>> Polygonum Cuspidatum
1. Anthraquinones from Polygonum cuspidatum as tyrosinase inhibitors for dermal use.
Leu YL, Hwang TL, Hu JW, Fang JY, Natural Products Laboratory, Graduate Institute of Natural Products, Chang Gung University, Kweishan, Taoyuan, Taiwan.2008 Apr;22(4):552-6.
"Four anthraquinones, physcion (1), emodin (2), citreorosein (3) and anthraglycoside B (6), and two stilbenes, resveratrol (4), and piceid (5), were isolated previously from the root of Polygonum cuspidatum. These bioactive compounds were examined for their antityrosinase potency. No antityrosinase activity was detected with treatment using stilbenes. On the other hand, the anthraquinones showed moderate to strong inhibition of tyrosinase. Physcion exhibited the most potent tyrosinase inhibition among the four anthraquinones examined, which was comparable to kojic acid. The ability of anthraquinones to permeate the skin was also examined. Based on the same thermodynamic activity, physcion showed a higher permeation compared with emodin (48-fold), suggesting it as a potent candidate for dermal use. As naturally occurring tyrosinase inhibitors, anthraquinones from P. cuspidatum may be useful as skin-whitening agents to inhibit tyrosinase for dermal use."
2. Inhibition of melanogenesis by piceid isolated from Polygonum cuspidatum.
Jeong ET, Jin MH, Kim MS, Chang YH, Park SG. Cosmetic Research & Development Center, LG Household & Healthcare Ltd., Daejeon, 305-343, Korea. Epub 2010 Oct 9.
"Piceid (5,4'-dihydroxystilbene-3-O-ß-D-glucopyranoside) is one of the stilbenes found in Polygonum cuspidatum. Previous studies have shown that this compound has little effect on tyrosinase inhibition when compared with other stilbenes in a cell-free tyrosinase assay. Furthermore, its role for melanogenesis in melanocytes is relatively unknown. In melanocytes, piceid inhibits tyrosinase activity and melanin production in a concentration-dependent manner. To explore the action of piceid on melanogenesis, we studied its effect on several key cellular enzymes and a transcriptional factor known to be involved in melanogenesis, including: tyrosinase, tyrosinase-related protein 1, tyrosinase-related protein 2, and microphthalmia-associated transcription factor. Interestingly, the effects of piceid on hypopigmentation and inhibition of tyrosinase activity were better than those of arbutin, which is well known to inhibit melanin formation in melanocytes. In addition, piceid suppressed the mRNA and protein expression of the aforementioned enzymes and transcriptional factor in a concentration-dependent manner. In this regards, our results showed that piceid represents a safe and new candidate for a skin-lightening agent."
3. Cosmetic ingredients for cellulite management.
Risky, Junior Member. August 30th, 2003, 03:50 AM.
"The majority of ingredients for reducing skin pigmentation are tyrosinase inhibitors and a paper at the IFSCC Congress [REF 3] described their
action and an in-vitro method for determining efficacy. As is usual with such tests the base line is provided by hydroquinone and the test
material, an extract from Broussonetia kazinoki (paper mulberry) and trade named Kazinol F was shown to be more effective than kojic acid,
ascorbic acid and hydroquinone. The anti-erythema and free radical scavenging activity of Kazinol F was also described and the material
shown not to be a sensitiser nor a primary irritant. Another paper [REF 4] described the skin whitening effects of Polygonum cuspidatum
(flowering bamboo) which inhibits tyrosinase synthesis and a third paper reported the results of screening one hundred plant extracts for
tyrosinase inhibition [REf 5]. Morus alba and Glycyrrhiza glabra showed >50% inhibitory activity against mushroom tyrosinase at a concentration
of 333mg/ ml. Other workers [REF 6] reported the effects of a liquorice extract on tyrosinase activity and as an anti-inflammatory and anti-
allergen agent; concluding that the material was ideal as an ingredient for reducing pigmentation in cosmetic products for sensitive skin."