Abstract

Obesity-linked type 2 diabetes (T2D) arises from chronic nutrient excess, ectopic lipid deposition, and 
unresolved inflammation that together blunt insulin signaling and exhaust β-cell function. Plant-derived 
antidiabetic compounds, flavonoids (quercetin, kaempferol), phenolic acids (chlorogenic, caffeic), alkaloids 
(berberine), terpenoids (curcumin), and saponins (ginsenosides) modulate AMPK–mTOR, PI3K–AKT, PPARs, 
bile-acid–FXR/TGR5, and NF-κB/NLRP3 axes. Yet most exhibit poor aqueous solubility, chemical instability, 
extensive first-pass metabolism, efflux via P-glycoprotein, and rapid clearance, yielding low and variable 
systemic exposure. Nanotechnology offers a route to overcome these barriers by tailoring size, surface 
chemistry, and cargo architecture to improve dissolution, protect labile structures, promote intestinal 
permeation, and direct biodistribution to metabolic tissues. Lipidic carriers (liposomes, solid lipid nanoparticles, 
nanostructured lipid carriers, phytosomes), polymeric nanoparticles (PLGA, chitosan, PEG-PCL), cyclodextrin 
complexes, and hybrid or stimuli-responsive systems have achieved substantial gains in apparent solubility, oral 
bioavailability, and pharmacodynamic potency for lead phytochemicals in obese and diabetic models. Surface 
ligands that recognize hepatocyte asialoglycoprotein receptors, adipose vasculature motifs, or β-cell GLP-1 
receptors enable tissue selectivity, while mucoadhesive and colon-targeted formulations reshape gut exposure 
to influence microbiome-host metabolism. This review synthesizes the pharmacokinetic obstacles facing plant 
bioactives, details design rules for nanocarriers that address dissolution–permeation–metabolism limits, and 
compares outcomes across platforms and payloads. We highlight considerations for scalability, safety, and 
regulatory acceptance, including critical quality attributes, in vitro–in vivo correlations, and human-relevant 
endpoints. Collectively, nanotechnology provides a pragmatic bridge from promising phytochemistry to 
translatable therapeutics capable of multi-target reprogramming in obesity-linked T2D without escalating 
systemic toxicity. Future studies should prioritize endotype-guided designs and combination payloads.