Effects of Polyphenols and Lignans of Phyllanthus amarus Schumach. and
Thonn. on IL-1β and TNF-α Secretions from LPS-induced THP-1-derived
Macrophages
Authors: Alam Javaid , Jantan Ibrahim , Yuandani  , Nafiah Mohd Azlan , Mesaik Muhammed Ahmed , Ibrahim Sarah 
Published: January 2024

Background:
Phyllanthus amarus exhibited immunosuppressive and anti-inflammatory
effects in several in vitro and in vivo studies. However, there is no report on the inhibitory effects of
its secondary metabolites on pro-inflammatory cytokines secretion from human THP-1-derived
macrophages.

background:
Phyllanthus amarus exhibited immunosuppressive and anti-inflammatory effects in several in vitro and in vivo studies. However, there is no report on the inhibitory effects of its secondary metabolites on pro-inflammatory cytokines secretion from human THP-1-derived macrophages.

Objective:
The objective of this study was to correlate the polyphenols (ellagic acid (EA), gallic acid
(GA), geraniin (GER), and corilagin (COR)) and lignans ((phyllanthin (PHY), hypophyllanthin
(HYPO), niranthin (NIR), phyltetralin (PHYLT), and isolintetralin (ISO)) of 80% ethanol extract of
P. amarus with their inhibitory effect against IL-1β and TNF-α secretions from LPS-induced THP-1-
derived macrophages.

Methods:
Chemical profiling of P. amarus was carried out by LC-MS/MS analysis. Validated
qualitative and quantitative reversed-phase HPLC analyses of the P. amarus extract were performed
for the determination of lignan and polyphenol contents. Human THP-1-derived macrophages were prepared
by treatment of THP-1 cells with phorbol 12-myristate 13-acetate (PMA). The inhibition of
cytokines released by the extract, lignans and polyphenols in the cells was investigated using ELISA assay.

method:
Chemical profiling of P. amarus was carried out by LC-MS/MS analysis. Validated qualitative and quantitative reversed phase HPLC analyses of the P. amarus extract were performed for determination of lignan and polyphenol contents. Human THP-1 derived macrophages were prepared by treatment of THP-1 cells with phorbol 12-myristate 13-acetate (PMA). The inhibition of cytokines release by the extract, lignans and polyphenols in the cells were investigated using ELISA assay.

Results:
P. amarus extract and its chemical constituents significantly reduced the levels of IL-1β and
TNF-α in a dose-dependent manner. At a dose of 50 μM, COR exhibited a maximum inhibition of
81.11% on TNF-α secretion, while GER showed 72.56% inhibition on IL-1β secretion. COR demonstrated
the strongest inhibition of TNF-α secretion, exhibiting an IC50 value of 9.06 μM, which was
comparable to that of dexamethasone (7.07 μM). Meanwhile, GER was the most potent against IL-
1β secretion, exhibiting an IC50 value of 20.09 μM. In the case of TNF-α secretion, the order of potency
observed among the active compounds, with regard to IC50 value, was COR > GER > HYPO >
PHY > NIR > GA > EA >ISO > PHYLT. For IL-1β secretion, the order of potency was GER > NIR
> COR > GA > EA > PHY > HYPO > PHYLT > 1SO.

Conclusion:
The polyphenol contents of P. amarus, especially COR and GER, contributed significantly
to the suppression of cytokines secretion, and they have the potential to be developed into
agents for the treatment of pathologic inflammation.