An estrogen synthesis inhibitor is a type of drug which
inhibit
Inhibitor or inhibition may refer to:
In biology
* Enzyme inhibitor, a substance that binds to an enzyme and decreases the enzyme's activity
* Reuptake inhibitor, a substance that increases neurotransmission by blocking the reuptake of a neurotra ...
s the
enzymatic
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...
synthesis
Synthesis or synthesize may refer to:
Science Chemistry and biochemistry
*Chemical synthesis, the execution of chemical reactions to form a more complex molecule from chemical precursors
** Organic synthesis, the chemical synthesis of organ ...
of
estrogen
Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal acti ...
s, such as
estradiol
Estradiol (E2), also spelled oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of the estrous and menstrual female reproductive cycles. Estradiol is responsible for the development of f ...
. They include:
*
Aromatase inhibitor
Aromatase inhibitors (AIs) are a class of drugs used in the treatment of breast cancer in postmenopausal women and in men, and gynecomastia in men. They may also be used off-label to reduce estrogen conversion when supplementing testosterone exog ...
s (CYP19A1 inhibitors): inhibit the synthesis of estrogens from
androgen
An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This inc ...
s
*
CYP17A1 inhibitor
A CYP17A1 inhibitor is a type of drug which enzyme inhibitor, inhibits the enzyme CYP17A1. It may inhibit both of the functions of the enzyme, 17α-hydroxylase and 17,20-lyase, or may be selective for inhibition of one of these two functions (gener ...
s (17α-hydroxylase/17,20-lyase inhibitors): inhibit the synthesis of androgens and therefore estrogens
*
3β-Hydroxysteroid dehydrogenase inhibitors (3β-HSD inhibitors): inhibit the synthesis of
progestogen
Progestogens, also sometimes written progestagens or gestagens, are a class of natural or synthetic steroid hormones that bind to and activate the progesterone receptors (PR). Progesterone is the major and most important progestogen in the body. ...
s and of more-potent androgens, thereby inhibiting the synthesis of estrogens
*
Cholesterol side-chain cleavage enzyme inhibitors (P450SCC/CYP11A1 inhibitors): inhibit the synthesis of
pregnenolone
Pregnenolone (P5), or pregn-5-en-3β-ol-20-one, is an endogenous steroid and precursor/ metabolic intermediate in the biosynthesis of most of the steroid hormones, including the progestogens, androgens, estrogens, glucocorticoids, and mineraloc ...
from
cholesterol
Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell mem ...
, thereby inhibiting the synthesis of most
steroid hormone
A steroid hormone is a steroid that acts as a hormone. Steroid hormones can be grouped into two classes: corticosteroids (typically made in the adrenal cortex, hence ''cortico-'') and sex steroids (typically made in the gonads or placenta). Wi ...
s (which are derived from pregnenolone) including estrogens
*
17β-Hydroxysteroid dehydrogenase inhibitors (17β-HSD inhibitors): inhibit the interconversion of estrogens, including the synthesis of estradiol from the less-potent
estrone
Estrone (E1), also spelled oestrone, is a steroid, a weak estrogen, and a minor female sex hormone. It is one of three major endogenous estrogens, the others being estradiol and estriol. Estrone, as well as the other estrogens, are synthesized ...
*
Steroid sulfatase inhibitor
Steroid sulfatase (STS), or steryl-sulfatase (EC 3.1.6.2), formerly known as arylsulfatase C, is a sulfatase enzyme involved in the metabolism of steroids. It is encoded by the ''STS'' gene.
Reactions
This enzyme catalyses the following chemi ...
s (STS inhibitors): inhibit the conversion of inactive
estrogen sulfates into active estrogens like estradiol
Inhibitors of cholesterol synthesis can also reduce estrogen production by inhibiting cholesterol production.
Estrogen synthesis inhibitors have medical applications in the treatment of
breast cancer
Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or a re ...
,
precocious puberty
In medicine, precocious puberty is puberty occurring at an unusually early age. In most cases, the process is normal in every aspect except the unusually early age and simply represents a variation of normal development. In a minority of childr ...
,
gynecomastia
Gynecomastia (also spelled gynaecomastia) is the abnormal non-cancerous enlargement of one or both breasts in males due to the growth of breast tissue as a result of a hormone imbalance between estrogens and androgens. Updated by Brent Wisse (1 ...
, and
hyperestrogenism
Hyperestrogenism, hyperestrogenic state, or estrogen excess, is a medical condition characterized by an excessive amount of estrogenic activity in the body.
Signs and symptoms
Signs of hyperestrogenism may include heightened levels of one or more ...
, among other
estrogen-dependent condition An estrogen-dependent condition can be that relating to the differentiation in the steroid sex hormone that is associated with the female reproductive system and sex characteristics. These conditions can fall under the umbrella of hypoestrogenism, h ...
s.
See also
*
Steroidogenesis inhibitor
A steroidogenesis inhibitor, also known as a steroid biosynthesis inhibitor, is a type of drug which inhibits one or more of the enzymes that are involved in the process of steroidogenesis, the biosynthesis of endogenous steroids and steroid horm ...
*
Androgen synthesis inhibitor An androgen synthesis inhibitor is a type of drug which inhibits the enzymatic synthesis of androgens, such as testosterone and dihydrotestosterone (DHT). They include:
* CYP17A1 inhibitors (17α-hydroxylase/17,20-lyase inhibitors): inhibit the s ...
*
Progesterone synthesis inhibitor
References
{{Estrogens and antiestrogens
Steroidogenesis inhibitors