Saponins as cytotoxic agents: a review

Exosomes: Cell-Derived Nanoplatforms for the Delivery of Cancer Therapeutics

Exosomes are cell-secreted nanovesicles that naturally contain biomolecular cargoes such as lipids, proteins, and nucleic acids. Exosomes mediate intercellular communication, enabling the transfer biological signals from the donor cells to the recipient cells. Recently, exosomes are emerging as promising drug delivery vehicles due to their strong stability in blood circulation, high biocompatibility, low immunogenicity, and natural targeting ability. In particular, exosomes derived from specific types of cells can carry endogenous signaling molecules with therapeutic potential for cancer treatment, thus presenting a significant impact on targeted drug delivery and therapy. Furthermore, exosomes can be engineered to display targeting moieties on their surface or to load additional therapeutic agents. Therefore, a comprehensive understanding of exosome biogenesis and the development of efficient exosome engineering techniques will provide new avenues to establish convincing clinical therapeutic strategies based on exosomes. This review focuses on the therapeutic applications of exosomes derived from various cells and the exosome engineering technologies that enable the accurate delivery of various types of cargoes to target cells for cancer therapy.

Nanoliposomal Cercodemasoide A and Its Improved Activities Against NTERA-2 Cancer Stem Cells

Recently, saponins derived from marine sources have received much attention because of their promising bioactivities, such as anticancer, anti-angiogenesis, and anti-inflammation. In particular, a triterpene saponin from the sea cucumber Cercodemas anceps Selenka, cercodemasoide A (CAN1), showed potent cytotoxicity against various cancer cell lines. Recent evidence has indicated that cancer stem cells (CSCs) could be a novel target for efficient cancer therapies. In order to improve the biopharmaceutical properties of CAN1, the compound was loaded into nanoliposomes as an ideal drug carrier. CAN1 was successfully incorporated into nanoliposomes as small unilamellar liposome vesicles with an average size of 73.39 ± 1.57 nm, zeta potential of −0.299 ± 0.046 mV, polydispersity index of 0.336 ± 0.038, and with an encapsulation efficiency of up to 62.9%. For the first time, CAN1 and its nanoliposomal forms have been shown to have a promising cytotoxic activity against NTERA-2 CSCs, with half-maximal inhibitory concentration (IC50) =1.03 ± 0.04 and 0.41 ± 0.03 µM, respectively. The CAN1 nanoliposomes also presented significantly improved activities in suppressing the growth of NTERA-2 3-dimensional tumorspheres (IC50 = 1.71 ± 0.06 µM) in comparison with the free form ( P < .05). The anti-CSC effects of CAN1 nanoliposomes on NTERA-2 cells were due to their apoptotic induction through enhancing caspase-3 activity (more than 2-fold) and arresting the cell cycle at the S phase ( P < .05). The obtained CAN1-encapsulated nanoliposomes suggest valuable applications in CSC-targeting treatment for more efficient clinical therapy.

Isolation and Characterisation of Two Quercetin Glucosides with Potent Anti-Reactive Oxygen Species (ROS) Activity and an Olean-12-en Triterpene Glucoside from the Fruit of Abelmoschus esculentus (L.) Moench

Abelmoschus esculentus (Okra) is used in the traditional treatment of cancer, hyperlipidaemia and hyperglycaemia. We, therefore, investigated its composition and potential cytotoxic or antioxidant properties that might underlie its phytotherapeutic applications. Its methanolic fruit extract yielded compounds 1, 2 and 3, identified through NMR, UV and MS analyses as olean-12-en-3-O-β-d-glucopyranoside, isoquercitrin (quercetin glucoside) and 5,7,3',4'-tetrahydroxy-flavonol-3-O-[β-d-glucopyranosyl-(1→6)]-β-d-glucopyranoside (quercetin diglucoside), respectively. Following 48 h exposure, oleanene glucoside was mildly toxic to the HeLa and the MRC5-SV2 cancer cells, isoquercitrin was not toxic except at 100 μg/ml in HeLa, and quercetin diglucoside elicited no toxicity. In a 2',7'-dichlorofluorescein diacetate (DCFDA) assay of intracellular levels of reactive oxygen species (ROS), hydrogen peroxide increased ROS levels, an effect not affected by oleanene glucoside but protected against by isoquercitrin and quercetin diglucoside, with IC₅₀ values, respectively, of 2.7±0.5 μg/ml and 1.9±0.2 μg/ml (3 h post-treatment) and 2.0±0.8 μg/ml and 1.5±0.4 μg/ml (24 h post-treatment.) This is the first report of this oleanene skeleton triterpenoid in the plant. The work provides some insight into why the plant is included in remedies for cancers, cardiovascular complications and diabetes, and reveals it as a potential source of novel therapeutics.

Structures/cytotoxicity/selectivity relationship of natural steroidal saponins against GSCs and primary mechanism of tribulosaponin A

Glioblastoma multiform (GBM) is the highly aggressive brain tumor with poor prognosis. Glioma stem cells (GSCs), small population of cancer cells that exist in GBM tissues, resistant to chemotherapy and radiotherapy and usually driving GBM recurrence, have been developed as effective therapeutic target. Steroidal saponins are one of important resources for anti-tumor agent and may be benefited to selectively clear GSCs. In this report, total of 97 natural steroidal saponins were investigated the relationship among structures/cytotoxicity/selectivity against GSCs, glioma cell lines and human untransformed cells, and revealed that tribulosaponin A was the most potent compound. Further investigation suggested that tribulosaponin A up-regulated the expression of NCF1 and NOX1 to accumulate ROS for triggering apoptosis in GSCs, but not in untransformed cells, and it was further supported by the assay that N-acetyl-l-cysteine (NAC) clearing ROS delayed GSCs apoptosis. Besides, tribulosaponin A damaged GSCs recapturing tumor spheres formation.

An Overview of Exosomes in Cancer Therapy: A Small Solution to a Big Problem

Exosomes are defined as a type of extracellular vesicle released when multivesicular bodies of the endocytic pathway fuse with the plasma membrane. They are characterized by their role in extracellular communication, partly due to their composition, and present the ability to recognize and interact with cells from the immune system, enabling an immune response. Their targeting capability and nanosized dimensions make them great candidates for cancer therapy. As chemotherapy is associated with cytotoxicity and multiple drug resistance, the use of exosomes targeting capabilities, able to deliver anticancer drugs specifically to cancer cells, is a great approach to overcome these disadvantages. The objective is to assess treatment efficiency in reducing tumor cells, as well as overall safety and response by cancer carriers. So far, results show exosomes as a promising therapeutic strategy in the fight against cancer. This review summarizes the characteristics and composition of exosomes, as well as explaining in detail the involved parties in the origin of exosomes. Furthermore, some considerations about exosome application in immunotherapy are addressed. The main isolation and loading methods are described to give an insight into how exosomes can be obtained and manipulated. Finally, some therapeutic applications of exosomes in cancer therapy are described.

Synthesis, Modification and Biological Activity of Diosgenyl β-d-Glycosaminosides: An Overview

Saponins are a structurally diverse class of natural glycosides that possess a broad spectrum of biological activities. They are composed of hydrophilic carbohydrate moiety and hydrophobic triterpenoid or steroid aglycon. Naturally occurring diosgenyl glycosides are the most abundant steroid saponins, and many of them exhibit various pharmacological properties. Herein, we present an overview of semisynthetic saponins syntheses-diosgenyl β-d-glycosaminosides (d-gluco and d-galacto). These glycosides possess a 2-amino group, which creates great possibilities for further modifications. A wide group of glycosyl donors, different N-protecting groups and various reaction conditions used for their synthesis are presented. In addition, this paper demonstrates the possibilities of chemical modifications of diosgenyl β-d-glycosaminosides, associated with functionalisation of the amino group. These provide N-acyl, N-alkyl, N,N-dialkyl, N-cinnamoyl, 2-ureido and 2-thiosemicarbazonyl derivatives of diosgenyl β-d-glycosaminosides, for which the results of biological activity tests (antifungal, antibacterial, anti-cancer and hemolytic) are presented.

Determination of the Cytotoxic Effect of Different Leaf Extracts from Parinari curatellifolia (Chrysobalanaceae)

Despite plants being a rich source of useful chemical compounds with different pharmacological properties, some of these compounds may be toxic to humans. Parinari curatellifolia, among its other important pharmacological activities, has been shown to have significant antiproliferative activity on cancer cell lines. Toxicity studies are required to determine the safety profile of P. curatellifolia in the consideration of its potential pharmaceutical benefits as a source of lead compounds in cancer therapy. The effects of P. curatellifolia on both the integrity of the erythrocyte membrane and on normal cells were determined. The dried leaf powder of P. curatellifolia was used in serial exhaustive extraction procedures using hexane, dichloromethane, ethyl acetate, acetone, ethanol, methanol, and water as solvents in addition to extraction using DCM: methanol in equal ratio. Alkaloids, flavonoids, and saponins were isolated from the ethanol extract. The leaf extracts were tested for haemolytic activity on sheep erythrocytes at concentrations of 0.625 to 5 mg/ml. The extracts were also tested for toxicity activity on normal mammalian cells such as the BALB/c mice peritoneal cells using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) at the concentrations of 6.3 to 50 μg/ml. In the haemolysis assays, none of the plant extracts had a significant haemolytic activity with the saponin-enriched extract having the maximum haemolytic activity of 12.2% for a concentration of 5 mg/ml. In the MTT cell viability assay, none of the 11 plant extracts had significant cytotoxicity. The water extract, however, had significant (p < 0.01) proliferative activity towards the murine immune cells at all concentrations. P. curatellifolia leaf extracts were, therefore, not toxic to both erythrocytes and immune cells, and the water extract may have immunostimulatory effects. It is concluded that P. curatellifolia leaf extracts are not toxic in vitro and, therefore, our results support the use of the plant for ethnomedicinal use.

Extracellular vesicles: A bright star of nanomedicine

Extracellular vesicles (EVs) have unique structural, compositional, and morphological characteristics as well as predominant physiochemical stability and biocompatibility properties. They play a crucial role in pathophysiological regulation, and also have broad prospects for clinical application in the diagnosis, prognosis, and therapy of disease, and tissue regeneration and repair. Herein, the biosynthesis and physiological functions and current methods for separation and identification of EVs are summarized. Specifically, engineered EVs may be used to enhance targeted therapy in cancer and repair damaged tissues, and they may be developed as an individualized imaging diagnostic reagent, among other potential applications. We will focus on reviewing recent studies on engineered EVs in which alterations enhanced their therapeutic capability or diagnostic imaging potential via physical, chemical, and biological modification approaches. This review will clarify the superior biological functions and powerful therapeutic potential of EVs, particularly with regard to new designs based on EVs and their utilization in a new generation of nanomedicine diagnosis and treatment platforms.

Water droplet surface tension method - An innovation in quantifying saponin content in quinoa seed

Quinoa surface borne saponins are bitter tasting anti-nutritional compounds that must be removed before consumption of the seed. To determine saponin content, the currently available standard afrosimetric foam test method only determines the presence of saponin via a rating of either 'acceptable' or 'unacceptable'. A water droplet surface tension (WDST) based innovative method was developed that can quantify saponin content in aqueous solutions with greater accuracy. The method comprised four steps: solution preparation, droplet creation, image capture and image analysis using Axisymmetric Drop Shape Analysis computer software. The method applied satisfactorily to saponin content up to 0.2 mg.ml^-1 as higher concentrations did not further reduce the surface tension. Results demonstrated that saponin concentration may be measured in the range 0.05 to 0.15 mg.ml^-1 (0.05 - 0.15% saponin by weight of seed). Validation of the WDST method on commercial and experimental samples offers quinoa processors an accurate inexpensive way of measuring saponin concentration to satisfy current seed quality specifications.

Current Prospects of Nutraceuticals: A Review

Nutraceuticals are dietary supplements, utilized to ameliorate health, delay senescence, prevent diseases, and support the proper functioning of the human body. Currently, nutraceuticals are gaining substantial attention due to nutrition and therapeutic potentials. Based on their sources, they are categorized as dietary supplements and herbal bioactive compounds. The global market for nutraceutical is huge i.e. approximately USD 117 billion. Herbal nutraceutical helps in maintaining health and promoting optimal health, longevity, and quality of life. Studies have shown promising results of nutraceuticals to treat several diseases, such as cancer, neurodegenerative diseases, cardiovascular diseases, etc. In the present review, an overview of various bioactive ingredients that act as nutraceuticals (carbohydrates, lipids, edible flowers, alkaloids, medicinal plants, etc.) and their role in health benefits, has been discussed. Further application of nutraceuticals in the prevention of various diseases has also been discussed.

Gene Editing by Extracellular Vesicles

CRISPR/Cas technologies have advanced dramatically in recent years. Many different systems with new properties have been characterized and a plethora of hybrid CRISPR/Cas systems able to modify the epigenome, regulate transcription, and correct mutations in DNA and RNA have been devised. However, practical application of CRISPR/Cas systems is severely limited by the lack of effective delivery tools. In this review, recent advances in developing vehicles for the delivery of CRISPR/Cas in the form of ribonucleoprotein complexes are outlined. Most importantly, we emphasize the use of extracellular vesicles (EVs) for CRISPR/Cas delivery and describe their unique properties: biocompatibility, safety, capacity for rational design, and ability to cross biological barriers. Available molecular tools that enable loading of desired protein and/or RNA cargo into the vesicles in a controllable manner and shape the surface of EVs for targeted delivery into specific tissues (e.g., using targeting ligands, peptides, or nanobodies) are discussed. Opportunities for both endogenous (intracellular production of CRISPR/Cas) and exogenous (post-production) loading of EVs are presented.

Exosome: A Review of Its Classification, Isolation Techniques, Storage, Diagnostic and Targeted Therapy Applications

Exosomes are nano-sized small extracellular vesicles secreted by cells, carrying nucleic acids, proteins, lipids and other bioactive substances to play a role in the body's physiological and pathological processes. Compared to synthetic carriers such as liposomes and nanoparticles, the endogeneity and heterogeneity of exosomes give them extensive and unique advantages in the field of disease diagnosis and treatment. However, the storage stability, low yield, low purity, and weak targeting of exosomes limit its clinical application. For this reason, further exploration is needed to optimize the above problems and facilitate future functional studies of exosomes. In this paper, the origin, classification, preparation and characterization, storage stability and applications of exosome delivery system are summarized and discussed by searching a large number of literatures.

Exosomal Formulation Escalates Cellular Uptake of Honokiol Leading to the Enhancement of Its Antitumor Efficacy

Honokiol is a phytochemical isolated from the Magnolia plant. It exhibits significant antitumor activity against a variety of cancer cell types via targeting of critical mediators of tumor progression, stromal remodeling, and chemoresistance. However, poor bioavailability and inefficient tumor uptake remain some of the hurdles in its translation as a therapeutically useful drug. Here, we developed a nanoformulation of honokiol using mesenchymal stem cell-derived exosomes, which are nonimmunogenic and express surface markers to support their tumor-targeted delivery. Maximum entrapment of honokiol occurred when it was mixed in a 1:4 weight ratio with exosomes and subjected to six cycles of sonication. Dynamic light scattering analysis demonstrated that the average size (∼175.3 nm), polydispersity (∼0.11), and integrity (∼12.9 mV) of exosomes remained in the desirable range post honokiol encapsulation. Exosome-encapsulated honokiol exhibited significantly higher therapeutic efficacy over the free honokiol in WST-1 growth and long-term clonogenicity assays. Flow cytometry-based cell cycle and live/dead cell assay, respectively, confirmed the enhanced effect of exosomal honokiol formulation on cell cycle arrest and apoptosis induction. More significant alterations in the expression of cell cycle- and survival-associated proteins were also observed in cancer cells treated with exosomal honokiol over free honokiol. Higher intracellular accumulation of honokiol was recorded in cancer cells treated with equivalent doses of honokiol as compared to the free honokiol. Together, our work is the first demonstration of exosomal encapsulation of honokiol and its improved antitumor efficacy resulting from improved cellular uptake.

Engineered Extracellular Vesicles: Tailored-Made Nanomaterials for Medical Applications

Extracellular vesicles (EVs) are emerging as promising nanoscale therapeutics due to their intrinsic role as mediators of intercellular communication, regulating tissue development and homeostasis. The low immunogenicity and natural cell-targeting capabilities of EVs has led to extensive research investigating their potential as novel acellular tools for tissue regeneration or for the diagnosis of pathological conditions. However, the clinical use of EVs has been hindered by issues with yield and heterogeneity. From the modification of parental cells and naturally-derived vesicles to the development of artificial biomimetic nanoparticles or the functionalisation of biomaterials, a multitude of techniques have been employed to augment EVs therapeutic efficacy. This review will explore various engineering strategies that could promote EVs scalability and therapeutic effectiveness beyond their native utility. Herein, we highlight the current state-of-the-art EV-engineering techniques with discussion of opportunities and obstacles for each. This is synthesised into a guide for selecting a suitable strategy to maximise the potential efficacy of EVs as nanoscale therapeutics.

Engineering of Exosomes: Steps Towards Green Production of Drug Delivery System

Targeting of therapeutic agents to their specific site of action not only increases the treatment efficacy, but also reduces systemic toxicity. Therefore, various drug delivery systems (DDSs) have been developed to achieve this target. However, most of those DDSs have several issues regarding biocompatibility and environmental hazard. In contrast to the synthetic DDSs, exosome-based natural carriers are biocompatible, biodegradable and safe for the environment. Since exosomes play a role in intercellular communication, they have been widely utilized as carriers for different therapeutic agents. This article was aimed to provide an overview of exosomes as an environment-friendly DDS in terms of engineering, isolation, characterization, application and limitation.

Ethnopharmacology of Fruit Plants: A Literature Review on the Toxicological, Phytochemical, Cultural Aspects, and a Mechanistic Approach to the Pharmacological Effects of Four Widely Used Species

Fruit plants have been widely used by the population as a source of food, income and in the treatment of various diseases due to their nutritional and pharmacological properties. The aim of this study was to review information from the most current research about the phytochemical composition, biological and toxicological properties of four fruit species widely used by the world population in order to support the safe medicinal use of these species and encourage further studies on their therapeutic properties. The reviewed species are: Talisia esculenta, Brosimum gaudichaudii, Genipa americana, and Bromelia antiacantha. The review presents the botanical description of these species, their geographical distribution, forms of use in popular medicine, phytochemical studies and molecules isolated from different plant organs. The description of the pharmacological mechanism of action of secondary metabolites isolated from these species was detailed and toxicity studies related to them were reviewed. The present study demonstrates the significant concentration of phenolic compounds in these species and their anti-inflammatory, anti-tumor, photosensitizing properties, among others. Such species provide important molecules with pharmacological activity that serve as raw materials for the development of new drugs, making further studies necessary to elucidate mechanisms of action not yet understood and prove the safety for use in humans.

Biomimetic nanovesicle design for cardiac tissue repair

Cardiovascular disease is a major cause of mortality and morbidity worldwide. Exosome therapies are promising for cardiac repair. Exosomes transfer cargo between cells, have high uptake by native cells and are ideal natural carriers for proteins and nucleic acids. Despite their proreparative potential, exosome production is dependent on parent cell state with typically low yields and cargo variability. Therefore, there is potential value in engineering exosomes to maximize their benefits by delivering customized, potent cargo for cardiovascular disease. Here, we outline several methods of exosome engineering focusing on three important aspects: optimizing cargo, homing to target tissue and minimizing clearance. Finally, we put these methods in context of the cardiac field and discuss the future potential of vesicle design.

Exosome: a significant nano-scale drug delivery carrier

In recent years, due to the limitations of the nature of therapeutic agents, many synthetic nano-delivery systems have emerged to enhance the efficacy of drugs. Extracellular vesicles are currently a class of natural nano-scale drug carriers released by cells. As a tiny vesicle with a lipid bilayer membrane that can be secreted by most cells in the body, exosomes carry and transmit important signal molecules, Therefore, they have been a research hotspot in biomedicine and biomaterials due to their size advantages and huge potential in drug therapy. Many people are optimistic about the clinical application prospects of exosomes and are actively exploring the broad functions of exosomes and developing exosome therapeutic agents to make positive contributions to human health. In this review, we provide basic knowledge and focus on summarizing the advantages of exosomes as drug carriers, methods of loading drugs, targeting strategies, in vivo and in vitro tracing methods, and some of the latest developments in exosomes as drug carriers. In particular, the review provides an outlook for this field.

In vitro evaluation and molecular docking of QS-21 and quillaic acid from Quillaja saponaria Molina as gastric cancer agents

The cytotoxic mechanism of the saponin QS-21 and its aglycone quillaic acid (QA) was studied on human gastric cancer cells (SNU1 and KATO III). Both compounds showed in vitro cytotoxic activity with IC₅₀ values: 7.1 μM (QS-21) and 13.6 μM (QA) on SNU1 cells; 7.4 μM (QS-21) and 67 μM (QA) on KATO III cells. QS-21 and QA induce apoptosis on SNU1 and KATO III, as demonstrated by TUNEL, Annexin-V and Caspase Assays. Additionally, we performed in silico docking studies simulating the binding of both triterpenic compounds to key proteins involved in apoptotic pathways. The binding energies (∆G_bin) thus calculated, suggest that the pro-apoptotic protein Bid might be a plausible target involved in the apoptotic effect of both triterpenic compounds. Although QA shows some antiproliferative effects on SNU1 cells cultured in vitro, our results suggest that QS-21 is a more powerful antitumor agent, which merits further investigation regarding their properties as potential therapeutic agents for gastric cancer.

Use of exosomes as vectors to carry advanced therapies

Exosomes are microvesicles of nanometric size involved in the communication between cells and tissues. Inside their bilipidic membrane they carry nucleic acids such as cargos (DNA, miRNA, etc.). Some of the advantages that make exosomes very attractive therapeutic vehicles are (i) their tropism through different tissues, (ii) the ability to pass biological barriers and (iii) the protection of the encapsulated material from the immune system and degradation. Viruses are some of the most widely employed gene therapy vehicles; however, they are still facing many problems, such as inefficient tropism to damaged areas and their elimination by the immune system. One of the functions attributed to exosomes is the elimination of substances that could be harmful to the cell, including viruses. Recently it has been investigated whether complete viruses or part of them could be encapsulated in exosomes, for a new viral-exosome gene therapy approach. Moreover, nanotechnology is another type of advanced therapy (together with gene and cell therapies) that can be used, among other utilities, to transfer genetic material. Recently the field of encapsulation of nanomaterials in exosomes, with or without gene transfer, is increasing. In this review we will summarize all of those studies.

Not all saponins have a greater antiprotozoal activity than their related sapogenins

The antiprotozoal effect of saponins varies according to both the structure of the sapogenin and the composition and linkage of the sugar moieties to the sapogenin. The effect of saponins on protozoa has been considered to be transient as it was thought that when saponins were deglycosilated to sapogenins in the rumen they became inactive; however, no studies have yet evaluated the antiprotozoal effect of sapogenins compared to their related saponins. The aims of this study were to evaluate the antiprotozoal effect of eighteen commercially available triterpenoid and steroid saponins and sapogenins in vitro, to investigate the effect of variations in the sugar moiety of related saponins and to compare different sapogenins bearing identical sugar moieties. Our results show that antiprotozoal activity is not an inherent feature of all saponins and that small variations in the structure of a compound can have a significant influence on their biological activity. Some sapogenins (20(S)-protopanaxatriol, asiatic acid and madecassic acid) inhibited protozoa activity to a greater extent than their corresponding saponins (Re and Rh₁ and asiaticoside and madecassoside), thus the original hypothesis that the transient nature of the antiprotozoal action of saponins is due to the deglycosilation of saponins needs to be revisited.

A Seed-Specific Regulator of Triterpene Saponin Biosynthesis in Medicago truncatula

Plants produce a vast array of defense compounds to protect themselves from pathogen attack or herbivore predation. Saponins are a specific class of defense compounds comprising bioactive glycosides with a steroidal or triterpenoid aglycone backbone. The model legume Medicago truncatula synthesizes two types of saponins, hemolytic saponins and nonhemolytic soyasaponins, which accumulate as specific blends in different plant organs. Here, we report the identification of the seed-specific transcription factor TRITERPENE SAPONIN ACTIVATION REGULATOR3 (TSAR3), which controls hemolytic saponin biosynthesis in developing M. truncatula seeds. Analysis of genes that are coexpressed with TSAR3 in transcriptome data sets from developing M. truncatula seeds led to the identification of CYP88A13, a cytochrome P450 that catalyzes the C-16α hydroxylation of medicagenic acid toward zanhic acid, the final oxidation step of the hemolytic saponin biosynthesis branch in M. truncatula In addition, two uridine diphosphate glycosyltransferases, UGT73F18 and UGT73F19, which glucosylate hemolytic sapogenins at the C-3 position, were identified. The genes encoding the identified biosynthetic enzymes are present in clusters of duplicated genes in the M. truncatula genome. This appears to be a common theme among saponin biosynthesis genes, especially glycosyltransferases, and may be the driving force of the metabolic evolution of saponins.

Mitigation of Rumen Methane Emissions with Foliage and Pods of Tropical Trees

Simple Summary

Methane produced by enteric fermentation contributes to the emission of greenhouse gases (GHG) into the atmosphere. Methane is one of the GHG arising from anthropogenic activities with the greater contribution to global warming. This paper provides a brief introduction to the potential use of tropical foliage trees, pods, and secondary metabolites to reduce methane emissions from ruminant supply chains. A better knowledge of the available strategies for efficient foliage use in the tropics is essential in order to ensure increasing livestock production while preserving the environment. The mitigation of rumen methane production through the use of the foliage and metabolites of tropical trees represents an interesting challenge for scientists working in the field of ruminant nutrition.

Abstract

Methane produced by enteric fermentation contributes to the emission of greenhouse gases (GHG) into the atmosphere. Methane is one of the GHG resulting from anthropogenic activities with the greater global warming contribution. Ruminant production systems contribute between 18% and 33% of methane emissions. Due to this, there has been growing interest in finding feed alternatives which may help to mitigate methane production in the rumen. The presence of a vast range of secondary metabolites in tropical trees (coumarins, phenols, tannins, and saponins, among others) may be a valuable alternative to manipulate rumen fermentation and partially defaunate the rumen, and thus reduce enteric methane production. Recent reports suggest that it is possible to decrease methane emissions in sheep by up to 27% by feeding them saponins from the tea leaves of Camellia sinensis; partial defaunation (54%) of the rumen has been achieved using saponins from Sapindus saponaria. The aim of this review was to collect, analyze, and interpret scientific information on the potential of tropical trees and their secondary metabolites to mitigate methane emissions from ruminants.

Extracellular Vesicle- and Extracellular Vesicle Mimetics-Based Drug Delivery Systems: New Perspectives, Challenges, and Clinical Developments

Extracellular vesicles (EVs) are small membrane-based nanovesicles naturally released from cells. Extracellular vesicles mimetics (EVMs) are artificial vesicles engineered from cells or in combination with lipid materials, and they mimic certain characteristics of EVs. As such, EVs facilitate intracellular communication by carrying and delivering biological materials, such as proteins, lipids, and nucleic acids, and they have been found to find organ tropism in preclinical studies. Because of their native structure and characteristics, they are considered promising drug carriers for future clinical use. This review outlines the origin and composition of natural EVs and EVM engineering and internalization. It then details different loading approaches, with examples of the drug delivery of therapeutic molecules. In addition, the advantages and disadvantages of loading drugs into EVs or EVMs as a drug delivery system are discussed. Finally, the advantages of EVMs over EVs and the future clinical translation of EVM-based drug delivery platforms are outlined.

Hyaluronidase inhibitory saponins and a trypanocidal isoflavonoid from the aerial parts of Oxytropis lanata

A chemical examination of an extract from the aerial part of Oxytropis lanata led to the isolation and identification of 36 compounds, including saponins, isoflavonoids, oxazoles, and glycosides. The three among them were previously unreported oleanane-type saponins. In trypanocidal screening, 5,7,4'-trihydroxyisoflavone showed inhibitory activity against Trypanosoma congolense (IC₅₀ = 10.5 μM), the causative agent of African trypanosomosis in animals; this activity was similar to that of active compounds from the roots of this plant. O. lanata is known to be a traditional medicinal plant in Mongolia for the treatment of inflammatory diseases. The anti-hyaluronidase effect of saponins 3, 5, 8, and 9, (IC₅₀ = 0.15-0.22 mM) was stronger than that of sodium cromoglicate, which was used as a reference drug (IC₅₀ = 0.37 mM). The chemical structures of the new saponins were determined based on HRFABMS, ¹H and ¹³C NMR, ¹H-¹H COSY, HMQC, HMBC, and ROESY spectroscopic data along with chemical procedures.

Surface activity and foaming properties of saponin-rich plants extracts

Saponins are amphiphilic glycosidic secondary metabolites produced by numerous plants. So far only few of them have been thoroughly analyzed and even less have found industrial applications as biosurfactants. In this contribution we screen 45 plants from different families, reported to be rich in saponins, for their surface activity and foaming properties. For this purpose, the room-temperature aqueous extracts (macerates) from the alleged saponin-rich plant organs were prepared and spray-dried under the same conditions, in presence of sodium benzoate and potassium sorbate as preservatives and drying aids. For 15 selected plants, the extraction was also performed using hot water (decoction for 15 min) but high temperature in most cases deteriorated surface activity of the extracts. To our knowledge, for most of the extracts this is the first quantitative report on their surface activity. Among the tested plants, only 3 showed the ability to reduce surface tension of their solutions by more than 20 mN/m at 1% dry extract mass content. The adsorption layers forming spontaneously on the surface of these extracts showed a broad range of surface dilational rheology responses - from null to very high, with surface dilational elasticity modulus, E' in excess of 100 mN/m for 5 plants. In all cases the surface dilational response was dominated by the elastic contribution, typical for saponins and other biosurfactants. Almost all extracts showed the ability to froth, but only 32 could sustain the foam for more than 1 min (for 11 extracts the foams were stable during at least 10 min). In general, the ability to lower surface tension and to produce adsorbed layers with high surface elasticity did not correlate well with the ability to form and sustain the foam. Based on the overall characteristics, Saponaria officinalis L. (soapwort), Avena sativa L. (oat), Aesculus hippocastanum L. (horse chestnut), Chenopodium quinoa Willd. (quinoa), Vaccaria hispanica (Mill.) Rauschert (cowherb) and Glycine max (L.) Merr. (soybean) are proposed as the best potential sources of saponins for surfactant applications in natural cosmetic and household products.

New lupane bidesmosides exhibiting strong cytotoxic activities in vitro

Triterpene bidesmosides are considered as highly cytotoxic saponins, usually less toxic against normal cells than monodesmosides, and less haemolytic. Biological activity of the betulin-type bidesmosides, rarely found in Nature, and seldom prepared due to serious synthetic problems, is poorly recognized. We report herein a protocol for the preparation of disubstituted lupane saponins (betulin bidesmosides) by treatment of their benzoates with potassium carbonate in dichloromethane / methanol solution. Cytotoxicity of all compounds was tested in vitro for a series of cancer cell lines, as well as normal human skin BJ fibroblasts. Presence of l-rhamnose moiety is crucial for cytotoxicity of betulin bidesmosides. On the other hand, l-arabinose fragment connected to lupane C-3 carbon atom significantly decreases activity. Presented results clearly show that betulin bidesmosides have significant clinical potential as anticancer agents.

Impact of moist cooking methods on colour, anti-nutritive compounds and phenolic metabolites in African nightshade (Solanum retroflexum Dun.)

Not much information is available on the changes of phenolic metabolites or anti-nutritive compounds in African nightshade leaves during moist cooking. Blanching methods (boiling, microwave, and steaming) using 5-20% lemon juice was compared with the plain water as a control. Lemon juice at 20% significantly increased the total colour differences (ΔE). Chlorophyll content and the overall acceptance were highest for samples steamed in 5% lemon juice. Steam blanching in plain water reduced the tannin, oxalate and phytate contents but showed higher comparative peak responses for steroidal saponins. Neochlorogenic, chlorogenic, and caffeoylmalic acid, kaempferol O-rhamnosyl hexoside, and rutin were identified blanched leaves. Principle component analysis (PCA) discriminated between blanching treatments while Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) showed clear group distinctions between the blanching treatments. Chlorogenic acid, neochlorogenic acid and cryptochlorogenic acid were the responsible biomarkers for the separation of the steam blanching treatments. Thus, steam blanching preserves the functional compounds in nightshade leaves.

Enhancing the Membranolytic Activity of Chenopodium quinoa Saponins by Fast Microwave Hydrolysis

Saponins are plant secondary metabolites. There are associated with defensive roles due to their cytotoxicity and are active against microorganisms. Saponins are frequently targeted to develop efficient drugs. Plant biomass containing saponins deserves sustained interest to develop high-added value applications. A key issue when considering the use of saponins for human healthcare is their toxicity that must be modulated before envisaging any biomedical application. This can only go through understanding the saponin-membrane interactions. Quinoa is abundantly consumed worldwide, but the quinoa husk is discarded due to its astringent taste associated with its saponin content. Here, we focus on the saponins of the quinoa husk extract (QE). We qualitatively and quantitively characterized the QE saponins using mass spectrometry. They are bidesmosidic molecules, with two oligosaccharidic chains appended on the aglycone with two different linkages; a glycosidic bond and an ester function. The latter can be hydrolyzed to prepare monodesmosidic molecules. The microwave-assisted hydrolysis reaction was optimized to produce monodesmosidic saponins. The membranolytic activity of the saponins was assayed based on their hemolytic activity that was shown to be drastically increased upon hydrolysis. In silico investigations confirmed that the monodesmosidic saponins interact preferentially with a model phospholipid bilayer, explaining the measured increased hemolytic activity.

HPLC characterization of molluscicidal component of Tamarindus indica and its mode of action on nervous tissue of Lymnaea acuminata

BACKGROUND

Fasciolosis is a water-borne disease with gastropods snail (Lymnaea acuminata) act as key-link is still burden for mankind especially in developing countries. Snail control is one of the important tools to trim down the frequency of fasciolosis.

OBJECTIVE

To evaluate the toxic effect and inhibitory potential of plant Tamarindus indica and their active constituent on the key enzyme of nervous tissue of snail L. acuminata.

METHOD

The present study deals with the chromatographic isolation and identification of molluscicidal component from Tamarindus indica bark and its effects on enzymes activities of vector snail L. acuminata.

RESULT

The toxicity study reveals that among all organic extract ethanol extract of T. indica bark (96 h LC50:127.4 mgL-1) was more effective than other organic extracts. The 96 h LC50 of column purified fraction of T. indica bark was 13.78 mgL-1 respectively. Saponin was isolated, characterized and identified as active molluscicidal component in the bark of T. indica by column chromatography, TLC and HPLC chromatographic methods. The in vivo and in vitro treatment of column purified fraction and saponin has significant inhibition in enzyme AChE, ACP and ALP activities. The study of inhibition kinetics indicates that inhibition of AChE and ALP is competitive, while ACP is uncompetitive in both the treatments.

CONCLUSION

Thus inhibition of these enzyme activities by T. indica bark column purified fraction and saponin in the snail L. acuminata may be the cause of its molluscicidal activity which leads snail death.

Phytochemical Study on Antioxidant and Antiproliferative Activities of Moroccan Caralluma europaea Extract and Its Bioactive Compound Classes

Background

Caralluma europaea (C. europaea) is a medicinal plant used in Moroccan popular medicine. Objective of the Study. The present work was aimed at identifying the chemical composition and the antioxidant and antiproliferative activities of hydroethanolic and bioactive compound classes of C. europaea) is a medicinal plant used in Moroccan popular medicine. Materials and Methods. The chemical composition was analyzed using HPLC. The antioxidant power was determined using both DPPH and FRAP assays. The antiproliferative activity was effectuated against cancerous cells using WST-1.

Results

The chemical analysis showed the presence of bioactive constituents such as quercetin, myricetin, and hesperetin. The polyphenol and flavonoid contents were estimated at 51.42 mg GA/g and 20.06 mg EQ/g, respectively. The EC₅₀ values of FRAP assay of hydroethanolic, flavonoid, saponin, and mucilage extracts were 5.196 mg/ml, 4.537 mg/ml, 3.05 mg/ml, and 6.02 mg/ml, respectively. The obtained IC₅₀ values with the DPPH test were 1.628 mg/ml, 1.05 mg/ml, 1.94 mg/ml, and 9.674 mg/ml, respectively. Regarding MDA-MB-231, saponins were highly effective even with the lowest concentration (15.62 μg/ml). The flavonoids decreased the cell viability with IC₅₀ values of 43.62 ± 0.06 μg/ml). The flavonoids decreased the cell viability with IC₅₀ values of 43.62 ± 0.06 μg/ml). The flavonoids decreased the cell viability with IC₅₀ values of 43.62 ± 0.06 

Conclusion

The present results suggest that C. europaea) is a medicinal plant used in Moroccan popular medicine.

The Gut Microbiota in Camellia Weevils Are Influenced by Plant Secondary Metabolites and Contribute to Saponin Degradation

The gut microbiome may play an important role in insect-plant interactions mediated by plant secondary metabolites, but the microbial communities and functions of toxic plant feeders are still poorly characterized. In the present study, we provide the first metagenome of gut bacterial communities associated with a specialist weevil feeding on saponin-rich and saponin-low camellia seeds, and the results reveal the correlation between bacterial diversity and plant allelochemicals. We also used cultured microbes to establish their saponin-degradative capacity outside the insect. Our results provide new experimental context to better understand how gut microbial communities are influenced by plant secondary metabolites and how the resistance mechanisms involving microbes have evolved to deal with the chemical defenses of plants.

The camellia weevil (CW [Curculio chinensis]) is a notorious host-specific predator of the seeds of Camellia species in China, causing seed losses of up to 60%. The weevil is capable of overcoming host tree chemical defenses, while the mechanisms of how these beetles contend with the toxic compounds are still unknown. Here, we examined the interaction between the gut microbes of CW and camellia seed chemistry and found that beetle-associated bacterial symbionts mediate tea saponin degradation. We demonstrate that the gut microbial community profile of CW was significantly plant associated, and the gut bacterial community associated with CW feeding on Camellia oleifera seeds is enriched with genes involved in tea saponin degradation compared with those feeding on Camellia sinensis and Camellia reticulata seeds. Twenty-seven bacteria from the genera Enterobacter, Serratia, Acinetobacter, and Micrococcus subsisted on tea saponin as a sole source of carbon and nitrogen, and Acinetobacter species are identified as being involved in the degradation of tea saponin. Our results provide the first metagenome of gut bacterial communities associated with a specialist insect pest of Camellia trees, and the results are consistent with a potential microbial contribution to the detoxification of tree-defensive chemicals.

IMPORTANCE The gut microbiome may play an important role in insect-plant interactions mediated by plant secondary metabolites, but the microbial communities and functions of toxic plant feeders are still poorly characterized. In the present study, we provide the first metagenome of gut bacterial communities associated with a specialist weevil feeding on saponin-rich and saponin-low camellia seeds, and the results reveal the correlation between bacterial diversity and plant allelochemicals. We also used cultured microbes to establish their saponin-degradative capacity outside the insect. Our results provide new experimental context to better understand how gut microbial communities are influenced by plant secondary metabolites and how the resistance mechanisms involving microbes have evolved to deal with the chemical defenses of plants.

Effects of Different Drying Methods on Untargeted Phenolic Metabolites, and Antioxidant Activity in Chinese Cabbage (Brassica rapa L. subsp. chinensis) and Nightshade (Solanum retroflexum Dun.)

Chinese cabbage (Brassica rapa L. subsp. chinensis) and Nightshade (Solanum retroflexum are popular traditional leafy vegetables consumed predominantly by rural Africans. Sun drying is adopted as a traditional method of postharvest preservation to store theses leaves during off seasons. The influence of different types of postharvest processing treatments, such as conventional oven drying, solar cabinet drying, sun drying and freeze drying, on the changes on colour properties and antioxidant components were investigated. Freeze-drying retained the ascorbic acid content, antioxidant activities, total chlorophyll content, green colour by reducing the colour difference (∆E). With regard to Chinese cabbage and Nightshade leaves, sun and microwave drying respectively had the most negative impact on all the identified phenolic compounds. The OPLS-DA and the UPLC–QTOF/MS and chemometric approach showed kaempferol-3-O-sophoroside, kaempferol-3-sophorotrioside-7-glucoside and hydroxyoctadecenedioic acid as the markers responsible for the separation of sun-dried samples from the other drying treatments in Chinese cabbage. Sinapoyl malate was not detected in sun-dried samples. Caffeoylmalic acid was identified as the marker compound to separate the other drying treatments from the microwave dried samples of Nightshade leaves. Trihydroxyoctadecadiene derivative and hydroxyoctadecanedioic acid were detected in microwaved samples. Due to the cost effectiveness, solar dryer cabinet treatment was recommended for drying both vegetables. The proximate analysis of solar dried functional powder of Chinese cabbage and Nightshade vegetables demonstrated higher contents of protein and dietary fibre.

Bio-selective hormonal breast cancer cytotoxic and antioxidant potencies of Melia azedarach L. wild type leaves

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1st report on physical qualities and phytochemical content of M. azedarach wild type leaves extract and fractions.

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Ethyl acetate fraction was the most active against bio-selective hormonal breast cancer T47D cell cytotoxic and antioxidant activities.

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The phytochemicals content of active fraction was steroids and triterpene saponin, limonoid (toosendanin, meliarachin, salannin, salannal, 12-hydroxyamoorastatin, meliacarpinin and its derivates), and flavonoids (quercetin glycoside).

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Significant (p < 0.05) correlations were observed between TPC, IC₅₀DPPH, FRAP and IC₅₀T47D.

Melia azedarach L. is used widely in traditional medicine for local or systemic ailments. Although studies exist on phytochemicals and potencies of Chinese and Indian cultivars of Melia, the present study investigated in vitro antioxidant properties of Melia wild type and its cytotoxicity against T47D cell. The ethanolic extract of the Melia leaves was fractionated with n-hexane, ethyl acetate and water, and the secondary metabolites were obtained. The antioxidant properties were determined with IC₅₀ DPPH (2,2-diphenyl-1-pycrylhydrazyl) radical and FRAP (ferric reducing antioxidant power), while the cytotoxicity was determined with the MTT method. The total phenolic (TPC) and β-sitosterol (SC) contents were also measured. The results showed that the ethyl acetate fraction had higher antioxidant and cytotoxic activities (IC₅₀ 211.89 ± 10.86 and 147.90 ± 8.49 μg/mL, respectively) than others. Significant (p < 0.05) correlations were observed between TPC, IC₅₀DPPH, FRAP and IC₅₀T47D. LC-EI MS analysis of the ethyl acetate fraction revealed the steroid and triterpenoid saponins, limonoids and quercetin glycosides, which influenced the medicinal properties of the Melia leaves. Melia azedarach L. wild type leaf extracts are a promising natural resource for managing breast cancer.

Cytotoxic, Antiproliferation, and Necrosis Effects of the n-Hexane Fraction Extract of Gendola Leaf (Basella rubra Linn.)

Breast cancer is the second most common cancer in women. Several studies have been conducted on natural materials to see the ability of its activity as a new anticancer compound. The purpose of this study was to determine the cytotoxic activity of Gendola leaf (Basella rubra Linn.) extracts and fractions, in inhibiting proliferation and inducing apoptosis of T47D breast cancer cells. The design of this study was experimental laboratory research using the in-vitro method. Cytotoxic and anti-proliferation tests on T47D cancer were using the MTT method, and the apoptosis test was using the flow cytometry method. Cytotoxic of extracts and fractions of n-hexane Gendola leaves were tested with a concentration series of 1000; 500; 250; 125; 62.5 μg/mL and doxorubicin was studied a series concentration of 0.5; 0.25; 0.125; 0.0625; 0.03125 μg/mL for 24 hours. Antiproliferation test used n-hexane fraction with a concentration series of 1IC50, ½IC50, ¼IC50, and ⅛IC50 with an incubation time of 24 and 48 hours. Apoptosis test utilized n-hexane fraction with a concentration series of 1IC50, ½IC50 with an incubation time of 24 hours. The results showed that the ethanol extract had IC50 424 μg/mL, n-hexane fraction 292 μg/mL. The n-hexane fraction had an anti-proliferation effect at a concentration of 1IC50 within 32 hours but was unable to induce T47D cell apoptosis. These results indicate that the n-hexane fraction of Gendola leaf has a cytotoxic effect, which can inhibit proliferation, that is unable to induce apoptosis but induce necrosis of T47D breast cancer cells.

Biologically Active Compounds and Antioxidant Activity of the Plants from CSBG SB RAS Collection of the Rosaceae Family (I)

The article presents Dara on the content of biologically active compounds (BAC) and the total phenolic antioxidants activity (TPA) evaluated for leaves and inflorescences of eight species from the Rosaceae family: Padus avium, Malus baccata, Alhemilla vulgaris, Potentilla inquinans, Filipendula vulgaris, F. palmata, Sanguisorba officinalis, S. alpina. It was determined that leaves and inflorescences contain flavonols, catechins, tannins, carotenoids, saponins, pectin substances. Usually, woody plants tend to accumulate less BAC and TPA than herbs. The highest level of flavonols and tannins was registered in inflorescences of F. vulgaris (12.25% and 45.02 %). The content of pectin substances was quite high, with the biggest share of protopectins (4.4-10.65%). The maximum quantity of catechins (4.76%) was found in the leaves of F. palmata, saponins – in the inflorescences of M. baccata (20.77%). The highest content of carotenoids was found in the leaves of plants, most notably in P. inquinans (1.00 mg/g). The highest antioxidant activity was recorded for water-ethanol extracts from inflorescences (up to 7.77 mg/g) and leaves (2.11 mg/g) of F. vulgaris and A. vulgaris plants due to increased content of phenolic compounds, in particular flavonols and tannins, compared to the other species.

Antiproliferative activity of new pentacyclic triterpene and a saponin from Gladiolus segetum Ker-Gawl corms supported by molecular docking study

A new triterpenoidal saponin identified as 3-O-[β-d-glucopyranosyl-(1 → 2)-β-d-glucopyranosyl-(1 → 4)-β-d-xylopyranosyl]-2β,3β,16α-trihydroxyolean-12-en-23,28-dioic acid-28-O-α-l-rhamnopyranosyl-(1 → 4)-α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranosyl-(1 → 2)-α-l-arabinopyranoside 1 together with a new oleanane triterpene identified as 2β,3β,13α,22α-tetrahydroxy olean-23,28-dioic acid 2 and 6 known compounds (3–8) have been isolated from Gladiolus segetum Ker-Gawl corms. The structural elucidation of the isolated compounds was confirmed using different chemical and spectroscopic methods, including 1D and 2D NMR experiments as well as HR-ESI-MS. Moreover, the in vitro cytotoxic activity of the fractions and that of the isolated compounds 1–8 were investigated against five human cancer cell lines (PC-3, A-549, HePG-2, MCF-7 and HCT-116) using doxorubicin as a reference drug. The results showed that the saponin fraction exhibited potent in vitro cytotoxic activity against the five human cancer cell lines, whereas the maximum activity was exhibited against the PC-3 and A-549 cell lines with the IC₅₀ values of 1.13 and 1.98 μg mL⁻¹, respectively. In addition, compound 1 exhibited potent activity against A-549 and PC-3 with the IC₅₀ values of 2.41 μg mL⁻¹ and 3.45 μg mL⁻¹, respectively. Interestingly, compound 2 showed the maximum activity against PC-3 with an IC₅₀ of 2.01 μg mL⁻¹. These biological results were in harmony with that of the molecular modeling study, which showed that the cytotoxic activity of compound 2 might occur through the inhibition of the HER-2 enzyme.

A new triterpenoidal saponin 1, a new oleanane triterpene 2, and 6 known compounds (3–8) have been isolated from Gladiolus segetum Ker-Gawl corms.

Seeds

A wide variety of plant species provide edible seeds. Seeds are the dominant source of human calories and protein. The most important and popular seed food sources are cereals, followed by legumes and nuts. Their nutritional content of fiber, protein, and monounsaturated/polyunsaturated fats make them extremely nutritious. They are important additions to our daily food consumption. When consumed as part of a healthy diet, seeds can help reduce blood sugar, cholesterol, and blood pressure.

The influence of steroidal and triterpenoid saponins on monolayer models of the outer leaflets of human erythrocytes, E. coli and S. cerevisiae cell membranes

The present paper discusses the use of monolayers of lipid mixtures mimicking the composition of biological membranes of bacteria, erythrocyte and yeast in the context of the anti-bacterial, hemolytic and anti-fungal activity of saponins. Saponins are plant-produced glycosidic biosurfactants with either steroidal or triterpenoidal aglycone. In the present study we used digitonin as a representative steroidal saponin (extracted from Digitalis purpurea) and a mixture of triterpenoid saponins from Quillaja saponaria Molina. The effect of saponins was studied first on monolayers consisting of single lipids characteristic for the given type of biological membrane, and then - on model mixed lipid monolayers. Finally, the monolayers were formed from total lipid extracts of natural cell membranes (E. coli and S. cerevisiae) to verify the results obtained in the simplified models. The effect of saponins on monolayers was studied by a combination of surface pressure relaxation, infrared reflection - absorption spectroscopy (IRRAS) and fluorescence microscopy. In line with expectations, sterols (cholesterol and ergosterol) play a major role in the saponin-lipid interactions in monolayers, which may explain especially the hemolytic and antifungal properties of saponins. In contrast, bacterial membranes are devoid of sterols, although the presence of similar compounds may be responsible for their affinity to saponins. Nevertheless, the effect of saponins on bacterial models is less pronounced than for the erythrocyte or fungal ones.

Engineered Extracellular Vesicles as a Reliable Tool in Cancer Nanomedicine

Fast diagnosis and more efficient therapies for cancer surely represent one of the huge tasks for the worldwide researchers' and clinicians' community. In the last two decades, our understanding of the biology and molecular pathology of cancer mechanisms, coupled with the continuous development of the material science and technological compounds, have successfully improved nanomedicine applications in oncology. This review argues on nanomedicine application of engineered extracellular vesicles (EVs) in oncology. All the most innovative processes of EVs engineering are discussed together with the related degree of applicability for each one of them in cancer nanomedicines.

The opportunistic effect of exosomes on Non-Hodgkin Lymphoma microenvironment modulation

There has been a shift in the paradigm of Non-Hodgkin lymphomas, changing from the classical genetic aberration-based model to a more complex and dynamic model involving tumor microenvironment interactions. In this instance, exosomes have emerged as important mediators in intercellular communication by providing survival and proliferation signals, licensing immune evasion and acquisition of drug resistance. The capability to transfer molecular cargo made exosomes a focus of research to understand cancer pathogenesis and its progression pathways. Several studies identified exosomes transporting tumor-released components in peripheral blood and focused on understanding their clinical relevance in the diagnosis, prognostic and in monitoring cancer progression. Moreover, due to their biophysical properties and physiological function, exosomes have drawn attention as potential therapeutic target and drug delivery vehicles. This review will discuss the function of exosomes in Non-Hodgkin lymphomagenesis, highlight their potential as diagnosis and prognosis biomarkers, and as new therapeutic opportunities in lymphoma management.

Extracellular Vesicles in Modifying the Effects of Ionizing Radiation

Extracellular vesicles (EVs) are membrane-coated nanovesicles actively secreted by almost all cell types. EVs can travel long distances within the body, being finally taken up by the target cells, transferring information from one cell to another, thus influencing their behavior. The cargo of EVs comprises of nucleic acids, lipids, and proteins derived from the cell of origin, thereby it is cell-type specific; moreover, it differs between diseased and normal cells. Several studies have shown that EVs have a role in tumor formation and prognosis. It was also demonstrated that ionizing radiation can alter the cargo of EVs. EVs, in turn can modulate radiation responses and they play a role in radiation-induced bystander effects. Due to their biocompatibility and selective targeting, EVs are suitable nanocarrier candidates of drugs in various diseases, including cancer. Furthermore, the cargo of EVs can be engineered, and in this way they can be designed to carry certain genes or even drugs, similar to synthetic nanoparticles. In this review, we describe the biological characteristics of EVs, focusing on the recent efforts to use EVs as nanocarriers in oncology, the effects of EVs in radiation therapy, highlighting the possibilities to use EVs as nanocarriers to modulate radiation effects in clinical applications.

Small extracellular vesicle loading systems in cancer therapy: Current status and the way forward

Systemic chemotherapy is a conventional and important strategy for inhibition of cancer progression, but it is usually accompanied by various adverse effects. Targeting drug delivery systems, effective tools to avoid the adverse effects of chemotherapy, have been intensively studied and developed. Recently, the emerging application of exosomes and exosome-mimics (small extracellular vesicles [sEVs]) in targeted drug delivery and therapeutics has been widely appreciated. The sEVs-based delivery system comprises three basic components: vesicles, cargoes and surface decorations. In this article, we review the current status, existing challenges and future directions in this field from the following aspects: selection and production of vesicles; cargoes and methods to load them into vesicles; modifications to the surfaces of vesicles; as well as ways to prolong the half-life of sEVs in the circulation. Existing and emerging data indicate that sEVs are promising nanocarriers for clinical use, but additional efforts are needed to translate research findings into therapeutic products.

Structural characterisation of new immunoadjuvant saponins from leaves and the first study of saponins from the bark of Quillaja brasiliensis by liquid chromatography electrospray ionisation ion trap mass spectrometry

INTRODUCTION

Quillaja brasiliensis (St. A. -Hil. & Tul) Mart (Quillajaceae) is a species native to South America, which is rich in saponins. Saponins are used in different industries, so there is a constant demand for this type of compound. Based on the wide range of applications for the saponins found in this species, notably as immunoadjuvants, we conducted a comprehensive study of this tree and its saponins.

OBJECTIVE

The purpose of this work is to complete the characterisation of the immunoadjuvant saponin fraction from Q. brasiliensis leaves and further study the saponin fraction obtained from Q. brasiliensis bark.

METHODOLOGY

Saponin fractions were studied using mass spectrometry in combination with classical methods of monosaccharide and methylation analysis. We performed direct infusion and liquid chromatography/electrospray ionisation ion trap multiple-stage mass spectrometry (DI-ESI-IT-MSⁿ and LC-ESI-IT-MS² ).

RESULTS

Seventy-five saponins, 21 from leaves and 54 from bark, were tentatively identified according to their molecular mass, fragmentation pattern and chromatographic behaviour. This work represents the first investigation of saponins from the bark of Q. brasiliensis and some of them presented new structural motifs not previously reported in the genus Quillaja.

CONCLUSION

The efficiency and selectivity of the data dependent LC-MS² method allowed the rapid profiling of saponins from Q. brasiliensis. The results of the monosaccharide and methylation analysis performed in saponins from Q. brasiliensis fractions and Q. saponaria Molina (Quillajaceae) fraction gives further support to the structures proposed according to the mass spectral data, validating the strategy used in the present work.

Discrimination of Regioisomeric and Stereoisomeric Saponins from Aesculus hippocastanum Seeds by Ion Mobility Mass Spectrometry

Modern mass spectrometry methods provide a huge benefit to saponin structural characterization, especially when combined with collision-induced dissociation experiments to obtain a partial description of the saponin (ion) structure. However, the complete description of the structures of these ubiquitous secondary metabolites remain challenging, especially since isomeric saponins presenting small differences are often present in a single extract. As a typical example, the horse chestnut triterpene glycosides, the so-called escins, comprise isomeric saponins containing subtle differences such as cis-trans ethylenic configuration (stereoisomers) of a side chain or distinct positions of an acetyl group (regioisomers) on the aglycone. In the present paper, the coupling of liquid chromatography and ion mobility mass spectrometry has been used to distinguish regioisomeric and stereoisomeric saponins. Ion mobility arrival time distributions (ATDs) were recorded for the stereoisomeric and regioisomeric saponin ions demonstrating that isomeric saponins can be partially separated using ion mobility on a commercially available traveling wave ion mobility (TWIMS) mass spectrometer. Small differences in the ATD can only be monitored when the isomeric saponins are separated with liquid chromatography prior to the IM-MS analysis. However, gas phase separation between stereoisomeric and regioisomeric saponin ions can be successfully realized, without any LC separation, on a cyclic ion mobility-enabled quadrupole time-of-flight (Q-cIM-oaToF) mass spectrometer. The main outcome of the present paper is that the structural analysis of regioisomeric and stereoisomeric natural compounds that represents a real challenge can take huge advantages of ion mobility experiments but only if increased ion mobility resolution is attainable.