DEVELOPMENT OF CHITOSAN NANOENCAPSULATED HOUTTUYNIA CORDATA THUNB. EXTRACT: EVALUATING THE EFFECT OF EXTRACT CONCENTRATION-LOAD ON MORPHOLOGY, STRUCTURE AND ANTIOXIDANT ACTIVITY : HOUTTUYNIA CORDATA THUNB. EXTRACT-LOADED CHITOSAN NANOPARTICLES

Abstract

Houttuynia cordata Thunb. extracted in 80% ethanol (HCE) was loaded in chitosan nanoparticles
(HCECS) using sodium tripolyphosphate through the ionic gelation method and the resulting HCECS
was evaluated for the effect of extract concentration-load on their morphology, structure and antioxidant
activity. The encapsulation efficiency (EE) of HCECS nanoparticles was seen to range from 55.5% to
86.0%, depending on the extract concentration. Particle size ranged from 331 nm to 409 nm, increasing
with increase in extract load, while polydispersity index ranged from 0.176 to 0.212, showing a
homogenous particle size distribution. Transmission electron microscopy displayed predominantly
spherical nanoparticles. FTIR analysis pointed towards the associations between the functional groups
of H. cordata phytochemicals and the chitosan polymer matrix, confirming successful encapsulation.
IC50 values of HCE were 135.77μg/ml and 118.28μg/ml for DPPH and ABTS, respectively. For the
HCECS nanoparticle, IC50 value of 299.49μg/ml and 149.90μg/ml at the concentration of 5mg/ml HCE
for DPPH and ABTS compared to 1mg/ml HCE, 766.08μg/ml and 159.22μg/ml, respectively were
observed. For the nanoparticle formulations, antioxidant activity increased as extract loading increased.
The results indicate that there is effect of HCE loading in the formulation of chitosan nanoparticles as
well as on the antioxidant activity, which highlights the importance of creating a balance between
encapsulation efficiency and antioxidant activity during nanoparticle development for H. cordata.