C(16)-C(22) oxygen-bridged analogues of ceDAF-12 and LXR ligands

Synthesis and Antitumor Activity of Diosgenin Hydroxamic Acid and Quaternary Phosphonium Salt Derivatives

Diosgenin, a component separated from Dioscorea plants, is an important starting material for steroid hormone drugs and semisynthetic steroids. In the work, two series of diosgenin derivatives were designed, synthesized, and evaluated for their cellular anticancer activities. Most of the target compounds exhibited good inhibitory activities against four cell lines, Aspc-1 (human colon adenocarcinoma cells), H358 (human nonsmall cell lung cancer cells), HCT116 (human colorectal adenocarcinoma cells), and SW620 (human metastatic pancreatic cancer cells). Among them, the representative compound 2.2f exhibited 7.9-341.7-fold antiproliferative activities against the above-mentioned four cell lines compared with the lead compound diosgenin.

CYP4V2 fatty acid omega hydroxylase, a druggable target for the treatment of metabolic associated fatty liver disease (MAFLD)

Fatty acids are essential in maintaining cellular homeostasis by providing lipids for energy production, cell membrane integrity, protein modification, and the structural demands of proliferating cells. Fatty acids and their derivatives are critical bioactive signaling molecules that influence many cellular processes, including metabolism, cell survival, proliferation, migration, angiogenesis, and cell barrier function. The CYP4 Omega hydroxylase gene family hydroxylate various short, medium, long, and very-long-chain saturated, unsaturated and polyunsaturated fatty acids. Selective members of the CYP4 family metabolize vitamins and biochemicals with long alkyl side chains and bioactive prostaglandins, leukotrienes, and arachidonic acids. It is uncertain of the physiological role of different members of the CYP4 omega hydroxylase gene family in the metabolic control of physiological and pathological processes in the liver. CYP4V2 is a unique member of the CYP4 family. CYP4V2 inactivation in retinal pigment epithelial cells leads to cholesterol accumulation and Bietti's Crystalline Dystrophy (BCD) pathogenesis. This commentary provides information on the role CYP4V2 has in metabolic syndrome and nonalcoholic fatty liver disease progression. This is accomplished by identifying its role in BCD, its control of cholesterol synthesis and lipid droplet formation in C. elegans, and the putative function in cardiovascular disease and gastrointestinal/hepatic pathologies.

Synthesis and biological activity of cyclopropyl Δ7-dafachronic acids as DAF-12 receptor ligands

The four cyclopropyl stereoisomers of Δ7-dafachronic acids were prepared from the bile acid hyodeoxycholic acid and employed as chemical tools to exploit the importance of the orientation and spatial disposition of the carboxyl tail and the C25-methyl group for the binding at the DAF-12 receptor. The synthesis route was based on (a) Walden inversion and stereoselective PtO₂-hydrogenation to convert the L-shaped 5β-cholanoid scaffold into the planar 5α-sterol intermediate; (b) two-carbon homologation of the side chain by Wittig and cyclopropanation reaction; and (c) formation of the 3-keto group and Δ7 double bond. The synthesized isomers were isolated and tested for their activity as DAF-12 ligands by AlphaScreen assays. Results showed a significant loss of potency and efficacy for all the four stereoisomers when compared to the parent endogenous ligand. Computational analysis has evidenced the configurational and conformational arrangement of both the carboxylic and the C25-methyl group of dafachronic acids as key structural determinants for DAF-12 binding and activation.

Dihydrodiosgenin inhibits endothelial cell-derived factor VIII and platelet-mediated hepatocellular carcinoma metastasis

Background: Our previous studies have demonstrated that diosgenin and diosgenin derivatives exhibit excellent antithrombotic activity via regulating platelet function and coagulation factor level. Platelets and blood coagulation system are highly associated with tumor hematogenous metastasis. Therefore, the purpose of this study was to evaluate whether dihydrodiosgenin (dydio) mediated-platelet inhibition or coagulation factor level modulation is involved in hepatocellular carcinoma cell (HCC) metastasis.

Methods: Cell viability was examined by MTT and colony formation assays. Platelet aggregation text and morphology were used to assess dydio’s role on tumor cell-induced platelet activation (TCIPA). Scratch assay, adhesion assay and Western blot were used to evaluate dydio’s role on platelet-mediated metastasis. Western blot and fluorescence detection were performed to clarify dydio's role on endothelial cell (EC) function. The mice lung metastasis model was constructed to investigated dydio’s function on coagulation factor and platelet-mediated metastasis.

Results: This study found that pretreatment with dydio caused a significant inhibition of TCIPA. Platelets exposed to dydio significantly inhibited their adhesion to tumor cells, meanwhile, releasates of platelets that pretreated with dydio led to diminished cancer cell proliferation and migration along with the increase of epithelial markers E-cadherin and loss of mesenchymal phenotype. Additionally, ECs pretreated with dydio suppressed factor VIII (FVIII) level which in turn restrained the activation of platelets and the adhesion of cancer cells or platelets to ECs. Interestingly, our study demonstrated that FVIII could promote HCC proliferation. In vivo study revealed that mice intragastrical (i.g.) administration with dydio significantly inhibited the lung metastasis of hepal-6 cells which is highly correlated with the altered platelet function and coagulation level.

Conclusion: Taken together, these results demonstrated that dydio altered platelet function and coagulation FVIII level, resulting in decreased metastatic potential of HCC. Thus, our study reveals that dydio exerts novel mechanisms of antitumor action beside its direct antitumor activity.

Recent advances in the synthesis of oxaspirolactones and their application in the total synthesis of related natural products

Oxaspirolactones are ubiquitous structural motifs found in natural products and synthetic molecules with a diverse biochemical and physicochemical profile, and represent a valuable target in natural product chemistry and medicinal chemistry.

Dihydrodiosgenin protects against experimental acute pancreatitis and associated lung injury through mitochondrial protection and PI3Kγ/Akt inhibition

BACKGROUND AND PURPOSE

Acute pancreatitis (AP) is a painful and distressing disorder of the exocrine pancreas with no specific treatment. Diosgenyl saponins extracted from from Dioscorea zingiberensis C. H. Wright have been reported to protect against experimental models of AP. Diosgenin, or its derivatives are anti-inflammatory in various conditions. However, the effects of diosgenin and its spiroacetal ring opened analogue, dihydrodiosgenin (Dydio), on AP have not been determined.

EXPERIMENTAL APPROACH

Effects of diosgenin and Dydio on sodium taurocholate hydrate (Tauro)-induced necrosis were tested, using freshly isolated murine pancreatic acinar cells. Effects of Dydio on mitochondrial dysfunction in response to Tauro, cholecystokinin-8 and palmitoleic acid ethyl ester were also assessed. Dydio (5 or 10 mg·kg^-1 ) was administered after the induction in vivo of Tauro-induced AP (Wistar rats), caerulein-induced AP and palmitoleic acid plus ethanol-induced AP (Balb/c mice). Pancreatitis was assessed biochemically and histologically. Activation of pancreatic PI3Kγ/Akt was measured by immunoblotting.

KEY RESULTS

Dydio inhibited Tauro-induced activation of the necrotic cell death pathway and prevented pancreatitis stimuli-induced mitochondrial dysfunction. Therapeutic administration of Dydio ameliorated biochemical and histopathological responses in all three models of AP through pancreatic mitochondrial protection and PI3Kγ/Akt inactivation. Moreover, Dydio improved pancreatitis-associated acute lung injury through preventing excessive inflammatory responses.

CONCLUSION AND IMPLICATIONS

These data provide in vitro and in vivo mechanistic evidence that the diosgenin analogue, Dydio could be potential treatment for AP. Further medicinal optimization of diosgenin and its analogue might be a useful strategy for identifying lead candidates for inflammatory diseases.