findings that identify gallbladder disorders in various liver diseases. Lastly, we provide the clinical aspect of gallbladder disorders in liver diseases and ways to enhance diagnostic and therapeutic approaches for congruent diagnosis. © 2023 American Physiological Society. Compr Physiol 13:4909-4943, 2023.

Cannabidiol and Cannabigerol Inhibit Cholangiocarcinoma Growth In Vitro via Divergent Cell Death Pathways.

Cholangiocarcinoma (CCA) is a rare and highly lethal disease with few effective treatment options. Cannabinoids, cannabidiol (CBD) and cannabigerol (CBG) are non-psychedelic components extracted from cannabis. These non-psychoactive compounds have shown anti-proliferative potential in other tumor models; however, the efficacy of CBD and CBG in CCA is unknown. Furthermore, two cell death pathways are implicated with CBD resulting in autophagic degeneration and CBG in apoptosis. HuCC-T1 cells, Mz-ChA-1 cells (CCA cell lines) and H69 cells (immortalized cholangiocytes), were treated with CBD and CBG for 24 to 48 h. The influence of these cannabinoids on proliferation was assessed via MTT assay. Apoptosis and cell cycle were evaluated via Annexin-V apoptosis assay and propidium iodide, respectively. The expression of proliferation biomarker Ki-67, apoptosis biomarker BAX, and autophagic flux biomarkers LC3b and LAMP1 were evaluated via immunofluorescence. Cell migration and invasion were evaluated via wound healing assay and trans-well migration invasion assays, respectively. The colony formation was evaluated via colony formation assay. In addition, the expression of autophagy gene LC3b and apoptosis genes BAX, Bcl-2, and cleaved caspase-3 were evaluated via Western blot. CBD and CBG are non-selective anti-proliferative agents yielding similar growth curves in CCA; both cannabinoids are effective, yet CBG is more active at lower doses. Low doses of CBD and CBG enhanced immortalized cholangiocyte activity. The reduction in proliferation begins immediately and occurs maximally within 24 h of treatment. Moreover, a significant increase in the late-stage apoptosis and a reduction in the number of cells in S stage of the cell cycle indicates both CBD and CBG treatment could promote apoptosis and inhibit mitosis in CCA cells. The fluorescent expression of BAX and LC3b was significantly enhanced with CBD treatment when compared to control. LAMP1 and LC3b colocalization could also be observed with CBD and CBG treatment indicating changes in autophagic flux. A significant inhibition of migration, invasion and colony formation ability was shown in both CBD and CBG treatment in CCA. Western blot showed an overall decrease in the ratio of anti-apoptotic protein Bcl-2 with respect to pro-apoptotic protein BAX with CBG treatment. Furthermore, CBD treatment enhanced the expression of Type II cell death (autophagic degeneration) protein LC3b, which was reduced in CBG-treated CCA cells. Meanwhile, CBG treatment upregulated Type I cell death (programmed apoptosis) protein cleaved caspase-3. CBD and CBG are effective anti-cancer agents against CCA, capable of inhibiting the classic hallmarks of cancer, with a divergent mechanism of action (Type II or Type I respectively) in inducing these effects.

Low-Dose Administration of Cannabigerol Attenuates Inflammation and Fibrosis Associated with Methionine/Choline Deficient Diet-Induced NASH Model via Modulation of Cannabinoid Receptor.

Non-Alcoholic Steatohepatitis (NASH) is the progressive form of Non-Alcoholic Fatty Liver Disease (NAFLD). NASH is distinguished by severe hepatic fibrosis and inflammation. The plant-derived, non-psychotropic compound cannabigerol (CBG) has potential anti-inflammatory effects similar to other cannabinoids. However, the impact of CBG on NASH pathology is still unknown. This study demonstrated the therapeutic potential of CBG in reducing hepatic steatosis, fibrosis, and inflammation. METHODS: 8-week-old C57BL/6 male mice were fed with methionine/choline deficient (MCD) diet or control (CTR) diets for five weeks. At the beginning of week 4, mice were divided into three sub-groups and injected with either a vehicle, a low or high dose of CBG for two weeks. Overall health of the mice, Hepatic steatosis, fibrosis, and inflammation were evaluated. RESULTS: Increased liver-to-body weight ratio was observed in mice fed with MCD diet, while a low dose of CBG treatment rescued the liver-to-body weight ratio. Hepatic ballooning and leukocyte infiltration were decreased in MCD mice with a low dose of CBG treatment, whereas the CBG treatment did not change the hepatic steatosis. The high dose CBG administration increased inflammation and fibrosis. Similarly, the expression of cannabinoid receptor (CB)1 and CB2 showed decreased expression with the low CBG dose but not with the high CBG dose intervention in the MCD group and were co-localized with mast cells. Additionally, the decreased mast cells were accompanied by decreased expression of transforming growth factor (TGF)-ß1. CONCLUSIONS: Collectively, the low dose of CBG alleviated hepatic fibrosis and inflammation in MCD-induced NASH, however, the high dose of CBG treatment showed enhanced liver damage when compared to MCD only group. These results will provide pre-clinical data to guide future intervention studies in humans addressing the potential uses of CBG for inflammatory liver pathologies, as well as open the door for further investigation into systemic inflammatory pathologies.