Background
Methods
Search strategy
Inclusion and exclusion criteria
Data extraction and quality assessment
Results
Results of the search
Study characteristics
Study (years) | Species (Sex,n) | Model, anesthetic, weight | Interventions | Research methods |
---|---|---|---|---|
Virginia 2005 | SD Rats (Male,6/6) | 6-OHDA induced (12μg, s.i.), Isofiuorane,200 g | Curcumin (50 mg/kg dissolve in 10% of Cremophor, gavage) for 4 days prior to lesioning | 1. IHC 2. HPLC analysis |
Pan 2007 | C57BL/6 mice (Male,30/10) | MPTP induced (30 mg/kg, i.p.), Pentobarbital, 20 g | Curcumin (5, 50, 150 mg/kg dissolve in 1% DMSO, i.p., respectively) for 4 days after surgery | 1. IHC 2. WB analysis |
Balusamy 2008 | C57BL/6 mice (Male,6/6) | BSO induced (3 mmol/kg, i.p.), NR, 25 g | Curcumin (50 mg/kg dissolve in saline, i.p., bw per day, for 1 and 3 days) | 1. WB analysis |
Rajeswari 2008 | Swiss albino mice (Male, 8/8) | MPTP induced (40 mg/kg, i.p.), NR, 25–30 g | Curcumin (80 mg/kg dissolve in DMSO, i.p.) for 7 days after surgery | 1. HPLC analysis |
Wang 2009 | C57BL/6 mice (Male,10/10) | MPTP induced (60 mg/kg, i.p.), NR, 25–30 g | Curcumin (15 mg/kg dissolve in DMSO, i.p.) for 4 days prior to lesioning and after surgery | 1. RT-PCR 2. HPLC analysis |
Song 2010 | C57BL/6 mice (Male,10/10) | MPTP induced (30 mg/kg, i.p.), NR, 23–25 g | Curcumin (50 mg/kg dissolve in DMSO, i.p.) for 5 days after surgery | 1. Behavioral tests and WB 2. IHC |
Peng 2010 | SD Rats (Male,20/20) | 6-OHDA induced (16μg, s.i.), Pentobarbital, 200–250 g | Curcumin (100 mg/kg dissolve in DMSO, gavage) for 4 weeks after surgery | 1. Behavioral tests 2. HPLC analysis |
Zahra 2012 | Wister rats (Male,8/8) | Homocysteine induced (2 mol/l, i.c.v.), NR, 250–300 g | Curcumin (50 mg/kg dissolve in saline, i.p.) for 10 days beginning 5 days prior to Hcy injection | 1. Behavioral tests 2. IHC and Tunel staining |
Du 2012 | Wister rats (Female,12/12) | 6-OHDA induced (20μg, s.i.), Chloral hydrate, 200–220 g | Curcumin pretreatment (200 mg/kg dissolve in saline) twice a day for 24 days in total | 1. HPLC analysis 2. IHC |
Yu 2012 | C57BL/6 mice (Male,10/10) | MPTP induced (30 mg/kg, i.p.), NR, 25 g | Curcumin (50 mg/kg dissolve in saline, i.p.) for 5 days after surgery | 1. Behavioral tests and WB 2. IHC and iron staining |
Guo 2012 | C57BL/6 mice (Male,30/10) | Lipidosome induced (1 μg/ml, s.i.), Chloral hydrate, 18-22 g | Curcumin (10, 20, 40 mg/kg dissolve in 1% DMSO, respectively, i.p.) for 4 days after surgery | 1. Behavioral tests and WB 2. Elisa, RT-PCR, IFC 3. Luciferase assay |
Tripanichkui 2013 | ICR strain mice (Male,7/7) | 6-OHDA induced (33μg, s.i.), Pentobarbital, NR | Curcumin (200 mg/kg dissolve in DMSO, i.p.) for 7 days after surgery | 1. IHC 2. Quantification Kits |
Ariana 2014 | Swiss albino mice (Male, 16/8) | Inhalation Mn induced, NR, 45–55 g | Curcumin (500 or 1500 PPM) was supplemented in the diet for 14 weeks | 1. Behavioral tests 2. Neurochemical Analysis |
Risk of bias
Study | Virginia 2005 | Pan 2007 | Balusamy 2008 | Rajeswar 2008 | Wang 2009 | Song 2010 | Peng 2010 | Zahra 2012 | Du 2012 | Yu 2012 | Guo 2012 | Tripanichkui 2013 | Ariana 2014 |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
A | √ | √ | √ | √ | √ | √ | √ | √ | √ | √ | √ | √ | √ |
B | √ | √ | √ | √ | √ | √ | √ | √ | |||||
C | √ | ||||||||||||
D | |||||||||||||
E | √ | √ | √ | √ | √ | √ | √ | √ | √ | √ | √ | √ | √ |
T | √ | √ | √ | √ | √ | √ | √ | √ | |||||
Total | 5 | 2 | 3 | 3 | 3 | 3 | 2 | 4 | 4 | 3 | 3 | 4 | 4 |
Neuroprotective mechanisms of curcumin
Study (years) | Outcome measures | Neuroprotection mechanism |
---|---|---|
Virginia 2005 | 1. TH-positive cells in the SN were increased by curcumin. 2. Striatal concentration of DA and its metabolites DOPAC and HVA | Phenomenon research. |
Pan 2007 | 1. TH-positive cells and protein level in the SNpc and striatum. 2. GFAP-positive cells and iNOS level in the SNpc | Anti-oxidant and anti-inflammatory. |
Balusamy 2008 | 1. Curcumin against GSH depletion-mediated oxidative stress, significantly restored total brain GSH levels in BSO mice. 2. Accumulation of ROS was prevented only by pretreatment with curcumin. | Anti-oxidant capabilities. |
Rajeswari 2008 | 1. Curcumin reversed the reduction in striatal DA and DOPAC levels; 2. MAO-B activity was reduced by curcumin treatment | Anti-oxidant capabilities. |
Wang 2009 | 1. Curcumin reversed the reduction in SNpc TH and DAT mRNA levels; 2. DA and DOPAC levels were restored by curcumin | Phenomenon research. |
Song 2010 | 1. Curcumin showed a significant increase in locomotion frequencies; 2. Curcumin increased the TH, DAT level and inhibits astrocyte activation in terms of GFAP. 3. Inhibitory effects of curcumin on JNK, c-Jun, and caspase-3. | Anti-inflammatory and anti-apoptosis. |
Peng 2010 | 1. Curcumin could ameliorate rotational behaviour; 2. DA level was restored by curcumin administration. | Phenomenon research. |
Zahra 2012 | 1. Curcumin prevented the decrease of locomotor activity. 2. The number of Nissl neurons on the left side of substantia nigra was significantly higher in curcumin group. 3. Effect of curcumin on Bax/Bcl-2. | Anti-apoptosis. |
Du 2012 | 1. Curcumin partly restored the levels of DA, DOPAC and HVA. 2. TH-positive neurons were restored by curcumin pretreatment. 3. Marked decrease of iron-positive cells was found in the curcumin pretreatment group. | Suppress the iron-induced degeneration. |
Yu 2012 | 1. Curcumin ameliorated open-field test; 2. TH, DAT levels were restored by curcumin and inhibited GFAP and TNF-a. | Anti-inflammatory. |
Guo 2012 | 1. Motor coordination of rota-rod test and hanging test were improved in the curcumin treatment group. 2. Curcumin suppressed nuclear translocation and NF-Kβ activity. 3 TNF-a and IL-1b were restored by curcumin. | Anti-inflammatory |
Tripanichkui 2013 | 1. Curcumin attenuated loss of TH fibers, diminished activation of GFAP and microgliosis, sustained SOD1 level. | Anti-inflammatory and anti-oxidant |
Ariana 2014 | 1.Curcumin produced similar deleterious effects in the beam-walking test and single-pellet test. 2. Curcumin showed no beneficial effects against Mn-induced disruption of hippocampal metal and neurotransmitter homeostasis (DA or serotonin). | No neuroprotection |