Effects of pharmacological serum from normal and liver fibrotic rats on HSCs

Protective mechanisms of medicinal plants targeting hepatic stellate cell activation and extracellular matrix deposition in liver fibrosis

During chronic liver injury, hepatic stellate cells (HSC) are activated and proliferate, which causes excessive extracellular matrix (ECM) deposition, leading to scar formation and fibrosis. Medicinal plants are gaining popularity as antifibrotic agents, and are often safe, cost-effective, and versatile. This review aims to describe the protective role and mechanisms of medicinal plants in the inhibition of HSC activation and ECM deposition during the pathogenesis of liver fibrosis. A systematic literature review on the anti-fibrotic mechanisms of hepatoprotective plants was performed in PubMed, which yielded articles about twelve relevant plants. Many of these plants act via disruption of the transforming growth factor beta 1 signaling pathway, possibly through reduction in oxidative stress. This reduction could explain the inhibition of HSC activation and reduction in ECM deposition. Medicinal plants could be a source of anti-liver fibrosis compounds.

Differential role of YiGanKang decoction in IL-1β induction of IL-1RI and AP-1 in rat hepatic stellate cell

BACKGROUND/AIM

YiGanKang, a combination of Chinese herbs, has anti-fibrosis effects in chronic liver diseases. The present study tries to demonstrate differential role of YiGanKang Decoction in interleukin-1β (IL-1β) induction of the type I receptor (IL-1RI) and the activator protein 1 (AP-1) in rat hepatic stellate cell (HSC).

METHODS

Flow cytometry was used to detect the IL-1RI expression. Electrophoretic mobility shift assays was used to detect AP-1 activity.

RESULTS

IL-1RI expression after IL-1β treatment for 0, 2, 10, 60, and 120 min was 227.08 (13.15), 268.43 (8.93), 442.97 (7.00), 367.66 (14.70), and 261.58 (15.08), respectively. The differences between IL-1RI expression after treatment for 10 and 60 min were significantly higher than the corresponding values in the control (P<0.01, P<0.01, respectively); After pretreatment with YiGanKang Decoction, IL-1RI expression induced by IL-1β was not decrease obviously; IL-1β could activate AP-1 in rat HSCs (P<0.01). Meanwhile YiGanKang Decoction could inhibit activity of AP-1 induced by IL-1β (P<0.01), and the inhibition rate was 42.71%.

CONCLUSION

YiGanKang Decoction could not decrease IL-1RI expression, but it could inhibit activity of AP-1 in rat HSCs induced by IL-1β.

Suppressive effects of YiGanKang, a combination of Chinese herbs, on collagen synthesis in hepatic stellate cell

BACKGROUND/AIM

Clinical practice and animal research demonstrated that YiGanKang, a combination of Chinese herbs, has anti-fibrosis effects in chronic liver diseases. However, the mechanism is not clear. The present study is to investigate the inhibiting mechanism of YiGanKang on collagen type I synthesis induced by Interleukin-1β(IL-1 β) in rat hepatic stellate cells (HSCs).

METHODS

Cultured rat HSCs were divided into 4 groups, control, IL-1β treated group, IL-1β+YiGanKang group and IL-1β+SB203580 (the p38 mitogen-activated protein kinase inhibitor) treated group. The expression of p38 mitogen-activated protein kinase (p38 MAPK), was evaluated by Western blot, collagen type I synthesis was examined by (3)H-Pro incorporation.

RESULTS

Type I collagen synthesis in HSCs increased significantly under the stimulation of IL-1β for 24h, YiGanKang could inhibit p38 expression and type I collagen synthesis, SB203580, a p38 inhibitor, can significantly reduce type I collagen synthesis.

CONCLUSION

IL-1β could stimulate the synthesis of type I collagen in rat HSCs, p38 mediate signal pathway between IL-1β and was type I collagen production. YiGanKang inhibits HSCs collagen synthesis induced by IL-1β via p38 inhibition.

Inhibition of Yigankang on proliferation of rat hepatic stellate cells induced by interleukin-1β

AIM: To study the mechanism of Yigankang in the proliferation inhibition of rat hepatic stellate cells (HSCs).

METHODS: The activation of JNK pathway was detected by Western blot, while the proliferation of HSCs was induced by interleukin-1β (IL-1β). The effect of JNK inhibitor SP600125 was measured by cell counting kit-8 (CCK-8) and AP-1 activity was evaluated by electrophoretic mobility shift assay.

RESULTS: Interleukin-1β up-regulated the proliferation of HSCs. After stimulation of IL-1β for 24 h, HSC proliferation increased significantly as compared with that in the controls (1.573 ± 0.026 vs 1.390 ± 0.073, P = 0.000). After treatment with different concentrations of SP600125 (10 µmol/L, 1.427 ± 0.113; 20 µmol/L, 0.772 ± 0.093; 40 µmol/L, 0.675 ± 0.074), HSC proliferation induced by IL-1β decreased significantly in comparison with that in the controls (1.560 ± 0.110) (P = 0.03; P = 0.000; P = 0.000). IL-1β activated JNK pathway in a time-dependent manner in rat HSCs. After stimulation of IL-1β for 0, 5, 15, 30, 60 and 120 min, the JNK activities were 0.982 ± 0.299, 1.501 ± 0.720, 2.133 ± 0.882, 3.360 ± 0.452, 2.181 ± 0.789, 1.385 ± 0.368, respectively. In comparison with those in the cells without IL-1β, JNK activities differed significantly at 15, 30 and 60 min (P = 0.002, P = 0.000, P = 0.001). Yigankang inhibited the activities of JNK (1.610 ± 0.242 vs 3.360 ± 0.452, P = 0.000) and AP-1 (342.43 ± 85.77 vs 597.70 ± 83.96, P < 0.01) obviously.

CONCLUSION: IL-1β can stimulate the proliferation of rat HSCs, and JNK signaling pathway was involved in the process. Yigankang can inhibit HSC proliferation induced by IL-1β through JNK/AP-1 pathway.

Comparison of protocatechuic aldehyde in Radix Salvia miltiorrhiza and corresponding pharmacological sera from normal and fibrotic rats by high performance liquid chromatography

AIM: To observe the effect of protocatechuic aldehyde on the proliferation of hepatic stellate cells (HSCs).

METHODS: Liver fibrosis was induced in rats by carbon tetrachloride (CCl₄). Then normal and fibrotic drug sera were extracted from rats. The effects of protocatechuic aldehyde, raw Radix Salvia miltiorrhiza and drug sera of Salvia miltiorrhiza on HSC growth were determined by CCK-8. The protocatechuic aldehyde was separated by high performance liquid chromatography (HPLC) in a Alltima C18 column (250 mm × 4.6 mm, 5 μm) with a mobile phase of acetonitrile-4% glacial acetic acid solution (gradient elution) at the wavelength of 281 nm.

RESULTS: Protocatechuic aldehyde, raw Radix Salvia miltiorrhiza and drug sera of Salvia miltiorrhiza were found to have inhibitory effects on proliferation of rat HSCs. Raw Radix Salvia miltiorrhiza had a stronger inhibitory effect than the drug sera. The fibrotic drug sera showed a higher suppressive effect than the normal drug sera (P < 0.05). Protocatechuic aldehyde was found in crude materials of both Radix Salvia miltiorrhiza and its corresponding drug sera. The average recovery (n = 6) was 110.5% for raw Salvia miltiorrhiza Bge, 102% for normal drug sera and 105.2% for fibrotic drug sera. The relative standard deviation (RSD) was 0.37%, 1.96% and 1.51%, respectively (n = 6). The contents of protocatechuic aldehyde were 0.22%, 0.15% and 0.19%, respectively (n = 6) (P < 0.05). The RSD was 0.33%, 0.75% and 1.24% (n = 6) for raw material of Radix Salvia miltiorrhiza, normal drug sera and fibrotic drug sera, respectively. The samples were stable for 6 d.

CONCLUSION: Protocatechuic aldehyde can inhibit the growth of HSCs. HPLC is suitable for the determination of virtual bioactive components of Chinese herbal medicines in vitro.

Interleukin-1 beta up-regulates tissue inhibitor of matrix metalloproteinase-1 mRNA and phosphorylation of c-jun N-terminal kinase and p38 in hepatic stellate cells

AIM: To study the relationship between interleukin-1beta (IL-1β) up-regulating tissue inhibitor of matrix metalloproteinase-1 (TIMMP-1) mRNA expression and phosphorylation of both c-jun N-terminal kinase (JNK) and p38 in rat hepatic stellate cells (HSC).

METHODS: RT-PCR was performed to measure the expression of TIMMP-1 mRNA in rat HSC. Western blot was performed to measure IL-1β-induced JNK and p38 activities in rat HSC.

RESULTS: TIMMP-1 mRNA expression (1.191 ± 0.079) was much higher after treatment with IL-1β (10 ng/mL) for 24 h than in control group (0.545 ± 0.091) (P<0.01). IL-1β activated JNK and p38 in a time-dependent manner. After stimulation with IL-1β for 0, 5, 15, 30, 60 and 120 min，the JNK activity was 0.982 ± 0.299，1.501 ± 0.720, 2.133 ± 0.882, 3.360 ± 0.452, 2.181 ± 0.789, and 1.385 ± 0.368, respectively. There was a significant difference in JNK activity at 15 min (P < 0.01), 30 min (P < 0.01) and 60 min (P < 0.01) in comparison to that at 0 min. The p38 activity was 1.061 ± 0.310，2.050 ± 0.863，2.380 ± 0.573, 2.973 ± 0.953, 2.421 ± 0.793, and 1.755 ± 0.433 at the 6 time points (0, 5, 15, 30, 60 and 120 min) respectively. There was a significant difference in p38 activity at 5 min (P < 0.05), 15 min (P < 0.01), 30 min (P < 0.01) and 60 min (P < 0.01) compared to that at 0 min. TIMMP-1 mRNA expression trended to decrease in 3 groups pretreated with different concentrations of SP600125 (10 µmol/L, 1.022 ± 0.113; 20 µmol/L, 0.869 ± 0.070; 40 µmol/L, 0.666 ± 0.123). Their decreases were all significant (P < 0.05, P < 0.01, P < 0.01) in comparison to control group (without SP600125 treatment, 1.163 ± 0.107). In the other 3 groups pretreated with different concentrations of SB203580 (10 µmol/L, 1.507 ± 0.099; 20 µmol/L, 1.698 ± 0.107; 40 µmol/L, 1.857 ± 0.054), the expression of TIMMP-1 mRNA increased. Their levels were higher than those in the control group (without SB203580 treatment, 1.027 ± 0.061) with a significant statistical significance (P < 0.01).

CONCLUSION: IL-1β has a direct action on hepatic fibrosis by up-regulating TIMMP-1 mRNA expression in rat HSC. JNK and p38 mitogen-activated protein kinases (MAPKs) are involved in IL-1β-induced TIMMP-1 gene expression, and play a distinct role in this process, indicating that p38 and JNK pathways cooperatively mediate TIMP-1 mRNA expression in rat HSC.