Antiviral Activity of Fritillaria thunbergii Extract against Human Influenza Virus H1N1 (PR8) In Vitro, In Ovo and In Vivo.

Influenza viruses cause respiratory diseases in humans and animals with high morbidity and mortality rates. Conventional anti-influenza drugs are reported to exert side effects and newly emerging viral strains tend to develop resistance to these commonly used agents. Fritillaria thunbergii (FT) is traditionally used as an expectorant for controlling airway inflammatory disorders. Here, we evaluated the therapeutic effects of FT extracts against influenza virus type A (H1N1) infection in vitro, in ovo, and in vivo. In the post-treatment assay, FT extracts showed high CC50 (7,500 µg/ml), indicating low toxicity, and exerted moderate antiviral effects compared to oseltamivir (SI 50.6 vs. 222) in vitro. Antiviral activity tests in ovo revealed strong inhibitory effects of both FT extract and oseltamivir against H1N1 replication in embryonated eggs. Notably, at a treatment concentration of 150 mg/kg, only half the group administered oseltamivir survived whereas the FT group showed 100% survival, clearly demonstrating the low toxicity of FT extracts. Consistent with these findings, FT-administered mice showed a higher survival rate with lower body weight reduction relative to the oseltamivir group upon treatment 24 h after viral infection. Our collective results suggest that FT extracts exert antiviral effects against influenza H1N1 virus without inducing toxicity in vitro, in ovo or in vivo, thereby supporting the potential utility of FT extract as a novel candidate therapeutic drug or supplement against influenza.

Topical anti-inflammatory and anti-oxidative effects of porcine placenta extracts on 2,4-dinitrochlorobenzene-induced contact dermatitis.

BACKGROUND: The placenta is a reservoir enriched with growth factors, hormones, cytokines and minerals. While several beneficial effects of placenta extracts on wound healing, anti-aging and anti-inflammatory responses have been reported, relatively limited mechanistic exploration has been conducted to date. Here, we provide compelling evidence of anti-inflammatory and anti-oxidative activities of porcine placenta extracts (PPE) against contact dermatitis in vivo. METHODS: A contact dermatitis mouse model was established by sensitizing the dorsal skin of BALB/c mice using the contact allergen, 2,4-dinitrochlorobenzene (DNCB), and molecular consequences of topical application of PPE were investigated. PPEs were pre-sterilized via γ-irradiation, which is a milder but more effective way of sterilizing biomolecules relative to the conventional autoclaving method. RESULTS: DNCB-induced skin lesions displayed clear contact dermatitis-like symptoms and topical application of PPE dramatically alleviated both local and systemic inflammatory responses. Inflammatory epidermal thickening was completely abrogated and allergen-specific serum IgE levels significantly reduced in the presence of PPE. Moreover, anti-oxidative activities of PPE were observed both in vitro and in vivo, which may lead to attenuation of inflammatory responses. Prolonged treatment with PPE strongly inhibited production of DNCB-induced reactive oxygen species (ROS) and subsequently prevented oxidative degradation of hyaluronic acid (HA), which triggers innate inflammatory responses. CONCLUSION: Our findings supply valuable insights into the mechanisms underlying the anti-inflammatory effects of PPE and provide a functional basis for the clinical application of PPE in inflammatory diseases.

Antiviral activity of Poncirus trifoliata seed extract against oseltamivir-resistant influenza virus.

The emergence of oseltamivir-resistant variants of influenza virus has highlighted the necessity for the development of more effective novel antiviral drugs. To date, numerous researchers have focused on developing antiviral drugs using natural resources, such as traditional herbal medicines. Poncirus trifoliata is widely used in oriental medicine as a remedy for gastritis, dysentery, inflammation and digestive ulcers. In this study, we investigated the potential antiviral effect of the Poncirus trifoliata orange seed extract against influenza virus. An ethanol extract of Poncirus trifoliata seeds (PTex) inhibited the activity of influenza viruses, in particular, oseltamivir- resistant strains, in Madin-Darby canine kidney cells. In contrast to oseltamivir, PTex exerted a significant inhibitory effect on the cellular penetration pathway of the virus rather than HA receptor binding. The potent antiviral effect and novel working mechanism of PTex support its further development as an effective natural antiviral drug with a wide spectrum of activity against influenza and oseltamivir-resistant viruses.