Fig 2: E2 inhibited the leptin promoter activity and p38 phosphorylation stimulated by LPA(A) pGL4.17-LP1 transfected cells were treated as above, BBR as 2.5 µM, and E2 at a dose of 100 pM. The luminescence was set as 1 in the vehicle group treated with DMSO. Values are expressed as mean ± SEM, **p < 0.01 versus the LPA-stimulated group treated with DMSO. ##p < 0.01 versus the LPA-stimulated group treated with E2. (B) E2 (100 pM) inhibited LPA-induced p38 phosphorylation at Thr180/Tyr182. HepG2 cells were treated and western blot was conducted as described above. (C) Schematic diagram illustrates BBR restrained liver tumorigenesis through antagonizing the ATX-LPA-LPAR2-p38-leptin axis, and reducing LPA-stimulated abnormal leptin transcription in hepatoma cells.

Fig 3: Berberine decreased ATX and LPAR2 expression in DEN model(A) ATX protein expression was detected by western blot of tumor and non-tumor tissues respectively from male mice 6 and 8 months after DEN injection, and normalized to that of ACTB (ß-actin). The ratio of ATX/ACTB was set as 1 in sham-treated group. Data are expressed as the mean ± SEM (n = 2–3). (B and E), ATX and LPAR2 mRNA expression was detected by real-time RT-PCR in tumor and non-tumor tissues of DEN-injected male mice, which was normalized to ACTB and presented as fold of that in the sham-treated group. Data are expressed as the mean ± SEM (n = 9). (C) Serum ATX was assayed by ELISA of the indicated groups 8 and 12 months after DEN injection for male and female mice respectively. Data were expressed as the mean ± SEM (n = 9–10). (D), serum LPA was examined by ELISA in female mice 12 months after DEN injection. Data are expressed as the mean ± SEM (n = 6). (F) HepG2 cells were subjected to 20 µM LPA combined with BBR (0.1 µM, 0.5 µM, 2.5 µM) and Met (250 µM) respectively for 18 h, after being starved overnight and pretreatment of BBR or Met for 4 h. LPAR2 mRNA was detected by real-time RT-PCR, which was normalized to ACTB and presented as fold of that in the DMSO group without LPA treatment. Values are the mean ± SEM of three independent experiments. *p < 0.05, **p < 0.01 versus that of DEN or LPA model group.