Methods of Betulin Extraction from Birch Bark

Antioxidant Activity, Antiproliferative Activity, Antiviral Activity, NO Production Inhibition, and Chemical Composition of Essential Oils and Crude Extracts of Leaves, Flower Buds, and Stems of Tetradenia riparia

The chemical composition of extracts (CEs) and essential oils (EOs) from Tetradenia riparia leaves, flower buds, and stems was analyzed. Antiproliferative activity against tumor cell lines, NO production inhibition, and antioxidant and antiviral activities were assessed. The CEs contained flavonoids, phenolic acids, coumarins, and saturated fatty acids. The EOs included monoterpenes, oxygenated sesquiterpenes, and diterpenes. NO production inhibition ranged from 76 to 247 µg mL-1, and antiproliferative activity exhibited GI50 between 20 and >204 µg mL-1, with low cytotoxicity (SI: 1.08 to 4.75). Reactive oxygen species inhibition ranged from 45 to 82%. Antioxidant activity varied when determined by the 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay (IC50: 0.51 to 8.47 mg mL-1) and ferric reducing antioxidant power (0.35 to 0.81 µM ferrous sulfate per mg). The reduction in β-carotene-linoleic acid co-oxidation varied between 76.13 and 102.25%. The total phenolic content of CEs and EOs was 10.70 to 111.68 µg gallic acid mg-1. Antiviral activity against herpes simplex virus type 1 (HSV-1) showed an EC50 between 9.64 and 24.55 µg mL-1 and an SI between 8.67 and 15.04. Leaf EOs exhibited an EC50 of 9.64 µg mL-1 and an SI of 15.04. Our study unveils the diverse chemical composition and multifaceted pharmacological properties of T. riparia, demonstrating its potential as a valuable source of bioactive compounds for therapeutic applications.

Drug Delivery Systems of Betulin and Its Derivatives: An Overview

Natural origin products are regarded as promising for the development of new therapeutic therapies with improved effectiveness, biocompatibility, reduced side effects, and low cost of production. Betulin (BE) is very promising due to its wide range of pharmacological activities, including its anticancer, antioxidant, and antimicrobial properties. However, despite advancements in the use of triterpenes for clinical purposes, there are still some obstacles that hinder their full potential, such as their hydrophobicity, low solubility, and poor bioavailability. To address these concerns, new BE derivatives have been synthesized. Moreover, drug delivery systems have emerged as a promising solution to overcome the barriers faced in the clinical application of natural products. The aim of this manuscript is to summarize the recent achievements in the field of delivery systems of BE and its derivatives. This review also presents the BE derivatives mostly considered for medical applications. The electronic databases of scientific publications were searched for the most interesting achievements in the last ten years. Thus far, it is mostly nanoparticles (NPs) that have been considered for the delivery of betulin and its derivatives, including organic NPs (e.g., micelles, conjugates, liposomes, cyclodextrins, protein NPs), inorganic NPs (carbon nanotubes, gold NPs, silver), and complex/hybrid and miscellaneous nanoparticulate systems. However, there are also examples of microparticles, gel-based systems, suspensions, emulsions, and scaffolds, which seem promising for the delivery of BE and its derivatives.

Induction of ferroptosis by natural products in non-small cell lung cancer: a comprehensive systematic review

Lung cancer is one of the leading causes of cancer-related deaths worldwide that presents a substantial peril to human health. Non-Small Cell Lung Cancer (NSCLC) is a main subtype of lung cancer with heightened metastasis and invasion ability. The predominant treatment approaches currently comprise surgical interventions, chemotherapy regimens, and radiotherapeutic procedures. However, it poses significant clinical challenges due to its tumor heterogeneity and drug resistance, resulting in diminished patient survival rates. Therefore, the development of novel treatment strategies for NSCLC is necessary. Ferroptosis was characterized by iron-dependent lipid peroxidation and the accumulation of lipid reactive oxygen species (ROS), leading to oxidative damage of cells and eventually cell death. An increasing number of studies have found that exploiting the induction of ferroptosis may be a potential therapeutic approach in NSCLC. Recent investigations have underscored the remarkable potential of natural products in the cancer treatment, owing to their potent activity and high safety profiles. Notably, accumulating evidences have shown that targeting ferroptosis through natural compounds as a novel strategy for combating NSCLC holds considerable promise. Nevertheless, the existing literature on comprehensive reviews elucidating the role of natural products inducing the ferroptosis for NSCLC therapy remains relatively sparse. In order to furnish a valuable reference and support for the identification of natural products inducing ferroptosis in anti-NSCLC therapeutics, this article provided a comprehensive review explaining the mechanisms by which natural products selectively target ferroptosis and modulate the pathogenesis of NSCLC.

Synthesis, Pharmacokinetic Profile, Anticancer Activity and Toxicity of the New Amides of Betulonic Acid-In Silico and In Vitro Study

Betulonic acid (B(O)A) is a pentacyclic lupane-type triterpenoid that widely exists in plants. There are scientific reports indicating anticancer activity of B(O)A, as well as the amides and esters of this triterpenoid. In the first step of the study, the synthesis of novel amide derivatives of B(O)A containing an acetylenic moiety was developed. Subsequently, the medium-soluble compounds (EB171 and EB173) and the parent compound, i.e., B(O)A, were investigated for potential cytotoxic activity against breast cancer (MCF-7 and MDA-MB-231) and melanoma (C32, COLO 829 and A375) cell lines, as well as normal human fibroblasts. Screening analysis using the WST-1 test was applied. Moreover, the lipophilicity and ADME parameters of the obtained derivatives were determined using experimental and in silico methods. The toxicity assay using zebrafish embryos and larvae was also performed. The study showed that the compound EB171 exhibited a significant cytotoxic effect on cancer cell lines: MCF-7, A-375 and COLO 829, while it did not affect the survival of normal cells. Moreover, studies on embryos and larvae showed no toxicity of EB171 in an animal model. Compared to EB171, the compound EB173 had a weaker effect on all tested cancer cell lines and produced less desirable effects against normal cells. The results of the WST-1 assay obtained for B(O)A revealed its strong cytotoxic activity on the examined cancer cell lines, but also on normal cells. In conclusion, this article describes new derivatives of betulonic acid-from synthesis to biological properties. The results allowed to indicate a promising direction for the functionalization of B(O)A to obtain derivatives with selective anticancer activity and low toxicity.

Obtaining New Biocompatible Composite Materials with Antibacterial Properties Based on Diatomite and Biologically Active Compounds

This study aimed to create new composite materials based on diatomite-a non-organic porous compound-through its surface modification with bioactive organic compounds, both synthetic and natural. Chloramphenicol, tetrahydroxymethylglycoluril and betulin were used as modifying substances. Composite materials were obtained by covering the diatomite surface with bioactive substance compounds as a solution and material dispersion in it. The materials were characterized by IR spectroscopy, SEM and X-ray photoelectron spectroscopy. For the biocomposites, the hemolytic effect, plasma proteins' adsorption on the surface and the antibacterial activity of the obtained materials were studied. Results show that the obtained materials are promising for medicine and agriculture.

Comparison of different extraction methods of active ingredients of Chinese medicine and natural products

Like other traditional medicine in the world, Chinese traditional medicine (CTM) has a long history, which is a treasure of the combination of medicine and Chinese classical culture even more than 5000 years. For thousands of years, CTM has made great contributions to the reproduction and health of the Chinese people. It was an efficient therapeutic tool under the guidance of Chinese traditional medical theory, its source is generally natural products, but there are also a small number of it are natural products after some processing methods. In fact, the definition of Chinese medicine (CM) includes both traditional and new CM developed by modern technology. It is well known that the chemical composition of most CM and natural products is very complex, for example, a single herb may contain hundreds of different chemicals, including active ingredients, side effects, and even toxic ingredients. Therefore, the extraction process is particularly crucial for the quality and clinical efficacy of CM and natural products. In this work, a new classification method was proposed to divide the extraction technologies of CM and natural products into 21 kinds in recent years and analyze their status, advantages, and disadvantages. Then put forward a new technical route based on ultra-high-pressure extraction technology for rapid extraction else while removing harmful impurities and making higher utilization of CM and natural products. It is a useful exploration for the extraction industry of medicinal materials and natural products in the world.

Synthesis, Pharmacological Properties, and Potential Molecular Mechanisms of Antitumor Activity of Betulin and Its Derivatives in Gastrointestinal Cancers

Gastrointestinal (GI) cancers are an increasingly common type of malignancy, caused by the unhealthy lifestyles of people worldwide. Limited methods of treatment have prompted the search for new compounds with antitumor activity, in which betulin (BE) is leading the way. BE as a compound is classified as a pentacyclic triterpene of the lupane type, having three highly reactive moieties in its structure. Its mechanism of action is based on the inhibition of key components of signaling pathways associated with proliferation, migration, interleukins, and others. BE also has a number of biological properties, i.e., anti-inflammatory, hepatoprotective, neuroprotective, as well as antitumor. Due to its poor bioavailability, betulin is subjected to chemical modifications, obtaining derivatives with proven enhanced pharmacological and pharmacokinetic properties as a result. The method of synthesis and substituents significantly influence the effect on cells and GI cancers. Moreover, the cytotoxic effect is highly dependent on the derivative as well as the individual cell line. The aim of this study is to review the methods of synthesis of BE and its derivatives, as well as its pharmacological properties and molecular mechanisms of action in colorectal cancer, hepatocellular carcinoma, gastric cancer, and esophageal cancer neoplasms.

Itaconic Acid as a Comonomer in Betulin-Based Thermosets via Sequential and Bulk Preparation

The inherent chemical functionalities of biobased monomers enable the production of renewably sourced polymers that further advance sustainable manufacturing. Itaconic acid (IA) is a nontoxic, commercially produced biobased monomer that can undergo both UV and thermal curing. Betulin is a biocompatible, structurally complex diol derived from birch tree bark that has been recently studied for materials with diverse applications. Here, betulin, IA, and biobased linear diacids, 1,12-dodecanedioic acid (C12) and 1,18-octadecanedioic acid (C18), were used to prepare thermosets using sequential and bulk curing methods. Thermoplastic polyester precursors were synthesized and formulated into polyester-methacrylate (PM) resins to produce sequential UV-curable thermosets. Bulk-cured polyester thermosets were prepared using a one-pot, solventless melt polycondensation using glycerol as a cross-linker. The structure-property relationships of the thermoplastic polyester precursors, sequentially prepared PM thermosets, and bulk-cured polyester thermosets were evaluated with varying IA content. Both types of thermosets exhibited higher storage moduli, Tgs, and thermal stabilities with greater IA comonomer content. These results demonstrate the viability of using IA as a comonomer to produce betulin-based thermosets each with tunable properties, expanding the scope of their applications and use in polymeric materials.

Pentacyclic Triterpenoid Phytochemicals with Anticancer Activity: Updated Studies on Mechanisms and Targeted Delivery

Pentacyclic triterpenoids (TTs) represent a unique family of phytochemicals with interesting properties and pharmacological effects, with some representatives, such as betulinic acid (BA) and betulin (B), being mainly investigated as potential anticancer molecules. Considering the recent scientific and preclinical investigations, a review of their anticancer mechanisms, structure-related activity, and efficiency improved by their insertion in nanolipid vehicles for targeted delivery is presented. A systematic literature study about their effects on tumor cells in vitro and in vivo, as free molecules or encapsulated in liposomes or nanolipids, is discussed. A special approach is given to liposome-TTs and nanolipid-TTs complexes to be linked to microbubbles, known as contrast agents in ultrasonography. The production of such supramolecular conjugates to deliver the drugs to target cells via sonoporation represents a new scientific and applicative direction to improve TT efficiency, considering that they have limited availability as lipophilic molecules. Relevant and recent examples of in vitro and in vivo studies, as well as the challenges for the next steps towards the application of these complex delivery systems to tumor cells, are discussed, as are the challenges for the next steps towards the application of targeted delivery to tumor cells, opening new directions for innovative nanotechnological solutions.

Methods of Analysis and Identification of Betulin and Its Derivatives

This scientific work presents practical and theoretical material on the methods of analysis and identification of betulin and its key derivatives. The properties of betulin and its derivatives, which are determined by the structural features of this class of compounds and their tendency to form dimers, polymorphism and isomerization, are considered. This article outlines ways to improve not only the bioavailability but also the solubility of triterpenoids, as well as any hydrophobic drug substances, through chemical transformations by introducing various functional groups, such as carboxyl, hydroxyl, amino, phosphate/phosphonate and carbonyl. The authors of this article summarized the physicochemical characteristics of betulin and its compounds, systematized the literature data on IR and NMR spectroscopy and gave the melting temperatures of key acids and aldehydes based on betulin.

Recent advances in natural small molecules as drug delivery systems

Drug delivery systems (DDSs) are a multidisciplinary approach toward the effective delivery of drugs to their target sites. Natural small molecule (NSM) compounds with anticancer activity, self-assembly and co-assembly functions show great potential for application as novel DDSs in the biomedical field. NSMs are widely sourced, have many modification sites, and readily form hydrogen bonds, π-π interactions, van der Waals interactions, and other non-covalent bonds in solvents, resulting in ordered structures. Moreover, their good biocompatibility and bioactivity allow compositions based on these compounds to be used in life science applications such as tissue engineering, drug delivery and cell imaging, showing the potential medical value of NSMs as DDSs. In this review, we summarise the role, assembly principles and applications of natural products such as triterpenoids, diterpenoids, sterols, alkaloids and polysaccharides in the construction of small molecule systems, which are expected to provide an important reference for the development of more active natural nanomaterials and the study of single or multi-component interactions.