Synthetic heteroprostanoids of A- and E-types as novel non-comprehensive inhibitors of adenylyl cyclase in rat hepatocytes

Synthesis of spirocyclic Δ4-isoxazolines via [3 + 2] cycloaddition of indanone-derived ketonitrones with alkynes

A [3 + 2] cycloaddition of indanone-derived nitrones and alkynes under mild conditions is developed, allowing facile synthesis of spirocyclicindenyl isoxazolines with structural diversity. The sequential protocol of generated in situ ketonitrone from unsaturated ketones and N-alkylhydroxylamines is also achieved successfully, affording the desired products in considerable yield with moderate to good diastereoselectivity. Moreover, the spirocyclic product can be conveniently transformed into indenyl-based allylic alcohol and enamide.

A [3 + 2] cycloaddition of indanone-derived nitrones with alkynes under mild conditions has been developed. It is a highly efficient and straightforward method for the synthesis of diverse spirocyclicindenyl isoxazolines.

Hepatoprotective action of prostaglandin A(2) analogs under CCl(4)-induced liver injury in vitro

AIM

The cytoprotective effects of six novel synthetic prostaglandin A(2) analogs against carbon tetrachloride (CCl(4)) as a toxic agent were studied with isolated rat liver hepatocytes in vitro.

RESULTS

It was found that hepatocytes treatment with CCl(4) induced: (i) a significant increase of lactic dehydrogenase (LDH) release from cytoplasm; (ii) leakage of glutamate dehydrogenase (GDH) and acid phosphatase from mitochondria and lysosomes, respectively; (iii) 10-fold increase of trien conjugates formation; and (iv) a reduction of free SH-groups by 50%. Prostanoids U-26, U-9 and U-34 decreased cytotoxic index of CCl(4) on average by 1.5-2.0 times and were more effective than PGI(2), the well-known hepatoprotector of prostanoids type. The protective action of the prostanoids was not a cAMP- or Ca(2+)-dependent process. However, prostanoids U-26, U-9 and U-34 normalized intracellular content of SH-groups, reduced trien conjugates formation by 60-80% and strongly prevented enzyme leakage through cellular membranes. They were also able to inhibit CCl(4) effects via decreasing cytochrome P(450)2E1 activity.

CONCLUSION

The results obtained demonstrate that prostanoids provide cytoprotective effects on liver hepatocytes through the prevention of lipid peroxidation of the plasma and the cellular membranes and maintenance of their barrier function.