Pterostilbene is the active ingredient of heart wood from Pterocarpus marsupium (Indian Kino Tree). The heart wood is used as an astringent and in the treatment of inflammation and diabetes. Pterostilbene is a stilbenoid chemically related to resveratrol and is found in blueberries and grapes. It belongs to the group of phytoalexins, 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.
Anti – diabetic activity:
Similar to what has been discovered with the drug metformin, 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 (Pari 2006). The antioxidant effect of pterostilbene on streptozotocin-nicotinamide-induced diabetic rats has been assessed. The activity of superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase and reduced glutathione was significantly decreased in liver and kidney of diabetic animals when compared with normal control. There were significant improvements in these activities after treatment with pterostilbene at a dose of 40 mg kg(-1) for six weeks. The increased levels of lipid peroxidation measured as thiobarbituric acid reactive substances (TBARS) in liver and kidney of diabetic rats were also normalized by treatment with pterostilbene. Chronic treatment of pterostilbene remarkably reduced the pathological changes observed in liver and kidney of diabetic rats. These results indicated the antioxidant property of pterostilbene.One research demonstrated that pterostilbene can lower the blood glucose levels in streptozotocin-induced hyperglycemic rats by 42%. (Manickam 1997).
Anti – cancer activity:
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. 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.
Lowers blood lipid and cholestrol activity:
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 ciprofibrate, a cholesterol-lowering drug predominantly used outside the United States. According to the study pterostilbene binds to PPARs, breaking down the cholesterol (Rimando 2005 & Satheesh 2008).
Pterostilbene has been shown to elicit significant antioxidant activity in vitro that is comparable to the activity of resveratrol. Research has demonstrated that pterostilbene inhibits citronellal thermo-oxidation by an EQ value of 355M (~90.9g/ml), and that pterostilbene scavenges for 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals with an EC50 value of approximately 30M (~7.68g/ml) (Manickam 1997).
The ability of pterostilbene to reduce the deleterious effects of aging was demonstrated in a study of resveratrol and six resveratrol analogues. Aged rats fed a diet containing pterostilbene showed a reversal of age-related cognitive behavioral deficits. (Joseph 2008)
|QUALITY CONTROL DEPARTMENT|
|Product Name||PTEROSTILBENE 90%|
|Botanical Name||Pterocarpus marsupium|
|Plant part||Heart wood|
|1||Description||White to off white color powder||Visual|
|2||Identification||To comply by HPLC||KVN/QC/STP-IN/022|
|3||Loss on drying||NMT 5.0%||USP <731>|
|4||Residue on Ignition||NMT 2.0%||USP <281>|
|5||Solubility||Soluble in Methanol||KVN/QC/STP-GT/028|
|6||Tapped Bulk density||0.4-0.9 g/ml||USP <616>|
|Sieve test (passes through)|
|7||#60 mesh||NLT 95.0% w/w||USP <786>|
Pterostilbene by HPLC
|NLT 90.0% w/w on dry basis||KVN/QC/STP-IN/020|
|10||Residual solvents||Should comply by ICH/USP||USP <467>|