Antioxidant Activity of Ixora parviflora in a Cell/Cell-Free System and in UV-Exposed Human Fibroblasts

Abstract

Polyphenols and flavonoids possess a variety of biological activities including antioxidant and anti-tumor activities. Ixora parviflora is a member of the flavonoid-rich Rubiaceae family of flowering plants and used as folk medicine in India. The aim of this study was to investigate the antioxidant activity of Ixora parviflora extract (IPE) in a cell-free system and erythrocytes, and the ability of IPE to inhibit reactive oxygen species (ROS) generation in human fibroblasts (Hs68) after ultraviolet (UV) exposure. Various in vitro antioxidant assays were employed in this study. The extraction yield of IPE was 17.4 ± 3.9%, the total phenolic content of IPE was 26.2 μg gallic acid equivalent (GAE)/mg leaves dry weight and the total flavonoids content was 54.2 ± 4.4 μg quercetin equvalent (QE)/mg extract. The content of chlorogenic acid was 9.7 ± 1.2 mg/g extract. IPE at 1000 μg/mL exhibited a reducing capacity of 90.5 ± 0.6%, a 1,1-diphenyl-2-picrylhydrazy (DPPH) radical scavenging activity of 96.0 ± 0.4%, a ferrous chelating activity of 72.2 ± 3.5%, a hydroxyl radical scavenging activity of 96.8 ± 1.4%, and a hydrogen peroxide scavenging activity of 99.5 ± 3.3%. IPE at 500 μg/mL also possessed inhibitory activity against 2,2′-azobis (2-methylpropionamidine) dihydrochloride (AAPH)-induced hemolysis of erythrocytes (89.4 ± 1.8%) and resulted in a 52.9% reduction in ROS generation in UV-exposed fibroblasts. According to our findings, IPE is a potent antioxidant and a potential anti-photoaging agent.

Photo-protective effect of americanin B against ultraviolet B-induced damage in cultured human keratinocytes

“…Solar radiation passes through the atmosphere and contributes to many kinds of skin disorders (Afaq et al, 2005), including immuno-suppression (Prasad and Katiyar, 2013), premature skin aging, and skin cancer (Thomas-Ahner et al, 2007). Intracellular generation of ROS such as superoxide anion, hydroxyl radical, singlet oxygen, and hydrogen peroxide results in the hazardous state of cellular oxidative stress, which is a crucial mediator of UVB-induced aging (Wen et al, 2011). At the molecular level, UVB can also induce intracellular ROS generation (Brenneisen et al, 2002), which can directly or indirectly cause oxidative damage to DNA, proteins, and lipids in the skin.…”

Neonauclea reticulata(Havil.) Merr Stimulates Skin Regeneration after UVB Exposure via ROS Scavenging and Modulation of the MAPK/MMPs/Collagen Pathway

“…The ability of Neonauclea reticulata extract to scavenge H 2 O 2 was determined spectrophotometrically as previously described [12]. Briefly, a 20 mM solution of H 2 O 2 was prepared in PBS (pH 7.4), added to various concentrations of Neonauclea reticulata extract that had been dissolved in methanol (50 to 2000  μ g/mL), and then allowed to stand at room temperature in the dark.…”

“…This assay is based on the use of an established nonfluorescent (DCFDA)/fluorescent (DCF) system that measures the levels of ROS, which are in turn responsible for the generation of fluorescence [12]. Hs68 cells were seeded in a 24-well plate at a density of 10 5 cells/well for 24 h, rinsed once with 0.5 mL PBS, and then exposed to UVB irradiation (302 nm, CL-1000 M, UVP, USA).…”

A new ent-kaurane diterpenoid from Ixora amplexicaulis

“…Previous investigations led to the isolation of many compounds including phenolics, peptides, terpenoids and sterols from plants of the genus (Ragasa et al 2004;Idowu et al 2010;Lee et al 2010;Ikram et al 2013). Pharmacological studies showed that extracts of the genus and the isolated compounds displayed extensive activities, such as antitumour, chemoprotective and antioxidant activities (Latha & Panikkar 1998;Wen et al 2011;Wickramasinghe et al 2014). But there was no report on Ixora amplexicaulis, which is a small shrub endemic to China.…”