Abstract
Diabetes mellitus (DM) is a metabolic endocrine disorder caused by decreased insulin
concentration or poor insulin response. Muntingia calabura (MC) has been used traditionally to
reduce blood glucose levels. This study aims to support the traditional claim of MC
as a functional food and blood-glucose-lowering regimen. The antidiabetic potential
of MC is tested on a
streptozotocin–nicotinamide (STZ-NA)-induced diabetic rat model by using the 1H-NMR-based metabolomic approach. Serum biochemical analyses reveal that treatment
with 250 mg/kg
body weight (bw) standardized freeze-dried (FD) 50% ethanolic MC extract (MCE 250)
shows favorable serum creatinine (37.77 ± 3.53 µM), urea (5.98 ± 0.84 mM) and glucose
(7.36 ± 0.57 mM)
lowering capacity, which was comparable to the standard drug, metformin. The clear
separation between diabetic control (DC) and normal group in principal component analysis
indicates the
successful induction of diabetes in the STZ-NA-induced type 2 diabetic rat model.
A total of nine biomarkers, including allantoin, glucose, methylnicotinamide, lactate,
hippurate, creatine,
dimethylamine, citrate and pyruvate are identified in ratsʼ urinary profile, discriminating
DC and normal groups through orthogonal partial least squares-discriminant analysis.
Induction of
diabetes by STZ-NA is due to alteration in the tricarboxylic acid (TCA) cycle, gluconeogenesis
pathway, pyruvate metabolism and nicotinate and nicotinamide metabolism. Oral treatment
with
MCE 250 in STZ-NA-induced diabetic rats shows improvement in the altered carbohydrate
metabolism, cofactor and vitamin metabolic pathway, as well as purine and homocysteine
metabolism.
Key words
Muntingia calabura
- Muntingiaceae - STZ-NA-induced diabetic rats -
1H-NMR-based metabolomics - carbohydrate metabolism - cofactors and vitamins metabolism
- urine metabolites