The lack of sufficient
scientific evidence prompted the
analytical
investigation of nephroprotective potential of the silk extract of Zea mays L., which is traditionally and ethnomedicinally
used for various disorders including kidney dysfunction. The present
study was conducted to investigate the phytochemical analysis and
demonstrate the nephroprotective potential of the methanolic silk
extract of Z. mays L. using a rodent
model. High-performance thin-layer chromatography (HPTLC) analysis
was carried out to standardize the methanolic silk extract of Z. mays (ZME) using naringenin as a marker. The metabolite
profiling of the ZME was carried out using ultrahigh-performance liquid
chromatography mass spectrometry (UPLC-MS) on a monolithic capillary
silica-based C18 column to identify bioactive compounds and for confirmation
of the identified markers. Furthermore, for acute toxicity study,
a single dose (2000 mg/kg bw) of the ZME was administered orally to
Wistar rats. Also, nephrotoxicity was induced in Wistar rats by injecting
diclofenac (DC) (50 mg/kg, bw, i.p.) at a single dose. The efficacy
of the ZME as a nephroprotective agent was then evaluated at doses
of 100, 200, and 400 mg/kg/day, bw, p.o. Furthermore, the kidney,
liver, antioxidant, inflammatory, and apoptotic biochemical markers
and histopathological and immunohistochemical alterations (caspase-3
and reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-4
(NOX-4)) were evaluated. Phytochemical analysis by HPTLC and UPLC-MS
revealed the presence of naringenin, vanillic acid, ferulic acid,
gallic acid (GA), ellagic acid, quercetin, and morin, along with other
bioactive constituents exhibiting multiple pharmacological properties.
The acute toxicity study of the ZME showed no mortality or any clinical
signs of toxicity through all the 14 days of the toxicity study at
a dose of 2000 mg/kg. Also, administration of DC caused a significant
elevation (P < 0.001) in kidney biochemical parameters
and also caused oxidative, inflammatory, and apoptotic stress. Furthermore,
DC also caused histopathological and immunohistochemical changes.
Pretreatment with the ZME attenuated the elevated biochemical markers
significantly at medium and high doses along with improvement in histopathological
and immunohistochemical damages and showing comparable results to
those of α-ketoanalogue. The present study verifies the traditional
claims of Z. mays silk alleviating
various kidney and related disorders by concluding the nephroprotective
potential of the ZME. The nephroprotective activity of the ZME is
attributed to the phytoconstituents present, acting as potent restoring
antioxidants and preventing inflammatory and apoptotic cellular damages
in rats. Thus, it holds promising potential in the management of nephrotoxicity.