Kaempferol protects mesangial cells from D-ribose-induced cell death. (a) Mesangial cells were exposed to D-ribose (10, 20, 30, 40, and 50 mM) for 24 h. Cell viability was assessed by CCK-8 assay and expressed relative to untreated control cells. (b) Mesangial cells were exposed to D-ribose (10, 20, 30, 40, and 50 mM) for 48 h. Cell viability was assessed by CCK-8 assay and expressed relative to untreated control cells. (c) Mesangial cells were exposed to D-ribose and treated with kaempferol (1, 2, and 5 μM) for 48 h. Cell viability was assessed by CCK-8 assay and expressed relative to untreated control cells. (d) Mesangial cells were exposed to D-ribose and treated with kaempferol (1, 2, and 5 μM) for 48 h. LDH release was expressed as a percentage of the maximum LDH release. Data were expressed as the mean ± SEM from independent experiments. Comparisons between multiple groups were analyzed by one-way ANOVA followed by the Turkey posttest. ##P < 0.01, relative to the control group; ∗P < 0.05 and ∗∗P < 0.01, relative to the D-ribose group.