Pterostilbene
Encyclopedia
Pterostilbene is a stilbenoid chemically related to resveratrol
and is found in blueberries and grapes. It belongs to the group of phytoalexin
s, agents produced by plants to fight infections. Based on animal studies it is thought to exhibit anti-cancer
, anti-hypercholesterolemia
, anti-hypertriglyceridemia
properties, as well as fight off and reverse cognitive decline. It is believed that the compound also has anti-diabetic properties, but so far very little has been studied on this issue.
as it is more easily transported into the cell and more resistant to degradation and elimination. In rats, pterostilbene's oral availability is 67%-94%, and its half-life has been published to be between 78 minutes and 104 minutes.
Pterostilbene has anti -inflammatory, antineoplastic, and antioxidant actions via modulations of gene expression and enzyme activity. In plants the substance displays antifungal and antiviral activities.
Focus of studies has been generally on the trans isomer of pterostilbene.
, a cholesterol-lowering drug predominantly used outside the United States.
According to the study pterostilbene binds to PPARs
, breaking down the cholesterol.
, pterostilbene has been shown to lower blood glucose levels in rats by as much as 56 percent, while simultaneously raising insulin and hemoglobin levels to near normal levels.
, or spinach
extracts, the rats that were fed blueberry extracts had a significant reversal in motor-skill decline due to aging as well as other cognitive impairments. All of the diets above, except the normal one, resulted in some reversal or reduction of cognitive decline but none greater than the blueberry group. Even when animal based studies yield positive results, the effects on humans may not be the same.
Additional work by Rimando and collaborators revealed a possible mechanism for pterostilbene's purported anti-cancer properties. Using mice cells, they demonstrated that pterostilbene, as well as other analogs of resveratrol, potently inhibits an enzyme called cytochrome P450. (Cytochromes are found within the cells of animals, plants, bacteria, and other microorganisms that transport electrons. They’re also a factor in people’s varying response to drugs and toxins entering their bodies. Cytochrome P450 enzymes activate a variety of compounds known as ”procarcinogens,” which can turn substances such as cigarette smoke
and pesticides into carcinogens.)
According to Rimando, Pterostilbene showed strong inhibitory activity, much more than resveratrol, against a particular form of cytochrome P450 in a mouse mammary gland culture assay.
has been touted for its heart healthy benefits, pterostilbene is not found in wine despite darker grapes having the highest concentrations among the fruit. The reason believed is that it is unstable in light and air.
Resveratrol
Resveratrol is a stilbenoid, a type of natural phenol, and a phytoalexin produced naturally by several plants when under attack by pathogens such as bacteria or fungi....
and is found in blueberries and grapes. It belongs to the group of phytoalexin
Phytoalexin
Phytoalexins are antimicrobial substances synthesized de novo by plants that accumulate rapidly at areas of incompatible pathogen infection. They are broad spectrum inhibitors and are chemically diverse with different types characteristic of particular plant species...
s, agents produced by plants to fight infections. Based on animal studies it is thought to exhibit anti-cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
, anti-hypercholesterolemia
Hypercholesterolemia
Hypercholesterolemia is the presence of high levels of cholesterol in the blood. It is not a disease but a metabolic derangement that can be caused by many diseases, notably cardiovascular disease...
, anti-hypertriglyceridemia
Hyperlipidemia
Hyperlipidemia, hyperlipoproteinemia, or hyperlipidaemia is the condition of abnormally elevated levels of any or all lipids and/or lipoproteins in the blood...
properties, as well as fight off and reverse cognitive decline. It is believed that the compound also has anti-diabetic properties, but so far very little has been studied on this issue.
Pharmacokinetics
Pterostilbene is a double-methylated version of resveratrol exhibiting a higher bioavailabilityBioavailability
In pharmacology, bioavailability is a subcategory of absorption and is used to describe the fraction of an administered dose of unchanged drug that reaches the systemic circulation, one of the principal pharmacokinetic properties of drugs. By definition, when a medication is administered...
as it is more easily transported into the cell and more resistant to degradation and elimination. In rats, pterostilbene's oral availability is 67%-94%, and its half-life has been published to be between 78 minutes and 104 minutes.
Pterostilbene has anti -inflammatory, antineoplastic, and antioxidant actions via modulations of gene expression and enzyme activity. In plants the substance displays antifungal and antiviral activities.
Focus of studies has been generally on the trans isomer of pterostilbene.
Lowering blood lipids and cholesterol
Studies that used animals fed on blueberry based diets found significant reduction in blood lipid count and cholesterol count. While lipids and cholesterol stored in the cells do not pose much harm, elevated lipid and cholesterol levels in the blood have been linked to heart disease and stroke. In the mentioned study blueberries were found to be more effective than ciprofibrateCiprofibrate
Ciprofibrate is a fibrate.Crystalline powder white or almost white.Melting point about 115 to 120°C....
, a cholesterol-lowering drug predominantly used outside the United States.
According to the study pterostilbene binds to PPARs
Peroxisome proliferator-activated receptor
In the field of molecular biology, the peroxisome proliferator-activated receptors are a group of nuclear receptor proteins that function as transcription factors regulating the expression of genes...
, breaking down the cholesterol.
Diabetes
Similar to what has been discovered with the drug metforminMetformin
Metformin is an oral antidiabetic drug in the biguanide class. It is the first-line drug of choice for the treatment of type 2 diabetes, in particular, in overweight and obese people and those with normal kidney function. Its use in gestational diabetes has been limited by safety concerns...
, pterostilbene has been shown to lower blood glucose levels in rats by as much as 56 percent, while simultaneously raising insulin and hemoglobin levels to near normal levels.
Cognitive decline
In a study of 40 19-month-old rats fed either a normal diet or a diet containing blueberry, strawberryStrawberry
Fragaria is a genus of flowering plants in the rose family, Rosaceae, commonly known as strawberries for their edible fruits. Although it is commonly thought that strawberries get their name from straw being used as a mulch in cultivating the plants, the etymology of the word is uncertain. There...
, or spinach
Spinach
Spinach is an edible flowering plant in the family of Amaranthaceae. It is native to central and southwestern Asia. It is an annual plant , which grows to a height of up to 30 cm. Spinach may survive over winter in temperate regions...
extracts, the rats that were fed blueberry extracts had a significant reversal in motor-skill decline due to aging as well as other cognitive impairments. All of the diets above, except the normal one, resulted in some reversal or reduction of cognitive decline but none greater than the blueberry group. Even when animal based studies yield positive results, the effects on humans may not be the same.
Possible anti-cancer effects
In 2002, Rimando and UIC collaborators found in experiments using rat mammary glands that pterostilbene possessed potent anti-oxidant characteristics and possible cancer-fighting properties at concentrations similar to resveratrol.Additional work by Rimando and collaborators revealed a possible mechanism for pterostilbene's purported anti-cancer properties. Using mice cells, they demonstrated that pterostilbene, as well as other analogs of resveratrol, potently inhibits an enzyme called cytochrome P450. (Cytochromes are found within the cells of animals, plants, bacteria, and other microorganisms that transport electrons. They’re also a factor in people’s varying response to drugs and toxins entering their bodies. Cytochrome P450 enzymes activate a variety of compounds known as ”procarcinogens,” which can turn substances such as cigarette smoke
Smoking
Smoking is a practice in which a substance, most commonly tobacco or cannabis, is burned and the smoke is tasted or inhaled. This is primarily practised as a route of administration for recreational drug use, as combustion releases the active substances in drugs such as nicotine and makes them...
and pesticides into carcinogens.)
According to Rimando, Pterostilbene showed strong inhibitory activity, much more than resveratrol, against a particular form of cytochrome P450 in a mouse mammary gland culture assay.
Human studies
No randomized human studies have been completed, however the first human clinical trial on the effect of pterostilbene on cholesterol and blood pressure should run from Dec 2010 to Jan 2013 at the University of Mississippi. Effect upon human health is an extrapolation of animal data. The data collected from rat studies suggest a dose of 50–100 mg of pterostilbene 2x/day, similar to the dosage of resveratrol.In wine
While resveratrolResveratrol
Resveratrol is a stilbenoid, a type of natural phenol, and a phytoalexin produced naturally by several plants when under attack by pathogens such as bacteria or fungi....
has been touted for its heart healthy benefits, pterostilbene is not found in wine despite darker grapes having the highest concentrations among the fruit. The reason believed is that it is unstable in light and air.
See also
- Phytonutrients
- PhytosterolPhytosterolPhytosterols, which encompass plant sterols and stanols, are steroid compounds similar to cholesterol which occur in plants and vary only in carbon side chains and/or presence or absence of a double bond. Stanols are saturated sterols, having no double bonds in the sterol ring structure. More than...
- BlueberryBlueberryBlueberries are flowering plants of the genus Vaccinium with dark-blue berries and are perennial...
- PiceatannolPiceatannolPiceatannol is a stilbenoid, a type of phenolic compound. It is a metabolite of resveratrol found in red wine.Astringin is a piceatannol glucoside.-Health effects:...
, a stilbenoid related to both resveratrol and pterostilbene. - List of phytochemicals and foods in which they are prominent