Inhibitory Activity of Honeysuckle Extracts against Influenza A Virus In Vitro and In Vivo

Honeysuckle has been used in the treatment of influenza virus infection for thousands of years in China.However,its main active components and the functional mechanisms remain to be elucidated.Here,four honeysuckle extracts,including acids extract,flavonoids extract,total extract and acids-flavonoids mixture,were prepared to clarify the main active antiviral components.The cytopathic effect reduction assay showed that all the four extracts inhibited the replication of influenza viruses H1N1,H3N2 and the oseltamivir-resistant mutant strain H1N1-H275Y.The acids-flavonoids mixture had the strongest inhibitory effects in vitro with EC_(50) values of 3.8,4.1,and >20 lg/m L against H1N1,H3N2 and H1N1-H275Y,respectively,showing competitive antiviral activity with oseltamivir and ribavirin.Honeysuckle acids extract also showed the most significant antiviral activity in vivo.Oral administration of the acids extract at a dosage of 600 mg/kg/d effectively alleviated viral pneumonia,maintained body weight and improved the survival rate to 30% of the mice infected with a lethal dose of H1N1.The results of time-of-drug addition experiment and neuraminidase (NA) inhibition assay showed that honeysuckle extracts had a broad-spectrum inhibitory effect against influenza virus NAs.The flavonoid extract showed the strongest inhibitory effect on the NA of influenza virus H7N9 with an IC_(50) of 24.7 lg/m L.These results suggested that these extracts might exert their antiviral activity by suppressing the release of influenza viruses.Briefly,our findings demonstrate that acids and flavonoids extracts of honeysuckle are the major antiviral active components,and the acids extract has the potential to be developed into an antiviral agent against influenza virus,especially for oseltamivirresistant viruses.

Anaphylaxis effect and substance basis of honeysuckle extract

Objective:To explore the anaphylaxis effect and anaphylaxis substances of honeysuckle.Methods:Rat peritoneal mast cells(PMC)were separated and purified,the cells were incubated with compound 48/80(0.02 g/L),physiological saline and honeysuckle extract(120 g/L)at 37°C for 0,15,30,45 and 60 min.Degranulation were observed by optical microscope and transmission electron microscope.Annexin V positive cell rate was detected by flow cytometry to reflect the degranulation rate of PMC.SD rats were supplied with honeysuckle extract by intravenous injection at a dose of 2.25 g/L.After administration,different parameters were analyzed,including the symptoms,histamine(HIS)and tryptase(MCT)levels,which were determined to explore the effect of anaphylaxis.Regression analysis was used to calculate the relationships between the peaks and the pharmacological effects to explore potentially anaphylactoid components.Results:The percentage of Annxin V positive cells and the degranulation ratio were markedly elevated in PMC treated with honeysuckle extract for more than 15 min(P<0.05).HIS and MCT level were significantly elevated after injection of honeysuckle extract for more than 15 min.Morphology of PMC and systemic symptoms were also changed compared with the controlled group(P<0.05).Regression analysis was used to calculate the relationship between peaks and pharmacological effects,and to determine peaks 7,10 and 13 as possible anaphylactoid ingredients.Conclusion:This study established a prospective method to clarify the anaphylactoid components of honeysuckle extract,which would provide guidance for screening anaphylactoid components in traditional Chinese medicine injections containing honeysuckle in the prescription.