Low-Dose Rifabutin Increases Cytotoxicity in Antimitotic-Drug-Treated Resistant Cancer Cells by Exhibiting Strong P-gp-Inhibitory Activity was written by Lee, Ji Sun;Oh, Yunmoon;Kim, Hyung Sik;Yoon, Sungpil. And the article was included in International Journal of Molecular Sciences in 2022.Reference of 80621-81-4 This article mentions the following:
The cytotoxicity of various antibiotics at low doses in drug-resistant cancer cells was evaluated. Low doses of rifabutin were found to markedly increase the cytotoxicity of various antimitotic drugs, such as vincristine (VIC), to P-glycoprotein (P-gp)-overexpressing antimitotic-drug-resistant KBV20C cells. Rifabutin was also found to exert high levels of P-gp-inhibitory activity at 4 and 24 h posttreatment, suggesting that the cytotoxicity of VIC + rifabutin was mainly due to the direct binding of rifabutin to P-gp and the reduction of VIC efflux by P-gp. The combination of VIC + rifabutin also increased early apoptosis, G2 arrest, and the DNA damaging marker, pH2AX protein. Interestingly, only the combination of VIC + rifabutin induced remarkable levels of cytotoxicity in resistant KBV20C cells, whereas other combinations (VIC + rifampin, VIC + rifapentine, and VIC + rifaximin) induced less cytotoxicity. Such finding suggests that rifabutin specifically increases the cytotoxicity of VIC in KBV20C cells, independent of the toxic effect of the ansamycin antibiotic. Only rifabutin had high P-gp-inhibitory activity, which suggests that its high P-gp-inhibitory activity led to the increased cytotoxicity of VIC + rifabutin. As rifabutin has long been used in the clinic, repositioning this drug for P-gp-overexpressing resistant cancer could increase the availability of treatments for patients with drug-resistant cancer. In the experiment, the researchers used many compounds, for example, (2S,16Z,18E,20S,21S,22R,23R,24R,25S,26R,27S,28E)-25-(Acetyloxy)-5,6,21,23-tetrahydroxy-27-methoxy-2,4,11,16,20,22,24,26-octamethyl-2,7-(epoxypentadeca[1,11,13]trienimino)benzofuro[4,5-e]pyrido[1,2-a]benzimidazole-1,15(2H)-dione (cas: 80621-81-4Reference of 80621-81-4).
(2S,16Z,18E,20S,21S,22R,23R,24R,25S,26R,27S,28E)-25-(Acetyloxy)-5,6,21,23-tetrahydroxy-27-methoxy-2,4,11,16,20,22,24,26-octamethyl-2,7-(epoxypentadeca[1,11,13]trienimino)benzofuro[4,5-e]pyrido[1,2-a]benzimidazole-1,15(2H)-dione (cas: 80621-81-4) belongs to benzofurans derivatives. Benzofuran derivatives have shown many biological activities, including antifungal and antimicrobial properties, and acting as antagonists of H3 receptors and angiotensin II. As benzofurans are prone to undergo ring opening of the heterocycle, examples of reduction of this type of aromatics by using dissolving metals are rather scarce.Reference of 80621-81-4
Referemce:
Benzofuran – Wikipedia,
Benzofuran | C8H6O – PubChem