Catalpol Modulates Lifespan via DAF-16/FOXO and SKN-1/Nrf2 Activation in Caenorhabditis elegans

Rehmannioside D mitigates disease progression in rats with experimental-induced diminished ovarian reserve via Forkhead Box O1/KLOTHO axis

This study aims to explore the impact of Rehmannioside D (RD) on ovarian functions of rats with diminished ovarian reserve (DOR) and its underlying mechanisms of action. A single injection of cyclophosphamide was performed to establish a DOR rat model, and fourteen days after the injection, the rats were intragastrically administrated with RD for two weeks. Rat estrus cycles were tested using vaginal smears. Ovarian tissues were histologically evaluated, the number of primordial, mature, and atretic follicles was calculated, and the apoptotic rate of granulosa cells. Follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E₂) levels were determined by ELISA assays. Protein levels of Forkhead Box O1 (FOXO1), KLOTHO, Bcl-2, and Bax were investigated in ovarian tissues of DOR rats. The binding between FOXO1 and KLOTHO was verified by ChIP assay. High-dose administration of RD into DOR rats improved their estrus cycles, increased ovarian index, enhanced the number of primordial and mature follicles, reduced the number of atretic follicle number, and ovarian granulosa cell apoptosis in addition to inhibiting FSH and LH levels and upregulating E₂ expression. FOXO1 and KLOTHO were significantly suppressed in DOR rats. FOXO1 knockdown partially suppressed the protective effects of RD on DOR rats, and KLOTHO overexpression could restore RD-induced blockade of DOR development despite knocking down FOXO1. FOXO1 antibody enriched KLOTHO promoter, and the binding between them was reduced in DOR group compared to that in sham group. RD improved ovarian functions in DOR rats and diminished granulosa cell apoptosis via the FOXO1/KLOTHO axis.

Bioactive Phytochemicals with Anti-Aging and Lifespan Extending Potentials in Caenorhabditis elegans

In the forms of either herbs or functional foods, plants and their products have attracted medicinal, culinary, and nutraceutical applications due to their abundance in bioactive phytochemicals. Human beings and other animals have employed those bioactive phytochemicals to improve health quality based on their broad potentials as antioxidant, anti-microbial, anti-carcinogenic, anti-inflammatory, neuroprotective, and anti-aging effects, amongst others. For the past decade and half, efforts to discover bioactive phytochemicals both in pure and crude forms have been intensified using the Caenorhabditis elegans aging model, in which various metabolic pathways in humans are highly conserved. In this review, we summarized the aging and longevity pathways that are common to C. elegans and humans and collated some of the bioactive phytochemicals with health benefits and lifespan extending effects that have been studied in C. elegans. This simple animal model is not only a perfect system for discovering bioactive compounds but is also a research shortcut for elucidating the amelioration mechanisms of aging risk factors and associated diseases.

Antidepressant mechanism of catalpol: Involvement of the PI3K/Akt/Nrf2/HO-1 signaling pathway in rat hippocampus

Catalpol is a major compound in Rehmanniae Radix with outstanding medicinal and nutritional values. Our previous studies have demonstrated catalpol's antidepressant effect, but its mechanisms remain unclear. This study aimed to explore the antidepressant mechanisms of catalpol via the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/nuclear factor E2-related factor 2(Nrf2)/heme oxygenase-1 (HO-1) pathway. Results demonstrated that chronic unpredictable mild stress (CUMS) for 5 consecutive weeks caused significant decreases in the sucrose preference and the horizontal and vertical scores of open-field test, as well as a significant increase in the swimming-immobility time of rats; catalpol administration significantly reversed the abnormality of these indicators. Further real-time fluorescent quantitative polymerase chain reaction and Western blotting results together showed that CUMS significantly downregulated the expression levels of hippocampal genes and proteins, including PI3K, Akt, Nrf2, HO-1, tropomyosin-related kinase B (TrkB), and brain-derived neurotrophic factor; catalpol administration significantly reversed the abnormal expression of these genes and proteins. CUMS also caused a significant decrease in the hippocampal superoxide dismutase, catalase, glutathione peroxidase, glutathione-s transferase, and reduced glutathione levels, as well as a significant increase in thiobarbituric acid reactive substances level in rats; catalpol administration significantly reversed the abnormality of these indicators. Taken together, this study confirmed for the first time that the antidepressant effect of catalpol on CUMS-induced depression involved the upregulation of the PI3K/Akt/Nrf2/HO-1 signaling pathway, thereby improving the hippocampal neurotrophic, neuroprotective, and antioxidant levels. The PI3K/Akt/Nrf2/HO-1 pathway-related molecules may serve as potential new biomarkers and candidate molecular targets for catalpol's antidepressant effects.

The Review of Anti-aging Mechanism of Polyphenols on Caenorhabditis elegans

Micronutrients extracted from natural plants or made by biological synthesis are widely used in anti-aging research and applications. Among more than 30 effective anti-aging substances, employing polyphenol organic compounds for modification or delaying of the aging process attracts great interest because of their distinct contribution in the prevention of degenerative diseases, such as cardiovascular disease and cancer. There is a profound potential for polyphenol extracts in the research of aging and the related diseases of the elderly. Previous studies have mainly focused on the properties of polyphenols implicated in free radical scavenging; however, the anti-oxidant effect cannot fully elaborate its biological functions, such as neuroprotection, Aβ protein production, ion channel coupling, and signal transduction pathways. Caenorhabditis elegans (C. elegans) has been considered as an ideal model organism for exploring the mechanism of anti-aging research and is broadly utilized in screening for natural bioactive substances. In this review, we have described the molecular mechanisms and pathways responsible for the slowdown of aging processes exerted by polyphenols. We also have discussed the possible mechanisms for their anti-oxidant and anti-aging properties in C. elegans from the perspective of different classifications of the specific polyphenols, such as flavonols, anthocyanins, flavan-3-ols, hydroxybenzoic acid, hydroxycinnamic acid, and stilbenes.

SKN-1 is involved in combination of apple peels and blueberry extracts synergistically protecting against oxidative stress in Caenorhabditis elegans

Increased consumption of fruits and vegetables is associated with reduced risk of age-related functional declines and chronic diseases, primarily attributed to their bioactive phytochemicals. Apples and blueberries are rich in phytochemicals with a wide range of biological activities and health benefits. Our previous research has shown the combination of apple peel extracts (APE) and blueberry extracts (BE) can synergistically promote the lifespan of Caenorhabditis elegans (C. elegans). The objectives of this study were to determine whether the extension of lifespan was involved in regulation of oxidative stress, and to explore the underlying mechanisms of action. The results showed that the combination of APE and BE could synergistically ameliorate oxidative stress by improving antioxidant enzyme activities and enhancing resistance to paraquat. Meanwhile, treatment with APE plus BE could down-regulate the overexpression of reactive oxygen species (ROS) and affect the expression of antioxidant related genes, including sod-3, cat-1, ctl-1, skn-1, mev-1 and isp-1. However, administration with APE plus BE abolished the extension of the lifespan of skn-1(zu135) mutants, and inhibited the expression of skn-1 downstream genes, including gcs-1, gst-4 and gst-7. In addition, supplementation with APE plus BE could promote the migration of SKN-1 into the nucleus, which eliminated improvement to ROS and paraquat. In conclusion, the combination of APE and BE could synergistically protect against oxidative stress in C. elegans via the SKN-1/Nrf2 pathway. This study provided the theoretical basis to explore the combination of phytochemicals in the prevention of aging regulated by oxidative stress.

Health and longevity studies in C. elegans: the "healthy worm database" reveals strengths, weaknesses and gaps of test compound-based studies

Several biogerontology databases exist that focus on genetic or gene expression data linked to health as well as survival, subsequent to compound treatments or genetic manipulations in animal models. However, none of these has yet collected experimental results of compound-related health changes. Since quality of life is often regarded as more valuable than length of life, we aim to fill this gap with the “Healthy Worm Database” (http://healthy-worm-database.eu). Literature describing health-related compound studies in the aging model Caenorhabditis elegans was screened, and data for 440 compounds collected. The database considers 189 publications describing 89 different phenotypes measured in 2995 different conditions. Besides enabling a targeted search for promising compounds for further investigations, this database also offers insights into the research field of studies on healthy aging based on a frequently used model organism. Some weaknesses of C. elegans-based aging studies, like underrepresented phenotypes, especially concerning cognitive functions, as well as the convenience-based use of young worms as the starting point for compound treatment or phenotype measurement are discussed. In conclusion, the database provides an anchor for the search for compounds affecting health, with a link to public databases, and it further highlights some potential shortcomings in current aging research.

Potential of Caenorhabditis elegans as an antiaging evaluation model for dietary phytochemicals: A review

Aging is an inevitable process characterized by the accumulation of degenerative damage, leading to serious diseases that affect human health. Studies on aging aim to develop pre-protection or therapies to delay aging and age-related diseases. A preventive approach is preferable to clinical treatment not only to reduce investment but also to alleviate pain in patients. Adjusting daily diet habits to improve the aging condition is a potentially attractive strategy. Fruits and vegetables containing active compounds that can effectively delay the aging process and reduce or inhibit age-related degenerative diseases have been identified. The signaling pathways related to aging in Caenorhabditis elegans are evolutionarily conserved; thus, studying antiaging components by intervening senescence process may contribute to the prevention and treatment of age-related diseases in humans. This review focuses on the effects of food-derived extracts or purified substance on antiaging in nematodes, as well as the underlying mechanisms, on the basis of several major signaling pathways and key regulatory factors in aging. The aim is to provide references for a healthy diet guidance and the development of antiaging nutritional supplements. Finally, challenges in the use of C. elegans as the antiaging evaluation model are discussed, together with the development that potentially inspire novel strategies and research tools.

Quercetin enhances motility in aged and heat-stressed Caenorhabditis elegans nematodes by modulating both HSF-1 activity, and insulin-like and p38-MAPK signalling

Quercetin is a yellow pigment that is found in many common dietary plants, and that protects against oxidative stress, inflammation, and arteriosclerosis. It has also been suggested to prolong the lifespan of, and enhance heat-stress tolerance in nematodes; thus, the present study investigated its effects on both the nematode life- and health span by assessing its capacity to promote nematode motility after aging and/or heat stress, as well as the mechanisms underlying these effects. The results of the conducted analyses showed that quercetin feeding prolonged lifespan, suppressed age-related motility retardation, improved motility recovery after heat stress, and decreased the production of both intercellular and mitochondrial reactive oxygen species in the analysed Caenorhabditis elegans strains, likely by modulating the insulin-like signalling (ILS) pathway and p38-mitogen-activated protein kinase (MAPK) pathway. In particular, the transcription factors DAF-16 and SKN-1 were found to mediate the observed quercetin-induced effects, consistent with their previously demonstrated roles as regulators of aging. Furthermore, we demonstrated, for the first time, that quercetin induced heat-stress tolerance in C. elegans by modulating HSF-1 expression and/or activity. Thus, the present study provides valuable insights into the mechanisms by which quercetin inhibit aging and enhance heat-stress tolerance via ILS and MAPK pathway in C. elegans.

Nobiletin Delays Aging and Enhances Stress Resistance of Caenorhabditis elegans

Nobiletin (NOB), one of polymethoxyflavone existing in citrus fruits, has been reported to exhibit a multitude of biological properties, including anti-inflammation, anti-oxidation, anti-atherosclerosis, neuroprotection, and anti-tumor activity. However, little is known about the anti-aging effect of NOB. The objective of this study was to determine the effects of NOB on lifespan, stress resistance, and its associated gene expression. Using Caenorhabditis elegans, an in vivo nematode model, we found that NOB remarkably extended the lifespan; slowed aging-related functional declines; and increased the resistance against various stressors, including heat shock and ultraviolet radiation. Also, NOB reduced the effects of paraquat stressor on nematodes and scavenged reactive oxygen species (ROS). Furthermore, gene expression revealed that NOB upregulated the expression of sod-3, hsp-16.2, gst-4, skn-1, sek-1, and sir-2.1, which was suggested that anti-aging activity of NOB was mediated most likely by activation of the target genes of the transcription factors including dauer formation (DAF)-16, heat-shock transcription factor (HSF)-1, and skinhead (SKN)-1. In summary, NOB has potential application in extension of lifespan, and its associated healthspan and stress resistances.

Fermented product of rice with Lactobacillus kefiranofaciens induces anti-aging effects and heat stress tolerance in nematodes via DAF-16

Rice kefiran is superior in functionality, has high concentration of mucilaginous polysaccharide, and low lipid content, compared to conventional kefiran. However, reports on its physiological functionality, especially studies on life expectancy and aging, in model organisms are rare. In this study, nematodes were used as model organisms that were fed rice kefiran, along with Escherichia coli OP50, as a result of which, the lifespan of nematodes was extended and age-related retardation of mobility was suppressed. It also increased the heat stress resistance in nematodes. Experiments using daf-16 deletion mutant revealed that rice kefiran functions via DAF-16. Thus, this study revealed the longevity, anti-aging and heat stress tolerance effects of rice kefiran in nematodes.

Liangyi Gao extends lifespan and exerts an antiaging effect in Caenorhabditis elegans by modulating DAF-16/FOXO

Liangyi Gao (LYG), a traditional Chinese medicine, is composed of Ginseng and Radix Rehmanniae Preparata, both of which have been shown to have antiaging properties. In Eastern countries, LYG is used to delay functional declines related to aging and has an obvious antiaging effect in clinical practice. However, little data from evidence-based medicine is available regarding whether LYG is beneficial overall, particularly with respect to lifespan, and how LYG functions. To address these issues, Caenorhabditis elegans, a useful organism for such studies, was employed to explore the antiaging effect and mechanism of LYG in this study. The results showed that LYG could obviously extend lifespan and slow aging-related declines in N2 wild-type C. elegans. To further characterize these antiaging effects and stress resistance, reproductive tests and other aging-related tests were performed. We found that LYG enhanced resistance against oxidative and thermal stress, reproduction, pharynx pumping, motility and growth in N2 wild-type C. elegans. In addition, we analyzed the mechanism for these effects by measuring the activity of superoxide dismutase (SOD) and the expression levels of aging-related genes. We found that LYG enhanced the activities of antioxidant enzymes and upregulated the genes daf-16, sod-3 and sir-2.1, which mediated stress resistance and longevity. In conclusion, LYG had robust and reproducible life-prolonging and antiaging benefits in C. elegans via DAF-16/FOXO regulation.

Regulation of Mitochondrial Biogenesis as a Way for Active Longevity: Interaction Between the Nrf2 and PGC-1α Signaling Pathways

Aging is a general degenerative process related to deterioration of cell functions in the entire organism. Mitochondria, which play a key role in energy homeostasis and metabolism of reactive oxygen species (ROS), require lifetime control and constant renewal. This explains recently peaked interest in the processes of mitochondrial biogenesis and mitophagy. The principal event of mitochondrial metabolism is regulation of mitochondrial DNA (mtDNA) transcription and translation, which is a complex coordinated process that involves at least two systems of transcription factors. It is commonly believed that its major regulatory proteins are PGC-1α and PGC-1β, which act as key factors connecting several regulator cascades involved in the control of mitochondrial metabolism. In recent years, the number of publications on the essential role of Nrf2/ARE signaling in the regulation of mitochondrial biogenesis has grown exponentially. Nrf2 is induced by various xenobiotics and oxidants that oxidize some Nrf2 negative regulators. Thus, ROS, in particular H₂O₂, were found to be strong Nrf2 activators. At present, there are two major concepts of mitochondrial biogenesis. Some authors suggest direct involvement of Nrf2 in the regulation of this process. Others believe that Nrf2 regulates expression of the antioxidant genes, while the major and only regulator of mitochondrial biogenesis is PGC-1α. Several studies have demonstrated the existence of the regulatory loop involving both PGC-1α and Nrf2. In this review, we summarized recent data on the Nrf2 role in mitochondrial biogenesis and its interaction with PGC-1α in the context of extending longevity.

Longevity and Stress Resistant Property of 6-Gingerol from Zingiber officinale Roscoe in Caenorhabditis elegans

In order to discover lifespan-extending compounds made from natural resources, activity-guided fractionation of Zingiber officinale Roscoe (Zingiberaceae) ethanol extract was performed using the Caenorhabditis elegans (C. elegans) model system. The compound 6-gingerol was isolated from the most active ethyl acetate soluble fraction, and showed potent longevity-promoting activity. It also elevated the survival rate of worms against stressful environment including thermal, osmotic, and oxidative conditions. Additionally, 6-gingerol elevated the antioxidant enzyme activities of C. elegans, and showed a dose-depend reduction of intracellular reactive oxygen species (ROS) accumulation in worms. Further studies demonstrated that the increased stress tolerance of 6-gingerol-mediated worms could result from the promotion of stress resistance proteins such as heat shock protein (HSP-16.2) and superoxide dismutase (SOD-3). The lipofuscin levels in 6-gingerol treated intestinal worms were decreased in comparison to the control group. No significant 6-gingerol-related changes, including growth, food intake, reproduction, and movement were noted. These results suggest that 6-gingerol exerted longevity-promoting activities independently of these factors and could extend the human lifespan.

Killed Bifidobacterium longum enhanced stress tolerance and prolonged life span of Caenorhabditis elegans via DAF-16

Probiotics are bacteria among the intestinal flora that are beneficial for human health. Bifidobacterium longum (BL) is a prototypical probiotic that is widely used in yogurt making, supplements and others. Although various physiological effects of BL have been reported, those associated with longevity and anti-ageing still remain elusive. Here we aimed to elucidate the physiological effects of killed BL (BR-108) on stress tolerance and longevity of Caenorhabditis elegans and their mechanisms. Worms fed killed BL in addition to Escherichia coli (OP50) displayed reduced body length in a BL dose-dependent manner. When compared with those fed E. coli alone, these worms had a higher survival rate following heat stress at 35°C and hydrogen peroxide-induced oxidative stress. A general decrease in motility was observed over time in all worms; however, killed BL-fed ageing worms displayed increased movement and longer life span than those fed E. coli alone. However, the longevity effect was suppressed in sir-2.1, daf-16 and skn-1-deficient worms. Killed BL induced DAF-16 nuclear localisation and increased the expression of the DAF-16 target gene hsp-12.6. These results revealed that the physiological effects of killed BL in C. elegans were mediated by DAF-16 activation. These findings contradict previous observations with different Bifidobacterium and Lactobacillus strains, which showed the role for SKN-1 independently of DAF-16.

Lifespan-extending property of 6-shogaol from Zingiber officinale Roscoe in Caenorhabditis elegans

Aging is a key risk factor for many diseases, understanding the mechanism of which is becoming more important for drug development given the fast-growing aging population. In the course of our continued efforts to discover anti-aging natural products, the active constituent 6-shogaol was isolated from Zingiber officinale Roscoe. The chemical structure of 6-shogaol was identified by comparison of its NMR data with literature values. The lifespan-extending effect of 6-shogaol was observed in a dose-dependent manner in Caenorhabditis elegans that has been widely used as a model organism for human aging studies. Mechanism of such action was investigated using C. elegans models, suggesting that 6-shogaol is capable of increasing stress tolerances via enzyme induction. The proposed mechanism was further supported by observation of the increase in SOD and HSP expressions upon treatment with 6-shogaol in transgenic strains of C. elegans which contain GFP-based reporters. In addition, the mechanism was elaborated by confirming that the effect observed for 6-shogaol is independent from other aging-related factors that are known to affect the aging process of C. elegans.

Methyl 3,4-Dihydroxybenzoate Enhances Resistance to Oxidative Stressors and Lifespan in C. elegans Partially via daf-2/daf-16

Genetic studies have elucidated mechanisms that regulate aging; however, there has been little progress in identifying drugs that retard ageing. Caenorhabditis elegans is among the classical model organisms in ageing research. Methyl 3,4-dihydroxybenzoate (MDHB) can prolong the life-span of C. elegans, but the underlying molecular mechanisms are not yet fully understood. Here, we report that MDHB prolongs the life-span of C. elegans and delays age-associated declines of physiological processes. Besides, MDHB can lengthen the life-span of eat-2 (ad1113) mutations, revealing that MDHB does not work via caloric restriction (CR). Surprisingly, the life-span–extending activity of MDHB is completely abolished in daf-2 (e1370) mutations, which suggests that daf-2 is crucial for a MDHB-induced pro-longevity effect in C. elegans. Moreover, MDHB enhances the nuclear localization of daf-16/FoxO, and then modulates the expressions of genes that positively correlate with defenses against stress and longevity in C. elegans. Therefore, our results indicate that MDHB at least partially acts as a modulator of the daf-2/daf-16 pathway to extend the lifespan of C. elegans, and MDHB might be a promising therapeutic agent for age-related diseases.

Physicochemical Characterization and Functional Analysis of the Polysaccharide from the Edible Microalga Nostoc sphaeroides

Nostoc colonies have been used as food and medicine for centuries, and their main supporting matrix is polysaccharides, which help Nostoc cells resist various environmental stresses including oxidative stress. Here we isolated a polysaccharide, nostoglycan, from cultured Nostocsphaeroides colonies and determined its physicochemical properties, which revealed a characteristic infrared absorption spectrum typical of polysaccharides and an amorphous morphology with rough surfaces. We also show that nostoglycan has strong moisture absorption and retention capacities and a high relative viscosity. Using Caenorhabditis elegans models, we then demonstrate that nostoglycan is capable of improving overall survival rate of the animals under increased oxidative stress caused by paraquat. Nostoglycan also reduces reactive oxygen species level, inhibits protein carbonyl formation and lipid peroxidation, and increases activities of superoxide dismutase and catalase in paraquat-exposed nematodes. As oxidative stress may drive tumor progression, we further demonstrate that nostoglycan can suppress the proliferation of several types of tumor cells and induce apoptosis of human lung adenocarcinoma A549 cells via caspase-3 activation. Together, our results yield important information on the physicochemical characteristics and demonstrate the antioxidant and anti-proliferative functions of nostoglycan, and thus provide an insight into its potential in food and health industries.

Emodin extends lifespan of Caenorhabditis elegans through insulin/IGF-1 signaling pathway depending on DAF-16 and SIR-2.1

The naturally occurring anthraquinone emodin has been serving primarily as an anti-bacterial and anti-inflammatory agent. However, little is known about its potential on anti-aging. This investigation examined the effect of emodin on lifespan and focused on its physiological molecular mechanisms in vivo. Using Caenorhabditis elegans (C. elegans) as an animal model, we found emodin could extend lifespan of worms and improve their antioxidant capacity. Our mechanistic studies revealed that emodin might function via insulin/IGF-1 signaling (IIS) pathway involving, specifically the core transcription factor DAF-16. Quantitative RT-PCR results illustrated that emodin up-regulated transcription of DAF-16 target genes which express antioxidants to promote antioxidant capacity and lifespan of worms. In addition, attenuated effect in sir-2.1 mutants suggests that emodin likely functioned in a SIR-2.1-dependent manner. Our study uncovers a novel role of emodin in prolonging lifespan and supports the understanding of emodin being a beneficial dietary supplement.

Current Perspective in the Discovery of Anti-aging Agents from Natural Products

Aging is a process characterized by accumulating degenerative damages, resulting in the death of an organism ultimately. The main goal of aging research is to develop therapies that delay age-related diseases in human. Since signaling pathways in aging of Caenorhabditis elegans (C. elegans), fruit flies and mice are evolutionarily conserved, compounds extending lifespan of them by intervening pathways of aging may be useful in treating age-related diseases in human. Natural products have special resource advantage and with few side effect. Recently, many compounds or extracts from natural products slowing aging and extending lifespan have been reported. Here we summarized these compounds or extracts and their mechanisms in increasing longevity of C. elegans or other species, and the prospect in developing anti-aging medicine from natural products.

Role of Nrf2/HO-1 system in development, oxidative stress response and diseases: an evolutionarily conserved mechanism

The multifunctional regulator nuclear factor erythroid 2-related factor (Nrf2) is considered not only as a cytoprotective factor regulating the expression of genes coding for anti-oxidant, anti-inflammatory and detoxifying proteins, but it is also a powerful modulator of species longevity. The vertebrate Nrf2 belongs to Cap 'n' Collar (Cnc) bZIP family of transcription factors and shares a high homology with SKN-1 from Caenorhabditis elegans or CncC found in Drosophila melanogaster. The major characteristics of Nrf2 are to some extent mimicked by Nrf2-dependent genes and their proteins including heme oxygenase-1 (HO-1), which besides removing toxic heme, produces biliverdin, iron ions and carbon monoxide. HO-1 and their products exert beneficial effects through the protection against oxidative injury, regulation of apoptosis, modulation of inflammation as well as contribution to angiogenesis. On the other hand, the disturbances in the proper HO-1 level are associated with the pathogenesis of some age-dependent disorders, including neurodegeneration, cancer or macular degeneration. This review summarizes our knowledge about Nrf2 and HO-1 across different phyla suggesting their conservative role as stress-protective and anti-aging factors.