Luteolin: The Authoritative Guide (2024)

What Is Luteolin?

Luteolin is a common flavonoid that exists in many types of plants including fruits, vegetables, and medicinal herbs. (source)

Flavonoids, as polyphenolic compounds, serve a crucial function in safeguarding plant cells against various threats such as microorganisms, insects, and UV radiation. Extensive research spanning cell cultures, animal trials, and population studies has underscored the potential health benefits of flavonoids for both humans and animals. These compounds, widely present in dietary sources like vegetables, fruits, and medicinal herbs, exhibit diverse properties as antioxidants, estrogenic modulators, and antimicrobial agents. Furthermore, emerging observations suggest a potential role of flavonoids in cancer prevention.

What Foods Contain Luteolin?

Vegetables and fruits such as celery, parsley, broccoli, onion leaves, carrots, peppers, cabbages, apple skins, and chrysanthemum flowers are luteolin rich.

Luteolin is also found in tea, olive fruit extract, vegetables and fruits (source)

What Is Luteolin Good For?

Plants abundant in luteolin have a longstanding history in Chinese traditional medicine, utilized to address a spectrum of ailments ranging from hypertension to inflammatory conditions and cancer. Luteolin, possessing diverse biological properties including anti-inflammatory, anti-allergic, and anticancer effects, exhibits a nuanced role as both an antioxidant and a pro-oxidant at the biochemical level. There exists a potential interplay among the various biological effects of luteolin, where, for example, its anti-inflammatory prowess may intersect with its anticancer potential. (source)

Antioxidant

Most flavonoids, including luteolin, are regarded as antioxidants. (source)

You may like to read my blog Oxidative Stress: The Complete Guide to learn more about antioxidants and oxidative stress.

Estrogenic And Anti-Estrogenic Activity

Estrogens function as pivotal hormones orchestrating the proliferation and specialisation of their designated target cells. Upon estrogen stimulation, the estrogen receptor (ER) undergoes activation, prompting DNA synthesis and cellular proliferation. Flavonoids, as natural phytoestrogens, exhibit the capacity to bind to ERs, thereby initiating their respective signaling cascades. Given its noteworthy estrogenic activity even at minimal concentrations, luteolin emerges as a promising candidate for hormone replacement therapy, presenting potential therapeutic utility in this context. (source)

Nonetheless, there exist reports delineating the anti-estrogenic properties of luteolin. This seemingly paradoxical effect can be attributed to its relatively modest estrogenic activity upon binding to ERs. Flavonoids exhibit a propensity to bind and activate ERs under conditions of estrogen deficiency. However, owing to their comparably diminished estrogenic potency—ranging from 103- to 105-fold lower than that of 17-β-estradiol—luteolin may serve as an anti-estrogenic agent by competitively inhibiting estrogen binding to ERs. Furthermore, another avenue through which luteolin exerts its anti-estrogenic influence is by impeding aromatase activity, responsible for converting androgens into estrogens. (source)

Anti-Inflammatory

Inflammation stands as a fundamental defence mechanism within the body, crucial for warding off infections and facilitating healing processes following injury. However, when inflammation becomes chronic, it can lead to debilitating conditions such as arthritis, chronic obstructive pulmonary disease, and cancer. During inflammation, macrophages undergo activation triggered by various molecules, including host cytokines and pathogenic toxins. Lipopolysaccharide (LPS), an endotoxin found in the outer membrane of Gram-negative bacteria, serves as a common instigator of inflammation. Activated macrophages respond by robustly generating inflammatory molecules like tumor necrosis factor α (TNFα), interleukins (ILs), and reactive oxygen species (ROS) and reactive nitrogen species (RNS).

These molecules facilitate the recruitment of inflammatory cells like neutrophils and lymphocytes to the site of infection, aiding in pathogen clearance. However, sustained production of these inflammatory mediators during chronic inflammation can contribute to the development of diseases such as cancer.

Luteolin demonstrates anti-inflammatory properties by suppressing the production of these cytokines and interfering with their signal transduction pathways. Animal experiments have shown that luteolin effectively mitigates LPS-induced inflammation, reducing TNFα release in serum and suppressing the expression of intercellular adhesion molecule-1 (ICAM-1) in the liver. Additionally, luteolin has been found to alleviate inflammation in lung tissue caused by pathogens like Chlamydia pneumoniae.

In vitro studies further elucidate luteolin’s anti-inflammatory effects, demonstrating its ability to inhibit TNFα and IL-6 release in murine macrophages stimulated by LPS. This inhibition is associated with the blockade of LPS-induced activation of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) family members ERK, p38, and JNK. These pathways play pivotal roles in macrophage activation and the response of tissue cells to inflammatory stimuli.

Given its multifaceted actions in various pathways implicated in chronic inflammation and its favourable safety profile, luteolin holds promise as an adjunct therapeutic option for inflammation and associated pain relief. Comprehensive reviews in the literature delve into luteolin’s anti-inflammatory effects, detailing its regulation of inflammatory mediators such as IL-6, IL-1β, TNF-α, COX-2 enzyme, prostaglandins, inducible nitric oxide synthase (iNOS), and metalloproteinases (MMPs) in both in vitro cell lines and in vivo animal models. These findings underscore the therapeutic potential of luteolin in managing chronic inflammatory conditions. (source)

Allergies

This comprehensive overview outlines the anti-inflammatory impacts of dietary constituents on mast cells (MC), elucidating the involved signalling pathways across both in vitro and in vivo settings. Among the notable agents studied, including butyrate, calcitriol, kaempferol, quercetin, luteolin, resveratrol, curcumin, and cinnamon extract, significant efficacy was observed in attenuating the release of preformed and newly synthesized mediators from MC, as well as in animal models. Randomised controlled trials (RCTs) have demonstrated promising outcomes, particularly with vitamin D, quercetin, EGCG, resveratrol, curcumin, and cinnamon extract, showcasing symptom improvement in allergic rhinitis (AR) patients and a reduction in inflammatory cell count.

Nonetheless, efforts to address the challenge of poor bioavailability associated with these nutrients remain a focal point of ongoing research endeavours. (source)

Pain Management

Over the past decade, natural compounds have garnered considerable attention for their potential therapeutic applications. Among these compounds, flavonoids have emerged as a extensively studied group of phytochemicals. These secondary metabolites of plants are widely distributed in fruits, vegetables, and herbs. Given their diverse pharmacological activities and favorable safety profiles, flavonoids hold promise as agents for combating chronic inflammation and neuropathy. Luteolin, a flavone abundantly present in various medicinal plants and herbs, exhibits a spectrum of pharmacological properties. Notably, its anti-inflammatory, antioxidant, neuroprotective, and analgesic effects offer significant potential for pain management strategies. (source)

Neuropathic Pain

It is a very promising agent against neuropathic pain, due to its effects on two molecular mechanisms involved in neuropathy pathogenesis: oxidative stress and inflammation. Its potent antioxidant abilities, its actions against neuroinflammation, along with its analgesic effects, justify luteolin as a possible complementary therapeutic compound in neuropathy. (source)

Neurodegenerative Conditions

Numerous preclinical investigations have revealed the multifaceted efficacy of luteolin against the underlying mechanisms implicated in neurodegenerative disorders such as Alzheimer’s, Parkinson’s, and Multiple Sclerosis. Luteolin exhibits the capacity to inhibit the activation of microglia and astrocytes, as well as mitigate the upregulation of inflammatory mediators including cytokines and iNOS, thereby reducing oxidative stress. These effects primarily stem from its modulation of key signaling pathways, notably the inhibition of NF-κB and the induction of Nrf2, among others.

While extensive evidence supports the neuroprotective role of luteolin within the central nervous system through both in vitro and in vivo studies, its potential benefits in addressing peripheral neuroinflammation remain less substantiated. Nevertheless, given the ubiquitous nature of the pathways governing inflammatory responses and oxidative damage across various tissues, it is reasonable to infer that luteolin’s therapeutic effects are likely to extend to the peripheral nervous system. This suggests a promising avenue for further exploration of luteolin’s potential in alleviating peripheral nerve damage. (source)

Multiple sclerosis

Luteolin with or without IFN-β, could be helpful in MS by not only inhibiting PBMC release of cytokines, but also by inhibiting T cells, which we recently showed can be super-stimulated by mast cells, an action also inhibited by luteolin. In addition to T cells, recent evidence implicates also TH2 processes typically associated with allergic reactions, which involve mast cells. In fact, mast cells have been considered as the next target for MS therapy. (source)

Anti-Cancer

Carcinogenesis is a long-lasting and multi-stage process that results from clonal expansion of mutated cells. A typical carcinogenic process can be divided into three stages: initiation, promotion, and progression. (source)

Luteolin is able to interfere with almost all of the characteristics of cancer cells.

Chemoprevention Agent

Based on the observations that luteolin is able to interfere with almost all the aspects of carcinogenesis, and it is relatively safe for animals and humans, it is assumed to be a potential chemopreventive agent against cancer through blocking cell transformation, suppressing tumor growth, and killing tumor cells. Using luteolin to suppress chronic inflammation can potentially prevent inflammation-associated carcinogenesis. (source)

Long‐COVID syndrome‐associated brain fog

While the potential inhibition of mast cells could offer therapeutic benefits in addressing COVID‐19 or long‐COVID syndrome, the absence of effective mast cell inhibitors poses a challenge. However, an alternative approach involves leveraging structurally related natural flavonoids like luteolin and quercetin, which are widely accessible and generally regarded as safe. These flavonoids boast broad-spectrum antiviral properties, hindering viral entry into host cells, mitigating neuroinflammation, and ameliorating cognitive decline.

Moreover, luteolin demonstrates superior brain penetrance, effectively inhibiting both microglia and mast cells, and has shown promise in reducing neuroinflammation and cognitive impairment, including Alzheimer’s disease, in both human and animal models.

Despite the challenges associated with oral absorption of luteolin and quercetin, their pharmacokinetic profile markedly improves with liposomal formulations utilising olive pomace oil. Notably, a luteolin formulation in olive pomace oil (NeuroProtek®) has exhibited efficacy in improving autism spectrum disorder, while another formulation (BrainGain®) has been effective in alleviating brain fog.

These liposomal formulations not only enhance oral absorption and bioavailability but also harness the neuroprotective and anti-inflammatory properties of olive pomace oil polyphenols, along with the memory-boosting effects of olive hydroxytyrosol present in BrainGain®.

Autism

A nutritional supplement containing a mixture of flavonoids, luteolin (100 mg), quercetin (70 mg), and rutin (30 mg), has shown to improve clinical outcome in children with autism spectrum disorder (ASD). Treatment with 2 capsules/20 kg of body weight for at least 4 weeks led to significant improvement in gastrointestinal and allergy symptoms in about 75% of the children, eye contact and attention in 50%, social interaction in 25%, and resumption of speech in about 10%. (source)

Recommended Product

• Recommended Product (U.K):
• Recommended Product (U.S.A): Luteolin.

Conclusions

In conclusion, the remarkable array of health benefits attributed to the flavonoid luteolin underscores its potential as a versatile therapeutic agent. From its potent anti-inflammatory and antioxidant properties to its neuroprotective effects and potential in addressing neurodegenerative diseases, luteolin emerges as a promising natural compound with wide-ranging applications in promoting human health and well-being. Furthermore, its accessibility in various dietary sources and the development of innovative delivery systems such as liposomal formulations present exciting opportunities for harnessing its full therapeutic potential. As research continues to unveil the intricacies of luteolin’s mechanisms of action and its therapeutic implications, the future holds great promise for this remarkable flavonoid in contributing to improved health outcomes and enhancing quality of life.