AHR and acne: Figures 6E–G demonstrate that the mRNA levels of IL-1β (1.368 ± 0.088 and 1.803 ± 0.367), IL-6 (1.131 ± 0.194 and 1.197 ± 0.952), and TNF-α (1.247 ± 0.104 and 1.095 ± 0.306) were significantly lower in the IAA and indole groups, compared to those in the acne group (2.672 ± 0.310, 2.148 ± 0.298, and 2.158 ± 0.193) (p < 0.05). All of the above inflammatory factors also could be upregulated by the AhR antagonist in the IAA+SR1 group (2.329 ± 0.386, 1.842 ± 0.037, and 2.331 ± 0.488) and indole+SR1 group (3.265 ± 0.099, 1.991 ± 0.042, and 1.807 ± 0.213) (p = 0.0101 and p < 0.05).