Naringenin, one of
the flavonoid components, is majorly
found in
and obtained from grapefruits and oranges. Naringenin also acts as
a potent antioxidant, which possesses hypolipidemic as well as anti-inflammatory
potential. Naringenin reduces the expressions of several inflammatory
mediators, viz., NF-κB, cycloxygenase-2, and other cytokine
mediators. In spite of having various biological effects, the clinical
application of naringenin is restricted due to its very poor aqueous
solubility. In the present study, the high-energy ball milling method
was employed for the preparation of naringenin nanoparticles without
using any chemical with an aim to enhance the anti-oxidant potential
of naringenin. The milled naringenin nanoparticles were characterized
for their physicochemical properties using scanning electron microscopy
(SEM) and X-ray diffraction. Additionally, the effects of milling
time and temperature were further assessed on the solubility of crude
and milled naringenin samples. The antioxidant potential of milled
naringenin was evaluated with various assays such as DHE, DCFDA, and
cleaved caspase-3 using SH-SY5Y human neuroblastoma cells. The nanoparticle
size of naringenin after milling was confirmed using SEM analysis.
Crystalline peaks for milled and crude samples of naringenin also
established that both the naringenin forms were in the crystalline
form. The solubility of naringenin was enhanced depending on the milling
time and temperature. Moreover, crude and milled naringenin were found
to be cytocompatible up to doses of 120 μM each for the duration
of 24 and 48 h. It was also observed that milled naringenin at the
doses of 1, 2, and 5 μM significantly reduced the levels of
reactive oxygen species (ROS) generated by H
2
O
2
and exhibited superior ROS scavenging effects as compared to those
of crude or un-milled forms of naringenin. Furthermore, milled naringenin
at the doses of 1 and 2 μM inhibited H
2
O
2
-induced cell death, as shown by immunofluorescence staining of cleaved
caspase-3 and Annexin-V PI flow cytometry analysis. Conclusively,
it could be suggested that the size reduction of naringenin using
high-energy ball milling techniques substantially enhanced the antioxidant
potential as compared to naïve or crude naringenin, which may
be attributed to its enhanced solubility due to reduced size.