This study evaluated the protective effects of lipid emulsion (LE) against bupivacaine-induced cytotoxicity in human rotator cuff fibroblasts (hRCFs). hRCFs were divided into control, bupivacaine alone (Bupivacaine), LE alone (LE), LE-pretreated bupivacaine (LE + Bupivacaine), N-acetylcysteine alone (NAC), and NAC-pretreated bupivacaine (NAC + Bupivacaine). Cell viability was assessed by MTT and Live/Dead assays; ROS production by DCF-DA; apoptosis by Annexin V/PI staining and TUNEL assay; cleaved caspase-3 and PARP expression by Western blot; cell cycle by FACS; cell proliferation by Ki-67 staining; and wound healing. Cell viability decreased in a bupivacaine concentration-dependent manner (p < 0.001). Pretreatment with LE or NAC improved cell viability compared with bupivacaine alone (p < 0.001). ROS levels were elevated by bupivacaine, whereas LE and NAC pretreatments significantly reduced ROS (p < 0.001). Bupivacaine-induced apoptosis was significantly attenuated by LE and NAC, as evidenced by reductions in apoptosis rate, expression levels of cleaved caspase-3 and PARP-1, TUNEL-positive nuclei, and the subG1 population (p < 0.05). Cell proliferation and wound healing were suppressed by bupivacaine but restored by LE and NAC pretreatment. This study demonstrates bupivacaine-induced cytotoxicity in hRCFs and suggests that LE and NAC mitigate these effects by reducing oxidative stress and promoting cell survival and wound healing.
Kim et al. (Thu,) studied this question.