Anti-complementary activity of two homogeneous polysaccharides from Eclipta prostrata.

Area of Science:

• Immunology
• Natural Product Chemistry
• Pharmacology

Background:

• Complement-mediated inflammation drives autoimmune disease pathology.
• Inhibiting complement activation presents a promising therapeutic strategy.
• Eclipta prostrata is explored for its bioactive compounds.

Purpose of the Study:

• To isolate and characterize polysaccharides from Eclipta prostrata with anticomplement activity.
• To evaluate the inhibitory effects of these polysaccharides on complement activation pathways.
• To investigate the preliminary mechanism of action for complement inhibition.

Main Methods:

• Anticomplement activity-guided fractionation using ion-exchange and size-exclusion chromatography.
• High-performance gel permeation chromatography (HPGPC) for molecular weight determination.
• Methylation analysis to determine polysaccharide linkage types.

Main Results:

• Two bioactive polysaccharides, EAP20-1 (5.2 kDa) and EAP20-2 (6.3 kDa), were isolated.
• Both polysaccharides, composed of d-Gal, l-Glc, and Ara, significantly inhibited classical and alternative complement pathways.
• No influence on the coagulation system was observed; inhibition involved interaction with complement components C1q, C1r, C1s, C2, C4, C5, C7, and C9.

Conclusions:

• Eclipta prostrata yields polysaccharides with potent anticomplement activity.
• EAP20-1 and EAP20-2 are promising candidates for developing novel therapeutics against autoimmune diseases.
• These compounds modulate complement activation through direct interaction with key complement factors.