Nanostructured lipid carriers loaded with resveratrol (RES-NLCs) delivered a 2.3-fold increase in peak plasma concentration (Cmax), 7-fold improvement in relative bioavailability, and a striking absolute bioavailability of 176% compared to a standard resveratrol solution in rats. Using a purpose-built mesenteric lymph duct–jugular vein reflux model, the researchers provided direct mechanistic confirmation — not inference — that intestinal lymphatic transport mediates this absorption enhancement. A 28-day repeated-dose toxicity study in ICR mice at 10 mg/kg showed no mortality, but did reveal statistically significant elevations in liver enzymes AST (p = 9×10⁻⁵) and ALT (p = 4.02×10⁻⁷), alongside increased liver coefficient.
Resveratrol's legendary bioavailability problem — routinely below 1% in humans — has long undermined its clinical translation despite decades of promising in vitro data. Lipid nanocarriers exploiting the lymphatic route elegantly sidestep first-pass hepatic metabolism, making this a conceptually sound and technically validated advance. The 176% absolute bioavailability figure, while notable, requires cautious interpretation: it reflects rat pharmacokinetics with inherent species-to-human extrapolation limits. More concerning is the hepatic signal — elevated transaminases without histopathological damage suggests subclinical hepatic stress that warrants dose-escalation and longer-duration studies before human applications are contemplated. This work is genuinely confirmatory in mechanism and incrementally promising for drug delivery platforms targeting poorly soluble polyphenols, but the liver enzyme findings introduce a safety asterisk that cannot be dismissed.
