Extraction and separation of lactate dehydrogenase inhibitors from Poria cocos (Schw.) Wolf based on a hyphenated technique and in vitro methods.

Stroke is one of the most common diseases worldwide. Lactate dehydrogenase inhibitors are widely used in the treatment of ischemic stroke, with natural products considered a promising source of lactate dehydrogenase inhibitors. In this study, ultrafiltration liquid chromatography coupled with mass spectrometry was used for the screening and identification of lactate dehydrogenase inhibitors from Poria cocos. Five lactate dehydrogenase inhibitors were selected: dehydropachymic acid, pachymic acid, dehydrotrametenolic acid, trametenolic acid, and eburicoic acid. The inhibitors were extracted and isolated with purities of 96.75, 98.15, 97.25, 95.46, and 94.88%, respectively, by using a new "hyphenated" strategy of microwave-assisted extraction coupled with counter-current chromatography and centrifugal partition chromatography by a two-phase solvent system of n-hexane/ethyl acetate/ethanol/water at the volume ratio 0.965:1.000:0.936:0.826 v/v/v/v. The bioactivity of the isolated compounds was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay in PC12 cells. The results also showed that the hyphenated technique of microwave-assisted extraction coupled with counter-current chromatography and centrifugal partition chromatography was an efficient method for the continuous extraction and online isolation of chemical constituents from medicinal herbs. Furthermore, the research route based on the activity screening, extraction, separation, and activity verification of the compounds offered advantages of efficiency, orientation, and objectivity.

Extraction, isolation, and aromatase inhibitory evaluation of low-polar ginsenosides from Panax ginseng leaves.

A hyphenated accelerated solvent extraction (ASE) technique was elaborately coupled with centrifugal partition chromatography (CPC), ultra-high-performance liquid chromatography (UHPLC), and photo-diode array detector (PDA). This approach was applied to obtain low-polar ginsenoside fractions from the leaves of Panax ginseng. The CPC fractions were isolated and analyzed using the hyphenated technique, and followed by testing and evaluation of their aromatase inhibitory effects. Subsequently, the aromatase inhibition rates of the compositions in the CPC fractions were calculated using a multivariable linear regression model. A biphasic ethyl acetate/n-butanol/ethanol/water solvent system with respective volume ratios of 10:2:2:8 was used for the ASE and CPC separation of 200g of leaves of P. ginseng raw material. The (lower) aqueous phase of the abovementioned solvent system was used as the extraction solvent. The ginsenosides were subjected to ASE, and the extraction solution was pumped into the sample loop and then directly into the CPC column. The CPC fractions were collected and monitored by an online UHPLC/PDA system at 5-min intervals. The aromatase inhibitory activities of CPC fractions were analyzed by a fluorescence method, with mathematical calculations indicating that the inhibition rates of ginsenosides Rk1, Rg5, Rs5, 20R-Rg3, and Rs4 exceeded 50.00%; indicating that the aforementioned chemical compounds have potential for further development. The results were validated by comparison with authentic standards, indicating that the method used in this research was accurate and advantageous for matrix analysis.

Cyanine-Curcumin Assembling Nanoparticles for Near-Infrared Imaging and Photothermal Therapy.

Near-infrared (NIR) imaging and photothermal therapy (PTT) based on the multifunctional cyanine dyes has shown great promise for cancer therapy. However, most of the PTT agents are often limited by low drug loading, short circulation time, and low biocompatibility. Herein, we developed cyanine-curcumin assembling nanoparticles (CCNPs) via a single-step reprecipitation method. IR-780-C4 (Cyc4) was employed as a photothermal and NIR imaging agent. Self-assembly of Cyc4 and curcumin in aqueous solution could be performed in the absence of surfactants or adjuvants, which is a simple and efficient way to fabricate nanomedicine with high drug loading. Formed CCNPs showed monodispersity, good stability in physiological conditions, and lower cytotoxicity. Moreover, CCNPs possess the high loading (70%) of cyanine dyes and a higher photothermal conversion efficacy than free Cyc4, which contribute to a decrease in the application dosage of cyanine dyes in cancer therapy. Importantly, CCNPs exhibited excellent NIR imaging capacity and photothermal tumor ablation under laser irradiation in vitro and in vivo. This work highlights the potential of using self-assembling of drug molecules to develop functional nanoparticles for drug delivery and cancer therapy.