Guggulsterone, a farnesoid X receptor antagonist lowers plasma trimethylamine-N-oxide levels: An evidence from in vitro and in vivo studies

The current study investigated the role of guggulsterone (GS), a farnesoid X receptor antagonist, in the choline metabolism and its trimethylamine (TMA)/flavin monooxygenases/trimethylamine-N-oxide (TMAO) inhibiting potential in a series of in vitro and in vivo studies as determined by high-performance liquid chromatography (HPLC), mass spectroscopy (MS), and liquid chromatography (LC)-MS techniques. Atherosclerosis (AS) was successfully induced in a group of experimental animals fed with 2% choline diet for 6 weeks. Serum lipid profiles such as total cholesterol, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and very low-density lipoprotein cholesterol were measured. Pro-inflammatory cytokines levels, markers for a hepatic injury, and oxidative stress markers were assessed. Interestingly, GS reduced the level of TMA/TMAO in both in vitro and in vivo studies as demonstrated by the peaks obtained from HPLC, MS, and LC-MS. Furthermore, GS exhibited cardioprotective and antihyperlipidemic effects as evidenced by the attenuation of levels of several serum lipid profiles and different atherogenic risk predictor indexes. GS also prevented hepatic injury by successfully restoring the levels of hepatic injury biomarkers to normal. Similarly, GS inhibited the production of pro-inflammatory cytokines levels, as well as GS, enhanced antioxidant capacity, and reduced lipid peroxidation. Histopathological study of aortic sections demonstrated that GS maintained the normal architecture in AS-induced rats. On the basis of results obtained from current investigation, we suggest that GS might have a great therapeutic potential for the treatment of AS.

Evaluation of 4-methyl-2-[(2-methylbenzyl) amino]-1,3-thiazole-5-carboxylic acid against hyperglycemia, insulin sensitivity, and oxidative stress-induced inflammatory responses and β-cell damage in the pancreas of streptozotocin-induced diabetic rats

4-Methyl-2-[(2-methylbenzyl) amino]-1,3-thiazole-5-carboxylic acid (bioactive compound (BAC)), a novel thiazole derivative, is a xanthine oxidase inhibitor and free radical scavenging agent. Effects of BAC on hyperglycemia, insulin sensitivity, oxidative stress, and inflammatory mediators were evaluated in streptozotocin (STZ)-induced neonatal models of non-insulin-dependent diabetes mellitus (NIDDM) rats where NIDDM was induced in neonatal pups with single intraperitoneal injection of STZ (100 mg/kg). The effect of BAC (10 and 20 mg/kg, p.o.) for 3 weeks was evaluated by the determination of blood glucose, oral glucose tolerance test (OGTT), HbA1c level, insulin level, insulin sensitivity, and insulin resistance (IR). Furthermore, inflammatory mediators (tumor necrosis factor-alpha and interleukin-6) and oxidative stress were estimated in serum and pancreatic tissue, respectively. Significant alteration in the level of blood glucose, OGTT, HbA1c, insulin level, insulin sensitivity, in addition variation in the antioxidant status and inflammatory mediators, and alteration in histoarchitecture of pancreatic tissue confirmed the potential of BAC in STZ-induced neonatal models of NIDDM rats. Pretreatment with BAC restored the level of glucose by decreasing the IR and increasing the insulin sensitivity. Furthermore, BAC balanced the antioxidant status and preserved the inflammatory mediators. Histological studies of pancreatic tissues showed normal architecture after BAC administration to diabetic rats. Altogether, our results suggest that BAC successfully reduces the blood glucose level and possesses antioxidant as well as anti-inflammatory activities. This leads to decreased histological damage in diabetic pancreatic tissues, suggesting the possibility of future diabetes treatments.