Antioxidant Activities of Jeju Wax Apple (Syzygium samarangense) and Safety of Human Keratinocytes and Primary Skin Irritation Test

Abstract

This study analyzed the antioxidant activity, cell viability, and human skin primary irritation test using the hot-water extracts of the Syzygium samarangense. As a result of the recent warmer climate, tropical plants have flourished on Jeju Island, and S. samarangense is one of these plants known to have biological activities. In this study, the hot-water extract of S. samarangense leaf and branch was analyzed. Antioxidant activity was measured by DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azino-bis(3-ethyl-benzthiazoline-6-sulfonic acid)) assays, and the DMPD (dimethyl-4-phenylenediamine) radical scavenging activity, nitrite scavenging activity, ferrous-ion chelating activity, cupric reducing antioxidant capacity, reducing power assay, ferric reducing antioxidant power, total phenol content, and total flavonoid content were also measured. In addition, cell viability was measured by MTT assay in human keratinocyte cells (HaCaT), and the safety of the extract for use on the skin was evaluated in the human skin primary irritation test. The antioxidant activities, except DMPD radical scavenging activity and ferrous-ion chelating activity, were stronger in the branch extract than in leaf extract, and the total phenol and flavonoid contents were also higher in the branch extract. Slight irritation was observed in the human skin primary irritation test. However, it was possible to observe sufficient antioxidant capacity at a concentration lower than the concentration used in the irritation test; therefore, if the concentration of the extract is appropriately adjusted, this suggests that it is a possible natural material suitable for use in cosmetics.

Imperatorin Positively Regulates Melanogenesis through Signaling Pathways Involving PKA/CREB, ERK, AKT, and GSK3β/β-Catenin

“…Primary skin irritation responses were assessed according to the PCPC guidelines. The reaction results for each test substance were calculated from the formula shown below [ 50 , 51 ]. The study was approved by the Industrial Review Board (IRB) of Dermapro Inc. and was conducted in accordance with the Helsinki Declaration as a declaration of the ethical principles for medical research after obtaining written consent from each volunteer (IRB number: 1-220777-A-N-01-DICN22080).…”

Green Honey Deli Water Apple (Syzygium aqueum (Burm. f.) Alston “Madu Deli Hijau”): Evaluation of Antioxidant Activities and Phytochemical Content

“…In the previous research, results showed that hot water branches extract of java apple (Syzygium samarangense) had an absorbance of 4.8 at 1000 µg/mL and hot water leaves extract of java apple has an absorbance of 4.1 at 1000 µg/mL, lower compared to L-ascorbic acid that had an absorbance of 4.2 at 100 µg/mL, according to CUPRAC method [21]. In the present research, antioxidant activities of green honey deli water apple leaves range from 10.79 to 221.47 mg AAE/g, branches range from 10.46 to 222.51 mg AAE/g, and fruits range from 19.45 to 25.04 mg AAE/g, according to CUPRAC method.…”

Anti-Inflammatory Effects of Psoralen Derivatives on RAW264.7 Cells via Regulation of the NF-κB and MAPK Signaling Pathways

“…The primary skin irritation response was evaluated in accordance with the PCPC guidelines. The skin reaction results for each test substance were calculated from the formula shown below [ 33 , 34 ]. This study was approved by the Institutional Review Board (IRB) of Dermapro Inc. and conducted according to the Declaration of Helsinki as a statement of ethical principles for medical research after obtaining written informed consent from each volunteer (IRB no.…”