Monk's pepper

Synonym(s): Vitex agnus-castus (VAC), vitex, chaste tree, chasteberry, Abrahams balm

Nutrient group: plant extracts & active ingredients

Sources and physiological effects

Dietary sources
Monk pepper (Vitex agnus-castus) is a traditional and very popular remedy for gynecological complaints, especially in the Anglo-American and European area. The red-black fruits of Vitex agnus-castus contain essential oil (with the main components 1,8-cineol, limonene, alpha-pinene, beta-pinene and sabinene), a mixture of flavonoids (e.g. casticin) and iridoids (e.g. agnuside and aucubine) (1). Components with structural similarities to sex hormones have also been isolated from leaves and flowers (2). The mechanism of action of Vitex agnus-castus could not yet be fully clarified, but may be based on a modulation of stress-induced prolactin secretion via dopamine, without direct influence on the luteinizing hormone (LH) and the follicle stimulating hormone (FSH) (2). Binding capacity to estrogen, opioid and dopamine receptors has been demonstrated in vitro. This binding also induces the expression of estrogen-dependent genes (3) (4). In various studies, Vitex agnus-castus showed clinical efficacy in the treatment of cyclical mastitis or mastodynia, premenstrual syndrome (PMS), premenstrual dysphoria, hyperprolactinemia, female sterility, premenstrual difficulties and for improvments to cycle rhythm.
Physiological functions
Anti-inflammatory	Inhibition of inflammation by the secondary plant compounds alpha-pinene, aucubin, agnuside and sabinene contained in the essential oil
Antifungal	Sabinene found in essential oil is effective against fungi
Antimicrobial	Alpha-pinene has an antimicrobial effect and additionally leads to bronchodilatation at low doses, Sabinen demonstrated an effect against microbes .
Antibacterial	1,8-Cineol manifests its bactericidal and expectorant effect in the lungs and sinuses, aucubin also has an antibiotic effect
Soothing	Aucubin has an additional soothing effect
	It can be assumed that the pharmacological effect of Vitex agnus-castus is not exclusively due to single constituents, but rather to the interaction of several constituents.

Detailed information

Vitex agnus-castus and premenstrual Syndrome (PMS)

Premenstrual Syndrome (PMS) is a complex of disorders that disrupt everyday life, occurring mainly in the second half of the cycle and associated with some mild but also severe symptoms. Physical complaints - such as water retention in tissues, abdominal pain and impure skin - are often accompanied by additional psychological complaints - such as tiredness, irritability and feelings of depression. Many women suffer from PMS symptoms to varying degrees. It is estimated that three quarters of women of childbearing age are affected. Since conventional PMS treatments with hormones and synthetic antidepressants are not well accepted, the phytotherapeutic agent monk's pepper extract is used. The popularity of complementary/alternative therapies has increased in recent years and these treatments have been used more frequently by women (48.9%) than by men (37.8%) (5). As early as 2011, a study confirmed the impact of Vitex agnus-castus on the most common symptom of menopause - hot flushes (6). In 2012, a review examined 13 randomised controlled trials on the use of Vitex agnus-castus in PMS, PMDS and hyperprolactinaemia and concluded that the plant is beneficial in the treatment of all three disorders and is well tolerated (7). In a placebo-controlled study, 20 mg of Vitex agnus castus extract was found to be the optimal dose for treating PMS symptoms. The extract significantly reduces PMS symptoms such as irritability, mood swings, anger, headache, bloating and breast tenderness (3), as well as water retention, cravings and irritability (8). It is also very well tolerated and only in a few cases displays mild and transient side effects (3). The effect of Vitex agnus-castus on migraine sufferers with premenstrual syndrome has also been documented. Of 107 women, 66 reported a dramatic reduction in PMS symptoms, 26 reported a slight reduction and 8 reported no effect. Overall, 42% of patients had half as many migraine attacks and 57% had headaches on half as many days per month. No patient suffered from significant side effects (9). Another study has shown that Vitex agnus-castus also contributes to the treatment of male and female infertility (10).

Vitex agnus-castus and premenstrual dysphoria (PMDD)

Premenstrual dysphoric disorder (PMDD) is a particular manifestation of premenstrual syndrome. The hormonal imbalance causes anxiety, irritability, feelings of depression and thoughts of suicide. A study carried out in Italy with 42 affected women demonstrated that both the administration of an antidepressant (20 to 40 mg fluoxetine) and 20 to 40 mg Vitex-agnus-castus extract have the same efficacy. In contrast to the antidepressant, there were no side effects when taking Vitex agnus-castus (11). In this context, US researchers found that the ingredients of monk's pepper bind not only to dopamine receptors, but also to opioid receptors. This could help relieve pain and reduce psychological symptoms (12).

Vitex agnus-castus and polycystic ovary syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is the most common cause of menstrual disorders and infertility in women and is characterized by irregular menstrual bleeding or the complete absence of menstruation. The predominance of male sex hormones can lead to additional hair loss, acne and depression. Australian scientists were able to prove through the analysis of 33 studies that Vitex agnus-castus can have a positive effect on menstrual disorders, PCOS and the increased production of male hormones. Furthermore, they found that Vitex agnus-castus can have a positive effect on menstrual irregularities after discontinuation of hormonal contraceptives and as a result of a weakened corpus luteum. Further analysis of the scientific literature indicated that Vitex agnus-castus regulates ovulation and improves metabolic hormone profile and fertility outcomes in PCOS (13).

Vitex agnus-castus, flushes and night sweats

Hot flushes are among the most common gynecological problems of menopausal syndrome. Due to the side effects of hormone therapy for the treatment of menopaue, herbal and complementary drugs are of increasing interest. One study investigated the influence of a combination of Vitex agnus-castus and Nigella sativa with Citalopram on healthy menopausal women with hot flushes. Based on the results, the addition of N. sativa and V. agnus-castus to Citalopram is a possible clinical application for improving therapeutic outcomes (14). A review article summarizing clinical studies on the mechanisms and effects of medicinal plants for the treatment of menopausal symptoms showed that Vitex agnus-castus was shown to be one of the most common medicinal plants involved in the treatment of menopausal syndrome via various mechanisms alongside sage (Salvia officinalis), lemon balm (Melissa officinalis) or black cumin (Nigella sativa), is 15). In this context, Israeli researchers have found that a combined plant extract of monk's pepper, milk thistle, Chinese angelica, black cohosh, American ginseng and meadow clover can alleviate symptoms in menopausal women. Among the 55 participants, the three-month intake of monk's pepper reduced hot flushes by 73% and night sweats by 69%. In 47 % of women, the hot flushes disappeared completely. Furthermore, sleep quality also improved (16).'

Indications

Dosing	Indication	Dosage
Physiological effects at a low intake	Regulation of hormonal activity and reduction of premenstrual symptoms due to hormonal fluctuations	20 mg/d
Physiological effects at a low intake	To improve mental and physical well-being, especially in the second half of the cycle	20 mg/d

Administration

General mode of administration
When	Vitex agnus-castus should be taken with plenty of liquid at mealtime.
Side effects
In rare cases, taking Vitex castus-agnus can lead to skin rashes, itching, urticaria and oedema.
Contraindications
It is not recommended to take Vitex agnus-castus in the case of existing pituitary tumors and breast carcinomas. Patients who are or have been suffering from estrogen-sensitive cancer should consult a doctor before taking this medicine. The same applies to patients who take dopamine agonists, dopamine antagonists, estrogens or antiestrogens. According to current knowledge, Vitex agnus-castus can act on the hypothalamic-pituitary axis. For this reason, patients with a disease of the pituitary gland should only take Vitex agnus-castus after consultation with a doctor. Pregnant and breastfeeding women, as well as children and adolescents under 18 years of age, are also advised not to take Vitex agnus-castus.

Interactions

Drug interactions
Dopamine antagonists (neuroleptics, prokinetics)	The dopaminergic effect of Vitex agnus-castus can lead to a mutual attenuation of effects when dopamine antagonists are taken at the same time.
Dopamine agonists (prolactin inhibitors)	The dopaminergic effect of Vitex agnus-castus can lead to an interaction when taking dopamine agonists at the same time.
Estrogen/antiestrogen	Vitex agnus-castus may influence the effect of estrogens and antiestrogens.
Nutrient interaction
No known relevant interactions to date.

References

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