Curcumin Improves Chronic Pain Induced Depression Through Regulating Serum Metabolomics in a Rat Model of Trigeminal Neuralgia

Figures & data

Figure 1 Curcumin alleviated mechanical allodynia induced by cobra venom intra-ION injection. (A) Schematic for the timeline of surgery (cobra venom or sterile saline injection) and curcumin administrations. (B) Mechanical allodynia induced by cobra venom intra-ION injection was attenuated by curcumin treatment. Two-way ANOVA, *P<0.05 vs the sham group, #P<0.05 vs the cobra venom group, n=8 or 9.

Figure 2 The effects of curcumin treatment on depression behaviors observed in rats with chronic pain. (A) Sucrose preferences were progressively reduced in rats with TN, and recovered by curcumin treatment. (B) Immobility time during forced swimming were progressively increased in rats with TN and normalized after curcumin treatment. Two-way ANOVA, *P<0.05 vs the sham group, #P<0.05 vs the cobra venom group, n=8 or 9.

Figure 3 Score-Plot of principal component analysis for different groups of rats. (A) Score-Plot of PCA for the serum samples collected from different groups 6 weeks after surgery. Black, sham group; Red, TN+vehicle group; and Blue, TN+curcumin group. (B) Score-Plot PCA for the serum samples collected at different time points after cobra venom intra-ION injection. Green, week 1; Orange, week 2; Grey, week 4; and Violet, week 6.

Figure 4 Partial least-squares discriminant analysis of metabolomics data in different experimental groups. (A) Score plot. Black, sham group; Red, TN group, and Blue, TN+ curcumin group. (B) 100-permutation test. (C) loading plot. (D) VIP value plot.

Table 1 Identified Metabolites from the Serum Collected at Different Time Points After Venom Cobra Intra-ION Injecton

VIP	M/Z	RT	Biomarker	[M+X]^+	Adduct MW	Delta (ppm)
2.01	263.1987	23.696	9-Pentadecenoic acid	263.1981	M+Na	6
1.63	301.1398	29.242	alpha-CEHC	301.141	M+Na	4
1.76	319.1932	29.417	Ubiquinone-2	319.1904	M+H	9
2.02	329.2457	28.233	5,8,11-Eicosatrienoic acid	329.2451	M+Na	2
1.64	377.2642	26.549	G(0:0/18:2(9Z,12Z)/0:0)	377.2662	M+Na	5
1.54	379.2794	29.885	MG(0:0/18:1(11Z)/0:0)	379.2819	M+Na	7
1.61	413.2657	27.193	9ʹ-Carboxy-alpha-chromanol	413.2662	M+Na	1
1.51	520.3376	20.843	LysoPC(18:2(9Z,12Z))	520.3398	M+H	4
1.51	524.3662	23.709	LysoPC(0:0/18:0)	524.3711	M+H	9
1.51	553.3871	30.444	LysoPE(22:1(13Z)/0:0)	553.3976	M+HN4	19
1.58	592.34	23.119	LysoPC(22:5(4Z,7Z,10Z,13Z,16Z)/0:0)	592.3374	M+Na	4
1.55	400.3399	23.276	MG(0:0/20:2(11Z,14Z)/0:0)	400.3421	M+NH4	6
1.99	334.2046	28.061	2-trans,4-cis-Decadienoylcarnitine	334.1989	M+Na	17
1.62	136.0219	14.858	Lysylvaline	263.2078	M+NH4	21

Figure 5 Serum metabolic profiling. (A) Heatmap of metabolic profiles at different time points after cobra venom intra-ION injection. (B) Heatmap of metabolic profiles in different groups of rats.

Table 2 Identified Metabolites from the Serum Collected from TN Rats Received Curcumin Treatment or Vehicle

VIP	M/Z	RT	Biomarker	[M+X]^+	Adduct MW	Delta	Ratio (Sham/Cobra Venom/Curcumin)	Ratio (1/2/4/6 Weeks)
2.11	400.3416	23.1	Thyroxine	M+H+Na	400.341588	0.000012	1.23/0/1.00	0/0/0/0
1.98	563.3063	20.51	Tauroursodeoxycholic acid	M+ACN+Na	563.312524	0.006224	1.00/0/0	0/1.00/0/0
1.96	352.3379	10.09	CE(20:0)	M+H+Na	352.321813	0.016087	1.00/6.02/0	1.70/1.37/1.19/1.00
1.96	553.3871	30.44	LysoPE(22:1(13Z)/0:0)	M+NH4	553.397613	0.010513	9.74/1.00/11.44	0/0/0/1.00
1.9	834.8802	1.14	Somatostatin	M+H+NH4	834.886702	0.006502	12.02/1.00/0	2.51/3.82/3.89/1.00
1.82	810.5966	33.55	PC(20:1(11Z)/16:0)	M+Na	810.598323	0.001723	12.55/1.00/5.54	3.81/12.28/7.64/1.00
1.77	1,107.617	20.49	Ganglioside GT1c (d18:0/24:0)	M+2H	1,107.598171	0.018829	1.00/0/0	1.07/1.45/1.00/0
1.7	1,531.913	21.79	Ganglioside GM2 (d18:1/23:0)	M+DMSO+H	1,531.928052	0.014852	14.53/15.38/1	1.00/1.34/1.52/1.49
1.7	1,088.6519	22.39	Trihexosylceramide (d18:1/9Z-18:1)	M+K	1,088.649373	0.002527	1.65/1.00/0	1.05/1.61/1.74/1.00
1.69	1,132.6215	20.85	Ganglioside GT1b (d18:0/26:0)	M+H+Na	1,132.604792	0.016708	1.47/1.00/1.04	1.04/1.49/1.05/1.00
1.69	539.3086	20.44	1-Oleoylglycerophosphoserine	M+NH4	539.309192	0.000592	2.47/1.00/0	1.00/1.95/2.16/1.09
1.68	264.2662	19.3	Cer(d18:1/14:0)	M+H+NH4	264.260947	0.005253	7.59/7.81/0	1.00/1.31/1.87/2.01
1.68	572.368	22.71	PC(18:1(9Z)e/2:0)	M+Na	572.368658	0.000658	5.71/1.00/1.43	4.04/4.14/3.49/1.00
1.64	504.304	20.6	LysoPE(0:0/18:0)	M+Na	504.306057	0.002057	1.29/1.00/0	3.58/1.00/1.38/3.92
1.64	542.3227	19.73	LysoPC(20:5(5Z,8Z,11Z,14Z,17Z))	M+H	542.324115	0.001415	9.73/5.47/1.00	1.20/1.65/1.79/1.00
1.6	1,530.9088	21.79	Ganglioside GD3 (d18:0/22:0)	M+H	1,530.925401	0.016601	4.86/5.22/1.00	1.00/1.34/1.52/1.49
1.56	520.3376	20.84	LysoPC(18:2(9Z,12Z))	M+H	520.339765	0.002165	1.41/1.41/1.00	1.12/1.00/1.13/1.06
1.56	540.3058	21.79	LysoPC(18:3(9Z,12Z,15Z))	M+Na	540.306057	0.000257	1.34/1.33/1.00	1.00/1.20/1.28/1.27
1.56	506.299	22.4	Lithocholyltaurine	M+Na	506.291062	0.007938	1.91/1.60/1.00	1.13/1.17/1.25/1.00
1.55	566.3179	20.96	LysoPC(20:4(8Z,11Z,14Z,17Z))	M+Na	566.321707	0.003807	1.14/1.00/1.41	1.51/1.17/1.00/1.09
1.55	541.3245	22.4	1-Stearoylglycerophosphoserine	M+NH4	541.324842	0.000342	2.59/1.95/1.00	1.00/1.88/2.03/1.55
1.54	569.3402	20.74	Deoxycholic acid 3-glucuronide	M+H	569.332024	0.008176	1.61/1.22/1.00	1.00/1.43/1.11/1.03
1.53	510.3868	25.74	LysoPC(O-18:0)	M+H	510.391801	0.005001	0/3.00/1.00	1.00/0/3.61/6.27
1.53	413.2673	23.63	9ʹ-Carboxy-alpha-chromanol	M+Na	413.266228	0.001072	0/3.54/1.00	2.84/1.00/1.34/6.01
1.53	522.3531	22.41	LysoPC(18:1(9Z))	M+H	522.355416	0.002316	1.61/1.42/1.00	1.20/1.16/1.20/1.00
1.51	526.2891	20.59	LysoPE(0:0/20:3(8Z,11Z,14Z))	M+Na	526.290407	0.001307	2.85/2.92/1.00	1.00/1.39/1.39/1.37
1.51	466.3025	22.42	LysoPC(14:1(9Z))	M+H	466.292815	0.009685	2.56/7.63/1.00	1.00/1.15/6.69/8.95
1.5	494.3218	20.09	LysoPC(16:1(9Z))	M+H	494.324115	0.002315	3.10/1.70/1.00	1.53/2.09/1.66/1.00
1.5	546.3526	21.68	LysoPC(18:0)	M+Na	546.353008	0.000408	2.34/1.22/1.00	2.15/2.62/1.77/1.00

Figure 6 Pathway enrichment analysis of metabolites changed by curcumin treatment. (A) Pathway analysis of the effects of curcumin treatment on (a) Ether lipid metabolism, (b) Glycerophospholipid metabolism, (c) Pentose and glucuronate interconversions, and (d) Starch and sucrose metabolism in TN rats. (B) Glycerophospholipid metabolism (C04598: 2-Acetyl-1-alkyl-sn-glycero-3-phosphocholine, C04317: 1-Alkyl-2-lyso-sn-glycero-3-phosphocholine). (C) Ether lipid metabolism (C00157: Phosphatidylcholine, C04230: 1-Acyl-sn-glycero-3-phosphocholine. C03033: Glucuronide). (D–F) The enrichment pathway analysis of the effects of curcumin treatment in TN rats.

Figure 7 The effects of curcumin treatment on the expression of serum metabolite in TN rats. Differentially expressed metabolite pathways and their associated signaling networks (potential biomarkers were labeled by green solid box.).