What is Apigenin?
Apigenin is a strong naturally occurring flavone (colourless crystalline ketone) present in numerous fruits and vegetables [1], as well as in many herbs and other plant foods such as parsley, onions, oranges, tea, chamomile, wheat and sprouts [2]. Due to its various health protective properties, apigenin has been used as a medicinal herb for ages [3].
What Does Apigenin Do?
As highly original as its natural source is, the biological scope of activity of apigenin makes it an exciting tool to exert preventive action against a wide range of diseases [1]. It is a potent antioxidant (scavenger) and anti-inflammatory compound and, through the modulation of a great variety of biological systems – respiratory, digestive, immune, and reproductive – has been found beneficial for the treatment of liver, lung, heart, kidney and neurological diseases as well as diabetes [1].
Apigenin also has anticancer effects; it has been shown to kill breast and prostate cancer cells by inducing apoptosis and cell-cycle arrest, inhibiting cell migration and invasion, reducing inflammation and lowering angiogenesis [1]. It has been shown to improve the efficiency of other drugs or reduce their toxicity, and improve the response to chemotherapy [1].
In addition, apigenin inhibited the growth of selected fungal pathogens, induced morphological changes in particular fungi, or altered the cell membrane potential, thereby increasing cell permeability [4].
For cardiovascular health specifically, apigenin has been shown to play a role in treating atherosclerosis, stroke, hypertension, ischaemia/reperfusion-induced myocardial injury, and diabetic cardiomyopathy and has a cardioprotective effect during chemotherapy-induced cardiotoxicity [5].
In the field of neurology, apigenin has been found to have neuroprotective effects and has been shown to reduce amyloid-beta peptides, which are associated with Alzheimer's disease [6].
Risk Factors of Apigenin?
Researchers have long examined whether apigenin—a flavonoid found in many fruits and vegetables—can contribute to maintaining good health, but we have discovered potential risk factors associated with it.
One of them is hepatotoxicity, damage to the liver, especially at higher doses. In an in-vivo test in which the Swiss mice received Apigenin at doses of 25, 50, 100, and 200 mg/k, elevated doses resulted in elevated liver enzymes, a marker of liver injury [7].
Another is the risk of herb-drug interactions, such as apigenin’s inhibitory effect on the molecular transporter of organic anion, OAT1, which is responsible for uptaking certain drugs (e.g., acyclovir) and may lead to undesirable drug toxicity because of increased plasma concentrations of those drugs during their uptake [8].
Finally, while Apigenin has anti-cancer activity in vitro and animal models, cancer patients should be aware that the efficacy and toxicity of supplementation in humans cannot be yet predicted. Because of unknown risks due to high doses or other reasons, people taking Apigenin should do so only with advanced medical consultation.
Benefits of Apigenin
Apigenin belongs to a group of flavone compounds (also called flavonoids) found in abundance in our diets, especially in fruits and vegetables. Recently, it has been investigated for its possible role as an anti-inflammatory and antioxidant compound, leading to the presumption of consistent prophylaxis against different pathologies [1].
Apigenin has a plethora of vital purposes, especially in treating liver, lung, heart and kidney disorders, brain functioning, regulating diabetes and preserving sound oral and skin health [1].
One of the most prevalent compounds, apigenin, is already well-documented in oncology as ‘an anti-cancer agent that can inhibit the proliferation and progression of numerous cancer types’ because of its ability to induce apoptosis and cell cycle arrest, inhibit cell invasion, migration, or angiogenesis, reduce inflammation, and enhance other drug effects, reducing their side effects and enhancing the responsiveness to chemotherapies [1].
Cardiovascular benefits include using apigenin in the treatment of atherosclerosis, stroke, hypertension, ischaemia/reperfusion-induced myocardial injury, and diabetic cardiomyopathy, as well as from drug-induced cardiotoxicity [5].
For skin health, apigenin benefits:
- UV-induced skin damage
- Vitiligo,
- Dermatitis,
- Wounds,
- Skin ageing, and
- Skin cancer
It mainly inhibits inflammation and improves endogenous antioxidant defence mechanisms [9].
With regards to neuroprotection, apigenin has been recognised as a promising agent for the amelioration of Alzheimer’s disease by relieving Aβ burden, suppressing the amyloidogenic process, reducing oxidative stress and reversing the ERK/CREB/BDNF pathway, respectively [6].
Does Apigenin Influence Testosterone?
Apigenin modulates testosterone levels, but the effects can be subtle and somewhat complicated because it depends on how the hormone is metabolised.
Some studies show that apigenin actually inhibits testosterone production. For example, apigenin was shown to decrease the activity of several enzymes related to testosterone biosynthesis in both rat and human cells. Apigenin can inhibit rat 3β-hydroxysteroid dehydrogenase, 17α-hydroxylase/17, 20-lyase and 17β-hydroxysteroid dehydrogenase 3 with IC50 values of 11.41±0.7, 8.98±0.10 and 9.37±0.07μM, respectively [10].
On the other hand, studies do show that apigenin can have a beneficial effect on testosterone levels under some circumstances – again, in mice fed a high-fat diet, apigenin was shown to partly improve testicular dysfunction and restore the level of certain key proteins involved in the synthesis of testosterone [11]. Another study reported that apigenin increased the expression of the steroidogenic acute regulatory (StAR) protein, a key regulator involved in the rate-limiting step of the testosterone biosynthesis pathway [12].
However, these studies were done in animal models or cell cultures, and we don’t yet know about apigenin’s effect on testosterone in humans. Therefore, further research is essential for the development of more precise data.