Table 1.

Summary of the effects of curcumin on TLR4/NF-κB p65 and CYP2E1/ROS /Nrf2 signalling pathways.

Signalling pathways	Effects	Target study / treatment	Type of animal study	Source
TLR4	Inhibition of TLR-4 Inhibition of Downstream Signalling Pathway: NF-κB, IRF3, MyD88, and TIRF Downregulation of Proinflammatory Cytokines TNF-α, IL-1, IL-2, IL-6, IL-8, and Mitogen-Activated Protein Kinase (MAPK) Suppression of Oxidative Stress Enzymes: Nitric Oxide Synthase, Cyclooxygenase, and Lipoxygenase	Acute inflammatory injury Experimental traumatic brain injury Cerebral Ischemia-Reperfusion Necroptosis inflammation in liver	Mice Rats Mice and rats Chicken	[92] [93] [94] [95]
NF-kB	Inhibition of the NF-κB Inflammatory Signalling Pathway Inhibition of Asthma Severity via HDAC1 (H3acK9) Modulation and NF-kB Suppression in a Mouse Model of Allergic Asthma Reduction of NF-kB and TNF-α Levels Decreased Expression and Translocation of NF-κB and p-NF-κB	Traumatic spinal cord injury Airway inflammation and fibrosis Pain intensity after high-intensity physical exercise Demyelination disease as diabetes mellitus (DM)	Rats Balb/c mice Clinical study Schwann cells (SCs)	[96] [97] [98] [99]
p65	Inhibition of NF-κB-p65 Translocation Reduces the Release of Inflammatory Factors Reduced p65 phosphorylation Inhibition of Proliferation and Expression of VEGF and NF-κB p65 Mitigation of Boldenone-Induced Neurobehavioral Disturbances in Rats: Normalization of Oxidant/Antioxidant Balance and Suppression of TLR4/MyD88/TRAF-6/NF-κB Pathway and Downstream Proinflammatory Signaling Molecules TNF-α and IL-1β	Lumbar intervertebral disc degeneration Pulp inflammation HRCECs induced by high glucose Boldenone-induced aggression in rats	Rats Human dental pulp stem cells (hDPSCs) Human retinal capillary endothelial cells (HRCECs) in vitro studies Rats	[100] [101] [102] [103]
CYP2E1	Inhibition of CYP2E1 Overexpression Induced by ACR in Liver and Kidney Tissues Inhibition of Cytochrome P4502E1 (CYP2E1), Sterol Regulatory Element-Binding Protein-1c (SREBP-1c), and Acetyl-CoA Carboxylase Production Hindering Profibrogenic Transcripts Linked with Myofibroblasts and Mouse Hepatic Fibrosis Enhancement of Alcohol Dehydrogenase (ADH) and Aldehyde Dehydrogenase (ALDH) Regulation: Effects on CYP2E1 Activity, Reactive Oxygen Species (ROS), Bax, Bcl-2, and Inflammatory Mediators IL-1β, IL-6, and TNF-α	Acrylamide-induced hepatic and renal impairment Alcohol-induced Fatty Liver Disease N, N′‑methylene bis acrylamide‑induced liver damage and hepatic cancer cell growth Hepatic toxicity	Rats Mice Mice (Mus musculus) Rats	[104] [105] [106] [107]
ROS	Increased ROS Level: Regulation of Cellular Redox Status and Mitochondrial Function Promotion of Glutathione Synthesis: Aiding in Recovery from Ethanol-Induced Liver Damage Exhibiting Hepatoprotective Effect against CYP-Induced Hepatotoxicity in Rats Inhibition of High Glucose-Induced Inflammatory Injury in RPECs by Interfering with the ROS/PI3K/AKT/mTOR Signalling Pathway	Mitochondrial function Ethanol-induced oxidative stress Cypermethrin Toxicity Glucose‑induced inflammatory injury	Mice Zebrafish Rats Human retinal pigment epithelial cells (RPECs)	[108] [109] [110] [111]
NRF2	Activation of NRF2 Signalling Pathway: Cellular Protection against Oxidative Injury	Acetaminophen-induced liver injury	Rats	[112]