Trends in Neurosciences
ReviewNeurohormetic phytochemicals: low-dose toxins that induce adaptive neuronal stress responses
Section snippets
Neurohormesis: what it is and how it works
Hormesis refers to a process in which exposure to a low dose of an agent that is toxic at higher doses induces a beneficial effect on the cell or organism. The term hormesis has been widely used in the toxicology field, where it is defined as ‘an adaptive response characterized by biphasic dose responses of generally similar quantitative features with respect to amplitude and range of the stimulatory response that are either directly induced or the result of compensatory biological processes
Health-promoting phytochemicals: an evolutionary perspective
Why do plant cells contain so many different chemicals that exert biological effects on organisms that ingest them? Evolutionary considerations suggest that many of the phytochemicals with biological activities that are beneficial for mammals evolved as toxins that protect the plants against insects and other damaging organisms [22]. In contrast to motile organisms. which can escape predators, immobile plants discourage predators by concentrating noxious chemicals in their leaves, flowers and
Phytochemical mechanisms of action on the nervous system: antioxidants and/or low-dose toxins?
Epidemiological studies of human populations, and experiments in animal models of neurodegenerative disorders, have provided evidence that phytochemicals in fruits and vegetables can protect the nervous system against disease 29, 30. The vast majority of studies of health benefits of phytochemicals have focused on the fact that many of the active chemicals possess antioxidant activity. Hundreds of articles have been published reporting neuroprotective effects of compounds in natural products,
Evidence that phytochemicals activate neurohormesis pathways
Although the number of phytochemicals reported to have beneficial effects on neurons in cell culture and in vivo is large, knowledge of the underlying cellular and molecular mechanisms is meager. In this section, we have chosen to focus on only a few phytochemicals for which there is accumulating evidence supporting a hormetic mechanism of action. They include resveratrol, sulforaphane, curcumins, catechins, allium and related organosulfur compounds, and hypericin (Figure 2).
Resveratrol, a
Concluding remarks
Many dietary and lifestyle factors that promote health of the nervous system might act by imposing a mild stress on neural cells, which respond to the stress by enhancing their ability to cope with more severe stress and resist disease. Physical exercise [78], dietary energy restriction [5] and cognitive stimulation [79] all induce adaptive cellular stress responses in neurons resulting in enhanced neurogenesis and synaptic plasticity, and resistance to injury and disease. Dietary energy
Acknowledgements
This work was supported by the National Institute on Aging Intramural Research Program, NIH.
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2023, Science of the Total Environment4-Hydroxycinnamic acid attenuates neuronal cell death by inducing expression of plasma membrane redox enzymes and improving mitochondrial functions
2023, Food Science and Human WellnessCitation Excerpt :Previously, we showed that overexpressed PM redox enzymes such as NQO1 and b5R enhanced mitochondrial functions and made neuronal cells more resistant to some toxic insults [69–71]. This study found that treatment of SH-SY5Y cells with HCA induced expression of NQO1 (Fig. 2A), similar to other neurohormetic phytochemicals such as sulforaphane, curcumin, and catechin [85]. HCA-dependent induction of NQO1 expression was consistent with its elevation of NQO1 activity (Fig. 2A).
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