Hepatocellular carcinoma (HCC) is difficult to treat, and gefitinib (GEF) monotherapy may offer limited therapeutic benefits. Combination or multimodal approaches are often required to achieve therapeutic efficacy in such cases. Betulin (BET), a naturally occurring triterpene, is used in combination with GEF to enhance therapeutic efficacy against HCC, but its clinical translation is not possible due to poor bioavailability and lack of targeted delivery. Therefore, we developed non-targeted and lactoferrin (Lf) grafted targeted liposomes of GEF (GEF-Lipo and GEF-Lf-Lipo) and BET (BET-Lipo and BET-Lf-Lipo) by the ethanol injection method and subsequently characterized them. The vesicular size of GEF-Lipo, GEF-Lf-Lipo, BET-Lipo, and BET-Lf-Lipo was found to be 119.5 ± 6.5, 159.1 ± 16.4, 140.7 ± 16.4, and 181.6 ± 4.8nm, respectively. Polydispersity index (PDI) of GEF-Lipo, GEF-Lf-Lipo, BET-Lipo, and BET-Lf-Lipo was found to be 0.329 ± 0.1, 0.371 ± 0.05, 0.33 ± 0.14, and 0.399 ± 0.030, respectively. Encapsulation efficiencies (EE%) of GEF-Lipo, GEF-Lf-Lipo, BET-Lipo, and BET-Lf-Lipo were found to be 84.7 ± 1.22%, 90.08 ± 1.73%, 91.4 ± 2.63%, and 93.21 ± 1.88%, respectively. Furthermore, the in vivo study has been performed to assess the effectiveness of mixtures of GEF-BET, GEF-BET-Lipo, and asialoglycoprotein receptor (ASGPR) targeted GEF-BET-Lf-Lipo. Physiological parameters and HCC biomarker AFP were quantified. AFP levels were significantly increased in the cancer control versus normal control (p < 0.0001) and were significantly reduced by treatment with pristine drugs, non-targeted liposomes, and targeted liposomes (p < 0.0001), supporting the therapeutic effects of the formulations. Morphological changes in liver tissue were evaluated through histopathological examination and scanning electron microscopy (SEM). Western blotting and immunohistochemistry (IHC) showed that both GEF-BET-Lipo and GEF-BET-Lf-Lipo treatments significantly reduced pSTAT3 expression and increased the levels of the apoptotic marker caspase-3. Overall, the findings support the enhanced antitumor potential of GEF-BET-Lf-Lipo against HCC in animals.

Malignant melanoma (MM) is a highly invasive and metastatic form of skin cancer. Betulinic acid (BA) and betulin (BE) possess pharmacological activities such as heat-clearing, detoxification, and anti-tumor effects, with BA showing potent selective cytotoxicity against melanoma cells. However, their underlying mechanisms in MM treatment remain unclear. Herein, this study systematically evaluated the anti-melanoma effects of BA and BE via integrated network pharmacology, in vitro and in vivo assays. Network pharmacology analysis revealed that BA and BE exerted anti-MM effects mainly by regulating apoptosis, angiogenesis and autophagy through the PI3K/AKT and MAPK signaling pathways. In vitro, both BA and BE inhibited colony formation and migration of B16-F10 cells, induced apoptosis by enhancing DNA damage and upregulating apoptotic protein expression, increased autophagic activity, and reduced ATP production and mitochondrial membrane potential (ΔΨm). These effects were closely associated with the inhibition of the PI3K/AKT/mTOR and MAPK pathways. Notably, BA showed stronger inhibitory effects than BE on the migration, invasion and tube formation of HUVECs. In vivo assays further confirmed that BA significantly suppressed melanoma growth in C57BL/6J mice by blocking the PI3K/AKT/mTOR and MAPK pathways. Collectively, BA and BE inhibit B16-F10 cell proliferation through the regulation of apoptosis and autophagy, with BA showing particularly promising potential as a candidate agent for MM therapy.

Background: To meet the urgent need for novel antibacterial agents that are active also against worrying superbugs, natural pentacyclic triterpenoids, including totally inactive betulin (BET) and betulinic acid (BA), as well as ursolic acid (UA), active on Gram-positive bacteria, have been chemically modified, achieving compounds 1–7. Methods: Triterpenoid derivatives 1–7 and all synthetic intermediates were characterized by chemometric-assisted FTIR and NMR spectroscopy, as well as by other analytical techniques, which confirmed their structure and high purity. Minimum inhibitory concentration values (MICs) of 1–7, BET, BA and UA were determined by the broth dilution method, using a selection of Gram-positive and Gram-negative clinically isolated superbugs. Results: Performed experiments evidenced that compounds 4–7 had potent antibacterial effects against Gram-positive methicillin-resistant Staphylococcus aureus and S. epidermidis (MRSA and MRSE), as well as against vancomycin-resistant Enterococcus faecalis and E. faecium (VRE). The antibacterial effects of 4–7 were due to the insertion of a triphenyl phosphonium (TPP) group and were higher than those reported so far for other BET, BA and UA derivatives, especially considering the complex pattern of resistance of the isolates used here and their clinical source. Conclusions: For the first time, by inserting TPP, a real activity (MICs 2–16 µg/mL) was conferred to inactive BET and BA (MICs > 1024 and 256 µg/mL). Moreover, the antibacterial effects of UA were improved 16- and 32-fold against MRSE and MRSA (MICs = 2 vs. 32 and 64 μg/mL). Future Perspectives: Based on these very promising microbiologic results, new experiments are currently underway with the best-performing compounds 5 and 7 (MICs = 2 μg/mL) on an enlarged number of Gram-positive isolates, to confirm their MICs. Moreover, investigations about their possible antibiofilm activity, time-killing curves and cytotoxicity on eukaryotic cells will be carried out to define their pharmacological behavior and clinical potential.

Prophylactic and therapeutic role of Betulin in mitigating obesity-related metabolic dysfunction in rats fed on high-fat diet.

In this study, we successfully developed a diselenide-based, triple-responsive intelligent nanogel, IR780@BEAP, for lung cancer therapy. Exploiting the elevated levels of reactive oxygen species (ROS) and glutathione (GSH) in the tumor microenvironment (TME), a ROS/GSH dual-responsive diselenide cross-linker (DSe5) was synthesized and used to cross-link betulin (BE) with Angelica polysaccharide (AP) while coloading the photosensitizer IR780. The resulting nanogel, IR780@BEAP, exhibited an appropriate particle size (137.7 ± 2.3 nm) and demonstrated excellent colloidal stability. Physicochemical characterization confirmed its dual responsiveness to ROS and GSH, facilitating rapid drug release within the TME. Under near-infrared (NIR) laser irradiation, IR780@BEAP demonstrated good photothermal and photodynamic effects, generating abundant ROS and significantly enhancing antitumor activity. Both in vitro and in vivo experiments confirmed that IR780@BEAP effectively inhibited lung cancer cell proliferation and metastasis, while also inducing apoptosis through combined chemo-phototherapy. Moreover, IR780@BEAP modulated macrophage immune activity by upregulating costimulatory molecules (CD40, CD80, and CD86) and MHC-II expression, thereby activating the immune system and exerting immunotherapeutic effects. Overall, IR780@BEAP, as a smart responsive nanogel, presents a promising approach for combined chemo-photoimmunotherapy in the treatment of lung cancer.

5-Fluorouracil (5-FU) remains the first-line chemotherapeutic agent for colorectal cancer. Although 5-FU significantly improves patient survival, its severe gastrointestinal toxicity-particularly intestinal injury and diarrhea-impairs treatment adherence and patient quality of life, often leading to therapeutic failure. Thus, effective interventions to prevent or mitigate these adverse effects are urgently needed. Betulin (BET), a natural pentacyclic triterpenoid derived primarily from birch bark, exhibits various biological activities, including anti-inflammatory, antioxidant, antiviral, and antitumor effects. Its anti-inflammatory and antioxidant properties suggest betulin (BET) as a promising candidate for alleviating chemotherapy-induced tissue damage. However, its impact on 5-FU-induced intestinal injury remains unclear. The findings of this study revealed that 5-FU led to significant intestinal injury by promoting cellular senescence and exacerbating the inflammatory response. BET mitigates these effects by decreasing senescence-associated β-galactosidase activity and downregulating key senescence markers such as p53, p21, and p16. Moreover, BET modulates senescence-associated secretory phenotype factors, thereby reversing the proinflammatory microenvironment elicited by 5-FU. Integrating network pharmacology, Mendelian randomization, and experimental validation, we identified the mechanistic target of rapamycin/mitogen-activated protein kinase signaling pathway as a pivotal mediator of BET's protective effects against 5-FU-induced intestinal injury. In conclusion, our study reveals that 5-FU-induced intestinal damage is driven by cellular senescence, which BET effectively ameliorates through suppression of senescence and inflammation. These findings provide a novel framework for targeting antisenescence strategies to alleviate chemotherapy-associated intestinal toxicity. SIGNIFICANCE STATEMENT: This study identifies betulin as a novel agent that alleviates 5-fluorouracil-induced intestinal injury by inhibiting cellular senescence and inflammation via the mechanistic target of rapamycin/mitogen-activated protein kinase pathways. These findings highlight antisenescence as a promising therapeutic strategy to mitigate chemotherapy-induced gastrointestinal toxicity.

Fabrication and characterization of betulin/hydroxypropyl-beta-cyclodextrin inclusion complex nanofibers: A potential edible antibacterial and antioxidant packaging material.

The aim of fabricating hybrid solid lipid nanoparticles (HSLN) was to enhance the delivery of betulin to triple negative breast cancer cells through the intravenous route via L-amino transporter system-1, using L-leucine-PLGA conjugate (Conj-HSLN) by hot high pressure homogenisation method. Betulin (BN), having potent anticancer and antioxidant activity, faces challenges due to poor water solubility and permeability, affecting its bioavailability. The results revealed Conj-HSLN with particle size 318.3 ± 0.25 nm. The percent cumulative BN release from Conj-HSLN was 57.763%, 24h. The cytotoxicity study in MB-MDA-231 cell depicts, LD50 67.73 µg/ml in Conj-HSLN. Pharmacokinetics study reveals enhanced Cmax and half-life in Conj-HSLN (32.12 ± 0.25 µg/ml, 4.72 ± 0.53 h) than raw BN (1.31 ± 0.21 µg/ml, 7.54 ± 0.34 h). Enhanced distribution at tumour site (11.5967% ID, 2h) in Conj-HSLN signifies the role of L-leucine in the transport system. Pharmacodynamic study shows mean tumour volume of 765.3 ± 85.884, and 1450.01 ± 219.361 mm3 in Conj-HSLN, and BN, respectively, at 3rd week of treatment. Standardised uptake value attributed reduced glucose uptake, due to inhibited tumour growth and proliferation, confirmed by tumour biomarkers assay, VEGF and Caspase-9. In conclusion, the targeted controlled release L-leucine conjugated-BN loaded HSLN is stable, safe, and effective against triple negative breast cancers.

Anomalous immune reactions associated with psoriasis initiate an inflammatory cascade, prompting rapid multiplication and buildup of skin cells, resulting in distinctive scaly patches covered by flaky, silvery-whitish scales. The major challenges associated with the current practice are limited therapeutics with poor pharmacodynamic behaviour, which led to the search for lead phyto-compounds with potent anti-inflammatory potentiality. The current research investigated the anti-inflammatory potential of some ethnopharmacologically relevant medicinal plants for managing psoriasis. In the preliminary computational screening, betulin (BE) shows more comparable vital molecular interactions with the targeted inflammatory markers. In a simulated biological mimetic environment, BE offers a more thermodynamically stable interaction with the GLUT-1 transporter than all other molecular targets, suggesting its pivotal role in downregulating the glucose uptake mechanism in the inflamed cells. The methanolic extract of Betula utilis D. Don (MEB) shows a significant dose-dependent anti-inflammatory activity at concentrations ranging from 5 to 100 µg/ml compared to other plant species. In a carrageenan-induced inflammation model, MEB (400 mg/kg) significantly reduces the paw thickness by 85.86% compared to the diclofenac sodium-treated group (p&lt;0.05). The in vitro and In-vivo anti-inflammatory responses were fine-tuned with cytokine assay. MEB (400 mg/kg) resulted in a notable decrease in pro-inflammatory marker concentrations, registering reductions of 58.48% in IL-17A, 72.56% in IL-4, 65.34% in IL-6, and 56.78% in TNF-α within the paw tissue which is closely related with the standard group. The potential of B. utilis D. Don as a therapeutic adjunct offers hope for more effective and targeted management of chronic skin inflammation conditions associated with psoriasis.

The triterpenes and saponin compounds of Gleditsia japonica Miq. play a key role in the suppression of various human tumor cell lines. Cytochrome P450 monooxygenases (CYP450s) are critical for the triterpene skeleton diversification and functional modification. This study systematically analyzed 104 full-length GjCYP450 genes in G. japonica from northeast China, classifying them into nine clans using bioinformatics. Co-expression modules and response patterns of GjCYP450s with triterpene pathway genes were constructed. Four genes - CYP710A157, CYP714E97, CYP716A377, and CYP71D752 - were selected for functional studies based on their high expression in different tissues of G. japonica and their homology with triterpenoid-related CYP450s in Arabidopsis thaliana. Co-expression of the CYP710A157 gene with the BpY gene (encoding β-amyrin synthase), and CYP71D752 with the BpW gene (encoding lupeol synthase) in tobacco significantly enhanced the catalytic efficiency of echinocystic acid (EA) and betulin (BT) compared to the control, by achieving 10.22-fold and 3.73-fold increases, respectively. Overexpression of CYP710A157 and CYP71D752 in Saccharomyces cerevisiae JWy602 yielded EA and BT at 3.25 mg l-1 and 13.84 mg l-1, respectively, whereas no product accumulation was detected in the control. Additionally, CYP710A157 and CYP714E97 enhanced yeast alkaline tolerance (500 mmol l-1 Na2CO3), while CYP716A377 and CYP71D752 improved their salt tolerance (10% NaCl). We reported the catalytic activity of CYP450 genes responsible for EA and BT synthesis within the CYP710A and CYP71D subfamilies in G. japonica for the first time here. These findings provide valuable genetic resources for plants' triterpene biosynthesis, including ginsenosides, and betulinic acid, and insights into regulating the triterpene metabolic network in G. japonica.

The purpose of this work is to examine how triterpenoids betulin (BE) and betulinic acid (BA) affect the thermotropic phase behaviour and bilayer packing in pulmonary surfactant membranes. Therefore, the interaction of these triterpenoids with dipalmitoylphosphatidylcholine (DPPC) bilayers is studied by differential scanning calorimetry (DSC), attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM), and quantum chemical computations with density functional theory (DFT). From DSC data, the effects are more pronounced with BE compared to BA. At BE concentration of 20mol%, the pretransition does not completely disappear and the lamellar phase transition broadens further. There are two indistinguishable peaks in the main phase transition, which may indicate the start of inhomogeneous mixing or phase separation in the gel phase. BA reduces the main transition temperature and almost completely eliminates the pretransition at concentrations of 1-10mol%. Endotherms continue to have a symmetric, broad form that suggests perfect mixing. From ATR-FTIR data, both triterpenoids display the CH2 antisymmetric stretching, C = O stretching, PO2- asymmetric stretching to higher wavenumber in DPPC system. These results indicate an increase in the lateral mobility and dehydration in the polar head group and glycerol-acyl chain interface of DPPC liposomes. From microscopic results, it is found that the addition of high concentration (20mol%) of BE and BA into pure DPPC membranes, single and double planar layers are formed, and the size of the liposomes increases. According to computational studies, the O131-H206 OH group of BE and the P24-O26 head group of DPPC formed a hydrogen bonding of 1.805Å between BE and DPPC in gas phase. This hydrogen bonding is observed between BA and DPPC via the P24-O26 head group of DPPC and the O132-H209 OH group of BA.

Alzheimer's disease (AD) is a neurodegenerative disorder that impairs learning and memory, with high rates of mortality. Birch bark has been traditionally used in the treatment of various skin ailments. Betulin (BT) is a key compound of birch bark that exhibits diverse pharmacological benefits and therapeutic potential in AD. However, the therapeutic effects and molecular mechanisms of BT in AD remain unclear. The present study aimed to predict the potential therapeutic targets of BT in the treatment of AD, and to determine the specific underlying molecular mechanisms through network pharmacology analysis and experimental validation. PharmMapper was used to predict the target genes of BT, and four disease databases were searched to screen for AD targets. The intersection targets were identified using the jveen website. Drug-disease target protein-protein interaction networks and hub genes were obtained and visualized using the Search Tool for the Retrieval of Interacting Genes/Proteins database and Cytoscape. The Database for Annotation, Visualization and Integrated Discovery was used for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, and AutoDock was used for molecular docking analysis of BT and hub genes. Subsequently, the network-predicted mechanisms of BT in AD were verified in vitro. A total of 495 BT and 1,386 AD targets were identified, and 120 were identified as potential targets of BT in the treatment of AD. The results of the molecular docking analysis revealed a strong binding affinity between BT and the hub genes. In addition, enrichment analyses of GO and KEGG pathways indicated that the neuroprotective effects of BT mainly involved the ‘PI3K-Akt signaling pathway’. The results of in vitro experiments demonstrated that pretreatment with BT for 2 h may ameliorate formaldehyde (FA)-induced cytotoxicity and morphological changes in HT22 cells, and decrease FA-induced Tau hyperphosphorylation and reactive oxygen species levels. Furthermore, the PI3K/AKT signaling pathway was activated and the expression levels of downstream proteins, namely GSK3β, Bcl-2 and Bax, were modified following pre-treatment with BT. Overall, the results of network pharmacology and in vitro analyses revealed that BT may reduce FA-induced AD-like pathology by modulating the PI3K/AKT signaling pathway, highlighting it as a potential multi-target drug for the treatment of AD.

The significance of synthetic foams as insulative materials stems from their mechanical and water resistance as well as their cost-effectiveness. Broadly, the design of building envelopes should also consider fire and mold resistance and the impacts on the environment (end of life and compostability). This study addresses these issues considering the ever-increasing demand for sustainable sources to develop highly porous insulative materials. We introduce a versatile strategy based on wet-foam laying of cellulosic fibers that leads to hierarchical structures whose performance is tailored by the surface incorporation of betulin (BT), a bioactive molecule extracted from tree bark, combined with poly(dimethylsiloxane) (PDMS) after installation of urethane linkages. As such, we introduce an eco-friendly alternative to traditional polyurethane foams with competitive mechanical and thermal insulation performance. The modification of the fiber foams at low BT loading simultaneously endows superhydrophobicity (water contact angle >150°), fire retardancy (self-extinguish within 10 s), microbial resistance, and durability (no degradation in soil conditions after 3 months). BT plays a critical role as an antimicrobial and hydrophobic agent that synergizes with PDMS to achieve fire resistance. The life cycle assessment of the BT-modified foams reveals a significant reduction in greenhouse gas emission and human toxicity compared with rigid polyurethane foams by 96 and 92%, respectively. Overall, the valorization of the bark-derived BT is demonstrated by considering the scalability and cost-effectiveness of solid foams designed to substitute petroleum-derived counterparts.

Worldwide, cervical cancer (CCa) is a major killer of women. As the conventional drugs used to treat cervical cancer are expensive and expose severe side effects, there is a growing demand to search for novel modifications. Therefore, in the current investigation employing a bioinformatic approach, we explored triterpenoids for their anti-cancer efficacy by targeting cervical cancer epigenetic proteins, namely DNMT3A, HDAC4, and KMT2C. The study utilized molecular docking, ADMET assay, Molecular Dynamic simulation, and DFT calculation to unveil Betulin (BE) as the potential lead compound. Comparative analysis with that standard drug indicated that BE has a better glide score with the target protein KM2TC (- 9.893 kcal/mol), HDAC4 (- 9.720 kcal/mol), and DNMT3A (- 7.811 kcal/mol), which depicts that BE could be a potent inhibitor of these three epigenetic proteins and exhibits favorable pharmacokinetic, pharmacodynamics and toxicity properties. Molecular Dynamics simulation revealed noteworthy structural stability and compactness. DFT analysis revealed higher molecular activity of BE and showed the most increased kinetic stability (δE = 0.254647 eV). Further, we employed In vitro analysis through MTT assay and found that BE has IC50 of 15 µg/ml. In conclusion, BE can potentially treat CCa upon further investigations using in vivo models for better understanding.

Osteoporosis, a terminal illness, has emerged as a global public health problem in recent years. The long-term use of bone anabolic drugs to treat osteoporosis causes multi-morbidity in elderly patients. Alternative therapies, such as allogenic and autogenic tissue grafts, face important issues, such as a limited source of allogenic grafts and tissue rejection in autogenic grafts. However, stem cell therapy has been shown to increase bone regeneration and decrease osteoporotic bone formation. Stem cell therapy combined with betulin (BET) supplementation might be adequate for bone remodeling and new bone tissue generation. In this study, the effect of BET on the viability and osteogenic differentiation of hFOB 1.19 cells was investigated. The cells were encapsulated in alginate-gelatin (AlGel) microbeads. In vitro tests were conducted during the 12 d of incubation. While BET showed cytotoxic activity (>1 µM) toward non-encapsulated hFOB 1.19 cells, encapsulated cells retained their functionality for up to 12 days, even at 5 µM BET. Moreover, the expression of osteogenic markers indicates an enhanced osteo-inductive effect of betulin on encapsulated hFOB 1.19, compared to the non-encapsulated cell culture. The 3D micro-environment of the AlGel microcapsules successfully protects the hFOB 1.19 cells against BET cytotoxicity, allowing BET to improve the mineralization and differentiation of osteoblast cells.

Core/shell nanofibers offer the advantage of encapsulating multiple drugs with different hydrophilicity in the core and shell, thus allowing for the controlled release of pharmaceutic agents. Specifically, the burst release of hydrophilic drugs from such fiber membranes causes an instantaneous high drug concentration, whereas a long and steady release is usually desired. Herein, we tackle the problem of the initial burst release by the generation of core/shell nanofibers with the hydrophilic antibiotic drug gentamycin loaded within a hydrophilic alginate core surrounded by a hydrophobic shell of poly(ε-caprolactone). Emulsion electrospinning was used as the nanofibrous mesh generation procedure. This process also allows for the loading of a hydrophobic compound, where we selected a natural antioxidant molecule, betulin (BTL), to detoxify the radicals. The resulting nanofibers exhibited a cylindrical shape with a core/shell structure. In vitro tests showed a controlled release of gentamicin from nanofibers via diffusion. The drug reached 93% release in an alginate hydrogel film but only 50% release in the nanofibers, suggesting its potential to minimize the initial burst release. Antibacterial tests revealed significant activity against both Gram-negative and Gram-positive bacteria. The antioxidant property of betulin was confirmed through the DPPH assay, where the incorporation of 20% BTL revealed 37.3% DPPH scavenging. The nanofibers also exhibited favorable biocompatibility in cell culture studies, and no harmful effects on cell viability were observed. Overall, this research offers a promising approach to producing core/shell nanofibrous mats with antibacterial and antioxidant properties, which could effectively address the requirements of wound dressings, including infection prevention and wound healing acceleration.

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.

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.

Betulinic acid (BA) and betulin (BE) are naturally pentacyclic triterpenes with documented biological activities, especially antitumor and anti-inflammatory activity. However, their bioavailability in vivo is not satisfactory in terms of medical applications. Thus, to improve the solubility and bioavailability so as to improve the efficacy, 28-O-succinyl betulin (SBE), a succinyl derivative of BE, was synthesized and its solubility, in vitro and in vivo anti-tumor activities, the apoptosis pathway as well as the pharmacokinetic properties were investigated. The results showed that SBE exhibited significantly higher solubility in most of the tested solvents, and showed a maximum solubility of 7.19 ± 0.66 g/L in n-butanol. In vitro and in vivo anti-tumor activity assays indicated both BA and SBE exhibited good anti-tumor activities, and SBE demonstrated better potential compared to BA. An increase in the ratio of Bad/Bcl-xL and activation of caspase 9 was found in SBE treated Hela cells, suggesting that the intrinsic mitochondrial pathway is involved in SBE induced apoptosis. Compared with BA, SBE showed much-improved absorption and bioavailability in pharmacokinetic studies.

The influence of conditions on the separation of betulin (BT), betulinic (BIA), and betulonic (BOA) acids by reversed-phase high-performance liquid chromatography (RP-HPLC) with isocratic elution was studied. It was shown that the order of peaks in chromatograms changed with varying the acetonitrile (ACN) content in the mobile phase, and a poor separation under certain conditions was observed. The highest peak resolution with minimal retention times was at a column temperature of 20 °C, flow rate of 0.25 ml/min, and 92.5% ACN in the mobile phase. The extracts from jujube (Ziziphus jujuba) dried fruit, chaga mushroom (Inonotus obliquus), and white birch bark (Betula pendula) were studied using the obtained conditions. For extracts from the first two sources, it was found that peaks of the compound studied interfered with unknown peaks. By varying the ACN content in the mobile phase with a small step from run to run and tracking the peaks, a baseline separation was achieved. The optimal % ACN in the mobile phase was 87 and 89 for the extracts from jujube and chaga mushroom, respectively. Jujube dried fruit was found to contain, in terms of dry weight of the jujube, 0.223 ± 0.008 mg/g of BIA and 0.044 ± 0.006 mg/g of BOA. Chaga mushroom studied contains 0.022 ± 0.004 mg/g of BT and 0.062 ± 0.009 mg/g of BIA. White birch bark contains 50.9 ± 0.7 mg/g of BT, 11.2 ± 0.3 mg/g of BIA, and 2.5 ± 0.3 mg/g of BOA.