Cytotoxic responses of human chondrocytes to bupivacaine, levobupivacaine, and ropivacaine

Abstract

Background Intra-articular injections of local anesthetics are used commonly in articular surgery. However, chondrocyte viability and metabolism may be adversely affected by various anesthetics. Objectives To assess the chondrotoxic effects of bupivacaine, levobupivacaine, and ropivacaine on human chondrocytes and elucidate possible mechanisms of chondrocyte death. Methods Cultured human chondrocytes (CHON-001) were exposed to 0.25% or 0.5% of bupivacaine, levobupivacaine, and ropivacaine in vitro. Cell viability was determined by flow cytometry after 15, 30, 60, and 120 min of exposure. Chondrocyte reactive oxygen species (ROS) production was measured every 10 min for up to 1 h using 2ʹ,7ʹ-dichlorodihydrofluorescein staining. Chondrocyte production of glycosaminoglycan was measured by capillary electrophoresis. NO production was measured using a colorimetric assay kit. Results We found a significant increase in chondrotoxicity dependent on exposure time and concentration of the anesthetic. At 60 min, chondrocyte viability was significantly (P < 0.05) decreased when exposed to 0.5% levobupivacaine (32.5%), or 0.25% or 0.5% bupivacaine (34.3% or 46.5%, respectively) compared with exposure to phosphate-buffered saline (PBS) vehicle as a control. Cell death at 120 min was mainly necrosis. There was no difference in viability after treatment with either concentration (0.25% or 0.5%) of ropivacaine at any time compared with exposure to PBS. We found increased production of NO, while ROS decreased after exposure to any of the anesthetics tested. Conclusions Ropivacaine may be safer than bupivacaine or levobupivacaine as an intra-articular analgesic. Chondrotoxicity of anesthetics in vitro may be mediated via a reactive nitrogen species-dependent pathway.

<i>In vitro</i> chondrotoxicity of bupivacaine, levobupivacaine and ropivacaine and their effects on caspase activity in cultured canine articular chondrocytes

“…Although the level of chondrotoxicity was similar between Lev 0.062% and Rop 0.062%, especially with the MTT assay, ropivacaine was the least chondrotoxic among the three local anesthetics. Similar to our findings, several studies have shown that ropivacaine is less chondrotoxic compared to other local anesthetics [ 6 , 14 , 19 , 31 ]. On the other hand, comparisons between bupivacaine and levobupivacaine have had mixed results.…”

“…While many studies have demonstrated the chondrotoxicity of local anesthetics [ 1 , 10 , 13 , 19 , 25 ], the mechanism of their cytotoxicity has not yet been fully elucidated [ 14 , 19 ]. Because local anesthetics are a mainstay in pain management, it is important to understand their effects on cell metabolism and function so as to provide appropriate recommendations for their safe application in clinical practice.…”

“…On the other hand, comparisons between bupivacaine and levobupivacaine have had mixed results. While bupivacaine is generally known to be one of the most chondrotoxic local anesthetics [ 16 , 22 ], levobupivacaine has been shown to be more chondrotoxic [ 11 ], less chondrotoxic [ 9 ], or having similar effects on chondrocyte viability as bupivacaine [ 19 ]. Further studies are required to clarify the reasons for these differences; however, this was not the focus of the current study.…”

“…Further studies are required to clarify the reasons for these differences; however, this was not the focus of the current study. Because the chondrotoxic effects of bupivacaine, levobupivacaine and ropivacaine have been established in previous studies [ 1 , 14 , 15 , 19 ], the first part of the experiments was done as a preliminary step to confirm their chondrotoxicity before evaluating the pathways of apoptosis involved through caspase activity.…”