P2X7 is involved in the anti-inflammation effects of levobupivacaine

Background: We sough to elucidate whether purinergic P2X7 receptor is actively involved in the effects of levobupivacaine on inhibiting microglia activation. Materials and methods: Microglia were treated with lipopolysaccharide (LPS, 50 ng/mL), LPS plus levobupivacaine (50 μM), or LPS plus levobupivacaine plus the P2X7 receptor agonist Bz-ATP (100 μM) and denoted as the LPS, LPS + Levo, and LPS + Levo + Bz-ATP group, respectively. Microglia activation was measured by assaying inflammatory molecules expression. Microglia activation was also measured by assaying neuronal cell viability using coculture of microglia and neurons, as activated microglia may cause neuron injury. We also measured the levels of P2X7 receptor activation in microglia using ethidium uptake assay. Results: Our data confirmed the effects of levobupivacaine on inhibiting inflammatory molecules upregulation in activated microglia, as the concentrations of interleukin (IL)-1β, tumor necrosis factor α, IL-6, and macrophage inflammatory protein 2, of the LPS + Levo group were significantly lower than those of the LPS group (all P < 0.05). Moreover, Bz-ATP significantly abrogated the inhibitory effects of levobupivacaine, as concentrations of IL-1β, tumor necrosis factor α, IL-6, and macrophage inflammatory protein 2 of the LPS + Levo + Bz-ATP group were significantly higher than those of the LPS + Levo group (all P < 0.05). In contrast, neuronal cell viability of the LPS + Levo group was significantly higher than those of the LPS and LPS + Levo + Bz-ATP groups (P = 0.012 and 0.002). Moreover, levels of P2X7 receptor activation of the LPS and LPS + Levo + Bz-ATP groups were significantly higher than that of the LPS + Levo group (P = 0.003 and 0.006). Conclusions: P2X7 receptor is involved in the effects of levobupivacaine on inhibiting microglial activation.