Inhibition of Adenocarcinoma TA3 Ascites Tumor Growth by Rifamycin Derivatives

Abstract

A growth inhibitory effect on adenocarcinoma TA3 ascites tumors in LAF₁/J mice resulted from the repeated IP administration of subtoxic doses of 3 rifamycin derivatives: rifampicin (Rif)¹, dimethylbenzyldesmethylrifampicin (DMB), and rifazone-8₂ (R-8₂). A high-viscosity methylcellulose vehicle was found to be essential for obtaining a uniform drug suspension and a significant antitumor effect by the least water soluble derivatives, DMB and R-8₂. The more hydrophilic derivative, Rif, was found to have a comparable growth inhibitory effect on TA3 cells when prepared in 0.9% NaCl solution with or without added methylcellulose. Oral or SC drug injections did not have an antitumor effect. The results of this study point to the importance of vehicle and route of administration in chemotherapy trials with these compounds.

Perigraft vascularization and incorporation of implanted Dacron prostheses are affected by rifampicin coating

“…9 Moreover, its real clinical benefit remains uncertain and is discussed controversially. 10,11 Besides its well characterized antibactericidal activity, rifampicin has also been shown in several studies to influence a variety of cellular processes, such as angiogenesis, 12 proliferation, 13 apoptosis, 14 and inflammation. 15 In the initial phase after implantation of a prosthetic vascular graft, these processes essentially contribute to the rapid formation of a new granulation tissue surrounding the implant.…”