Extra virgin olive oil-based phospholipid complex/self-microemulsion enhances oral absorption of salvianolic acid B through inhibition of catechol-O-methyltransferase-mediated metabolism

Insight into Formation, Synchronized Release and Stability of Co-Amorphous Curcumin-Piperine by Integrating Experimental-Modeling Techniques

Intermolecular interactions between drug and co-former are crucial in the formation, release and physical stability of co-amorphous system. However, the interactions remain difficult to investigate with only experimental tools. In this study, intermolecular interactions of co-amorphous curcumin-piperine (i.e., CUR-PIP CM) during formation, dissolution and storage were explored by integrating experimental and modeling techniques. The formed CUR-PIP CM exhibited the strong hydrogen bond interaction between the phenolic OH group of CUR and the CO group of PIP as confirmed by FTIR, ss 13C NMR and molecular dynamics (MD) simulation. In comparison to crystalline CUR, crystalline PIP and their physical mixture, CUR-PIP CM performed significantly increased dissolution accompanied by the synchronized release of CUR and PIP, which arose from the greater interaction energy of H2O-CUR molecules and H2O-PIP molecules than CUR-PIP molecules, breaking the hydrogen bond between CUR and PIP molecules, and then causing a pair-wise solvation of CUR-PIP CM at the molecular level. Furthermore, the stronger intermolecular interaction between CUR and PIP was revealed by higher binding energy of CUR-PIP molecules, which contributed to the excellent physical stability of CUR-PIP CM over amorphous CUR or PIP. The study provides a unique insight into the formation, release and stability of co-amorphous system from MD perspective. Meanwhile, this integrated technique can be used as a practical methodology for the future design of co-amorphous formulations.

Crystallization inhibitory effects of konjac glucomannan, sodium alginate and xanthan gum on curcumin in supersaturated solution

Supersaturating drug delivery system (SDDS) is a promising approach to enhance the solubility of hydrophobic functional components. However, SDDS is thermodynamically unstable and crystallization tends to occur. In this work, curcumin was used as a model compound, and the crystallization inhibitory effect of konjac glucomannan (KGM), sodium alginate (SA) and xanthan gum (XTG) on curcumin in supersaturated solution was investigated. Amorphous solubility of curcumin was determined using ultraviolet extinction, fluorescence spectroscopy and dynamic light scattering methods. Nucleation induction time (NIT) and crystal growth rate of curcumin were evaluated using ultraviolet probe in the absence and presence of various natural polysaccharides (NPs). Results showed that amorphous solubility of curcumin was approximately 30 μg/mL in pH 6.8 phosphate buffer. NPs used in this work restrained nucleation or crystal growth of curcumin effectively. The NITs of curcumin in the absence of NPs and in the presence of XTG, KGM and SA (1 μg/mL) were 3.7, 60.7, 20.0 and 8.0 min, respectively. The crystal growth rate of curcumin in the absence of NPs and in the presence of XTG, SA and KGM (1 μg/mL) were 0.0103, 0.00752, 0.00286 and 0.000306 min^-1, respectively. The nucleation inhibitory effect of NPs on curcumin was ranked as XTG > KGM > SA. The order of crystal growth inhibition capacity of NPs was KGM > SA > XTG. In conclusion, NPs could be incorporated into SDDS to maintain supersaturation of hydrophobic components for enhanced bioavailability.

A self-microemulsion enhances oral absorption of docetaxel by inhibiting P-glycoprotein and CYP metabolism

Oral absorption of docetaxel was limited by drug efflux pump p-glycoprotein (P-gp) and cytochrome P450 enzyme (CYP 450). Therefore, co-loading agent that inhibits P-gp and CYP450 in self-nanoemulsifying drug delivery systems (SMEs) is considered a promising strategy for oral delivery of docetaxel. In this study, curcumin was selected as an inhibitor of P-gp and CYP450, and it was co-encapsuled in SMEs to improve the oral bioavailability of docetaxel. SMEs quickly dispersed in water within 20 s, and the droplet size was 32.23 ± 2.21 nm. The release rate of curcumin from DC-SMEs was higher than that of docetaxel in vitro. Compared with free docetaxel, SMEs significantly increased the permeability of docetaxel by 4.6 times. And competitive experiments showed that the increased permeability was the result of inhibition of p-gp. The half-life and oral bioavailabilty of DC-SMEs increased about 1.7 times and 1.6 times than docetaxel SMEs, which indicated that its good pharmacokinetic behavior was related to the restriction of hepatic first-pass metabolism. In conclusion, DC-SME was an ideal platform to facilitate oral delivery of docetaxel through inhibited P-gp and CYP 450.

Therapeutic effect and underlying mechanism of Shenkang injection against cisplatin-induced acute kidney injury in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Shenkang injection (SKI), a Chinese patent medicine injection, has been approved for the treatment of chronic kidney disease (CKD) due to its definite clinical therapeutic efficacy. However, the effect and associated underlying mechanism of Shenkang injection against cisplatin (CDDP)-induced acute kidney injury (AKI) has not yet been well elucidated.

AIM OF THE STUDY

This study aims to investigate the therapeutic effect and associated underlying mechanism of Shenkang injection against CDDP-induced AKI.

MATERIALS AND METHODS

We established a CDDP-induced AKI mouse model to evaluate renal function by biochemical markers measurement and to observe histopathological alterations by haemotoxylin and eosin (HE)-staining sections of renal. In addition, the distribution of representative components of SKI in the kidneys of mice was evaluated by liquid chromatography tandem mass spectrometry (LC-MS/MS). Furthermore, the degree of oxidative stress and inflammation were assessed by detecting the levels of inflammatory cytokines and oxidants, while the related mechanisms were elucidated by network pharmacology.

RESULTS

CDDP could induce excessive inflammation and severe injury to the kidneys of mice. However, SKI significantly ameliorated the kidney damages and improved the renal function by reducing the levels of renal function markers (SCr, BUN and urine protein), and inhibiting the production of inflammatory cytokines IL-34, IL-6 and TNF-α. SKI repaired oxidative balance through up-regulation of antioxidants SOD and GSH and down-regulated oxidants MDA. Moreover, 4 components from SKI were detected in the kidney by LC-MS/MS quantification. In addition, pharmacology network indicated the PI3K/AKT, TNF, MAPK, and p53 were the possible signaling pathways for the therapeutic effect of SKI against CDDP-induced AKI, which were related to inflammation, oxidative stress and apoptosis.

CONCLUSION

In the present study, we for the first time demonstrated that SKI alleviates CDDP-induced nephrotoxicity by antioxidant and anti-inflammation via regulating PI3K/AKT, MAPK, TNF, and p53 signaling pathways. The study may provide a scientific rationale for the clinical indication of SKI.