Abstract:
Pancreatic β-cells are highly susceptible to oxidative stress due to their limited antioxidant defense.
Excessive reactive oxygen species production in β-cells induces insulin protein aggregation, enhancing
the progression of diabetes. Recently, plant antioxidants have gained attention as potential anti-diabetic
therapeutics. A. marina, a mangrove plant rich in bioactive phytochemicals, is known for its antioxidant
properties. However, comparative evaluation of antioxidant capacities in different plant parts and their
protective effects against insulin aggregation remain unknown. This study aimed to determine the antidiabetic potential of A. marina by comparing the antioxidant capacities of root, leaf, flower, and stem
extracts and investigating the protective effects against oxidative stress–induced insulin protein
aggregation. Plant parts of A. marina were collected, air-dried, powdered, and methanol extracts were
made. Antioxidant activity was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay,
while inhibition of oxidative stress (H2O2) induced insulin aggregation was evaluated using an in vitro
spectroscopic assay by monitoring absorbance changes at 460nm. Leaf extracts showed the highest
extraction yield (40%), whereas stem, root, and flower extracts exhibited lower yields (20%). DPPH
assay demonstrated variable antioxidant capacities among plant parts, with stem extract showing the
highest (71.70±0.28%), followed by root (55.88±3.30%), flower (32.45±3.56%), and leaf extracts
(26.76±3.25%). Insulin aggregation analysis revealed that stem extract exerted the strongest antiaggregation effect, reducing aggregated protein levels to 20.75±3.23%, relative to the aggregated
control (100%). Root, leaf, and flower extracts reduced aggregation to 78.23±8.06%, 69.89±8.17%, and
89.25±1.29%, respectively. The strong antioxidant profile of stem extracts paralleled their enhanced
ability to suppress insulin aggregation, suggesting a relationship between antioxidant capacities and
prevention of oxidative protein aggregation. Overall, findings indicate that A. marina possesses
promising anti-diabetic potential, highlighting its therapeutic value.
