Rhizoma Bletillae polysaccharide elicits hemostatic effects in platelet-rich plasma by activating adenosine diphosphate receptor signaling pathway

The rhizosphere microbiome and its influence on the accumulation of metabolites in Bletilla striata (Thunb.) Reichb. f

BACKGROUND

Bletilla striata (Thunb.) Reichb. f. (B. striata) is a perennial herbaceous plant in the Orchidaceae family known for its diverse pharmacological activities, such as promoting wound healing, hemostasis, anti-inflammatory effects, antioxidant properties, and immune regulation. Nevertheless, the microbe-plant-metabolite regulation patterns for B. striata remain largely undetermined, especially in the field of rhizosphere microbes. To elucidate the interrelationships between soil physics and chemistry and rhizosphere microbes and metabolites, a comprehensive approach combining metagenome analysis and targeted metabolomics was employed to investigate the rhizosphere soil and tubers from four provinces and eight production areas in China.

RESULTS

Our study reveals that the core rhizosphere microbiome of B. striata is predominantly comprised of Paraburkholderia, Methylibium, Bradyrhizobium, Chitinophaga, and Mycobacterium. These microbial species are recognized as potentially beneficial for plants health. Comprehensive analysis revealed a significant association between the accumulation of metabolites, such as militarine and polysaccharides in B. striata and the composition of rhizosphere microbes at the genus level. Furthermore, we found that the soil environment indirectly influenced the metabolite profile of B. striata by affecting the composition of rhizosphere microbes. Notably, our research identifies soil organic carbon as a primary driving factor influencing metabolite accumulation in B. striata.

CONCLUSION

Our fndings contribute to an enhanced understanding of the comprehensive regulatory mechanism involving microbe-plant-metabolite interactions. This research provides a theoretical basis for the cultivation of high-quality traditional Chinese medicine B. striata.

Chitosan nonwoven fabric composited calcium alginate and adenosine diphosphate as a hemostatic bandage for acute bleeding wounds

Acute bleeding following accidental injury is a leading cause of mortality. However, conventional hemostatic bandages impede wound healing by inducing excessive blood loss, dehydration, and adherence to granulation tissue. Strategies such as incorporating active hemostatic agents and implementing chemical modifications can augment the properties of these bandages. Nevertheless, the presence of remote thrombosis and initiators may pose risks to human health. Here, a hemostatic bandage was developed by physically combined chitosan nonwoven fabric, calcium alginate sponge, and adenosine diphosphate. The presented hemostatic bandage not only exhibits active and passive mechanisms for promoting clotting but also demonstrates excellent mechanical properties, breathability, ease of removal without causing damage to the wound bed or surrounding tissues, as well as maintaining an optimal moist environment conducive to wound healing. In vitro evaluation results indicated that the hemostatic bandage possesses favorable cytocompatibility with low levels of hemolysis. Furthermore, it effectively aggregates various blood cells while activating platelets synergistically to promote both extrinsic and intrinsic coagulation pathways. In an in vivo rat model study involving liver laceration and femoral artery injury scenarios, our developed hemostatic bandage demonstrated rapid clot formation capabilities along with reduced blood loss compared to commercially available fabrics.

Dual properties of pharmacological activities and preparation excipient: Bletilla striata polysaccharides

Bletilla striata has been used for thousands of years and shows the functions of stopping bleeding, reducing swelling, and promoting healing in traditional applications. For Bletilla striata, Bletilla striata polysaccharides (BSP) is the main active ingredient, exhibiting biological functions of anti-inflammatory, anti-oxidant, anti-fibrotic, immune modulation, anti-glycation, and so on. In addition, BSP has exhibited the characteristics of excipient such as bio-adhesion, bio-degradability, and bio-safety and has been prepared into a series of preparations such as nanoparticles, microspheres, microneedles, hydrogels, etc. BSP, as both a drug and an excipient, has already aroused more and more attention. In this review, publications in recent years related to the extraction and identification, biological activities, and excipient application of BSP are reviewed. Specifically, we focused on the advances in the application of BSP as a formulation excipient. We hold opinion that BSP not only needed more researches in the mechanisms, but also the development into hydrogels, nano-formulations, tissue engineering, and so on. And we believe that this paper provides a beneficial reference for further BSP innovation and in-depth research and promotes the use of these natural products in pharmaceutical applications.

A Natural Self-Assembled Gel-Sponge with Hierarchical Porous Structure for Rapid Hemostasis and Antibacterial

Developing hemostatic agents with reliable biosafety and high efficiency has paramount clinical significance for saving lives. Herein, inspired from traditional Chinese medicine, a sponge (BC-S) with hierarchical porous structure is proposed for the treatment of bleeding. The BC-S is prepared by a simple self-assembly method employing Bletilla Striata polysaccharide and quaternary amine alkaloids (QA) from Bletilla Striata and Coptidis Rhizoma. The ideal cation donor encapsulated in the helical structure of BSP enlarges the inter-layer space of sponge by the action of electrostatic repulsion, forming wider channels which can accelerate the diversion speed of absorbed blood. Then, platelets and erythrocytes are trapped tightly in the reticular structure and extruded to deformation, activation. Subsequently, fibrin network forms and reinforces the internal multilayer mesh, blocks the outflow of blood. QA is released from the sponge skeleton mainly driven by a combination of surface erosion and potentially solution diffusion among pore to provide long-term antibacterial activity. Benefiting from the well-designed structure and the effective hemostatic mechanism, the BC-S displays more excellent hemostatic performance in different models in vivo and in vitro compared with typical gelatin hemostatic sponge. This work is expected to boost the development of emerging hemostatic agents.

Extraction, structural-activity relationships, bioactivities, and application prospects of Bletilla striata polysaccharides as ingredients for functional products: A review

Bletilla striata is a well-known medicinal plant with high pharmaceutical and ornamental values. Polysaccharide is the most important bioactive ingredient in B. striata and has various health benefits. Recently, B. striata polysaccharides (BSPs) have attracted much attention from industries and researchers due to their remarkable immunomodulatory, antioxidant, anti-cancer, hemostatic, anti-inflammatory, anti-microbial, gastroprotective, and liver protective effects. Despite the successful isolation and characterization of B. striata polysaccharides (BSPs), there is still limited knowledge regarding their structure-activity relationships (SARs), safety concerns, and applications, which hinders their full utilization and development. Herein, we provided an overview of the extraction, purification, and structural features, as well as the effects of different influencing factors on the components and structures of BSPs. We also highlighted and summarized the diversity of chemistry and structure, specificity of biological activity, and SARs of BSP. The challenges and opportunities of BSPs in the food, pharmaceutical, and cosmeceutical fields are discussed, and the potential development and future study direction are scrutinized. This article provides comprehensive knowledge and underpinnings for further research and application of BSPs as therapeutic agents and multifunctional biomaterials.

Effects of Walnut Bark Extract on the Human Platelet Aggregation, Adhesion, and Plasmatic Coagulation In Vitro

Thrombosis is the formation of a clot within a blood vessel. Antithrombotic drugs are used for treating thrombosis, which can be the cause of hemorrhage. Currently, there is a need to discover novel antithrombotic drugs. Walnut is widely used to treat a wide range of health complaints. In this study, walnut bark extract was tested in hemostasis parameters: platelets adhesion, aggregation, and plasmatic coagulation in human blood. The crude aqueous extract of walnut bark was prepared by infusion and tested in vitro on hemostasis. Through blood collection from healthy volunteer donors, we studied different parameters of the primary hemostasis: platelet adhesion on the collagen-coated surface under flow, ADP, collagen, thrombin, and arachidonic acid-induced platelet aggregation, and of the secondary hemostasis by measuring prothrombin time (PT) and activated partial thromboplastin (APTT) parameters. All experiments are realized in the absence and presence of the extract and repeated at least twice. The obtained data showed that the extract (1 and 2 mg/mL) significantly (p < 0.001) reduced the activated platelet adhesion on the collagen-coated surface. In the same way, the effect of the extract on platelet aggregation seems to depend on its concentration and on the nature of the agonist. The strongest inhibition of aggregation was observed in the case of collagen at 1 mg/mL, while there was no observed effect on arachidonic acid-induced aggregation. Moreover, the extract (1 mg/mL) affects the extrinsic, intrinsic, and common pathways of the human blood coagulation cascade by extending significantly (p < 0.001), both PT and APTT times. This study provides evidence that walnut bark extract, by its antiadhesive, antiaggregant, and anticoagulant activities, could be considered as a serious source of biological compounds for the prevention and treatment of thrombosis.

Calcium alginate/silk fibroin peptide/Bletilla striata polysaccharide blended microspheres loaded with tannic acid for rapid wound healing

Biodegradable natural polymers are receiving increasing attention as potential candidates for wound dressing. In the present study, composite microspheres (mCSB) based on calcium alginate (CA), silk fibroin peptide (SP), and Bletilla striata polysaccharide (BSP) were prepared by the reverse emulsion method. The excellent swelling properties of microspheres enable them to rapidly promote thrombosis. Microspheres can increase the platelet aggregation index to 1.5 and the aggregation rate of red blood cells to as high as 80 %. Furthermore, tannic acid (TA)-loaded microspheres demonstrate a slow-release effect on TA; this allows the microspheres to exhibit good long-lasting antibacterial properties. Due to the synergistic effects of SP and TA, the cell senescence was delayed, with a 126.69 % survival rate of fibroblasts after 3 days of incubation. In addition, TA led to a rapid reduction in inflammation levels, with a wound closure rate of >92.80 % within 7 days. The multifunctional TA-loaded mCSB has great application potential for rapid wound healing and the treatment of wound hemostasis.

A Dual-Cross-Linked Hydrogel Patch for Promoting Diabetic Wound Healing

Diabetic wound treatment faces significant challenges in clinical settings. Alternative treatment approaches are needed. Continuous bleeding, disordered inflammatory regulation, obstruction of cell proliferation, and disturbance of tissue remodeling are the main characteristics of diabetic wound healing. Hydrogels made of either naturally derived or synthetic materials can potentially be designed with a variety of functions for managing the healing process of chronic wounds. Here, a hemostatic and anti-inflammatory hydrogel patch is designed for promoting diabetic wound healing. The hydrogel patch is derived from dual-cross-linked methacryloyl-substituted Bletilla Striata polysaccharide (B) and gelatin (G) via ultraviolet (UV) light. It is demonstrated that the B-G hydrogel can effectively regulate the M1/M2 phenotype of macrophages, significantly promote the proliferation and migration of fibroblasts in vitro, and accelerate angiogenesis. It can boost wound closure by normalizing epidermal tissue regeneration and depositing collagen appropriately in vivo without exogenous cytokine supplementation. Overall, the B-G bioactive hydrogel can promote diabetic wound healing in a simple, economical, effective, and safe manner.