Determination of Antioxidant, Cytotoxicity, and Acetylcholinesterase Inhibitory Activities of Alkaloids Isolated from Sophora flavescens Ait. Grown in Dak Nong, Vietnam

Quaternity method for integrated screening, separation, extraction optimization, and bioactivity evaluation of acetylcholinesterase inhibitors from Sophora flavescens Aiton

INTRODUCTION

Sophora flavescens Aiton (Fabaceae), a ubiquitous plant species in Asia, contains a wide range of pharmacologically active compounds, such as flavonoids, with potential anti-Alzheimer's disease (anti-AD) effects.

OBJECTIVES

The objective of the study is to develop a quaternity method for the screening, isolation, extraction optimization, and activity evaluation of acetylcholinesterase (AChE)-inhibiting compounds from S. flavescens to realize high-throughput screening of active substances in traditional Chinese medicine and to provide experimental data for the development of anti-AD drugs.

METHODS

With AChE as the target molecule, affinity ultrafiltration and liquid chromatography-mass spectrometry were applied to screen for potential inhibitors of the enzyme in S. flavescens. Orthogonal array experiments combined with the multi-objective Non-Dominated Sorting Genetic Algorithm III was used for the first time to optimize the process for extracting the active substances. Enzyme inhibition kinetics and molecular docking studies were performed to verify the potential anti-AD effects of the active compounds.

RESULTS

Five AChE-inhibiting compounds were identified: kushenol I, kurarinone, sophoraflavanone G, isokurarinone, and kushenol E. These were successfully separated at purities of 72.88%, 98.55%, 96.86%, 96.74%, and 95.84%, respectively, using the n-hexane/ethyl acetate/methanol/water (4.0/5.0/4.0/5.0, v/v/v/v), n-hexane/ethyl acetate/methanol/water (5.0/5.0/6.0/4.0, v/v/v/v), and n-hexane/ethyl acetate/methanol/water (4.9/5.1/5.7/4.3, v/v/v/v) mobile phase systems. Enzyme inhibition kinetics revealed that kushenol E had the best inhibitory effect.

CONCLUSION

This study elucidates the mechanism of action of five active AChE inhibitors in S. flavescens and provides a theoretical basis for the screening and development of anti-AD and other therapeutic drugs.

Multi-faceted potential of sophoridine compound's anti-arrhythmic and antioxidant effects through ROS/CaMKII pathway

Cardiac arrhythmias remain a significant cause of mortality and morbidity, for novel antiarrhythmic therapies. This study states that the first report of sophoridine (SPN), a quinolizidine alkaloid derived from traditional Chinese herbs, shows promise as a potential candidate due to its anti-arrhythmic and antioxidant properties. The study found that cell viability in H9C2 rat cardiomyocytes remained stable even when treated with SPN at a higher dosage of 100 μg/ml. This phenomenon was accompanied by increases in mitochondria-derived reactive oxygen species (ROS) and calcium/calmodulin-dependent protein kinase II (CaMKII) signaling, at 50 and 100 μg/ml. Glucose fluctuations regulate ventricular arrhythmias caused by SPN by activating the ROS/CaMKII pathway. Experimental models using zebrafish provided additional evidence supporting the regulatory effects of SPN on heart rate. In addition, the administration of SPN resulted in substantial deregulation of crucial genes involved in heart development (nppa, nppb, tnnt2a) at the transcriptional level in zebrafish. These findings provide insight into the various pharmacological properties of SPN and this opens up new possibilities for anti-arrhythmic treatment strategies.

Ultrafast and Highly Efficient Laser Extraction of Matrine and Oxymatrine from Sophora flavescens for the Anticancer Activity

Matrine and oxymatrine are mainly obtained from Sophora flavescens using the high-temperature and prolonged solvent extraction methods currently employed in industries. In this study, an ultrafast and highly efficient method for extracting matrine and oxymatrine from S. flavescens at room temperature using laser technology, specifically, laser extraction, was demonstrated. The laser extraction rates for matrine and oxymatrine from S. flavescens at room temperature for 1 min were 266.40 and 936.80 mg(g·h)-1, respectively. These rates were 1400 times higher than those achieved with conventional solvent extraction. These results mean that 1 min of laser extraction is equivalent to 24 h of solvent extraction. The reason for such a high efficiency is that laser-induced cavitation can accelerate the rapid release of alkaloid molecules in plant cells. Mass spectrum, nuclear magnetic resonance, and Fourier-transform infrared spectrum analyses of the extracted matrine and oxymatrine compounds confirmed that they are the same as the products of solvent extraction. Furthermore, it was found that the anticancer activity of laser-extracted compounds is slightly better than that of conventionally solvent-extracted ones, likely due to the slight change in the microstructure or conformation of these compounds under laser irradiation. These findings demonstrated that the laser extraction method was ultrafast and highly efficient, unveiling a novel approach to alkaloid extraction. This discovery will have significant implications for the extraction and utilization of alkaloids from plants.

Biochar and organic fertilizer drive the bacterial community to improve the productivity and quality of Sophora tonkinensis in cadmium-contaminated soil

Excessive Cd accumulation in soil reduces the production of numerous plants, such as Sophora tonkinensis Gagnep., which is an important and widely cultivated medicinal plant whose roots and rhizomes are used in traditional Chinese medicine. Applying a mixture of biochar and organic fertilizers improved the overall health of the Cd-contaminated soil and increased the yield and quality of Sophora. However, the underlying mechanism between this mixed fertilization and the improvement of the yield and quality of Sophora remains uncovered. This study investigated the effect of biochar and organic fertilizer application (BO, biochar to organic fertilizer ratio of 1:2) on the growth of Sophora cultivated in Cd-contaminated soil. BO significantly reduced the total Cd content (TCd) in the Sophora rhizosphere soil and increased the soil water content, overall soil nutrient levels, and enzyme activities in the soil. Additionally, the α diversity of the soil bacterial community had been significantly improved after BO treatment. Soil pH, total Cd content, total carbon content, and dissolved organic carbon were the main reasons for the fluctuation of the bacterial dominant species. Further investigation demonstrated that the abundance of variable microorganisms, including Acidobacteria, Proteobacteria, Bacteroidetes, Firmicutes, Chloroflexi, Gemmatimonadetes, Patescibacteria, Armatimonadetes, Subgroups_ 6, Bacillus and Bacillus_ Acidiceler, was also significantly changed in Cd-contaminated soil. All these alterations could contribute to the reduction of the Cd content and, thus, the increase of the biomass and the content of the main secondary metabolites (matrine and oxymatrine) in Sophora. Our research demonstrated that the co-application of biochar and organic fertilizer has the potential to enhance soil health and increase the productivity and quality of plants by regulating the microorganisms in Cd-contaminated soil.