Abstract
Phyllanthus species (Family Euphorbiaceae) has been used in traditional medicine of several countries as a cure for numerous diseases, including jaundice and hepatitis. This study is an attempt to evaluate the immunomodulatory activity of various fractions, column eluents of ethyl acetate fraction, and their polyphenols. Phyllanthus maderaspatensis were standardized using high-performance liquid chromatography to identify and quantify polyphenols, and purification of polyphenols was carried out using vacuum liquid chromatography. Subsequently, we tested various fractions, column eluents of ethyl acetate fraction, and polyphenols in vitro to assess their impact on nitric oxide (NO) production in LPS-stimulated mouse macrophage RAW 264.7 cells. The ethyl acetate fraction (100 mu g mL(-1)) had a more significant stimulatory effect on LPS-stimulated NO production by the RAW 264.7 cells. We found that the ethyl acetate fraction contains a high amount of catechin, quercetin, ellagic acid kaempferol, and rutin, which are responsible for immunomodulation. The ethyl acetate fraction at concentrations of 25 and 50 mu g mL(-1) had a significant inhibitory effect and 100 mu g mL(-1) had a more significant stimulatory effect when compared with the LPS control. The percentage of inhibition by LPS control ranged from zero percentage, kaempferol ranged from 45.4% at 50 mu g mL(-1) to 41.88% at 100 mu g mL(-1), catechin ranged from 50% at 50 mu g mL(-1) to 35.28% at 100 mu g mL(-1), rutin ranged from 36.2% at 50 mu g mL(-1) to 47.44% at 100 mu g mL(-1), gallic acid ranged from 28.4% at 50 mu g mL(-1) to 50.9% at 100 mu g mL(-1), ellagic acid ranged from 45.12% at 50 mu g mL(-1) to 38.64% at 100 mu g mL(-1), and purified quercetin ranged from 26.2% at 50 mu g mL(-1) to 45.48% at 100 mu g mL(-1). As NO plays an important role in the immune function, polyphenols' treatment could modulate several aspects of host defense mechanisms owing to the stimulation of the inducible nitric oxide synthase.