Topical gel based nanoparticles for the controlled release of oleanolic acid: design and in vivo characterization of a cubic liquid crystalline anti-inflammatory drug.

BACKGROUND: Oleanolic acid (OA) has multiple pharmaceutical applications including anti-inflammatory activity, but low permeability of the molecule limits its widespread use. METHODS: A cubic liquid crystalline nanoparticle (LCNP)-based gel was prepared as a potential topical delivery system for OA. The LCNP-based gel was optimized using rheological, drug release kinetic, and ex vivo permeation studies. RESULTS: The studies showed that the OA was trapped in the interior of the LCNP with a crystal form of Pn3m space. The optimized LCNP formulation performed well using in vitro release studies for up to 12 h (85.49 ± 0.21%). Ex vivo permeation studies showed that the LCNP-based gel formulation was superior to a standard gel formulation. The r2 value from the Peppas equation indicated good linearity, but showed irregular (non-Fickian) diffusion, suggesting that drug release was controlled by multiple processes. CONCLUSIONS: In this study, OA-loaded LCNPs were prepared by the precursor method, resulting in a well-characterized OA-LCNP gel preparation. The gel was shown to be effective in a rodent carrageenan-induced hind paw inflammation model with sustained efficacy after a single application.

Characterization, expression, and functional analysis of polyamine oxidases and their role in selenium-induced hydrogen peroxide production in Brassica rapa.

BACKGROUND: Selenium (Se)-induced phytotoxicity has been linked to oxidative injury triggered by the accumulation of reactive oxygen species (ROS) due to the disturbance of anti-oxidative systems. However, the way Se stress induces hydrogen peroxide (H2 O2 ) production in plants is a long-standing question. Here we identified the role of polyamine oxidase (PAO) in H2 O2 production in the root of Brassica rapa upon Se stress. RESULTS: Studying Se-induced growth inhibition, H2 O2 accumulation, and oxidative injury in the root of Brassica rapa, we found that excessive Se exposure resulted in a remarkable increase in PAO activity. Inhibition of PAO activity led to decreased H2 O2 content and alleviated oxidative injury in the Se-treated root. These results indicated that Se stress induced PAO-dependent H2 O2 production. A total of six BrPAO family members were discovered in the genome of B. rapa by in silico analysis. Se stress pronouncedly upregulated the expression of most BrPAOs and further transient expression analysis proved that it could lead to H2 O2 production. CONCLUSION: These results suggest that Se stress upregulates the expression of a set of BrPAOs which further enhances PAO activity, contributing to H2 O2 generation in roots. © 2019 Society of Chemical Industry.

Cinnamaldehyde promotes root branching by regulating endogenous hydrogen sulfide.

BACKGROUND: Cinnamaldehyde (CA) has been widely applied in medicine and food preservation. However, whether and how CA regulates plant physiology is largely unknown. To address these gaps, the present study investigated the beneficial effect of CA on root branching and its possible biochemical mechanism. RESULTS: The lateral root (LR) formation of pepper seedlings could be markedly induced by CA at specific concentrations without any inhibitory effect on primary root (PR) growth. CA could induce the generation of endogenous hydrogen sulfide (H2S) by increasing the activity of L-cysteine desulfhydrase in roots. By fluorescently tracking endogenous H2S in situ, it could be clearly observed that H2S accumulated in the outer layer cells of the PR where LRs emerge. Sodium hydrosulfide (H2S donor) treatment induced LR formation, while hypotaurine (H2S scavenger) showed an adverse effect. The addition of hypotaurine mitigated the CA-induced increase in endogenous H2S level, which in turn counteracted the inducible effect of CA on LR formation. CONCLUSION: CA showed great potential in promoting LR formation, which was mediated by endogenous H2S. These results not only shed new light on the application of CA in agriculture but also extend the knowledge of H2S signaling in the regulation of root branching.

[Formulation Optimization of Zuojin Floating-Bioadhesive Pellets by Central Composite Design-Response Surface Methodology].

OBJECTIVE: To optimize the formulation of Zuojin floating-bioadhesive pellets by the central composite design-response surface methodology (CCD-RSM). METHODS: In the formulation design using CCD-RSM, independent variables were the amounts of sodium bicarbonate (X1), HPMC (X2) and MCC (X3) as factors. Small pills roundness, 12 h floating rate and the percentages of in vitro cumulative releases at 2,6 and 12 h were dependent variables. Multilinear and quadratic model were used to estimate the relationship between the dependent and the independent variables. According to best model, the contour plots and RSM were drawn, and the optional formulation was selected. According to the optional formulation,the pellets were prepared and validated. RESULTS: The quadratic was the best fitting mode. Small pills roundness was 15.04 °. 12 h floating rate was 75.07%. Percentages of in vitro cumulation release at 2,6 and 12 h of the option formulation pellets was 27.01%, 70.00% and 84.61%, respectively. The actual value was close to the predicted value. Deviation was less than 5%. CONCLUSION: Quadratic model was preferred in the optimization of formulation due to the statistical confidence. The multi-objective simultaneous optimization of Zuojin floating pellet formulation can be achieved by the central composite design-response surface methodology.

Lysis of Microcystis aeruginosa with extracts from Chinese medicinal herbs.

Boiling water extracts of 66 selected Chinese medicinal herbs were screened for their anticyanobaterial activity against Microcystis aeruginosa by the soft-agar overlayer (SAO) method. Results indicated that extracts from 16 materials could inhibit the growth of this bacterial species. Among these anticyanobacterial samples, eight extracts showed low minimum inhibitory concentrations (MIC), including four extracts with MICs between 1 and 6 mg/mL, and four extracts with MICs < 1 mg/mL which could be considered useful to prevent the outbreak of cyanobacteria before the appearance of cyanobacterial blooms. Further study showed that three extracts with MIC values < 1 mg/mL induced intensive chlorophyll-a lysis within 7 days at the MIC. The results suggested that highly efficient anticyanobacterial compounds must be involved in the inhibitory activities. The final results indicated these three extracts (from Malaphis chinensis, Cynips gallae-tinctoriae and Fructus mume) had the potential to be developed as algicides due to their remarkably anticyanobacterial activities.