Jojoba oil

Niacinamide (NIA), k-C RG, polyvinylpyrrolidone (PVP), jojoba oil, tween 80, oleic acid, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) powder, k-carrageenan, chloroform, jojoba oil, trypsin, and phosphate-buffered saline (PBS) were supplied by Sigma-Aldrich (Alabaster, AL, USA). l-α-phosphatidylcholine (EPC) was purchased from Avanti Polar Lipids (Alabaster, AL, USA). Ethanol absolute (≥99.8%) and methanol (≥99.8% HPLC grade) were obtained from Fisher Chemical (Thermo Fisher Scientific, Loughborough, UK). Double-deionized water was provided by an ultra-pure water system (Arium Pro, Sartorius AG, Gottingen, Germany). The porcine ears were acquired in a local slaughterhouse (Porto, Portugal). Reagents were weighted in a digital analytical balance Kern ACJ/ACS 80-4 (Kern & Sohn; Balingen, Germany). The pH measurements were achieved using a Crison pH meter GLP 22 with a Crison 52-02 tip (Crison; Barcelona, Spain).

Male C57BL/6J mice (age, 8 weeks) purchased from Daehan Biolink (Eumseong, Korea) were housed under controlled conditions (22 ± 2°C, relative humidity of 50 ± 5%, and 12 h light/dark cycle), and were provided ad libitum access to standard rodent chow (Daehan Biolink) and water. All mice were acclimated for 7 d before the experiments. All animal experiments were approved by the Animal Experimental Ethics Committee of Chungnam National University (Daejeon, Korea) and were performed in accordance with institutional guidelines. To determine the hair growth-promoting effect, the hair on the back of the mice was first removed using an animal hair clipper without damaging the skin, and then the fine hair remaining on the skin was removed using a bit hair removal cream (Church & Dwight, Kent., UK). After a one-day recovery period, 24.75 mL of distilled water, 3.75 mL of 100% ethanol, and 1.5 mL of jojoba oil (Sigma-Aldrich, St. Louis, MO, USA), which served as a moisturizing agent, were mixed and used as a control. In the control group, only the vehicle (jojoba oil only), 1% WEML, and 0.3% minoxidil (TAE GUK PHARM., Chungcheongnam-do, Korea) were added to the vehicle at different concentrations, and 200 μL of each sample was applied to the back of depilated mice using a brush once a day.

The whey protein isolate (WPI) of the purity min. 90% protein (BiPRO) was purchased from Davisco Foods International Inc. (La Sueur, MN, USA). Jojoba oil was supplied from Sigma ALDRICH (Lima, Peru). Anhydrous glycerol was purchased from Avantor Performance Materials Poland S.A. (Gliwice, Poland).