Research Paper Advance Articles

Formulated Chinese medicine Shaoyao Gancao Tang reduces NLRP1 and NLRP3 in Alzheimer’s disease cell and mouse models for neuroprotection and cognitive improvement

Neuroprotective effect of SG-Tang in Aβ-GFP-expressing SH-SY5Y cells inflamed with HMC3 conditioned medium. (A) Experimental flow chart. Aβ-GFP SH-SY5Y cells were plated in medium with retinoic acid (RA, 10 μM) on day 1, and treated with SG-Tang (100 μg/ml) next day for 8 h, followed by doxycycline (Dox, 5 μg/ml) addition to induce Aβ-GFP expression. On day 6, DMEM-F12 medium without retinoic acid addition (− RA) was mixed with HMC3 conditioned medium (CM/±IFN-γ, 1:1 ratio) and added to the cells for 2 days. (B) iNOS, NLRP1, NLRP3, TNF-α, IL-1β and IL-6 levels, (C) ROS production, GFP fluorescence and caspase-1 activity, (D) neurite length, process and branch were assessed on day 8 (n = 3). For normalization, the relative iNOS, NLRP1, NLRP3, TNF-α, IL-1β, IL-6 and ROS levels in uninduced and CM/-IFN-γ stimulated cells were set as 100%. P values: comparisons between induced (Dox+, + CM/-IFN-γ) vs. uninduced (Dox-,+ CM/-IFN-γ) cells (#: P ##: P ###: P &: P &&: P $$: P $$$: P P P P post hoc Tukey test).

Figure 3. Neuroprotective effect of SG-Tang in Aβ-GFP-expressing SH-SY5Y cells inflamed with HMC3 conditioned medium. (A) Experimental flow chart. Aβ-GFP SH-SY5Y cells were plated in medium with retinoic acid (RA, 10 μM) on day 1, and treated with SG-Tang (100 μg/ml) next day for 8 h, followed by doxycycline (Dox, 5 μg/ml) addition to induce Aβ-GFP expression. On day 6, DMEM-F12 medium without retinoic acid addition (− RA) was mixed with HMC3 conditioned medium (CM/±IFN-γ, 1:1 ratio) and added to the cells for 2 days. (B) iNOS, NLRP1, NLRP3, TNF-α, IL-1β and IL-6 levels, (C) ROS production, GFP fluorescence and caspase-1 activity, (D) neurite length, process and branch were assessed on day 8 (n = 3). For normalization, the relative iNOS, NLRP1, NLRP3, TNF-α, IL-1β, IL-6 and ROS levels in uninduced and CM/-IFN-γ stimulated cells were set as 100%. P values: comparisons between induced (Dox+, + CM/-IFN-γ) vs. uninduced (Dox-,+ CM/-IFN-γ) cells (#: P < 0.05, ##: P < 0.01, ###: P < 0.001), induced and inflamed (Dox+, + CM/+IFN-γ) vs. induced (Dox+, + CM/-IFN-γ) cells (&: P < 0.05, &&: P < 0.01), induced and inflamed (Dox+, + CM/+IFN-γ) vs. uninduced (Dox-, + CM/-IFN-γ) cells ($$: P < 0.01, $$$: P < 0.001), or SG-Tang treated (+ CM/+IFN-γ, +SG-Tang) vs. untreated (+ CM/+IFN-γ) cells (*: P < 0.05, **: P < 0.01, ***: P < 0.001). (One-way ANOVA with a post hoc Tukey test).