Plant products play an important role because of their medicinal activity. A wide variety of active phytochemicals peptides have been found to possess therapeutic applications against various functionally and genetically diverse viruses. Influenza A viruses (IAV) causes acute respiratory diseases in humans, birds, and other mammals, representing one of the major threats to public health.
In this study, the antiviral activity of Allium sativum L., Allium cepa L., and Zingiber officinale Roscoe against Avian Influenza H9 virus was evaluated in ovo. The aqeous extracts of Allium sativum L., Allium cepa L., and Zingiber officinale Roscoe were prepared by using macerate technique. From the macerate, nine different dilutions i.e. 8000 ƒÊg/ml, 4000 ƒÊg/ml, 2000 ƒÊg/ml, 1000 ƒÊg/ml, 500 ƒÊg/ml, 250 ƒÊg/ml, 125 ƒÊg/ml, 62.5 ƒÊg/ml and 31.25 ƒÊg/ml of the extracts were prepared in normal saline. For each plant extract; Allium sativum L., Allium cepa L., Zingiber officinale Roscoe 100 embryonated chicken eggs were assigned to 20 groups, each group containing 5 embryonated chicken eggs (nine for antiviral activity, nine for cytotoxic activity, and two groups were kept positive and negative control respectively) and marked them with lead pencil. The different concentrations of the plant extracts were mixed with virus and 0.2 ml inoculum was inoculated to 9th to 10th day embryonated chicken eggs along with positive and negative controls containing only virus and normal saline respectively. The embryonated chicken eggs were incubated at 37oC and were checked after 12-72 hrs. After 72 hr post inoculation, all the eggs were chilled in refrigerator at 4oC for 12 hrs and the allantoic fluid was harvested. The antiviral activity was calculated as embryo survival percentage, positive or negative spot Hemagglutination activity and determination of virus titre by Hemagglutination Test. The cytotoxicity of Allium sativum L., Allium cepa L., Zingiber officinale Roscoe extracts was evaluated by only inoculating the extracts of respective concentrations as used for antiviral activity in embryonated chicken eggs and incubating for 72 hrs. The results were analyzed by ANOVA by means of SPSS.
All the concentrations of Allium sativum L. were non toxic while three concentrations showing antiviral activity were 8000 ƒÊg/ml, 4000 ƒÊg/ml and 2000 ƒÊg/ml. While in case of Allium cepa L. all the concentration i.e. 8000 ƒÊg/ml, 4000 ƒÊg/ml, 2000 ƒÊg/ml, 1000 ƒÊg/ml, 500 ƒÊg/ml, 250 ƒÊg/ml, 125 ƒÊg/ml, 62.5 ƒÊg/ml and 31.25 ƒÊg/ml were non cytotoxic and five concentrations i.e. 8000 ƒÊg/ml, 4000 ƒÊg/ml, 2000 ƒÊg/ml, 1000 ƒÊg/ml and 500 ƒÊg/ml show potent antiviral activity. In case of Zingiber officinale Roscoe two concentrations 8000 ƒÊg/ml, 4000 ƒÊg/ml were virucidal and all concentration 8000 ƒÊg/ml, 4000 ƒÊg/ml, 2000 ƒÊg/ml, 1000 ƒÊg/ml, 500 ƒÊg/ml, 250 ƒÊg/ml, 125 ƒÊg/ml, 62.5 ƒÊg/ml and 31.25 ƒÊg/ml were non cytotoxic. So the present study suggested the presence of antiviral activity of plant extracts of Allium sativum L., Allium cepa L., Zingiber officinale Roscoe, so they can be used for prevention and treatment of various viral diseases.