Table 1.

Physiological Roles of Signalling Molecules Commonly Cited in the Body of the Paper

Molecules	Physiological role
NF-κB	Represents family of 5 structurally similar inducible transcription factors (p50, p52, RelA, RelB, and c-Rel) whose activity governs that of plethora of genes involved in effecting or regulating immune and inflammatory pathways and modulating several aspects of mitochondrial performance and energy production.
Nrf-2	A transcription factor that, once translocated to nucleus, associates with small Maf proteins and subsequently binds to ARE in promoter regions of target genes involved in cellular antioxidant response network, stimulating their transcription.
KEAP-1	A cysteine-rich molecule that binds to Nrf-2 in cytoplasm, promoting its degradation by ubiquitin proteasome pathway.
PPARα and PPARγ	Ligand-governed members of nuclear hormone receptor superfamily. Their activation generally increases expression of genes by binding to PPREs within their promoter regions in tandem with a retinoid X receptor. In certain circumstances, activation of PPARα or PPARγ may inhibit expression of gene clusters via interaction with other molecules such as NF-KB, SIRT-1, and PGC 1 alpha. PPARα and PPARγ activation provokes range of antioxidant, antiapoptotic, and antiinflammatory effects and plays major role in regulation of metabolism and mitochondrial dynamics.
FOXO	A FOXO class member of FOX protein family of transcription factors widely distributed in periphery and brain. Plays major role in regulating antioxidant responses, metabolism, energy production, and autophagy, including mitophagy and mitogenesis, by targeting promoter sequences on plethora of genes, generally leading to upregulation. This may be alone or in combination with range of other enzymes or coactivators such as SIRT-3, AMPK, and PGC 1alpha.
Sirtuins	Mammalian SIRTs function as NAD+-dependent deacylases and play many roles in regulating expression of genes involved in energy metabolism, cellular survival, inflammation, circadian rhythm regulation, and DNA repair. SIRT1 is found in cytosol and nucleus, modulates activity of transcription factors such as NF-KB p53, FOXOs, PPARs PGC1α, and PARP1. SIRT-3 is located in mitochondria and plays indispensable role in energy production and protecting organelles against oxidative and nitrosative stress.
Peroxisome proliferator-activated receptor-gamma coactivator	PGC-1alpha is a member of large family of transcription coactivators that acts as key player in regulation of energy metabolism by increasing mitochondrial biogenesis and stimulating mitochondrial respiration. Increased activity of this molecule also upregulates mitochondrial and cellular antioxidant responses.

Abbreviations: AMPK, AMP-activated protein kinase; ARE, antioxidant response element; FOX, forkhead box; KEAP1, Kelch ECH associating protein 1; NAD, Nicotinamide adenine dinucleotide; NF-κB, Nuclear factor-κB; Nrf-2, nuclear factor erythroid 2-related factor 2; PARP1, Poly (ADP-ribose) polymerase 1; PGC 1 alpha, Pparg coactivator 1 alpha; PPARalpha, Peroxisome proliferator-activated receptor alpha; PPRAgamma, Peroxisome proliferator-activated receptor gamma; PPREs, Peroxisome proliferator hormone response elements; SIRT-1, Sirtuin 1; SIRT-3, Sirtuin 3.