Stigmasterol – a

plant sterol Phytosterols are phytosteroids, similar to cholesterol, that serve as structural components of biological membranes of plants. They encompass plant sterols and stanol ester, stanols. More than 250 sterols and related compounds have been identified ...

(''

phytosterol Phytosterols are phytosteroids, similar to cholesterol, that serve as structural components of biological membranes of plants. They encompass plant sterols and stanols. More than 250 sterols and related compounds have been identified. Free phyto ...

'') – is among the most abundant of plant

sterol Sterol is an organic compound with formula , whose molecule is derived from that of gonane by replacement of a hydrogen atom in position 3 by a hydroxyl group. It is therefore an alcohol of gonane. More generally, any compounds that contain the go ...

s, having a major function to maintain the structure and

physiology Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical ...

cell membrane The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment ( ...

s. In the

European Union The European Union (EU) is a supranational political and economic union of member states that are located primarily in Europe. The union has a total area of and an estimated total population of about 447million. The EU has often been des ...

, it is a

food additive Food additives are substances added to food to preserve flavor or enhance taste, appearance, or other sensory qualities. Some additives have been used for centuries as part of an effort to preserve food, for example vinegar (pickling), salt (salt ...

listed with

E number E numbers ("E" stands for "Europe") are codes for substances used as food additives, including those found naturally in many foods such as vitamin C, for use within the European Union (EU) and European Free Trade Association (EFTA). Commonly ...

E499 Stigmasterol-rich plant sterols is a food additive. It is a mixture derived from soybeans that consists of the plant sterols stigmasterol, β-sitosterol, campesterol, and brassicasterol, with stigmasterol representing >85% of the mixture. Its E ...

, and may be used in food manufacturing to increase the phytosterol content, potentially lowering the levels of

LDL cholesterol Low-density lipoprotein (LDL) is one of the five major groups of lipoprotein that transport all fat molecules around the body in extracellular water. These groups, from least dense to most dense, are chylomicrons (aka ULDL by the overall densit ...

Discovery

Once called ''Wulzen factor'' in the mid-20th century, stigmasterol was discovered by the University of California physiologist

Rosalind Wulzen Rosalind Wulzen (b. 1882 or 1886) was an American physiologist, known for her discovery of the "Anti-Stiffness Factor," or "Wulzen Factor." Born in Oakland, California, Wulzen attended the University of California Berkeley for her bachelor's, mast ...

(born 1886).

Natural occurrences

Stigmasterol is an unsaturated

occurring in the plant fats or oils of numerous plants, such as

soybean The soybean, soy bean, or soya bean (''Glycine max'') is a species of legume native to East Asia, widely grown for its edible bean, which has numerous uses. Traditional unfermented food uses of soybeans include soy milk, from which tofu an ...

calabar bean ''Physostigma venenosum'', the Calabar bean or ordeal bean, is a leguminous plant, Endemic to tropical Africa, with a seed poisonous to humans. It derives the first part of its scientific name from a curious beak-like appendage at the end of the ...

, and

rape seed Rapeseed (''Brassica napus ''subsp.'' napus''), also known as rape, or oilseed rape, is a bright-yellow flowering member of the family Brassicaceae (mustard or cabbage family), cultivated mainly for its oil-rich seed, which naturally contains a ...

, and in herbs used in

herbalism Herbal medicine (also herbalism) is the study of pharmacognosy and the use of medicinal plants, which are a basis of traditional medicine. With worldwide research into pharmacology, some herbal medicines have been translated into modern reme ...

practices, including the Chinese herbs ''

Ophiopogon japonicus ''Ophiopogon japonicus'' (dwarf lilyturf, mondograss, fountainplant, monkeygrass; ja, リュウノヒゲ ''ryu-no-hige'' ("dragon's beard") or ジャノヒゲ ''ja-no-hige'' ("snake's beard") is a species of ''Ophiopogon'' native to China, Indi ...

'' (Mai men dong), in ''

Mirabilis jalapa ''Mirabilis jalapa'', the marvel of Peru or four o'clock flower, is the most commonly grown ornamental species of ''Mirabilis'' plant, and is available in a range of colors. ''Mirabilis'' in Latin means wonderful and Jalapa (or Xalapa) is the st ...

''. Stigmasterol is a constituent of various vegetables,

legume A legume () is a plant in the family Fabaceae (or Leguminosae), or the fruit or seed of such a plant. When used as a dry grain, the seed is also called a pulse. Legumes are grown agriculturally, primarily for human consumption, for livestock f ...

s, nuts,

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...

s, and unpasteurized milk.

Pasteurization Pasteurization or pasteurisation is a process of food preservation in which packaged and non-packaged foods (such as milk and fruit juices) are treated with mild heat, usually to less than , to eliminate pathogens and extend shelf life. The ...

will inactivate stigmasterol. Edible oils contains higher amount than vegetables.

Uses

Stigmasterol is a food additive in manufactured food products in the United Kingdom and European Union. It was introduced as a precursor by

Percy Lavon Julian Percy Lavon Julian (April 11, 1899 – April 19, 1975) was an American research chemist and a pioneer in the chemical synthesis of medicinal drugs from plants. He was the first to synthesize the natural product physostigmine and was a pioneer in ...

for industrial large-scale manufacture of

semisynthetic Semisynthesis, or partial chemical synthesis, is a type of chemical synthesis that uses chemical compounds isolated from natural sources (such as microbial cell cultures or plant material) as the starting materials to produce novel compounds with ...

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 ...

, a valuable human

hormone A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are required ...

that plays an important physiological role in the regulatory and tissue rebuilding mechanisms related to

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 ...

effects, as well as acting as an intermediate in the biosynthesis of

androgens 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 ...

, estrogens, and

corticoids Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are involve ...

. It is also used as the precursor of vitamin D₃. The

Upjohn The Upjohn Company was a pharmaceutical manufacturing firm founded in 1886 in Hastings, Michigan, by Dr. William E. Upjohn who was an 1875 graduate of the University of Michigan medical school. The company was originally formed to make ''friabl ...

company used stigmasterol as the starting raw material for commercial synthesis of

cortisone Cortisone is a pregnene (21-carbon) steroid hormone. It is a naturally-occurring corticosteroid metabolite that is also used as a pharmaceutical prodrug; it is not synthesized in the adrenal glands. Cortisol is converted by the action of the enzy ...

in 1959.

Research

As one of the major phytosterols, stigmasterol is included among sterol compounds in the diet having potential to reduce the risk of cardiovascular diseases. Consumption of 2 grams per day of plant sterols is associated with a reduction in blood

of 8–10%, possibly lowering cardiovascular disease risk. As a factor in cellular processes of plants, stigmasterol may have roles in plant stress responses, metabolism, and enzymes involved in biosynthesis of plant cell membranes. Stigmasterol has also been shown to exert anti-angiogenic and anti-cancer effects via the downregulation of TNF-alpha and VEGFR-2.

Potential precursor of boldenone

Being a steroid, stigmasterol is precursor of anabolic steroid

boldenone Boldenone (developmental code name RU-18761), is a naturally occurring anabolic–androgenic steroid (AAS) and the 1(2)- dehydrogenated analogue of testosterone. Boldenone itself has never been marketed; as a pharmaceutical drug, it is used as ...

Boldenone undecylenate Boldenone undecylenate, or boldenone undecenoate, sold under the brand names Equipoise and Parenabol among others, is an androgen and anabolic steroid (AAS) medication which is used in veterinary medicine, mainly in horses. It was formerly used i ...

is commonly used in veterinary medicine to induce growth in cattle, but it is also one of the most commonly abused anabolic steroids in sports. This led to suspicion that some athletes testing positive for boldenone didn't consume the steroid itself, but rather consumed foods rich in stigmasterol; this turned out not to be the case.

References