Xanthine oxidase inhibitory activity and antihyperuricemic effect of Moringa oleifera Lam. leaf hydrolysate rich in phenolics and peptides.

ETHNOPHARMACOLOGICAL RELEVANCE: Moringa oleifera Lam. leaf (MOL), a rich source of protein and phenolics, was traditionally used to treat various diseases including headaches, fevers, sore throat and dyslipidemia. Recently, MOL was reported to possess antioxidant, anti-dyslipidemia and hepato-renal protective activities, indicating that MOL could become a potential agent to improve metabolic disorders associated with hyperuricemia. The antihyperuricemic effect of MOL hydrolysate (MOLH) with high contents of phenolics and peptides remains unknown. AIM OF THE STUDY: The aim of this study is to investigate xanthine oxidase (XO) inhibitory activity of MOLH, to clarify phenolic and peptide profiles of MOLH, and to evaluate possible mechanism underlying the antihyperuricemic effect of MOLH. MATERIALS AND METHODS: MOLH was prepared by enzymatic hydrolysis using commercial trypsin. XO inhibitory activity was determined by XO reaction-UPLC-MS coupling method. The chemical profiles of the phenolic and peptide fractions of MOLH were determined by UPLC-QTOF-MS/MS. The antihyperuricemic effect of MOLH was evaluated in a potassium oxonate-induced hyperuricemic rat model at doses of 200 and 500 mg/kg. Serum uric acid (UA), urea nitrogen, creatinine (CRE), triglyceride (TG), total cholesterol, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol levels, serum XO activity, liver malondialdehyde (MDA) equivalent level, renal tumor necrosis factor-α and interleukin-1ß levels, and protein expression of renal urate-anion transporter 1, glucose transporter 9 and ATP-binding cassette transporter G2 were determined. RESULTS: The phenolic and peptide fractions played key roles in inhibiting XO activity and blocking uric acid production. Five flavonoids and sixteen polypeptides were identified in the phenolic and peptide fractions of MOLH, respectively. MOLH (200 and 500 mg/kg) could effectively reduce the serum UA level of hyperuricemic rats (p < 0.001) by regulation of serum XO activity (p < 0.05 at 200 mg/kg, p < 0.01 at 500 mg/kg) and renal urate transporters. Besides, MOLH could improve metabolic disorders associated with hyperuricemia by its multiple actions on liver MDA (p < 0.001), serum CRE (p < 0.05 at 500 mg/kg) and serum TG (p < 0.001). CONCLUSION: The results provided scientific evidence that MOLH rich in phenolics and peptides ameliorated hyperuricemia and metabolic disorders. This study validated the potential use of MOLH for regulation of hyperuricemia.

Three dimensional plasmonic assemblies of AuNPs with an overall size of sub-200 nm for chemo-photothermal synergistic therapy of breast cancer.

Three dimensional plasmonic assemblies of gold nanoparticles (AuNPs) (gold 3D-PAs) have been recently developed for photothermal therapy, Raman imaging, photoacoustic imaging or X-ray computed tomography imaging because they can generate an enhanced electromagnetic field between the gaps of neighboring AuNPs and significantly improve the localized surface plasmon resonance (LSPR) effect in the near-infrared (NIR) region. However, the sizes of most reported gold 3D-PAs are too large (>300 nm) for in vivo applications as cancer theranostic agents because a size of about 200 nm is often considered to be the upper limit for successful drug delivery based on the enhanced permeation and retention (EPR) effect. Herein, we propose a novel strategy to fabricate the gold 3D-PAs with an overall size of sub-200 nm, whose self-assembly process was verified by TEM, DLS and UV-vis spectroscopy. The cell experiments demonstrate that our gold 3D-PAs allow combined chemotherapy and photothermal therapy. The histopathology assessments indicate that the toxicity of our gold 3D-PAs to normal tissues (side effect) is negligible. The animal experiments indicate that our gold 3D-PAs have a weak chemotherapeutic efficacy without NIR laser irradiation at a low DOX dosage, but shows an excellent therapeutic effect with NIR laser irradiation at the same DOX dosage due to the synergy of chemo-photothermal therapy.