forsythiaside and 1-1-diphenyl-2-picrylhydrazyl

Forsythiae Fructus (FF), the dried fruit of Forsythia suspensa, has been widely used as a heat-clearing and detoxifying herbal medicine in China. Green FF (GF) and ripe FF (RF) are fruits of Forsythia suspensa at different maturity stages collected about a month apart. FF undergoes a complex series of physical and biochemical changes during fruit ripening. However, the clinical uses of GF and RF have not been distinguished to date. In order to comprehensively compare the chemical compositions of GF and RF, NMR-based metabolomics coupled with HPLC and UV spectrophotometry methods were adopted in this study. Furthermore, the in vitro antioxidant and antibacterial activities of 50% methanol extracts of GF and RF were also evaluated. A total of 27 metabolites were identified based on NMR data, and eight of them were found to be different between the GF and RF groups. The GF group contained higher levels of forsythoside A, forsythoside C, cornoside, rutin, phillyrin and gallic acid and lower levels of rengyol and β-glucose compared with the RF group. The antioxidant activity of GF was higher than that of RF, but no significant difference was observed between the antibacterial activities of GF and RF. Given our results showing their distinct chemical compositions, we propose that NMR-based metabolic profiling can be used to discriminate between GF and RF. Differences in the chemical and biological activities of GF and RF, as well as their clinical efficacies in traditional Chinese medicine should be systematically investigated in future studies.

Topics: Anti-Bacterial Agents; Antioxidants; Bacillus subtilis; Biphenyl Compounds; Cyclohexanones; Drugs, Chinese Herbal; Escherichia coli; Forsythia; Fruit; Gallic Acid; Glucose; Glucosides; Glycosides; Hydroxyl Radical; Picrates; Plant Extracts; Proton Magnetic Resonance Spectroscopy; Pseudomonas aeruginosa; Rutin; Staphylococcus aureus

Forsythia suspensa extract has been proved as a potential antioxidant in the recent years. The present study was undertaken to obtain the optimal antioxidant fraction in vitro and examine its antioxidative potential against diquat-induced oxidative stress in male Sprague Dawley rats in vivo. In vitro, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging experiment indicated that the CH2Cl2 fraction of F. suspensa (FSC) exerted the strongest scavenging activities; forsythoside A, forythialan A and phillygenin from it might be the major antioxidant constituents. In vivo, pretreatment of rats with different doses of FSC (25, 50 and 100 mg/kg bw) and vitamin C (100 mg/kg bw, positive control) for 15 days significantly lowered the tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and interleukin-6 (IL-6) in plasma compared to the negative control group. Also, FSC significantly increased the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and the levels of glutathione (GSH) in plasma, liver and kidney whereas it decreased the levels of malondialdehyde (MDA) in plasma and kidney. Moreover, the protective effect of FSC (100 mg/kg bw) was better than vitamin C. These results revealed that FSC exerted a protective effect against diquat-induced oxidative stress and is worthy of becoming a potential dietary antioxidant.

Topics: Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Cytokines; Diquat; Forsythia; Free Radicals; Fruit; Glycosides; Herbicides; Indicators and Reagents; Kidney; Lignans; Liver; Male; Oxidative Stress; Oxidoreductases; Picrates; Rats; Rats, Sprague-Dawley

Forsythia suspensa (Thunb.) Vahl. has been widely used in traditional medicines in Asia to treat gonorrhoea, erysipelas, inflammation, pyrexia, ulcer and other diseases. Recently the investigation has been focused on the antioxidant and antibacterial activity of this plant. However, limited scientifically proven information is available. We isolated two compounds (forsythiaside and forsythin) from this plant. The aims of this investigation, therefore, were to assay antioxidant activity and antibacterial properties of the two main and distinctive compounds isolated and to exploit antioxidants and antibacterial agents from natural compounds. The antioxidant activity was estimated using the 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity method and the in-vitro antimicrobial activity was evaluated by microtitre plate method. Forsythiaside was found to possess strong antioxidant and antibacterial activity but forsythin was much weaker. Owing to these properties, the study can be further extended to exploit the possible application of forsythiaside as an alternative antioxidant and antibacterial agent of natural origin.

Topics: Anti-Bacterial Agents; Antioxidants; Biphenyl Compounds; Bridged Bicyclo Compounds, Heterocyclic; Drugs, Chinese Herbal; Escherichia coli; Forsythia; Free Radical Scavengers; Furans; Glycosides; Medicine, East Asian Traditional; Microbial Sensitivity Tests; Picrates; Plant Extracts; Pseudomonas aeruginosa; Staphylococcus aureus