Secondary bile acids ⇒ Ursodeoxycholic acid {90000394}

Shared Reference Notes

• [1.1] [#Primary bile acids, #Secondary bile acids] 
  - Primary #Bile Acids are conjugated in several different forms and secreted into the intestine. - a small portion (~5%) of the Primary #Bile Acids (about 200 to 800 mg daily in humans) escapes the reabsorption in Ileum and reaches the colon where gut bacteria convert them into secondary #Bile Acids (SBAs), such as #Deoxycholic acid (DCA), ursodeoxycholic acid (UDCA), and #Lithocholic acid (LCA). - majority (90% to 95%) of SBAs are reabsorbed into colonocytes to return to the liver for detoxification and recycling.
• [#Colon adenomas, #Colorectal cancer] [#Deoxycholic acid, #Secondary bile acids] - UDCA has microbiome-changing and DCA‐lowering prpperties. - treatment with UDCA, decreased recurrence of adenomas with high-grade dysplasia. - DCA also stimulates the uptake of polyamines in CRC cells, which also have tumorigenic effects.
• [1.2] [#Dementia with Lewy bodies (DLB)] 
  - #Ruminococcus torques and #Collinsella are also major #Secondary bile acids-producing bacteria, we quantified fecal bile acids and found that the production of ursodeoxycholic acid (UDCA) was high in DLB.
• [1.3] [#Blood Brain Barrier Integrity] 
  - #Deoxycholic acid and ursodeoxycholic acid, may also modulate BBB integrity.
• [1.4] [#Hepatocellular cancer] 
  - hepatocellular carcinoma > Ursodeoxycholic acid and #Ursocholic acid were significantly enriched in the feces of patients with objective responses and strongly correlated with the abundance of #Lachnoclostridium.
• [1.5] [#Parkinson’s Disease] [#Alpha-synuclein] 
  - Ursodeoxycholic acid is another secondary bile acid that has neuroprotective effects an can prevent the damaging effects of #Deoxycholic acid and #Lithocholic acid. - In a chronic PD mouse model, pretreatment with tauroursodeoxycholic acid can protect against dopaminergic neuronal damage, prevent microglial and astroglial activation, as well as the dopamine and 3-4-dihydroxyphenulacetic acid reductions caused by MPTP. - Pretreatment with tauroursodeoxycholic acid can prevent protein oxidation and autophagy, in addition to inhibiting α-synuclein aggregation
• [1.6] 
  - UDCA has been found to activate the epidermal growth factor receptor (EGFR)/ Raf-1/ extracellular regulating kinase (ERK) signaling pathway in #Colorectal cancer.
• [#Diabetes Type 2] [#Ruminococcus gnavus] - R. gnavus was found to have a positive correlation with #Glycine ursodeoxycholic acid (GUDCA) levels, which have been shown to improve metabolism by promoting fat thermogenesis
• [#Inflamatory bowel disease] [#Ruminococcus gnavus] - R. gnavus has also been reported as a producer of ursodeoxycholic acid (UDCA) > It possesses an enzyme that can degrade 7-keto #Lithocholic acid (LCA) into UDCA. - Administration of UDCA has been shown to increase colonic LCA levels and inhibit caspase-3 cleavage. - Abnormal apoptosis in intestinal epithelial cells (IECs) can disrupt the integrity of the intestinal barrier, leading to bacterial infiltration and triggering an inflammatory cascade.
• [#Obesity] - UDCA alters the profile of free fatty acids (FFAs) by inhibiting lipogenesis, promoting FAO, and reducing fatty acid uptake in adipose tissue.
• [#Ruminococcus gnavus] - R. gnavus has been reported to produce UDCA.
• [1.7] [#Autism] 
  - UDCA, also lower in future ASD, has shown therapeutic promise in conditions spanning metabolic disease, #Autoimmune disease, chronic inflammatory disease, and neuropathology. - Its ability to cross the blood-brain barrier is notable, with anti-inflammatory and anti-apoptotic mechanisms possibly linked to dopamine and mitochondrial regulation.
• [1.8] [#Alzheimer’s disease] [#Reactive Oxygen Species] 
  - UDCA reduces the levels of ROS, tumor necrosis factor alpha (TNFα), and interleukin-1 beta (IL-1β), exerting anti-apoptotic, #Oxidative stress and inflammatory effects in AD

References Notes