1. The efficacy study of the combination of tripeptide-10-citrulline and acetyl hexapeptide-3. A prospective, randomized controlled study
Vassiliki Raikou, Athanasia Varvaresou, Irene Panderi, Effie Papageorgiou J Cosmet Dermatol. 2017 Jun;16(2):271-278. doi: 10.1111/jocd.12314. Epub 2017 Feb 2.
Background: Bioactive peptides have beneficial effects on the skin. Objective: We investigated to evaluate the effect of acetyl hexapeptide-3 and tripeptide-10 citrulline and the possible synergism between these two peptides. Methods: Twenty-four healthy volunteers were randomized to receive combination of acetyl hexapeptide-3 with tripeptide-10 citrulline (Group G1), tripeptide-10 citrulline (Group, G2), acetyl hexapeptide-3 (Group G3), or neither peptide (Group G4) for 60 days. Skin properties evaluated included skin microtopography, parameters cR2 and cR3, and transepidermal water loss (TEWL) using a skin visioscan and a tewameter, respectively. Results: After 20 days, the measurements between G1 and G2 groups (cR2 P=.045, cR3 P=.044), G2 and G3 groups (cR2 P=.017, cR3 P=.017), G3 and G4 groups (CR2 P=.022), and G2 and G4 groups (cR3 P=.028) from baseline were significant. After 60 days, measurements between groups G1 and G3 (cR2 P=.016, cR3 P=.025), groups G2 and G3 (cR2 P=.044, cR3= P=.044), and groups G1 and G4 (cR2 P=.025) were significant. After 20 days, changes in TEWL between groups G1 and G3 (P=.03), groups G2 and G3 (P=.045), and groups G3 and G4 (P=.025) were significant. After 40 days, changes between groups G2 and G3 (P=.028) and groups G3 and G4 (P=.01) from baseline were significant. Conclusion: Our results confirm the antiwrinkle activity of acetyl hexapeptide-3. A significant decrease in TEWL with acetyl hexapeptide-3 treatment is observed. We provided clinical evidence for the antiwrinkle efficacy of tripeptide-10 citrulline and possibly TEWL. The underlying mechanism by which these two peptides can act synergistically was not clear in this study.
2. The angiotensin hexapeptide 3-8 fragment potently inhibits [125I]angiotensin II binding to non-AT1 or -AT2 recognition sites in bovine adrenal cortex
M F Jarvis, G W Gessner, C Q Ly Eur J Pharmacol. 1992 Aug 25;219(2):319-22. doi: 10.1016/0014-2999(92)90312-r.
In the present studies, ligand competition experiments were conducted to examine the ability of angiotensin II peptide agonists and nonpeptide AT1- and AT2-selective receptor antagonists to inhibit the binding of [125I]angiotensin II to bovine adrenal cortical membranes. Angiotensin II, angiotensin III, the All-(3-8) hexapeptide fragment of angiotensin II, and the AT1-selective receptor antagonist L-158,809, inhibited [125I]angiotensin II binding in a biphasic fashion indicative of a ligand interaction at more than one recognition site. Approximately 20% of low affinity [125I]angiotensin II binding was inhibited only by high micromolar concentrations of L-158,809. RG 13647 (1(-1,4-benzodioxan-2-methyl)-5-diphenylacetyl-4,5,6,7-tetra hydro-1H-imidazo- [4,5,c]-pyridine-6-carboxylic acid) represents a potent and AT2-selective analog of PD 123177 and showed weak activity in competing for [125I]angiotensin II binding with an IC50 value of 100 microM. When subsequent competition studies were conducted in the presence of 1 microM L-158,809 to block [125I]angiotensin II to the AT1 receptor subtype, the angiotensin II agonists produced monophasic inhibition curves with AII-(3-8) showing the greatest activity (IC50 = 6 nM) followed by angiotensin III (IC50 = 15 nM) much greater than angiotensin II (IC50 = 110 nM). RG 13647 was not found to significantly inhibit this portion of [125I]angiotensin II binding. These data demonstrate that bovine adrenal cortex contains both the AT1 receptor subtype, as well as, a novel class of [125I]angiotensin II recognition sites which may be analogous to the recently described angiotensin IV (AT4) receptor.
3. Facial rejuvenation: combining cosmeceuticals with cosmetic procedures
Joy D Wisniewski, Dana L Ellis, Mary P Lupo Cutis. 2014 Sep;94(3):122-6.
Cosmetic patients are looking for a more youthful appearance without spending a lot of money, feeling any pain, or experiencing any postprocedure downtime. New cosmeceutical therapies can be used adjuvant to chemical peels, lasers, and injectables, making antiaging regimens less painful and requiring less postprocedural healing time. Adjunctive agents can be used to enhance chemical peels and decrease postinflammatory hyperpigmentation (PIH). Topical retinoids used prior to ablative laser treatments can aid in faster postprocedure healing and reepithelialization. Cosmeceuticals that contain both antioxidants and anti-inflammatories can help reduce postprocedure inflammation. Acetyl hexapeptide-3 is an effective topical agent for decreasing wrinkles and can be used as an adjunct to intramuscular botulinum neurotoxin, which may reduce the number of injections needed. Topical hyaluronic acid also would help patients who are averse to needles or are just starting to get wrinkles and are looking for noninvasive therapy. This article reviews combinations of cosmeceuticals with cosmetic procedures that dermatologists may want to consider discussing with their cosmetic patients.
