Search Results (47)

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a master regulator of the cellular antioxidant response and a promising therapeutic target for Parkinson’s disease (PD). Resibufogenin (RBG), a bioactive bufadienolide from toad venom, has been identified as a potential Nrf2 agonist; however, its application is limited by cytotoxicity and poor drug-like properties. Herein, we report the rational design, synthesis, and biological evaluation of a series of RBG derivatives modified at the C3, C14–C15, and C17 positions. Systematic structure–activity relationship (SAR) studies identified 2-5c, featuring a C3 2-chloroacryloyl group and a C17 pyrimidine substitution, as a potential Nrf2 activator (EC₅₀ = 4.18 μM), exhibiting approximately 7-fold greater activity than RBG. Importantly, 2-5c demonstrated neuroprotective effects in MPP⁺-induced BV2 microglial cells and effectively ameliorated motor deficits in an MPTP-induced PD mouse model. These findings suggest that 2-5c represents a promising candidate for further investigation in the development of novel Nrf2-based therapies for PD. Full article

Kalanchoe daigremontiana, a succulent herbaceous plant in the Crassulaceae family from Madagascar, has gained global popularity as an ornamental and medicinal species. This review examines the traditional uses, phytochemical composition, biological properties, toxicological aspects, and regulatory challenges of K. daigremontiana. The traditional medicinal uses of its leaves and roots include treating burns, rheumatic disorders, hypertension, diabetes, kidney pain, diarrhea, cough, fever, gastric issues, anxiety, inflammation, and cancer. Chemical compounds identified include phenolic acids, flavonoids, tannins, alkaloids, glycosides, saponins, sterols, terpenes, and fatty acids, with phenolic compounds and bufadienolides being predominant. In vitro studies of the crude extracts, bufadienolide-rich fractions, and isolated compounds have shown antioxidant, antibacterial, antifungal, antiviral, antiparasitic, anthelmintic, anti-inflammatory, anticoagulant, anti-aging, cytotoxic, antitumoral, and antiproliferative properties. In vivo studies have demonstrated hepatoprotective, skincare, and cardiac-glycoside-like effects. While crude extracts and bufadienolide-rich fractions have shown toxic effects in 2-week-old chicks, guinea pigs, and Artemia salina, no toxicity has been reported in goats, broiler chickens, laying hens, or human erythrocytes. Although K. daigremontiana-based products are commercially available as dietary supplements with various health claims, these lack scientific validation. Despite the potential pharmaceutical applications of K. daigremontiana, further research is needed to determine its effects, dosage, mechanisms, long-term safety, and side effects, with clinical studies essential to validate its therapeutic potential. Full article

Liver cancer remains a significant global health challenge, with hepatocellular carcinoma (HCC) being the most prevalent form. Despite advancements in treatment, high recurrence rates and the limited efficacy of conventional therapies highlight the need for novel interventions. Cinobufagin (CB), a bufadienolide extracted from the parotid secretion of Bufo gargarizans and B. melanostictus, has emerged as a promising compound with multiple antitumor mechanisms. This comprehensive review assesses the current evidence regarding CB and its containing medicine, cinobufacini, in liver cancer models. Cinobufacini is a traditional Chinese medicine extract, whereas CB refers specifically to one of its active components. The pharmacodynamic actions of CB include induction of apoptosis, DNA damage, inhibition of proliferation and migration, and modulation of key oncogenic pathways such as PI3K/Akt/mTOR, Akt/ERK, and AURKA-mTOR-eIF4E. Additionally, CB disrupts tumor metabolism and induces oxidative stress. Preclinical studies, both in vitro and in vivo, demonstrate significant antitumor efficacy. However, concerns remain regarding CB’s toxicity profile at high doses. This review emphasizes the therapeutic potential of CB in HCC treatment and advocates for further translational research to optimize its clinical applicability, dosage, and safety. Full article

The genus Kalanchoe (Crassulaceae) comprises approximately 125 species of succulents distributed across Madagascar, Africa, Arabia, Australia, Southeast Asia, and tropical America. Traditionally regarded as “miracle plants”, Kalanchoe species are employed for treating inflammatory, infectious, metabolic, and cardiovascular conditions; this is associated with their abundant content of polyphenols, including phenolic acids and flavonoids such as quercetin, kaempferol, luteolin, rutin, and patuletin. However, robust clinical evidence remains limited. This review integrates pharmacological and bioinformatic perspectives by analyzing more than 70 studies published since 2000 on 15 species, including Bryophyllum. As an in silico complement, the genome of Kalanchoe fedtschenkoi was used to predict genes (AUGUSTUS), perform homology searches against Arabidopsis thaliana, and model three key enzymes: CHS, CYP90, and VEP1. The AlphaFold2/ColabFold models showed conserved catalytic motifs, and molecular docking with representative ligands supported the plausibility of biosynthetic pathways for flavonoids, brassinosteroids, and bufadienolides. The available evidence highlights chemopreventive, antibacterial, anti-inflammatory, antiviral, antioxidant, and cytotoxic activities, primarily associated with flavonoids and bufadienolides. Significant gaps remain, such as the lack of gene–metabolite correlations and the absence of standardized clinical trials. Overall, Kalanchoe represents a promising model that requires multi-omics approaches to enhance its phytopharmaceutical potential. Full article

Bufadienolides exert broad-spectrum pharmacological activities relevant to cardiology and novel cancer treatments. Their efficacy, toxicity, and pharmacokinetic profiles are significantly affected by modifications at carbon-3 (C3) of the steroid core. We have applied molecular dynamics simulations to characterize the consequences of (i) variations in size of the substituent at C3, (ii) the type of linker at C3 (ether vs. N-methoxy), and (iii) stereochemistry (C3β vs. C3α) for derivatives’ interactions with Na⁺,K⁺-ATPase. The model compounds included bufalin, bufalin-N-glucose, bufalin-O-glucose as well as digoxigenin, digoxigenin monodigitoxoside and digoxin. It was shown that the optimal size of the substituent is a trade-off between the ability to form stabilizing interactions and steric and entropic interferences. The former is strongly affected by the nature of the linker due to its impact on the spatial position of the ligand: N-methoxy linker imposes rotational restrictions and places the core into a less favorable position compared to an ether bond. Similarly, the change from β- to α-anomer delocalizes the substituent precluding contacts with amino acid residues of the binding site. The presented mechanistic model of bufadienolide interactions with Na⁺,K⁺-ATPase helps to anticipate the consequences of modifications while designing derivatives with high anticancer activity but reduced cardiotoxicity. Full article

Kalanchoe pinnata, commonly known as the “miracle plant” or “life plant”, is a succulent species traditionally used for various health conditions. Recent research investigations have intensified interest in this species due to its diverse repertoire of bioactive constituents, including flavonoids, alkaloids, triterpenes, and glycosides. These compounds have been associated with multiple therapeutic effects, notably antioxidant, anti-inflammatory, and antidiabetic activities. Although several studies have highlighted the positive effects of the extracts of K. pinnata on key factors contributing to the pathophysiology and complications of diabetes mellitus, a systematic overview focusing on the use of these extracts and their bioactive constituents in the management of the disease is lacking. This literature review summarizes the phytochemical composition, traditional uses, and recent scientific data supporting the antidiabetic potential of K. pinnata, with a particular focus on its effects on glycemic control, as well as inflammatory and oxidative homeostasis, toxicity, safety, and potential clinical implications. The phytochemical constituents discussed include quercetin, kaempferol, apigenin, epigallocatechin gallate (EGCG), avicularin, and bufadienolides, along with a presentation of representative structures. The review also covers the potential mechanisms of action in diabetes mellitus. The survey of available literature highlights the effects of K. pinnata on indices of diabetes mellitus, including enhancing insulin sensitivity, mitigating oxidative stress and inflammation, lowering blood glucose levels, and the potential adverse effects. These results point to the promising prospect for K. pinnata use in the management of diabetes mellitus and its associated complications, while underscoring the need for more rigorous investigations, including well-controlled clinical trials. Full article

Skin aging is accelerated by inflammation processes generated by oxidative stress and external factors such as UV radiation. Plants belonging to the genus Kalanchoe that are rich sources of antioxidants could potentially strengthen the skin barrier if used as ingredients in cosmetic formulations. However, their use is limited due to the contents of bufadienolides, known cardiotoxins. This study aimed to establish a semi-quantitative profile of bufadienolides in the juices of K. blossfeldiana, K. daigremontiana, and K. pinnata using UHPLC combined with charged aerosol detection (CAD) and high-resolution mass spectrometry (HR-MS). Additionally, the study determined the ability of bufadienolides to penetrate the skin barrier using the Bronaugh Diffusion Cell Apparatus and Strat-M membrane. The study also assessed the ferric and molybdenum-reducing powers, as well as the radical scavenging capabilities of these plants juices using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) methods. The in vitro antihyaluronidase and antityrosinase activities and sun protection factor (SPF) were evaluated spectrophotometrically, indicating moderate capability to inhibit the skin enzymes, but low SPF protection for all analyzed juices. The semi-qualitative analysis demonstrated the presence of bufadienolides occurring in two juices from K. daigremontiana and K. pinnata, with the highest contents of 1,3,5-bersaldegenin-orthoacetate, bryophyllin-A/bryotoxin-C, bersaldegenin-acetate/bryophyllin-C, and diagremontianin. After passing through the skin model, no bufadienolide compounds were present in the subcutaneous filtrate. Antiradical and reduction assays revealed the antioxidant potential of K. blossfeldiana and K. pinnata. These results indicate that Kalanchoe juices have antiaging potential and appear safe for dermal applications. Full article

Glioblastoma (GBM) is the most common and lethal intracranial tumor in adults. Despite advances in the understanding of the molecular events responsible for disease development and progression, survival rates and mortality statistics for GBM patients have been virtually unchanged for decades and chemotherapeutic drugs used to treat GBM are limited. Arsenic derivatives, known as highly effective anticancer agents for leukemia therapy, has been demonstrated to exhibit cytocidal effects toward GBM cells by inducing cell death, cell cycle arrest, inhibition of migration/invasion, and angiogenesis. Differentiation induction of glioma stem-like cells (GSCs) and inhibition of neurosphere formation have also been attributed to the cytotoxicity of arsenic derivatives. Intriguingly, similar cytotoxic effects against GBM cells and GSCs have also been observed in natural agents such as anthocyanidins, tetrandrine, and bufadienolides. In the current review, we highlight the available data on the molecular mechanisms underlying the multifaceted anticancer activity of arsenic compounds and natural agents against cancer cells, especially focusing on GBM cells and GCSs. We also outline possible strategies for developing anticancer therapy by combining natural agents and arsenic compounds, as well as temozolomide, an alkylating agent used to treat GBM, in terms of improvement of chemotherapy sensitivity and minimization of side effects. Full article

Background and Objectives: The Chansu injection (CSI), a sterile aqueous solution derived from Chansu, is applied in clinical settings to support antitumor and anti-radiation treatments. CSI’s principal active components, bufadienolides (≥90%), demonstrate potential effects on pancreatic cancer (PDAC), but their underlying mechanisms remain unclear. This study aimed to elucidate the antitumor effects and pathways associated with CSI in PDAC. Methods: Network pharmacology and bioinformatics analyses explored CSI’s mechanisms against PDAC. MTT, colony-formation, and migration assays evaluated CSI’s impact on proliferation and migration in PANC-1 and MIA PACA-2 cells, both as a single agent and in combination with erlotinib (EGFR inhibitor). Cell cycle analysis employed flow cytometry. Animal experiments were performed on tumor-bearing mice, with targets and pathways assessed via molecular docking and western blotting. Results: CSI treatment suppressed PDAC cell proliferation and migration by inducing G2/M phase arrest. Network pharmacology, bioinformatics, and molecular docking indicated that CSI’s anti-PDAC effects may involve EGFR pathway modulation, with CSI lowering p-EGFR/KRAS/p-ERK1/2 pathway expressions in PDAC cells. Additionally, sustained KRAS activation in mediating erlotinib resistance in PDAC and CSI potentiated erlotinib’s antitumor effects through enhanced KRAS and p-ERK1/2 inhibition. CSI also enhanced erlotinib’s efficacy in tumor-bearing mice without causing detectable toxicity in renal, cardiac, or hepatic tissues at therapeutic doses. Conclusions: CSI as an adjuvant used in antitumor and anti-radiation therapies enhanced erlotinib’s antitumor effects through modulation of the KRAS pathway. CSI and erlotinib’s synergistic interaction represents a promising approach for addressing erlotinib resistance in PDAC treatment. Full article

Cinobufagin (CB), a bufadienolide, has shown promising potential as an anticancer agent, particularly in combating lung cancer. This systematic review synthesizes preclinical evidence on CB’s effects against lung cancer, focusing on its mechanisms of action, efficacy, and potential clinical implications. We analyzed data from various preclinical studies involving both in vitro cell line models and in vivo animal models. The reviewed studies indicate that CB effectively reduces cell viability, induces apoptosis, and inhibits cell proliferation, migration, and invasion across multiple lung cancer cell lines and xenograft models. Specifically, CB was found to decrease cell viability and increase apoptosis in lung cancer cells by modulating key molecular pathways, including Bcl-2, Bax, cleaved caspases, caveolin-1, FLOT2, Akt, STAT3, and FOXO1. In vivo studies further demonstrated significant inhibition of tumor growth with minimal toxicity. However, limitations include reliance on in vitro models, which may not fully represent in vivo tumor dynamics, and a lack of long-term safety data. The studies also vary in their methodologies and cell line models, which may not accurately encompass all lung cancer subtypes or predict human responses. Despite these limitations, CB’s ability to target specific molecular pathways and its promising results in preclinical models suggest it could be a valuable addition to lung cancer treatment strategies. Our review suggests further clinical trials to validate its efficacy and safety in humans. Future research should explore combination therapies and optimize delivery methods to enhance clinical outcomes. Full article

The traditional Chinese medicine toad venom (Venenum bufonis) has been extensively used to treat various diseases, including cancers, in China and other Southeast Asian countries. The major constituents of toad venom, e.g., bufadienolides and alkaloids, exhibit broad-spectrum pharmacological effects in cancers. Herein, two new bufadienolides (1 and 2), along with eleven known compounds (3–13) were successfully isolated from Bufo melanostictus Schneider. Their structures were elucidated by extensive spectroscopic data and X-ray diffraction analysis. Furthermore, four lactam derivatives were synthesized through the transformation of bufadienolides lactones. The inhibitory effects of these compounds against human prostate cancer cell lines PC-3 and DU145 were evaluated. The outcomes indicated a notable trend, with a substantial subset displaying nanomolar range IC₅₀ values against PC-3 and DU145 cells, underscoring their pronounced cytotoxicity. Moreover, a noteworthy distinction surfaces, wherein lactones consistently outperformed their lactam counterparts, further validating their heightened potency for the treatment of prostate cancer. This study contributes significant preclinical evidence substantiating the therapeutic viability of bufadienolides and toad venom as intervention strategies for prostate cancer. Full article

Toad Venom (TV) is the dried product of toxic secretions from Bufo bufo gargarizans Cantor (BgC) or B. melanostictus Schneider (BmS). Given the increasing medical demand and the severe depletion of wild toads, a number of counterfeit TVs appeared on the market, posing challenges to its quality control. In order to develop an efficient, feasible, and comprehensive approach to evaluate TV quality, a thorough analysis and comparison of chemical compounds among legal species BgC and BmS, as well as the main confusion species B. andrewsi Schmidt (BaS) and B. raddei Strauch (BrS), were conducted by ultra-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS), high performance liquid chromatography (HPLC), sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and Nano LC-MS/MS analyses. We identified 126 compounds, including free or conjugated bufadienolides, indole alkaloids and amino acids, among the four Bufo species. The content of main bufadienolides, such as gamabufotalin, bufotalin, bufalin, cinobufagin, and resibufogenin, and the total protein contents varied widely among 28 batches of TV due to their origin species. The sum of the five bufadienolides within the BgC, BmS, BaS, and BrS samples were 8.15–15.93%, 2.45–4.14%, 11.15–13.50%, and 13.21–14.68%, respectively. The total protein content of BgC (6.9–24.4%) and BaS (19.1–20.6%) samples were higher than that of BmS (4.8–20.4%) and BrS (10.1–13.7%) samples. Additionally, a total of 1357 proteins were identified. There were differences between the protein compositions among the samples of the four Bufo species. The results indicated that BgC TV is of the highest quality; BaS and BrS TV could serve as alternative resources, whereas BmS TV performed poorly overall. This research provides evidence for developing approaches to evaluate TV quality and selecting the proper Bufo species as the origin source of TV listed in the Chinese pharmacopoeia. Full article

Amphibians are widely known as a prolific source of bioactive metabolites. In this work, we isolated and characterized compounds with antiparasitic activity from the oocytes of the toad Rhinella alata collected in Panama. Bio-guided isolation and structural elucidation were carried out using chromatographic and spectroscopic techniques, respectively. The organic extract was subjected to solid phase extraction followed by HPLC purification of the fraction with in vitro activity against Trypanosoma cruzi trypomastigotes. Seven steroids (1–7) of the bufadienolide family were isolated, and their structures were determined using NMR and MS analyses; of these 19-formyl-dyscinobufotalin, (3) is reported as a new natural product. Compounds 1 and 3–7 resulted in a good anti-trypanosomal activity profile. Among these, 16β-hydroxyl-hellebrigenin (1) and bufalin (7) showed significant selectivity values of >5 and 2.69, respectively, while the positive control benznidazole showed a selectivity of 18.81. Furthermore, molecular docking analysis showed compounds 1, 3 and 7 interact through H-bonds with the amino acid residues GLN-19, ASP-158, HIS-159 and TRP-177 from cruzipain at the catalytic site. Given the lack of therapeutic options to treat American trypanosomiasis, this work can serve as the basis for further studies that aim for the development of bufadienolides or their derivatives as drugs against Chagas disease. Full article

The current nanomedicinal approach combines medicinal plants and nanotechnology to create new scaffolds with enhanced bioavailability, biodistribution and controlled release. In an innovative approach to herb encapsulation in nanosized chitosan matrices, wild-grown Romanian Helleborus purpurascens was used to prepare two new chitosan nanocarriers. The first carrier preparation involved the nanoencapsulation of hellebore in chitosan. The second carrier emerged from two distinct stages: hellebore-AgNPs phyto-carrier system succeeded by nanoencapsulation in chitosan. The morphostructural characteristics and thermal behavior of these newly prepared nanocarriers were examined using FT-IR, XRD, DLS, SEM, EDS and thermogravimetric analyses. In addition, the encapsulation yield, encapsulation efficiency and encapsulation contents were investigated. The antioxidant activity was estimated using four in vitro, noncompetitive methods: total phenolic assay; 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay; phosphomolybdate (i.e., total antioxidant capacity); and iron(III)-phenanthroline antioxidant assay. Moreover, this study reports the first low-molecular-weight metabolite profile of wild-grown Romanian Helleborus purpurascens Waldst. & Kit. A total of one hundred and five secondary metabolites were identified in the mass spectra (MS)-positive mode from fourteen secondary metabolite categories (alkaloids, butenolides, bufadienolides, phytoecdysteroids, amino acids and peptides, terpenoids, fatty acids, flavonoids, phenolic acids, sterols, glycosides, carbohydrates, nucleosides and miscellaneous). The collective results suggest the potential application is a promising new antioxidant vehicle candidate in tumor therapeutic strategy. Full article

Triple-negative breast cancer (TNBC) is a highly aggressive type of breast cancer and has a poor prognosis. As standardized TNBC treatment regimens cause drug resistance and tumor recurrence, the development of new TNBC treatment strategies is urgently required. Bufotalin is a bufadienolide isolated from the skin and parotid venom glands of the toad Bufo gargarizan, and has several pharmacological properties, including antiviral, anti-inflammatory, and anticancer activities. However, the anticancer effect and underlying molecular mechanisms of action of bufotalin in TNBC have not been fully studied. In the current study, we investigated the effects of bufotalin on the growth and metastasis of MDA-MB-231 and HCC1937 TNBC cells. Bufotalin potently inhibited the proliferation of both TNBC cell lines by promoting cell cycle arrest and caspase-mediated apoptosis. Furthermore, bufotalin effectively suppressed the migration and invasion of both TNBC cell lines by regulating the expression of key epithelial-mesenchymal transition (EMT) biomarkers, matrix metalloproteinases (MMPs), and integrin α6. Notably, the anticancer effect of bufotalin in TNBC cells was associated with the downregulation of the signal transducer and activator of the transcription 3 (STAT3) signaling pathway. Collectively, our results suggest that the natural compound bufotalin may exert antiproliferative and antimetastatic activities in TNBC cells by modulating the apoptotic pathway and the STAT3/EMT axis. Full article