What is Luteolin?
Luteolin is a plant pigment belonging to the flavonoid family. Dietary sources include citrus fruits, broccoli, carrots, celery, parsley and oregano (1). Supplementation with luteolin is believed to confer longevity benefits. Most of the research that exists on the benefits of luteolin have been in vivo (animal or organism research) and in vitro (cell research).
Effects of luteolin on oxidative stress
Oxidative stress causes cell and DNA damage; it is akin to cellular aging. Oxidative stress is an imbalance between antioxidants and free radicals or reactive oxygen species (ROS) within the cell. Since luteolin is a flavonoid, it acts as an antioxidant to control oxidative stress. It has been noted to suppress ROS and inhibit ROS-related cellular damage (8, 9). In addition, luteolin has been noted to activate an important antioxidant gene pathway, nuclear factor erythroid 2-related factor 2 (Nrf2), which confers additional antioxidative benefits (8).
Effects of luteolin on inflammation
Chronic inflammation is directly related to the acceleration of aging and the development of diseases of aging (10). In animal studies, luteolin has been shown to prevent inflammation of the lungs, nose and brain via the inhibition of pro-inflammatory cytokines (11, 63). In mice, luteolin also prevents viral-induced inflammation in the breast and lung (14, 15). Additionally, in various cells luteolin inhibits major signaling associated with inflammation, including Nf-kB, TLR4, and cytokine expression (12-14).
Effects of luteolin on heart health
Several studies have found that luteolin supports heart health. Studies in mice have shown that luteolin strengthens heart cells and heart contractions (2, 4). Other animal studies have found that luteolin prevents damage of heart tissues and heart cell death (3, 4). Luteolin was also found to reduce oxidative stress-induced damage during a simulated heart attack in the isolated hearts of mice (5). Another possible heart benefit of luteolin is the prevention of atherosclerosis, via the reduction of inflammation and fat buildup in blood vessels, which has also been found in mice (6, 7).
Effects of luteolin on the brain and nervous system
Across various animal and cell studies, luteolin has been shown to have neuroprotective effects and to support nerve development. This effect is likely due to luteolin’s ability to reduce glutamate levels, suppress brain inflammation and deter oxidative stress. These benefits support hippocampal neuron growth and prevent the mutation of neural proteins (16-20). Additionally, animal research in mice with Alzheimer’s Disease have supported this evidence (21-23). Research has also shown that luteolin ameliorates the symptoms of Alzheimer’s in mice through increasing cognition, memory and balance (21-23). Similarly, in cell assays, luteolin has also been shown to protect human brain cells against cellular aging caused by oxidative stress and Alzhiemer’s-associated inflammation and proteins (24, 25).
Luteolin supplementation may also protect against depression. Studies in mice and cells have found that luteolin may protect nerves in the hippocampus, the brain region dedicated to emotions and memory, and also activate gamma-aminobutyric acid (GABA) receptors, associated with improved mood (26-28). In mice, luteolin supplementation has also been shown to decrease symptoms of parkinson’s disease, multiple sclerosis, and brain trauma (29-32).
All in all, luteolin supplementation may be an effective route to suppress brain inflammation, suppress oxidative stress induced brain damage and enhance beneficial neural cell signaling pathways.
Effects of luteolin on cancer
Due to luteolin’s antioxidant properties, it is believed that luteolin can protect against cancer. Animal studies have shown that luteolin can prevent the growth of prostate, breast, lung, stomach, colon, ovarian and liver cancers (33-42). Similarly, cell studies have found that luteolin confers protection for pancreatic and brain cancer (43-48). Research also suggests that luteolin may help to reduce drug-resistant cancer cell growth, via inducing cancer cell apoptosis, and enhance chemotherapy effectiveness (47,48).
Effects of luteolin on the immune system
Luteolin supplementation has been shown to enhance the immune system in various ways. In animal studies, luteolin blocks lipopolysaccharide-induced (LPS) inflammation which is associated with bacterial infection (49-52). In fact, one study found that luteolin’s ability to block LPS-induced inflammation enhanced animal survival rate (52). In support of this attribute, cell studies have shown similar results (53, 54). Luteolin has also been found to inhibit viral spread in mice, including both Epstein-Barr and hepatitis B (55-57). A cell study also supports this evidence, suggesting that luteolin has antiviral capacities against Japanese encephalitis virus (58).
Effects of luteolin on skin aging
Animal research has found that luteolin may reverse skin aging and prevent the development of skin cancer (59, 60). This effect is likely due to the antioxidative properties of luteolin, which protect the skin from sun damage.
Effects of luteolin on male hormones
For men, luteolin supplementation may also confer hormone benefits. Cell studies have shown that luteolin inhibits aromatase, which may prevent the conversion of male sex hormones into estrogen (61). In this sense, luteolin may work to boost testosterone levels. For instance, in mice exposed to a strong electromagnetic field, luteolin boosted testosterone levels (62). However, further research is needed to investigate these effects more thoroughly.
What does this all mean?
Preclinical research on luteolin suggests that it has intriguing anti-inflammatory and antioxidant properties which may confer benefits to the heart, brain, immune system, nervous system, skin and hormones. It also may offer protection against specific cancers. Most of the clinical trials investigating these effects in humans are still underway. The doses seen in research are doses more likely to be found in supplements as opposed to the diet. As always, weigh the pros and the cons based on the current evidence and reach out to your physician if you’re interested in supplementation. It is advised that pregnant women, individuals with cervical cancer and children avoid supplementation with luteolin.
Author: Jacqueline Seymour
Jacki is a Master’s student at USC, home of Dr. Valter Longo’s Longevity Institute, where she’s studying her passion for life: Gerontology(the science of aging) and Nutrition.
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