|
| Plant extracts/phytochemicals (plant source)/natural products/substances | Study model | Neuroprotective activities | References |
|
| Arctigenin extracted from Fructus arctii | Rotenone-induced rats | (i) Improved behavioral changes | [234] |
| (ii) Decreased dopaminergic neuronal loss in the substantia nigra pars compacta |
| (iii) Decreased α-synuclein immunopositive |
| (iv) Increased GSH and activities of superoxide dismutase and glutathione peroxidase |
| (v) Decreased malondialdehyde level |
| (vi) Decreased inflammatory markers (TNF-α, IL-1β, IL-6, interferon-gamma (IFN-γ), and prostaglandins E2 level) in the substantia nigra pars compacta |
| (vii) Decreased NF-κB and COX-2 expressions in the substantia nigra pars compacta |
| (viii) Reduced GFAP and Iba-1 expressions |
|
| Apium graveolens L. | MPTP-induced mouse | (i) Ameliorated MPTP-induced behavioral impairment | [235] |
| (ii) Attenuated oxidative stress |
| (iii) Decreased monoamine oxidase activity |
| (iv) Protected dopaminergic neurons |
|
| Agaricus blazei extract | Rotenone-induced mouse | (i) Restored the rotenone-induced motor and nonmotor behavioral deficits | [236, 237] |
| (ii) Attenuated oxidative stress by decreasing TBARS level and increasing GSH level and superoxide dismutase, catalase, and glutathione peroxidase activities |
| (iii) Attenuated neuroinflammation markers (TNF-α, IL-1β, IL-6, COX-2, GFAP, Iba-1, iNOS expressions) in the substantia nigra pars compacta |
| (iv) Decreased NF-κB level in the substantia nigra pars compacta |
| (v) Increased BDNF expression in the substantia nigra pars compacta |
| (vi) Attenuated the decrease in tyrosine hydroxylase expression in the substantia nigra pars compacta |
| (vii) Attenuated the depletion of striatal dopamine level |
|
| Dihydromyricetin (DHM) (a natural flavonoid extracted from Ampelopsis grossedentata) | MPTP-induced mouse | (i) Attenuated MPTP-induced mouse behavioral impairments and dopaminergic neuron loss | [238] |
| (ii) Attenuated the MPTP-induced deficit in movement balance |
| (iii) Improved exploratory and locomotor activity |
| (iv) Attenuated the decrease in tyrosine hydroxylase and vesicular monoamine transporter 2 expression in the striatum and substantia nigra pars compacta |
|
| Agaropentaose, agaro-oligosaccharide monomer which is hydrolysates of agarose isolated from red algae | 6-ODHA-induced neurotoxicity in SH-SY5Y cells | (i) Reduced intracellular ROS level | [239] |
| (ii) Inhibited loss of mitochondrial membrane potential |
| (iii) Inhibited the activation of NF-κB |
| (iv) Enhanced the activities of superoxide dismutase, glutathione reductase, glutathione peroxidase |
| (v) Reduced malondialdehyde level |
| (vi) Reduced the number of apoptotic cells |
| (vii) Suppressed the cleaved of caspase 3 |
| (viii) Decreased the Bax/Bcl-2 ratio |
|
| Boswellic acids | Rotenone-induced rats | (i) Increased motor functions | [240] |
| (ii) Ameliorated percent of degenerating neuronal in the substantia nigra pars compacta |
| (iii) Increased percent of viable neurons in the substantia nigra pars compacta |
| (iv) Reduced inflammatory markers (TNF-α, IL-6, COX-2) |
| (v) Decreased NF-κB level |
| (vi) Increased striatal dopamine level |
| (vii) Increased nigral tyrosine hydroxylase immunostaining |
|
| Capsicum annuum L. extract | Rotenone-induced mouse | (i) Inhibited the increase of brain malondialdehyde and nitric oxide levels | [241] |
| (ii) Restored brain GSH level and paraoxonase-1 (PON1) activity |
| (iii) Attenuated the increase in brain 5-lipoxygenase activity |
| (iv) Restored brain cholinesterase activity |
| (v) Decreased GFAP-positive immunoreactivity in the cerebral cortex |
| (vi) Prevented the neuronal degeneration in the substantial nigra, cerebral cortex, and hippocampus |
|
| Coeloglossum viride var. bracteatum extract | MPTP-induced neurotoxicity in mouse and glutamate-induced excitotoxicity in primary cortical neuron cultures | (i) Inhibited glutamate-induced excitotoxicity in vitro | [242] |
| (ii) Inhibited glutamate-induced in the decrease of phosphorylated Akt and Bcl-2 |
| (iii) Prevented dopaminergic neuronal loss |
|
| Curcuminoids (Curcuma longa (L.) rhizomes) | MPTP-induced mouse | (i) Prevented the depletion of dopamine and tyrosine hydroxylase immunoreactivity | [243] |
| (ii) Reversed GFAP and iNOS protein expressions |
| (iii) Reduced proinflammatory cytokine and total nitrite generation in the striatum |
| (iv) Improved motor performance and gross behavioral activity, as determined by rotarod and open field tests |
|
| β-Caryophyllene, a plant-derived cannabinoid compound known as phytocannabinoid | Rotenone-induced rats | (i) Rescued dopaminergic neurons | [244] |
| (ii) Prevented dopaminergic neuronal loss in the substantia nigra and striatal dopamine fibers |
| (iii) Reduced Iba-1 and GFAP expressions |
| (iv) Decreased the number of activated astrocytes and microglia |
| (v) Attenuated proinflammatory cytokines (IL-1b, IL-6, and TNF-α) in the midbrain tissues and inflammatory mediators (COX-2 and iNOS expressions) in the cytoplasmic fraction of striatal tissue lysates |
| (vi) Restored antioxidant enzymes and glutathione depletion |
| (vii) Inhibited lipid peroxidation |
|
| Fish oil supplementation (rich in omega-3 polyunsaturated fatty acids) | 6-OHDA-induced rats | (i) Mitigated the loss of substantia nigra neurons and nerve terminals in the striatum | [245] |
| (ii) Reduced the density of iNOS-immunoreactive cells and microglia (OX-42) and astrocyte (GFAP) reactivity |
|
| Germinated brown rice | Rotenone-induced rats | (i) Enhanced the motor activity in rotenone-induced rats | [246] |
| (ii) Decreased serum and brain TNF-α, dopaminergic neuronal loss, motor deficits, the percentage of apoptotic cells |
| (iii) Attenuated the dopaminergic neuronal cell loss |
| (iv) Attenuated histopathological changes in substantia nigra neurons with visible nuclei and |
| (v) Increased the number of surviving dopaminergic neurons |
| (vi) Decreased the number of apoptotic cells |
| (vii) Increased the number of viable cells |
| (viii) Decreased TNF-α level in the serum and in brain |
|
| Oxalis corniculata extract | MPTP-induced mouse | (i) Improved memory retention and retrieval | [247] |
|
| Olive leaf extract (Olea europaea L.) | Rotenone-induced rats | (i) Suppressed oxidative stress by decreasing lipid peroxidation level and increasing midbrain antioxidant enzymes activities | [248] |
| (ii) Inhibited the depletion of tyrosine hydroxylase-positive neurons |
|
| Puerarin (an active component of Pueraria montana var. lobata (willd.) Sanjappa & Pradeep) | MPTP-induced mouse | (i) Attenuated MPTP-induced behavioral deficits, dopaminergic neuronal degeneration, and dopamine depletion | [249] |
| (ii) Enhanced glutathione activity, glial cell line-derived neurotrophic factor (GDNF) expression, and PI3K/Akt pathway activation, which might ameliorate MPTP injection-induced progressive elevation of ROS formation in mouse |
| (iii) Ameliorated MPTP-reduced lysosome-associated membrane protein type 2A (Lamp 2A) expression |
|
| Rosmarinic acid isolated from callus of Perilla frutescens | 6-OHDA-induced rats | (i) Restored the striatal dopamine level | [250] |
| (ii) Increased the number of tyrosine hydroxylase |
| (iii) Decreased the iron level in the substantia nigra |
| (iv) Upregulated the ratio of Bcl-2/Bax gene expression in the substantia nigra |
|
| Sophora tomentosa extract | MPTP-induced mouse | (i) Alleviated MPTP-induced motor deficits | [251] |
| (ii) Attenuated the decrease in the number of tyrosine hydroxylase-positive neurons in the substantia nigra |
| (iii) Restored the depletion of striatal dopamine level |
| (iv) Restored GSH level and antioxidant enzyme activities and decreased lipid peroxidation in the striatum |
| (v) Decreased the expression of α-synuclein and GSK-3β phosphorylation in the striatum |
|
| Tinospora cordifolia ethanol extract | 6-OHDA-induced rats | (i) Increased the dopamine levels and complex I activity | [252] |
| (ii) Attenuated iron asymmetry ratio |
| (iii) Reduced oxidative stress |
| (iv) Restored 6-OHDA-induced behavioral changes in locomotor activity |
| (v) Reduced the degree of catalepsy |
| (vi) Increased the time of fall in rotarod test |
|
| Tribulus terrestris extract | Rotenone-induced mouse | (i) Ameliorated motor dysfunction | [253] |
| (ii) Increased the percentage of viable neurons |
| (iii) Increased the number of tyrosine hydroxylase |
| (iv) Attenuate inflammatory markers (iNOS and COX-2 mRNA expression) |
| (v) Reduced DNA damage markers (8-oxo-2′-deoxyquanosine and MTH1 expression) |
| (vi) Suppressed oxidative stress by increasing GSH and activities of superoxide dismutase and catalase and decreasing malondialdehyde level |
| (vii) Downregulated CD11b mRNA expression (microglia marker) |
| (viii) Improved striatal dopamine level |
|
| Ethyl acetate fraction of Urtica dioica linn. | MPTP-induced rats | (i) Improved the motor function and oxidative defense alteration | [254] |
| (ii) Decreased the increased concentration of lipid peroxidation and nitrite concentration |
| (iii) Restored the decreased GSH level and activity of catalase |
| (iv) Attenuated the proinflammatory cytokines (TNF-α and IL-β) |
| (v) Restored the level of dopamine and its metabolites |
| (vi) Protected the dopaminergic neurons |
|
| Zingiber zerumbet (L.) Smith ethyl acetate extract | Paraquat-induced rats | (i) Decreased lipid peroxidation and protein oxidation | [255] |
| (ii) Increased level of GSH and the activities of antioxidant enzymes |
| (iii) Prevented neuronal damage |
|
