A progesterone synthesis inhibitor, or progestogen synthesis inhibitor, is a type of drug which
inhibits 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
progesterone
Progesterone (P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the m ...
. They include:
*
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 hormones (which are derived from pregnenolone) including progesterone
*
3β-Hydroxysteroid dehydrogenase inhibitors (3β-HSD inhibitors): inhibit the conversion of pregnenolone into progesterone
Inhibitors of cholesterol synthesis can also reduce progesterone production by inhibiting cholesterol production.
Progesterone synthesis inhibitors have been researched for medical applications including use as
contraceptive
Birth control, also known as contraception, anticonception, and fertility control, is the use of methods or devices to prevent unwanted pregnancy. Birth control has been used since ancient times, but effective and safe methods of birth contr ...
s,
abortifacient
An abortifacient ("that which will cause a miscarriage" from Latin: ''abortus'' "miscarriage" and '' faciens'' "making") is a substance that induces abortion. This is a nonspecific term which may refer to any number of substances or medications, ...
s, and
oxytocics, though ultimately they have never been marketed for such indications.
Examples of such agents include the 3β-HSD inhibitors
azastene
Azastene (INN, USAN) (developmental code name WIN-17625) is a steroidogenesis inhibitor described as a contraceptive, luteolytic, and abortifacient which was never marketed. It acts as a competitive inhibitor of 3β-hydroxysteroid dehydrogenase ...
(WIN-17625) and
epostane
Epostane (INN, USAN, BAN) (developmental code name WIN-32729) is an inhibitor of 3β-hydroxysteroid dehydrogenase (3β-HSD) that was developed as a contraceptive, abortifacient, and oxytocic drug but was never marketed. By inhibiting 3β-HSD, ...
(WIN-32729). Since progesterone is a
precursor
Precursor or Precursors may refer to:
*Precursor (religion), a forerunner, predecessor
** The Precursor, John the Baptist
Science and technology
* Precursor (bird), a hypothesized genus of fossil birds that was composed of fossilized parts of unr ...
of many other steroid hormones, progesterone synthesis inhibitors can also be used medically as inhibitors of the synthesis of these other steroid hormones, including of
androgens,
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,
glucocorticoid
Glucocorticoids (or, less commonly, glucocorticosteroids) are a class of corticosteroids, which are a class of steroid hormones. Glucocorticoids are corticosteroids that bind to the glucocorticoid receptor that is present in almost every vertebr ...
s,
mineralocorticoid
Mineralocorticoids are a class of corticosteroids, which in turn are a class of steroid hormones. Mineralocorticoids are produced in the adrenal cortex and influence salt and water balances (electrolyte balance and fluid balance). The primary mi ...
s, and
neurosteroid
Neurosteroids, also known as neuroactive steroids, are endogenous or exogenous steroids that rapidly alter neuronal excitability through interaction with ligand-gated ion channels and other cell surface receptors. The term ''neurosteroid'' was coin ...
s.
See also
*
Steroidogenesis inhibitor
*
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 syn ...
*
Estrogen synthesis inhibitor An estrogen synthesis inhibitor is a type of drug which inhibits the enzymatic synthesis of estrogens, such as estradiol. They include:
* Aromatase inhibitors (CYP19A1 inhibitors): inhibit the synthesis of estrogens from androgens
* CYP17A1 inhibit ...
References
{{Progestogens and antiprogestogens
Steroidogenesis inhibitors