Immune boosting activity of aqueous lemongrass (Cymbopogon citratus) leaf extract on native chickens (Gallus gallus domesticus) challenged with Newcastle disease

Newcastle Disease is a highly infectious disease which can cause up to a 100% mortality in native chickens and no treatment has been yet found for it. Lemongrass (Cymbopogon citratus) is a plant that has alkaloid, saponin, tannin, and flavonoid to combat Newcastle disease. This study aims to measure and compare the antibody titre gain of Philippine native chickens treated with different dilutions of C. citratus aqueous extract. Fofty-four two-month-old chickens were infected with live virus-concentrated solution. Blood was collected from all the samples prior to infection and after the treatment. Samples were grouped into four treatment groups A, B, C, and D, according to the dilution factor. Samples from the treatment group A were given with 1 mL undiluted C. citratus extract, treatment group B with 5-fold dilution, treatment C with 10-fold dilution, and treatment D with 20-fold dilution. Antibody titre gain was determined by hemagglutination inhibition. Result show that there is a significant increase with the antibody titre gain for unvaccinated and vaccinated groups. Unvaccinated samples do not require a treatment diluted in a specific volume of distilled water while vaccinated samples require a treatment diluted in 9 mL distilled water for an optimal antibody increase when infected with ND. Treated samples have an increase in the average live weight with treatments B and C exhibiting a significant increase. Survival rate of the chickens is also high with 85.21%.

This work is partially supported by the Central Philippine University - College of Agriculture, Resources, and Environmental Science, and as well as the Department of Agriculture Region 6. The authors also gratefully acknowledge the helpful comments and suggestions of the reviewers Mrs. Catherine Joy Mediodia, Mr. Angelo Olvido, Mrs. Anelyn Hapitan, Mrs. Athenes Joy Presno-Aban, Ms. Zenith Villorente, and Mr. Justin Brian Chiongson, which have improved the presentation.