Transformation of Phosphorus during (Hydro)thermal Treatments of Solid Biowastes: Reaction Mechanisms and Implications for P Reclamation and Recycling.

Phosphorus (P) is an essential nutrient for all organisms, thus playing unique and critical roles at the food-energy-water nexus. Most P utilized by human activities eventually converges into various solid biowastes, such as crop biomass, animal manures, and sewage sludges. Therefore, integration of efficient P recovery practices into solid biowaste management will not only significantly reduce the dependence on limited geological P resources but also reduce P runoff and related water contamination issues associated with traditional waste management strategies. This study reviews the applications of (hydro)thermal techniques for the treatment of solid biowastes, which can greatly facilitate P recovery in addition to waste volume reduction, decontamination, and energy recovery. Research showed that P speciation (including molecular moiety, complexation state, and mineralogy) can experience significant changes during (hydro)thermal treatments, and are impacted by treatment techniques and conditions. Changes in P speciation and overall properties of the products can alter the mobility and bioavailability of P, and subsequent P reclamation and recycling efficiency of the treatment products. This review summarizes recent progresses in this direction, identifies the challenges and knowledge gaps, and provides a foundation for future research efforts targeting at sustainable management of nutrient-rich biowastes.

On the structure of aspongopusin recently isolated from Aspongopus chinensis.

The 2,5-disubstituted oxazole recently proposed for aspongopusin, a natural product isolated from Aspongopus chinensis, was synthesized through an unambiguous route. The synthetic sample showed (1)H and (13)C NMR entirely different from those in the literature, revealing that the initially assigned structure was incorrect. The spectroscopic data for the given structure are thus made available for the first time.

Curcumin delivery by methoxy polyethylene glycol-poly(caprolactone) nanoparticles inhibits the growth of C6 glioma cells.

As a potential anticancer agent, curcumin (Cum) has been reported for its chemopreventive and chemotherapeutic activity in a series of cancers through influencing cell cycle arrest, differentiation, apoptosis, etc. Therefore, the potential activity against various cancers of Cum raises the possibility of its application as a novel model drug in nanoparticle-based delivery systems. The current study reported a spherical core-shell structure curcumin-loaded nanoparticle (Cum-np) formed by amphilic methoxy polyethylene glycol-poly(caprolactone) (mPEG-PCL) block copolymers. Characterization tests indicated that Cum was incorporated into mPEG-PCL-based nanoparticles with high encapsulation efficiency due to its lipophilicity. The incorporated Cum could be released from Cum-np in a sustained manner. Cum was effectively transported into the cells by nanoparticles through endocytosis and localized around the nuclei in the cytoplasms. In vitro studies proved that the cytotoxicity of Cum-np would be pro-apoptosis effect against rat C6 glioma cell line in a dose-dependent manner. The present results suggest that Cum-np could be a potential useful chemotherapeutic formulation for malignant glioma therapy. Moreover, the development of traditional Chinese medicine with nanoscale drug formation warrants more intensive research for its clinical applications.

[Protective effect of Xingnaojing and Xuesaitong injections on cerebral ischemic reperfusion injury in rats].

OBJECTIVE: To investigate the mechanism of protective effect of Xingnaojing and Xuesaitong injections on cerebral ischemic reperfusion injury in rats. METHODS: The focal cerebral ischemia & reperfusion model was established by middle cerebral artery occlusion (MCAO). A total of 152 male SD rats were randomly assigned into 19 groups: sham operated group, Xingnaojing group, Xingnaojing plus Xuesaitong group and control group according to different reperfusion durations: 2, 4, 8, 24, 48, 72 h. Each group had 8 rats. Rats in Xingnaojing group received the ip injections of Xingnaojing (1 ml x 100 (-1) x d(-1)) until an onset of ischemia; Xingnaojing plus Xuesaitong group received the ip injections of Xingnaojing (1 ml x 100 g(-1) x d(-1)) and Xuesaitong (1 ml x 100 g(-1) x d(-1)) until an onset of ischemia; In the meantime, rats in control group received the same ip dose of saline. The levels of SOD and MDA were detected. The number of apoptotic neurons was detected by terminal-deoxynucleotidyl transferase medicated nick end labeling (TUNEL). RESULTS: During ischemic reperfusion, the MDA content of brain homogenate increased while the SOD activity decreased (P < 0.05). Xingnaojing could significantly inhibit the increase of MDA after cerebral ischemic reperfusion (P < 0.05) and the decrease of SOD activity in rats. The changes of SOD and MDA were smaller in the Xingnaojing plus Xuesaitong group than those in the Xinnaojing group (P < 0.01). The number of apoptotic neurons in the Xingnaojing group was significantly lower than that in control group (P < 0.05). And the number of apoptotic neurons in the Xingnaojing plus Xuesaitong group was even lower than that in the Xingnaojing group(4,8 h: P < 0.05, 24, 48, 72 h: P < 0.01). CONCLUSION: The Xingnaojing plus Xuesaitong injection has protective function after cerebral ischemic reperfusion.

Enhanced growth inhibition effect of resveratrol incorporated into biodegradable nanoparticles against glioma cells is mediated by the induction of intracellular reactive oxygen species levels.

Resveratrol (Res) has been reported to elicit many cellular responses including cell cycle arrest, differentiation, and apoptosis. This makes it a novel and potential anticancer agent. Moreover, the lipophilicity of Res raises the possibility of its application as a potential model drug in nanoparticle based delivery systems. Resveratrol is incorporated into mPEG-PCL based nanoparticles with high encapsulation efficiency due to its lipophilicity. The significant finding of the current study is that Res-loaded nanoparticles at lower concentration could lead to significantly higher cell death compared to equivalent dose of free Res and this difference of cytotoxicity could not be abrogated by the antioxidant Vitamin E. Furthermore, free Res shows significant less cytotoxicity than the equivalent dose of Res-loaded nanoparticles with the preconditioning of Vitamin E. Meanwhile, reactive oxygen species (ROS) determination revealed the significantly lower intracellular ROS levels in Res-treated cells compared to nanoparticle-treated cells. Therefore, the differential cytotoxicity between Res and Res-loaded nanoparticles may be mediated by the discrepancy of intracellular ROS levels. The present results suggest that Res-loaded nanoparticles could be a potential useful chemotherapeutic formulation for malignant glioma therapy and the development of traditional Chinese medicine with nanoscale drug formation warrants more intensive research in order to evaluate its clinical feasibility.

Absorption and metabolism of Astragali radix decoction: in silico, in vitro, and a case study in vivo.

To profile absorption of Astragali Radix decoction and identify its orally absorbable constituents and their metabolites, four complementary in silico, in vitro, and in vivo methods, i.e., a computational chemistry prediction method, a Caco-2 cell monolayer model experiment, an improved rat everted gut sac experiment, and a healthy human volunteer experiment, were used. According to the in silico computation result, 26 compounds of Astragali Radix could be regarded as orally available compounds, including 12 flavonoids. In the in vitro and in vivo experiments, 21 compounds were tentatively identified by high-performance liquid chromatography-diode array detection-electrospray ion trap tandem mass spectrometry data, which involved calycosin, formononetin, (6aR,11aR)-3-hydroxy-9,10-dimethoxypterocarpan, 7,2'-dihydroxy-3',4'-dimethoxyisoflavan, calycosin-7-O-beta-D-glucoside, formononetin-7-O-beta-D-glucoside, 7,2'-dihydroxy-3',4'-dimethoxyisoflavan-7-O-beta-D-glucoside-6''-O-malonate, (6aR,11aR)-3-hydroxy-9,10-dimethoxypterocarpan-3-O-beta-D-glucoside, and phase II metabolites calycosin-7-O-beta-D-glucuronide, formononetin-7-O-beta-D-glucuronide, (6aR,11aR)-3-hydroxy-9,10-dimethoxypterocarpan-3-O-beta-D-glucuronide, 7,2'-dihydroxy-3',4'-dimethoxyisoflavan-7-O-beta-D-glucuronide, and calycosin sulfate. Calycosin and formononetin were proved absorbable by four methods; (6aR,11aR)-3-hydroxy-9,10-dimethoxypterocarpan and 7,2'-dihydroxy-3',4'-dimethoxyisoflavan were proved absorbable by three methods; formononetin-7-O-beta-D-glucoside and (6aR,11aR)-3-hydroxy-9,10-dimethoxypterocarpan-3-O-beta-D-glucoside were proved absorbable by two methods. The existence of calycosin-7-O-beta-D-glucuronide, formononetin-7-O-beta-D-glucuronide, (6aR,11aR)-3-hydroxy-9,10-dimethoxypterocarpan-3-O-beta-D-glucuronide, 7,2'-dihydroxy-3',4'-dimethoxyisoflavan-7-O-beta-D-glucuronide, and calycosin sulfate was proved by two or three methods. We found that besides isoflavones, pterocarpans and isoflavans also could be metabolized by the intestine during absorption, and the major metabolites were glucuronides. In conclusion, the present study demonstrated that the flavonoids in Astragali Radix decoction, including isoflavones, pterocarpans, and isoflavans, could be absorbed and metabolized by the intestine. These absorbable compounds, which were reported to have various bioactivities related to the curative effects of Astragali Radix decoction, could be regarded as an important component of the effective constituents of Astragali Radix decoction.