Drug-Herb Synergistic Interactions between Clopidogrel and Natural Medicine.

INTRODUCTION: Natural medicine (NM) has been used since ancient times for therapeutic purposes worldwide. Presently, the combination of clopidogrel and NM with a reasonable synergistic effect has gained increasing acceptance in clinical therapeutics. METHODS: Here, we have performed a comprehensive retrieval of literature published in both English and Chinese databases until August 1, 2022, studying the synergistic interactions of clopidogrel and NM through pharmacokinetic/pharmacodynamic (PK-PD) analyses. We retrieved 7, 3, and 5 studies on PK analysis and 3, 3, and 8 studies on PD analysis for the interaction of clopidogrel with single herbal medicines, bioactive compounds, and herbal prescriptions, respectively. Most studies on NM have been found to mainly focus on preclinical observations, and there have been fewer clinical PK analyses. RESULTS: A potential drug-herb interaction has been observed to occur when clopidogrel and NM were metabolized by an enzyme network comprising P-gp, CES1, and CYP450. In contrast, most PD studies have focused on clinical observations, and few preclinical findings have been reported. Some cases have suggested that the combination of the two types of drugs would alter the antiplatelet efficacy and adverse effects. Studies on PK, however, have shown significant or slightly varying results for the drug prototype and its metabolites. CONCLUSION: In the combination therapies, the interaction between clopidogrel and NM was found to alter antiplatelet aggregation pathways and P2Y12 receptor function.

Lead Drug Discover Strategies from Natural Medicines Based on Network Pharmacology.

The need for therapeutics to overcome development of existing diseases research to discover new lead agents. In the face of public health challenges worldwide, natural medicines play a pivotal role in innovative lead drug discovery. Network pharmacology can easily construct complicated poly-pharmacology network based on lead compound, biological function, and bioactive target proteins, which meets the overall feature of natural medicines, and enable to elucidate the action mechanism at molecule-protein level with systematic view. In this work, we first summarized the recent progress delineating lead drug development and its interaction with natural medicines. Second, we focused on the relationship between natural medicines and network pharmacology. Additionally, we discussed current issues and potential prospects for the lead drug discover from natural medicines by network pharmacology. Further investigations should be focus on relevant structural analysis for biological experiment, also the dynamic and quantitative network development. In summary, it is a rational approach for innovative lead drug discovery, and with the development of structure and biology research, this approach makes it a very powerful method for the lead molecules in a high-throughput manner from a comprehensive and powerful special multi-compound to target protein/disease poly pharmacology network.

Synthesis and Discovery of Ligustrazine-Heterocycle Derivatives as Antitumor Agents.

Ligustrazine (TMP) is a natural pyrazine alkaloid extracted from the roots of Ligusticum Chuanxiong Hort, which has the potential as an antitumor agent. A series of 33 ligustrazine-heterocycle (TMPH) derivatives were designed, synthesized, and investigated via antitumor screening assays, molecular docking analysis, and prediction of drug-like properties. TMP was attached to other heterocyclic derivatives by an 8-12 methylene alkyl chain as a linker to obtain 33 TMPH derivatives. The structures were confirmed by 1H-NMR, 13C-NMR, and high-resolution mass spectroscopy spectral (HR-MS) data. The antiproliferative activity against human breast cancer MCF-7, MDA-MB-231, mouse breast cancer 4T1, mouse fibroblast L929, and human umbilical vein endothelial HUVEC cell lines was evaluated by MTT assay. Compound 12-9 displayed significant inhibitory activity with IC50 values in the low micromolar range (0.84 ± 0.02 µM against the MDA-MB-231 cell line). The antitumor effects of compound 12-9 were further evaluated by plate cloning, Hoechst 33 342 staining, and annexin V-FITC/PI staining. The results indicated that compound 12-9 inhibited the proliferation and apoptosis of breast cancer cells. Furthermore, molecular docking of compound 12-9 into the active site of the Bcl-2, CASP-3, and PSMB5 target proteins was performed to explore the probable binding mode. The 33 newly synthesized compounds were predicted to have good drug-like properties in a theoretical study. Overall, these results indicated that compound 12-9 inhibited cell proliferation through PSMB5 and apoptosis through Bcl-2/CASP-3 apoptotic signaling pathways and had good drug-like properties. These results provided more information, and key precursor lead derivatives, in the search for effective bioactive components from Chinese natural medicines.

LEAFY COTYLEDON 2: A Regulatory Factor of Plant Growth and Seed Development.

Transcription factors are key molecules in the regulation of gene expression in all organisms. The transcription factor LEAFY COTYLEDON 2 (LEC2), which belongs to the DNA-binding protein family, contains a B3 domain. The transcription factor is involved in the regulation of important plant biological processes such as embryogenesis, somatic embryo formation, seed storage protein synthesis, fatty acid metabolism, and other important biological processes. Recent studies have shown that LEC2 regulates the formation of lateral roots and influences the embryonic resetting of the parental vernalization state. The orthologs of LEC2 and their regulatory effects have also been identified in some crops; however, their regulatory mechanism requires further investigation. Here, we summarize the most recent findings concerning the effects of LEC2 on plant growth and seed development. In addition, we discuss the potential molecular mechanisms of the action of the LEC2 gene during plant development.

Functions of PPR Proteins in Plant Growth and Development.

Pentatricopeptide repeat (PPR) proteins form a large protein family in land plants, with hundreds of different members in angiosperms. In the last decade, a number of studies have shown that PPR proteins are sequence-specific RNA-binding proteins involved in multiple aspects of plant organellar RNA processing, and perform numerous functions in plants throughout their life cycle. Recently, computational and structural studies have provided new insights into the working mechanisms of PPR proteins in RNA recognition and cytidine deamination. In this review, we summarized the research progress on the functions of PPR proteins in plant growth and development, with a particular focus on their effects on cytoplasmic male sterility, stress responses, and seed development. We also documented the molecular mechanisms of PPR proteins in mediating RNA processing in plant mitochondria and chloroplasts.

Sanguisorba parviflora (Maxim.) Takeda alleviates cyclophosphamide-induced leukopenia by regulating haematopoietic cell-specific protein 1-associated protein X-1 gene expression.

WHAT IS KNOWN AND OBJECTIVE: We have previously shown that the saponins of Sanguisorba parviflora (Maxim.) Takeda (Sp. T) relieved cyclophosphamide-induced myelosuppression in leukopenic mice. Haematopoietic cell-specific protein 1-associated protein X-1 (HAX-1) participated in the survival of neutrophils through the regulation of mitochondrial function. The aim of the present study was to comprehensively identify the role of HAX-1 in the mechanism of leukopenia alleviation by Sp. T. METHODS: HAX-1 gene and protein expression levels in peripheral blood neutrophils were examined using real-time quantitative reverse transcription-polymerase chain reaction, western blot and immunohistochemical assays. Neutrophil apoptosis was measured using flow cytometry. Mitochondrial function was determined via assessments of the reactive oxygen species (ROS) generation and mitochondrial membrane potential (ΔΨm) integrity levels. RESULTS AND DISCUSSION: The HAX-1 gene expression level in the peripheral blood neutrophils was significantly lower in patients with leukopenia than in healthy donors. The saponins of Sp. T induced HAX-1 expression and promoted myeloid progenitor cell (mEB8-ER cell) viability. HAX-1 overexpression reduced the production of ROS and maintained ΔΨm integrity. Cyclophosphamide-induced mitochondrial dysfunction and apoptosis could be abrogated by treatment with Sp. T or metformin. WHAT IS NEW AND CONCLUSION: Our data suggest a mechanism through which Sp. T protects against chemotherapy-induced leukopenia by regulating HAX-1 gene expression in a mitochondrial-dependent manner.

Sanguisorba parviflora (Maxim) Takeda alleviates cyclophosphamide-induced leukopenia via regulating the hematopoietic cell-specific protein 1-associated protein X-1 gene.

WHAT IS KNOWN AND THE OBJECTIVE: Our previous studies have shown that saponins of Sanguisorba parviflora (Maxim) Takeda (Sp. T) relieved cyclophosphamide-induced myelosuppression in mice with leukopenia. The hematopoietic cell-specific protein 1-associated protein X-1 (HAX-1) participated in the survival of neutrophils through the regulation of mitochondrial function. This study aimed to comprehensively identify the role of HAX-1 in Sp. T to alleviate leukopenia. METHODS: HAX-1 expression was examined in the peripheral blood neutrophils using real-time polymerase chain reaction (PCR), Western blot analysis and immunohistochemical staining. Neutrophil apoptosis was measured by flow cytometry. Mitochondrial function was evaluated via reactive oxygen species (ROS) generation and mitochondrial membrane potential (ΔΨm) integrity. RESULTS AND DISCUSSION: Our study indicated that the expression of the HAX-1 gene was significantly decreased in the peripheral blood neutrophils of leukopenia patients compared with healthy donors. The saponins of Sp. T induced HAX-1 expression and promoted myeloid progenitor cell (mEB8-ER cell) viability, while overexpression of HAX-1 reduced the production of reactive oxygen species (ROS) and maintained the integrity of the mitochondrial membrane potential. Cyclophosphamide-induced mitochondrial dysfunction and apoptosis could be abrogated by treatment with Sp. T or the addition of metformin. WHAT IS NEW AND OUR CONCLUSION: Our data support a mechanism where Sp. T protects against chemotherapy-induced leukopenia by regulating HAX-1 gene expression in a mitochondrial-dependent manner.

Seed-specific activity of the Arabidopsis ß-glucosidase 19 promoter in transgenic Arabidopsis and tobacco.

KEY MESSAGE: The promoter of the Arabidopsis thaliana ß-glucosidase 19 gene directs GUS expression in a seed-specific manner in transgenic Arabidopsis and tobacco. In the present study, an 898-bp putative promoter of the Arabidopsis ß-glucosidase 19 (AtBGLU19) gene was cloned. The bioinformatics analysis of the cis-acting elements indicated that this putative promoter contains many seed-specific elements, such as RY elements. The features of this promoter fragment were evaluated for the capacity to direct the ß-glucuronidase (GUS) reporter gene in transgenic Arabidopsis and tobacco. Histochemical and fluorometric GUS analyses of transgenic Arabidopsis plants revealed that the AtBGLU19 promoter directed strong GUS activity in late-maturing seeds and dry seeds, whereas no GUS expression was observed in other organs. The results indicated that the AtBGLU19 promoter was able to direct GUS expression in a seed-specific manner in transgenic Arabidopsis. In tobacco, the intensity of the staining and the level of GUS activity were considerably higher in the seeds than in the other tissues. These results further confirmed that the AtBGLU19 promoter is seed specific and can be used to control transgene expression in a heterologous plant system.

Preparation of Neogambogic Acid Nanoliposomes and its Pharmacokinetics in Rats.

OBJECTIVE: To prepare neogambogic acid nanoliposomes (GNA-NLC) and study its pharmacokinetics (PK) in rats. STUDY DESIGN: An experimental study. PLACE AND DURATION OF STUDY: Mudanjiang Medical University, Mudanjiang, China, from January 2016 to October 2017. METHODOLOGY: GNA-NLC was prepared by emulsion evaporation-low temperature solidification. The entrapment efficiency, average particle size, and zeta potential were investigated. Male Wistar rats were injected with 1 mg/mL gambogic acid and GNA-NLC into the caudal vein respectively, and the plasma concentration was determined by UPLC- MS/MS. The pharmacokinetic parameters of the two agents were compared. RESULTS: GNA-NLC prepared in this study were mostly spherical spheroids with an average particle size of 146.35 ±1.72 nm, polydispersity coefficient of 0.26 ±0.02, zeta potential of -28.24 ±0.13 MV, entrapment efficiency of 84.63%, and drug loading capacity of 4.23%. DSC showed that neogambogic acid nanoparticles had formed and neogambogic acid was amorphous in the matrix. The pharmacokinetics results in rats showed that GNA-NLC plasma concentration was significantly higher than that of common preparation of gambogic acid, with a half-life period of 10.14 ±0.03 hours, 4.57 times that of gambogic acid. AUC0 ~ 24h of gambogic acid in GNA-NLC lipidosome was 58.36 ±0.23 μg/h/mL, 4.83 times that of gambogic acid. CONCLUSION: GNA-NLC can be prepared successfully by emulsion evaporation-low temperature solidification. The method is simple and easy to control. The GNA-NLC has a long cycle, and high blood concentration, sustained release compared with the raw material gambogic acid.

Sodium Copper Chlorophyllin Catalyzed Chemoselective Oxidation of Benzylic Alcohols and Diarylmethanes in Water.

We report the highly efficient and chemoselective oxidation of benzylic alcohols catalyzed by sodium copper chlorophyllin in water, producing corresponding arylcarbonyl compounds. Importantly, the catalytic system exhibits a wide substrate scope and high functional group tolerance. Moreover, secondary alcohols and even diarylmethanes were smoothly oxidized to the desired aryl ketones with excellent yields.

A low-temperature-responsive element involved in the regulation of the Arabidopsis thaliana At1g71850/At1g71860 divergent gene pair.

KEY MESSAGE: The bidirectional promoter of the Arabidopsis thaliana gene pair At1g71850/At1g71860 harbors low-temperature-responsive elements, which participate in anti-correlated transcription regulation of the driving genes in response to environmental low temperature. A divergent gene pair is defined as two adjacent genes organized head to head in opposite orientation, sharing a common promoter region. Divergent gene pairs are mainly coexpressed, but some display opposite regulation. The mechanistic basis of such anti-correlated regulation is not well understood. Here, the regulation of the Arabidopsis thaliana gene pair At1g71850/At1g71860 was investigated. Semi-quantitative RT-PCR and Genevestigator analyses showed that while one of the pair was upregulated by exposure to low temperature, the same treatment downregulated the other. Promoter::GUS fusion transgenes were used to show that this behavior was driven by a bidirectional promoter, which harbored an as-1 motif, associated with the low-temperature response; mutation of this sequence produced a significant decrease in cold-responsive expression. With regard to the as-1 motif in the native orientation repressing the promoter's low-temperature responsiveness, the same as-1 motif introduced in the reverse direction showed a slight enhancement in the promoter's responsiveness to low-temperature exposure, indicating that the orientation of the motif was important for the promoter's activity. These findings provide new insights into the complex transcriptional regulation of bidirectional gene pairs as well as plant stress response.

Structural and functional analysis of an asymmetric bidirectional promoter in Arabidopsis thaliana.

Bidirectional promoters are relatively abundant in eukaryotic genomes, suggesting that they have an important biological significance. As yet, few of these promoters have been characterized in detail. Here, using a promoter::GUS transgene approach has revealed that the intergenic region of Arabidopsis thaliana divergent genes At1g71850 and At1g71860 is an asymmetric bidirectional promoter, which exhibits an orientation-dependent expression profile. The strength of the forward promoter was greater than that of the reverse promoter, and their tissue specificities were not identical. Deletion analyses revealed that this bidirectional promoter could be divided into three functional regions. The basal level and tissue specificity of the promoter in the reverse orientation were regulated positively by region II and negatively by region III, whereas promoter activity in the forward orientation was regulated negatively by region II and positively by region I. Thus the 52-bp stretch of region II had a dual function, enhancing expression in the reverse orientation and suppressing it in the forward orientation. These results demonstrated that the activity of the At1g71850-At1g71860 bidirectional promoter was modulated by complex interactions between both positive and negative cis-acting elements. These findings will enhance our understanding of the regulatory mechanisms of plant bidirectional promoters.

Melanoma cells express ICOS ligand to promote the activation and expansion of T-regulatory cells.

CD4(+)CD25(+)Foxp3(+) T-regulatory cells (Tregs) accumulate in tumors; however, little is known about how the tumor environment influences this process. Here we show that human melanomas express inducible T-cell costimulator ligand (ICOS-L/B7H) that can provide costimulation through ICOS for the expansion of activated Tregs maintaining high Foxp3 and CD25 expression as well as a suppressive function. Thus, ICOS-L expression by melanoma tumor cells may directly drive Treg activation and expansion in the tumor microenvironment as another mechanism of immune evasion.

Isolation and functional analysis of a strong specific promoter in photosynthetic tissues.

PNZIP gene promoter has been cloned from Pharbitis nil by adaptor PCR, which conforms to eukaryotic promoter characteristic. Primer extension analysis showed that the transcription start site was located 122 nucleotides upstream of the translation start site of PNZIP gene. According to the characteristic of PNZIP promoter, a series of deletions were purposely made by PCR. Five deletion fragments were fused to upstream of GUS gene and transferred into tobacco. Fluorometric GUS assay showed that five different length promoters all could specifically drive GUS gene expression in photosynthetic tissues and their activities decreased along with the gradual deletion of PNZIP promoter. In addition, the activity of full-length promoter was 9 times higher than that of CaMV 35S in leaf. PNZIP promoter may have two putative cis-elements, GAAATA and GATACT, which relate to gene expression in photosynthetic tissues. GATACT may determine the gene specific expression in photosynthetic tissues, while GAAATA, perhaps, as an enhancer, increases the intensity of gene expression.