Figure 2.

Characterization of human primary synoviocytes (FLSs) and analysis of cell viability. (A) Human primary FLSs, isolated by synovial membranes and cultured in vitro, were stained with anti-vimentin primary antibody and with Alexa Fluor 488 (green) secondary antibody. (B) Cell viability was assessed by the MTS colorimetric method, and FLSs were treated with three concentrations, 1, 0.5, and 0.1 mg/mL of Harpagophytum procumbens root extract (HPE) dissolved in deionized water (HPE_H2O), DMSO (HPE_DMSO), 100% v/v EtOH (HPE_EtOH100), and 50% v/v EtOH (HPE_EtOH50), for 24, 48, and 72 h. Cell viability of treated samples was normalized to the untreated cells, which is reported as 100% and represented by a horizontal line.