Although fullerol is not genotoxic [46], it was reported that a maximal dose (100 μg/ml, approximate 88.7 μM) of fullerol induced cytotoxic injury on human endothelial cells [47] and was cytotoxic to human lens epithelial cells at concentrations higher than 20 μM [48]. These suggest that the cytotoxicity of fullerol is cell type dependant. Two processes may account for the observed phenomena. First, during the process of cellular uptake, fullerol may cause damage to the cell membrane and organelles. Second, although fullerol is a “free radical sponge”, the photoexcitation of fullerene derivatives efficiently produces an excited triplet state and, through energy and electron transfer to molecular oxygen, produce both singlet molecular oxygen and superoxide which may injure cells [48]. The balance between ROS scavenging and production mediates its cytoprotection or photo-cytotoxicity on cells. We performed both LDH leakage assay and WST-1 assay to investigate short-term and relatively long-term cytotoxicity of fullerol. We found significantly higher cytotoxicity of 10 μM fullerol after 24h of culture, and there was no significant difference among the ≤1 μM (0.1 and 1 μM) and low control (0 fullerol) groups (Fig. 1) during the 7d-culture period. Therefore, we used 1 μM fullerol in our study. However, in the following in vivo study, local injection of fullerol into vertebral body in a mouse disc degeneration model, we will rigorously test the dose window of fullerol to maximize its anti-oxidative and anti-inflammatory effects, as well as minimize the side effects.
In conclusion, we believe that this is the first observation that fullerol, a potent antioxidant agent, suppresses IL-1 β-induced ROS and inflammatory cytokine production, inhibits the adipogenic differentiation of vBMSCs in vitro and, therefore, may prevent vertebral fatty marrow deposition and inflammatory responses during disc degeneration. One important concept raised in this study is that in addition to direct treatment of IVD for disc degeneration, we could rectify the lesions in vertebral bone marrow, which eventually would facilitate IVD treatment. However, this treatment strategy requires further investigation both in vitro and in vivo. We propose that further studies with fullerol may be lead to the development of an effective agent for the treatment of symptomatic IVD degeneration.
read full article at link below..