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 stanols. More than 250 sterols and related compounds have been identified. Free phytos ...

(''

phytosterol 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 ...

'') – is among the most abundant of plant

sterol A sterol is any organic compound with a Skeletal formula, skeleton closely related to Cholestanol, cholestan-3-ol. The simplest sterol is gonan-3-ol, which has a formula of , and is derived from that of gonane by replacement of a hydrogen atom on ...

s, having a major function to maintain the structure and

physiology Physiology (; ) is the science, scientific study of function (biology), functions and mechanism (biology), mechanisms in a life, living system. As a branches of science, subdiscipline of biology, physiology focuses on how organisms, organ syst ...

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

s. In the

European Union The European Union (EU) is a supranational union, supranational political union, political and economic union of Member state of the European Union, member states that are Geography of the European Union, located primarily in Europe. The u ...

, 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, such as vinegar ( pickling), salt ( salting), smoke ( smoking) and sugar ( crystallization), have been used f ...

listed with

E number E numbers, short for Europe numbers, 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 dens ...

Discovery

Once called ''Wulzen factor'' in the mid-20th century, stigmasterol was discovered by the University of California physiologist Rosalind Wulzen (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. Soy is a staple crop, the world's most grown legume, and an important animal feed. Soy is a key source o ...

calabar bean ''Physostigma venenosum'', the Calabar bean or ordeal bean, is a leguminous plant, Endemism, 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 e ...

, and

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

, and in herbs used in

herbalism Herbal medicine (also called herbalism, phytomedicine or phytotherapy) is the study of pharmacognosy and the use of medicinal plants, which are a basis of traditional medicine. Scientific evidence for the effectiveness of many herbal treatments ...

practices, including the Chinese herbs ''

Ophiopogon japonicus ''Ophiopogon japonicus'' (dwarf lilyturf, mondograss, fountainplant, monkeygrass; ''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, India, Japan, Nepal, and Vie ...

'' (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 Legumes are plants in the pea family Fabaceae (or Leguminosae), or the fruit or seeds of such plants. When used as a dry grain for human consumption, the seeds are also called pulses. Legumes are grown agriculturally, primarily for human consum ...

nuts Nut often refers to: * Nut (fruit), fruit composed of a hard shell and a seed * Nut (food), a dry and edible fruit or seed, including but not limited to true nuts * Nut (hardware), fastener used with a bolt Nut, NUT or Nuts may also refer to: A ...

seed In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds ...

s, and unpasteurized milk.

Pasteurization In food processing, pasteurization (American and British English spelling differences#-ise, -ize (-isation, -ization), also pasteurisation) is a process of food preservation in which packaged foods (e.g., milk and fruit juices) are treated wi ...

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. Julian was the first person to synthesize the natural product physostigmine, and a pio ...

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 ma ...

, a valuable human

hormone A hormone (from the Ancient Greek, Greek participle , "setting in motion") is a class of cell signaling, signaling molecules in multicellular organisms that are sent to distant organs or tissues by complex biological processes to regulate physio ...

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

estrogen Estrogen (also spelled oestrogen in British English; see spelling differences) is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three ...

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

androgens An androgen (from Greek ''andr-'', the stem of the word meaning ) is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This includes ...

, 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 involved ...

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

Upjohn The Upjohn Company was an American pharmaceutical manufacturing firm (est. 1886) in Hastings, Michigan, by Dr. William E. Upjohn, an 1875 graduate of the University of Michigan medical school. The company was originally formed to make ''friable ...

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. Cortisol is converted by the action of the enzyme corticosteroid 11-beta-dehydrogenase ...

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 ...

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, as humans do not appear to convert stigmasterol from food into boldenone. Calves have been reported to convert photosterol into boldenone, but even then the amounts in urine are below doping limits.

References