An exploratory metabolomic study reveals the Dipsacus asper-Achyranthes bidentate herb pair against osteoarthritis by modulating imbalance in polyunsaturated fatty acids and energy metabolism.

Osteoarthritis (OA) is a degenerative joint disease primarily affecting the cartilage. The therapeutic potential of the Dipsacus asper-Achyranthes bidentate herb pair for OA has been acknowledged, yet its precise mechanism remains elusive. In this study, we conducted a comprehensive analysis of metabolomic changes and therapeutic outcomes in osteoarthritic rats, employing a gas chromatography-mass spectrometry-based metabolomics approach in conjunction with histopathological and biochemical assessments. The rats were divided into six groups: control, model, positive control, Dipsacus asper treated, Achyranthes bidentata treated, and herb pair treated groups. Compared to the model group, significant reductions in levels of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and iNOS were observed in the treated groups. Multivariate statistical analyses were employed to investigate metabolite profile changes in serum samples and identify potential biomarkers, revealing 45 differential biomarkers, with eighteen validated using standard substances. These analytes exhibited excellent linearity across a wide concentration range (R2>0.9990), with intra- and inter-day precision RSD values below 4.69% and 4.83%, respectively. Recoveries of the eighteen analytes ranged from 93.97% to 106.59%, with RSD values under 5.72%, underscoring the method's reliability. Treatment with the herbal pair effectively restored levels of unsaturated fatty acids such as linoleic acid and arachidonic acid, along with glucogenic amino acids. Additionally, levels of phosphoric acid and citric acid were reversed, indicating restoration of energy metabolism. Collectively, these findings highlight the utility of metabolomic analysis in evaluating therapeutic efficacy and elucidating the underlying molecular mechanisms of herb pairs in OA treatment.

HKUST-1 Derived Hollow C-Cu2-x S Nanotube/g-C3 N4 Composites for Visible-Light CO2 Photoreduction with H2 O Vapor.

As the main component of syngas, reducing CO2 to CO with high selectivity through photocatalysis could provide a sustainable way to alleviate energy shortage issues. Developing a photocatalytic system with low cost and high performance that is environmentally friendly is the ultimate goal towards CO2 photoreduction. Herein, an efficient and economic three-component heterojunction photocatalyst is designed and fabricated for converting CO2 to CO in the absence of organic sacrificial agents. The heterojunction is made of Cu2-x S nanotubes coated with a carbon layer (C-Cu2-x S) and g-C3 N4 . By using the classical MOF material HKUST-1 as a precursor, hollow tubular-like metal sulfides (C-Cu2-x S) with carbon coating were synthesized and further loaded on g-C3 N4 , forming a three-component heterojunction C-Cu2-x S@g-C3 N4 . The carbon coat in C-Cu2-x S@g-C3 N4 acts as an electron reservoir, which facilitates electron-hole pair separation. The optimized C-Cu2-x S@g-C3 N4 acted as a photocatalyst in CO2 reduction with a high reactivity of 1062.6 µmol g-1 and selectivity of 97 %. Compared with bare g-C3 N4 (158.4 µmol g-1 ) and C-Cu2-x S, the reactivity is nearly 7 and 23-fold enhanced and this CO generation rate is higher than most of the reported Cu2 S or g-C3 N4 composites under similar conditions. The prominent activity may result from enhanced light adsorption and effective charge separation. This work might open up an alternative method for the design and fabrication of high-performance and low-cost photocatalysts for efficiently and durably converting CO2 to CO with high selectivity.

Photoreduction of carbon dioxide under visible light by ultra-small Ag nanoparticles doped into Co-ZIF-9.

Metal-organic frameworks (MOFs) are well-known porous materials able to adsorb CO2, and their performance in CO2 reduction has attracted much attention from researchers. A classical Co-MOF, Co-ZIF-9, has been proposed as a novel photocatalyst for reducing CO2 into chemical feedstocks. Herein, Co-ZIF-9 with a rod-like structure was obtained through reflux. Ultra-small silver nanoparticles (Ag NPs, smaller than 5 nm) were doped into Co-ZIF-9 by the photodeposition method. With the assistance of a photosensitizer, the resultant composite Ag@Co-ZIF-9 shows catalytic reactivity in converting CO2 into CO under visible light irradiation. Compared with bare Co-ZIF-9, the photocatalytic performance of Ag@Co-ZIF-9 increases by more than twofold (around 28.4 µmol CO) and the selectivity is enhanced by about 20% (22.9 µmol H2) for 0.5 h of irradiation. This demonstrates that Ag NPs doping may provide a possible way to promote the efficiency and selectivity of MOF materials in CO2 photoreduction.