Attenuation of berberine on lipopolysaccharide-induced inflammatory and apoptosis responses in β-cells via TLR4-independent JNK/NF-κB pathway

Figures & data

Figure 1. The structure of BBR (chemical formula: C₂₀H₁₈NO₄, molecular weight: 336.36).

Figure 2. Effect of BBR on LPS-induced celll viability in NIT-1 or INS-1 cells. Cells were treated with BBR at a concentration of 0.1813, 0.3625, 0.625, 1.25, 2.5, 5.0 and 10.0 μM in the presence of 1 μg/ml LPS. MTT assay was preformed in NIT-1 cells (A and B) while colony formation assays were preformed in NIT-1 cells and INS-1 cells (C). The OD value of samples was detected by MTT method at 570 nm. Data are expressed as mean ± SD (n = 18). **p < 0.01 versus blank; #p < 0.05, ##p < 0.01 versus LPS.

Table 1. Effect of BBR on LPS-induced inflammatory cytokines and insulin level (n = 12).

Groups	MCP-1 (pg/ml)	IL-6 (pg/ml)	TNF-α (pg/ml)	Insulin (pg/ml)
Blank control	387.6 ± 76.4	1443.6 ± 163.5	458.5 ± 103.1	114.7 ± 12.6
LPS (100 ng/ml)	573.2 ± 100.5^a	1893.2 ± 211.7^a	1605.7 ± 128.3^a	632.5 ± 74.9^a
BBR (5 μM) + LPS (100 ng/ml)	417.7 ± 63.8^b	1455.3 ± 142.8^b	529.4 ± 34.7^b	179.3 ± 54.6^b
BBR (2.5 μM) + LPS (100 ng/ml)	478.3 ± 94.5^c	1557.2 ± 235.1^c	816.9 ± 117.8^b	202.8 ± 47.0^b
BBR (1.25 μM) + LPS (100 ng/ml)	503.2 ± 67.9	1687.9 ± 174.6	1162.7 ± 99.7	366.1 ± 83.2^c
TAK-242 (1 μM) + LPS (100 ng/ml)	420.5 ± 45.6^d	1512.6 ± 190.3^d	593.2 ± 109.4^d	226.5 ± 53.2^d
SP-600125 (1 μM) + LPS (100 ng/ml)	449.9 ± 37.2^d	1584.4 ± 111.5^d	633.4 ± 58.5^d	277.4 ± 30.7^d

Data are expressed as mean ± SD.

^ap < 0.01 versus blank control.

^bp < 0.01 versus LPS alone.

^cp < 0.05.

^dp < 0.01 versus LPS alone.

Figure 3. Effects of BBR on cell cycle distribution and apoptosis in cultured NIT-1 cells. Flow cytometric analysis of the DNA content in control (Aa), LPS-treated model group (Ab), BBR of 2.5 μM (Ac) and 5.0 μM (Ad), TAK-242 of 1 μM (Ae) or SP-600125 of 1 μM (Af). (A) PI staining and flow cytometric analysis of cell cycle distribution in treated NIT-1 cells. (B) Relative apoptosis ratio.

Figure 4. BBR attenuated JNK/NF-κB pathway in NIT-1 cells involving the inflammation response. NIT-1 cells were treated with BBR (1.25 μM, 2.5 μM and 5.0 μM), TAK-242 (1 μM) or SP-600125 (1 μM) before LPS stimulation (100 ng/ml). p-JNK (1:1000) and p65 NF-κB (1:1000) expression was detected by Western blot. β-Actin (1:1000) was used for internal reference. (A) The brands of p-JNK and p65 NF-κB; (B) the relative level of p-JNK and p65 NF-κB. Data are taken from individual experiments and expressed as mean ± SD (n = 3). **p < 0.01 versus blank control; #p < 0.05, ##p < 0.01 versus LPS alone; $$p < 0.01 versus LPS alone.

Figure 5. Effect of BBR on NF-κB expression in INS-1 cells. Cells were treated with BBR (5μM), TAK-242 (1 μM) and SP-600125 (1 μM) prior to LPS stimulation (100 ng/ml). (A) Expression of NF-κB in INS-1 cells by Western blotting. (B) Relative expression ratio of NF-κB. Data are expressed as mean ± SD (n = 3). *p < 0.05 versus blank; #p < 0.05 versus LPS.