Two phenolic antioxidants in Suoyang enhance viability of •OH-damaged mesenchymal stem cells: comparison and mechanistic chemistry

Abstract

Background Suoyang originates from a psammophyte named Cynomorium songaricum Rupr and has been known as a phenolic-antioxidant-enriched traditional Chinese herbal medicine. The present study attempted to investigate the protective effect of phenolic antioxidants in Suoyang towards •OH-mediated MSCs and then further discusses the chemical mechanisms.MethodsThe lyophilized aqueous extract of Suoyang (LAS) was prepared and characterized using HPLC. Then, two phenolic antioxidant references, epicatechin and luteolin-7-O-β-D-glucoside, along with LAS, were investigated for their effects on the viability of •OH-treated MSCs using the 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl (MTT) assay. The comparison and mechanistic chemistry of epicatechin and luteolin-7-O-β-D-glucoside were further explored using various antioxidant assays, including PTIO•-scavenging, FRAP (ferric ion reducing antioxidant power), ABTS+•-scavenging, and DPPH•-scavenging. Their Fe2+-binding capacities were also compared using ultraviolet (UV) spectra.ResultsThe HPLC analysis indicated that there are 8 phenolic antioxidants in LAS, including epicatechin, luteolin-7-O-β-D-glucoside, gallic acid, protocatechuic acid, catechin, isoquercitrin, phlorizin, and naringenin. The MTT assay revealed that epicatechin could more effectively increase the survival of •OH-treated MSCs than luteolin-7-O-β-D-glucoside. Similarly, epicatechin exhibited higher antioxidant abilities than luteolin-7-O-β-D-glucoside in the DPPH•-scavenging, ABTS+•-scavenging, FRAP, and PTIO•-scavenging assays. In the Fe2+-binding assay, luteolin-7-O-β-D-glucoside gave a stronger UV peak at 600 nm, with ε = 2.62 × 106 M−1 cm−1, while epicatechin produced two peaks at 450 nm (ε = 8.47 × 105 M−1 cm−1) and 750 nm (ε = 9.68 × 105 M−1 cm−1).ConclusionAs two reference antioxidants in Suoyang, epicatechin and luteolin-7-O-β-D-glucoside can enhance the viability of •OH-damaged MSCs. Such a beneficial effect may be from their antioxidant effects, including direct-antioxidant and indirect-antioxidant (i.e., Fe2+-binding) processes. In the direct-antioxidant process, proton (H+), one electron (e), or even hydrogen-atom (•H) transfer may occur to fulfill radical-scavenging (especially •OH-scavenging); in this aspect, epicatechin is superior to luteolin-7-O-β-D-glucoside due to the presence of more phenolic –OHs. The additional –OHs can also be responsible for the better cytoprotective effect. In terms of indirect-antioxidant potential, however, epicatechin is inferior to luteolin-7-O-β-D-glucoside due to the absence of a hydroxyl-keto moiety. These findings will provide new information about medicinal psammophytes for MSC transplantation.Electronic supplementary materialThe online version of this article (doi:10.1186/s13065-017-0313-1) contains supplementary material, which is available to authorized users.

The Traditional Chinese Medicine “Hu-Qian-Wan” Attenuates Osteoarthritis-Induced Signs and Symptoms in an Experimental Rat Model of Knee Osteoarthritis

“…Phenolic antioxidants epicatechin and luteolin-7-O- β -D-glucoside extracted from C. songaricum Rupr. exhibit superior antioxidative activities over those of other phenolic antioxidants in •OH-damaged MSCs [ 41 ]. The 39 flavonoid compounds identified in citrus ( Citrus reticulate Blanco) fruit, particularly the flavonoid glycosides didymin, hesperidin, neohesperidin, poncirin, and naringin, display marked anti-oxidative activity [ 42 ].…”

Standards-Based UPLC-Q-Exactive Orbitrap MS Systematically Identifies 36 Bioactive Compounds in Ampelopsis grossedentata (Vine Tea)

“…According to the previous method [64,65], the lyophilized aqueous extract of vine tea was prepared through four steps: decoction, filtration, concentration and lyophilization. Subsequently, the lyophilized aqueous extract was redissolved in methanol and filtered through a 0.45 μm membrane, in line with the method [66,67].…”

Structural characteristic of polysaccharide isolated from Nostoc commune, and their potential as radical scavenging and antidiabetic activities

“…In vitro antioxidant activities determination. According to our previously described method 65,68,69 , HNCP3, UNCP4 and Vc solutions with different concentrations (0.2 mg/mL, 0.4 mg/mL, 0.6 mg/mL, 0.8 mg/ mL, 1.0 mg/mL) were prepared to evaluate their antioxidant activities in terms of DPPH radical scavenging ability, superoxide anion scavenging ability and hydroxyl radical scavenging ability. To be specific, 1 mL of crude polysaccharides of HNCP3 and UNCP4 with concentrations of 0.2 mg/mL, 0.4 mg/mL, 0.6 mg/mL, 0.8 mg/mL and 1.0 mg/mL were added into the test tubes.…”