Effect of caffeinated and decaffeinated coffee on serum uric acid and uric acid clearance, a randomised within-subject experimental study.

OBJECTIVES: The effect of coffee on serum uric acid (SUA) has shown conflicting results. This study was to determine the effects of caffeinated coffee (CC) and decaffeinated coffee (DC) on SUA, serum xanthine oxidase activity (sXOA) and urine uric acid clearance (UAC). METHODS: This was a prospective randomised within-subject experimental study design of 51 healthy male participants. Each study period consisted of 3 periods, including a control, an intervention, and washout period for 1, 3 and 1 week, respectively. During the intervention period, the participants received 2, 4 or 6 gram/day of coffee, either CC or DC. RESULTS: For DC groups, SUA significantly decreased by 6.5 (±1.1) mg/dL to 6.2 (±1.1) mg/dL during the intervention period (p=0.014). sXOA significantly increased by 0.05 (±0.07) nmol/min/mL to 0.20 (±0.38) nmol/min/mL during the intervention period (p=0.010) of CC. For UAC, there was no significant change with CC or DC. In hyperuricaemic participants, SUA significantly decreased by 7.7 (±0.7) mg/dL to 7.2 (±0.7) mg/dL during the intervention period (p=0.028) of DC. For non-hyperuricaemic, CC significantly increased SUA by 5.9 (±0.7) mg/dL to 6.2 (±0.9) mg/dL during the intervention period (p=0.008) and significantly decreased SUA to 6.0 (±0.8) mg/dL (p=0.049) during the withdrawal period. A significant increase of sXOA according with SUA in CC groups from 0.05 (±0.07) nmol/min/mL to 0.25 (±0.44) nmol/min/mL during the intervention period (p=0.040) was presented in non-hyperuricaemic participants. CONCLUSIONS: DC had a significant decrease of SUA during the intervention period. However, in non-HUS participants, SUA significantly increased in CC.

Germacrone and sesquiterpene-enriched extracts from Curcuma aeruginosa Roxb. increase skin penetration of minoxidil, a hair growth promoter.

Minoxidil is approved for topical treatment of androgenic alopecia but hampered by poor cutaneous absorption. Recently, the randomized control trial showed that hair loss treatment of minoxidil was improved by co-application of the anti-androgen, Curcuma aeruginosa Roxb. extract. Here, we aimed to show that the apparent synergism arises from improved cutaneous penetration of minoxidil by bioactive compound, germacrone or C. aeruginosa (as an n-hexane extract, or essential oil). The partition coefficient of germacrone was determined by HPLC. Skin penetration was measured ex vivo on Franz diffusion cells using full thickness human foreskin as membranes. The receiver solution was sampled hourly for 8 h after which the skin was removed, the stratum corneum separated, and minoxidil assayed in this and in the remaining viable skin layer by HPLC. Skin penetration of minoxidil with 0.2 and 2% extract was increased ~ 4-fold (accumulated amount in receiver + skin viable layer after 8 h). Furthermore, germacrone enhanced minoxidil flux by ~ 10-fold and C. aeruginosa essential oil by ~ 20-fold. This work suggests three clinical consequences: (i) minoxidil efficacy is promoted, (ii) lower doses of minoxidil suffice, and (iii) C. aeruginosa extract/essential oil or germacrone can supplement treatment outcomes by acting as anti-androgen, thereby introducing a more effective topical treatment strategy for androgenic alopecia.

Polymeric micelles of PEG-PE as carriers of all-trans retinoic acid for stability improvement.

The topical application of all-trans retinoic acid (ATRA) is an effective treatment for several skin disorders, including photo-aging. Unfortunately, ATRA is susceptible to light, heat, and oxidizing agents. Thus, this study aimed to investigate the ability of polymeric micelles prepared from polyethylene glycol conjugated phosphatidylethanolamine (PEG-PE) to stabilize ATRA under various storage conditions. ATRA entrapped in polymeric micelles with various PEG and PE structures was prepared. The critical micelle concentrations were 97-243 µM, depending on the structures of the PEG and PE molecules. All of the micelles had particle diameters of 6-20 nm and neutral charges. The highest entrapment efficiency (82.7%) of the tested micelles was exhibited by ATRA in PEG with a molecular weight of 750 Da conjugated to dipalmitoyl phosphatidylethanolamine (PEG(750)-DPPE) micelles. The PEG(750)-DPPE micelle could significantly retard ATRA oxidation compared to ATRA in 75% methanol/HBS solution. Up to 87% of ATRA remained in the PEG(750)-DPPE micelle solution after storage in ambient air for 28 days. This result suggests that PEG(750)-DPPE micelle can improve ATRA stability. Therefore, ATRA in PEG(750)-DPPE micelle is an interesting alternative structure for the development of cosmeceutical formulations.