Brazilin cream from Caesalpinia sappan inhibit periodontal disease: in vivo study.

Background: Gingivitis is an inflammation of the gums that is the initial cause of the development of periodontal disease by the activity of Nuclear Factor-kappa B (NF-κB), Interleukin-1ß (IL-1ß), Interleukin-6 (IL-6), p38, and Tumor Necrosis Factor-α (TNF-α). Unaddressed chronic inflammation can lead to persistent disturbances in other parts of the body. Brazilin is a naturally occurring plant chemical that may have antibacterial and anti-inflammatory effects. Treatment based on the natural plant compound, brazilin, is developed in the form of a topical cream for easy application. Objective: The aim is to develop the natural compound brazilin in the form of a topical cream as an anti-inflammatory agent to reduce NF-κB expression through Imunohistochemistry (IHC) methods, and the expression of pro-inflammatory genes IL-1ß, IL-6, p38, and TNF-α. Methods: Male Sprague-Dawley rats were induced with gingivitis using P. gingivalis bacteria. The observed groups included rats treated with a single application of brazilin cream and rats treated with two applications of brazilin cream. The treatment was administered for 15 days. On days 3, 6, 9, 12, and 15, anatomical wound observations and wound histology using hematoxylin-eosin and Masson's Trichrome staining were performed. NF-κB protein expression was analyzed using the IHC method. Gingival inflammation gene expression of NF-κB, IL-1ß, IL-6, p38, and TNF-α was measured using q-RTPCR. Results: Single and double applications of brazilin cream increased angiogenesis and decreased NF-κB protein expression, in addition to the IL-1ß, IL-6, p38, and TNF-α gene expressions. Conclusion: In a rat gingivitis model, Brazilin cream may function as an anti-inflammatory agent in the gingival tissue.

Regulation of cellular and molecular markers of epithelial-mesenchymal transition by Brazilin in breast cancer cells.

Breast cancer is the most common invasive neoplasm and the leading cause of cancer death in women worldwide. The main cause of mortality in cancer patients is invasion and metastasis, where the epithelial-mesenchymal transition (EMT) is a crucial player in these processes. Pharmacological therapy has plants as its primary source, including isoflavonoids. Brazilin is an isoflavonoid isolated from Haematoxilum brasiletto that has shown antiproliferative activity in several cancer cell lines. In this study, we evaluated the effect of Brazilin on canonical markers of EMT such as E-cadherin, vimentin, Twist, and matrix metalloproteases (MMPs). By Western blot, we evaluated E-cadherin, vimentin, and Twist expression and the subcellular localization by immunofluorescence. Using gelatin zymography, we determined the levels of secretion of MMPs. We used Transwell chambers coated with matrigel to determine the in vitro invasion of breast cancer cells treated with Brazilin. Interestingly, our results show that Brazilin increases 50% in E-cadherin expression and decreases 50% in vimentin and Twist expression, MMPs, and cell invasion in triple-negative breast cancer (TNBC) MDA-MB-231 and to a lesser extend in MCF7 ER+ breast cancer cells. Together, these findings position Brazilin as a new molecule with great potential for use as complementary or alternative treatment in breast cancer therapy in the future.

Chemoenzymatic formal synthesis of (+)-brazilin.

Herein, the manuscript presents a chemoenzymatic formal synthetic route of (+)-brazilin, a homoisoflavonoid natural product with a chroman skeleton cis-fused with a 2,3-dihydro-1H-indene unit, which is isolated from the traditional Chinese medicine, Caesalpinia sappan L. The key feature of the synthetic strategy includes an enzyme-mediated desymmetrization by employing lipase from Candida antarctica type B (CALB) and a one-pot SN2/hydrolysis reaction.

Inhibition of oxidative stress of Biancaea sappan (L) Tod. from Java.

Increased reactive oxygen species and advanced glycation end products are often associated with human ageing and degenerative diseases. Biancaea sappan L serves as a medicinal plant and a healthy drinks ingredient in Java. However, the pharmacological investigation of the plant native to this island is still lacking in depth. In the current study, DNA barcoding using the marker gene maturase K (matK), evaluation of the chemical composition, total phenolic content (TPC) and antioxidant properties, antiglycation, anti-ß-amyloid, anti-inflammatory, and selective cytotoxic activities were performed. B. sappan shares well-known phytoconstituents with other members of the genus Biancaea. The heartwood ethanol extract possesses the most prominent antioxidant, anti-inflammatory, and anti-ß-amyloid effects. The aqueous extract demonstrated a most substantial anti-glycation activity and was rich in phenolics. The ethanol extract from heartwood exhibited the highest cytotoxicity against SW-48, indicating B. sappan heartwood from Java holds promise as antioxidants and may selectively inhibit colorectal cancer.

Hydroxymethylation hydroxylation of 1,3-diarylpropene through a catalytic diastereoselective Prins reaction: cyclization logic and access to brazilin core.

A catalytic diastereoselective Prins reaction for hydroxymethylation and hydroxylation of 1,3-diarylpropene was successfully utilized to prepare various 1,3-dioxanes 7 in 14-88% yields. Take advantage of the synthetic intermediate 7h, the key B/C rings in brazilin core could be constructed by the sequential of Friedel-Crafts/Ullmann-Ma rather than Ullmann-Ma/Friedel-Crafts reactions.

Brazilin Actuates Ferroptosis in Breast Cancer Cells via p53/SLC7A11/GPX4 Signaling Pathway.

OBJECTIVE: To investigate the mechanism of induction of ferroptosis by brazilin in breast cancer cells. METHODS: Breast cancer 4T1 cells were divided into 6 groups: control, brazilin 1/2 half maximal inhibitory concentration (IC50), IC50, 2×IC50, erastin (10 µg/mL) and capecitabine (10 µg/mL) groups. The effect of brazilin on the proliferation of 4T1 cells was detected by cell counting kit-8 assay, and the treatment dose of brazilin was screened. The effect of brazilin on the mitochondrial morphology of 4T1 cells, and the mitochondrial damage was evaluated under electron microscopy. The levels of Fe2+, reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH) and glutathione peroxidase 4 (GPX4) were estimated using various detection kits. The invasion and migration abilities of 4T1 cells were detected by scratch assay and transwell assay. The expressions levels of tumor protein p53, solute carrier family 7 member 11 (SLC7A11), GPX4 and acyl-CoA synthetase long-chain family member 4 (ACSL4) proteins were quantified by Western blot assay. RESULTS: Compared to the control group, the 10 (1/2 IC50), 20 (IC50) and 40 (2×IC50) µg/mL brazilin, erastin, and capecitabine groups showed a significant decrease in the cell survival rate, invasion and migration abilities, GSH, SLC7A11 and GPX4 protein expression levels, and mitochondrial volume and ridge (P<0.05), and a significant increase in the mitochondria membrane density, Fe2+, ROS and MDA levels, and p53 and ACSL4 protein expression levels (P<0.05). CONCLUSIONS: Brazilin actuated ferroptosis in breast cancer cells, and the underlying mechanism is mainly associated with the p53/SLC7A11/GPX4 signaling pathway.

Tetracyclic homoisoflavanoid (+)-brazilin: a natural product inhibits c-di-AMP-producing enzyme and Streptococcus mutans biofilms.

The tenacious biofilms formed by Streptococcus mutans are resistant to conventional antibiotics and current treatments. There is a growing need for novel therapeutics that selectively inhibit S. mutans biofilms while preserving the normal oral microenvironment. Previous studies have shown that increased levels of cyclic di-AMP, an important secondary messenger synthesized by diadenylate cyclase (DAC), favored biofilm formation in S. mutans. Thus, targeting S. mutans DAC is a novel strategy to inhibit S. mutans biofilms. We screened a small NCI library of natural products using a fluorescence detection assay. (+)-Brazilin, a tetracyclic homoisoflavanoid found in the heartwood of Caesalpinia sappan, was identified as one of the 11 "hits," with the greatest reduction (>99%) in fluorescence at 100 µM. The smDAC inhibitory profiles of the 11 "hits" established by a quantitative high-performance liquid chromatography assay revealed that (+)-brazilin had the most enzymatic inhibitory activity (87% at 100 µM) and was further studied to determine its half maximal inhibitory concentration (IC50 = 25.1 ± 0.98 µM). (+)-Brazilin non-competitively inhibits smDAC's enzymatic activity (Ki = 140.0 ± 27.13 µM), as determined by a steady-state Michaelis-Menten kinetics assay. In addition, (+)-brazilin's binding profile with smDAC (Kd = 11.87 µM) was illustrated by a tyrosine intrinsic fluorescence quenching assay. Furthermore, at low micromolar concentrations, (+)-brazilin selectively inhibited the biofilm of S. mutans (IC50 = 21.0 ± 0.60 µM) and other oral bacteria. S. mutans biofilms were inhibited by a factor of 105 in colony-forming units when treated with 50 µM (+)-brazilin. In addition, a significant dose-dependent reduction in extracellular DNA and glucan levels was evident by fluorescence microscopy imaging of S. mutans biofilms exposed to different concentrations of (+)-brazilin. Furthermore, colonization of S. mutans on a representative model of enamel using suspended hydroxyapatite discs showed a >90% reduction with 50 µM (+)-brazilin. In summary, we have identified a drug-like natural product inhibitor of S. mutans biofilm that not only binds to smDAC but can also inhibit the function of smDAC. (+)-Brazilin could be a good candidate for further development as a potent therapeutic for the prevention and treatment of dental caries.IMPORTANCEThis study represents a significant advancement in our understanding of potential therapeutic options for combating cariogenic biofilms produced by Streptococcus mutans. The research delves into the use of (+)-brazilin, a natural product, as a potent inhibitor of Streptococcus mutans' diadenylate cyclase (smDAC), an enzyme crucial in the formation of biofilms. The study establishes (+)-brazilin as a non-competitive inhibitor of smDAC while providing initial insights into its binding mechanism. What makes this finding even more promising is that (+)-brazilin does not limit its inhibitory effects to S. mutans alone. Instead, it demonstrates efficacy in hindering biofilms in other oral bacteria as well. The broader spectrum of anti-biofilm activity suggests that (+)-brazilin could potentially serve as a versatile tool in a natural product-based treatment for combating a range of conditions caused by resilient biofilms.

Article review: Brazilin as potential anticancer agent.

Brazilin is the main compound in Caesalpinia sappan and Haematoxylum braziletto, which is identified as a homoisoflavonoid based on its molecular structure. These plants are traditionally used as an anti-inflammatory to treat fever, hemorrhage, rheumatism, skin problems, diabetes, and cardiovascular diseases. Recently, brazilin has increased its interest in cancer studies. Several findings have shown that brazilin has cytotoxic effects on colorectal cancer, breast cancer, lung cancer, multiple myeloma, osteosarcoma, cervical cancer, bladder carcinoma, also other cancers, along with numerous facts about its possible mechanisms that will be discussed. Besides its flavonoid content, brazilin is able to chelate metal ions. A study has proved that brazilin could be used as an antituberculosis agent based on its ability to chelate iron. This possible iron-chelating of brazilin and all the studies discussed in this review will lead us to the statement that, in the future, brazilin has the potency to be a chemo-preventive and anticancer agent. The article review aimed to determine the brazilin mechanism and pathogenesis of cancer.

Brazilin-Ce nanoparticles attenuate inflammation by de/anti-phosphorylation of IKKß.

Inflammation is associated with a series of diseases like cancer, cardiovascular disease and infection, and phosphorylation/dephosphorylation modification of proteins are important in inflammation regulation. Here we designed and synthesized a novel Brazilin-Ce nanoparticle (BX-Ce NPs) using Brazilin, which has been used for anti-inflammation in cardiovascular diseases but with narrow therapeutic window, and Cerium (IV), a lanthanide which has the general activity in catalyzing the hydrolysis of phosphoester bonds, to conferring de/anti-phosphorylation of IKKß. We found that BX-Ce NPs specifically bound to Asn225 and Lys428 of IKKß and inhibited its phosphorylation at Ser181, contributing to appreciably anti-inflammatory effect in cellulo (IC50 = 2.5 µM). In vivo mouse models of myocardial infarction and sepsis also showed that the BX-Ce NPs significantly ameliorated myocardial injury and improved survival in mice with experimental sepsis through downregulating phosphorylation of IKKß. These findings provided insights for developing metal nanoparticles for guided ion interfere therapy, particularly synergistically target de/anti-phosphorylation as promising therapeutic agents for inflammation and related diseases.

Designed complexes combining brazilein and brazilin with betanidin for dye-sensitized solar cell application: DFT and TD-DFT study.

Dye-sensitized solar cells (DSSCs) are promising third-generation photovoltaic cell technology owing to their easy fabrication, flexibility and better performance under diffuse light conditions. Natural pigment sensitizers are abundantly available and environmentally friendliness. However, narrow absorption spectra of natural pigments result in low efficiencies of the DSSCs. Therefore, combining two or more pigments with complementary absorption spectra is considered an appropriate method to broaden the absorption band and boost efficiency. This study reports three complex molecules: brazilin-betanidin-oxane (Braz-Bd-oxane), brazilin-betanidin-ether (Braz-Bd-ether) and brazilein-betanidin-ether (Braze-Bd-ether), obtained from the etherification and bi-etherification reactions of brazilin dye and brazilein dye with betanidin dye. The equilibrium geometrical structure properties, frontier molecular orbital, electrostatic surface potential, reorganization energy, chemical reactivities, and non-linear optical properties of the studied dyes were investigated using density functional theory (DFT)/B3LYP methods, with 6-31+G(d,p) basis sets and LANL2DZ for light atom and heavy atoms respectively. The optical-electronic properties were calculated using TD-DFT/B3LYP/6-31+G(d,p) for isolated dye and TD-DFT/CAM-B3LYP/6-31G(d,p)/LANL2DZ for dyes@(TiO2)9H4. The results reveal that spectra for Braz-Bd-oxane and Braze-Bd-ether complexes red-shifted compared to the individually selected dyes. The simulated absorption spectra of the adsorbed dyes on (TiO2)9H4 are red-shifted compared to the free dye. Moreover, Braz-Bd-oxane and Braz-Bd-ether exhibit better charge transfer and photovoltaic properties than the selected natural dyes forming these complexes. Based on the dyes' optoelectronic properties and photovoltaic properties, the designed molecules Braz-Bd-oxane and Braze-Bd-ether are considered better candidates to be used as photosensitizers in dye solar cells.

Brazilin-7-acetate, a novel potential drug of Parkinson's disease, hinders the formation of α-synuclein fibril, mitigates cytotoxicity, and decreases oxidative stress.

Parkinson's disease (PD) is a prevalent neurodegenerative disorder characterized by the accumulation of α-synuclein (α-Syn) aggregates. However, there are currently no effective therapies for PD. Brazilin, an inhibitor of α-Syn aggregation, is unstable and toxic. Therefore, we have developed and synthesized derivatives of brazilin. One of these derivatives, called brazilin-7-acetate (B-7-A), has shown reduced toxicity and a stronger effect on inhibiting α-Syn aggregation. It showed that B-7-A prevented the formation of α-Syn fibers and disrupted existing fibers in a dosage-dependent manner. Additionally, B-7-A significantly reduced the cytotoxicity of α-Syn aggregates and alleviated oxidative stress in PC12 cells. The beneficial effects of B-7-A were also confirmed using the Caenorhabditis elegans model. These effects included preventing the accumulation of α-Syn clumps, improving behavior disorder, increasing lifespan, reducing oxidative stress, and protecting against lipid oxidation and loss. Finally, B-7-A showed good ADMET properties in silico. Based on these findings, B-7-A exhibits potential as a prospective treatment for PD.

Effects of Encapsulation of Caesalpinia sappan L. with Cyclodextrins for Bovine Mastitis.

The main components of Caesalpinia sappan L. (CS) are brazilin and brazilein, which show high potential in pharmacologic applications. However, these have been drastically limited by the poor water solubility and stability. The present study investigates the formation of inclusion complexes F1, F2, and F3 between CS and ß-cyclodextrin (ßCD), hydroxypropyl-ß-cyclodextrin (HPßCD), and methyl-ß-cyclodextrin (MßCD), respectively. These complexes were characterized by Fourier transform infrared spectroscopy (FT-IR). The results showed that the highest encapsulation efficiency and loading capacity of CS extract were 44.24% and 9.67%, respectively. The solubility and stability of CS extract were significantly increased through complexation in phase solubility and stability studies. The complexes F1-F3 showed mainly significant antibacterial activities on gram-positive bacteria pathogens causing mastitis. Moreover, the expression levels of COX-2 and iNOS were significantly decreased in LPS-induced inflammatory cells at concentrations of 50 and 100 µg/mL. In addition, treatment of complex F3 (CS/MßCD) in bovine endothelial cells remarkably increased the chemokine gene expression of CXCL3 and CXCL8, which were responsible for immune cell recruitment (9.92 to 11.17 and 8.23 to 9.51-fold relative to that of the LPS-treated group, respectively). This study provides a complete characterization of inclusion complexes between CS extract and ßCD, HPßCD, and MßCD for the first time, highlighting the impact of complex formation on the pharmacologic activities of bovine mastitis.

Brazilin inhibits bladder cancer by promoting cell necroptosis.

Brazilin possesses anticancer effects, but the mechanisms are poorly understood. This study investigated the mechanisms of brazilin-induced cell death in the T24 human bladder cancer cell line. Low serum cell culture and the lactate dehydrogenase assay were used to confirm the antitumor effect of brazilin. Annexin V and propidium iodide double staining, transmission electron microscopy, fluo-3-AM assay for Ca2+ mobilization and caspase activity assay were performed to identify the type of cell death after brazilin treatment. Mitochondria membrane potentials were measured using JC-1. Quantitative real-time polymerase chain reaction and western blot analyses were performed to verify the expression of the necroptosis-related genes and proteins receptor interacting protein 1 (RIP1), RIP3 and mixed lineage kinase domain-like (MLKL). The results showed that brazilin induced necrosis in T24 cells and upregulated the mRNA and protein levels of RIP1, RIP3 and MLKL and Ca2+ influx. The necroptosis-mediated cell death was rescued by the necroptosis inhibitor necrostatin-1 (Nec-1), but not by the apoptosis inhibitor z-VAD-fmk. Brazilin repressed caspase 8 expression and decreased the mitochondrial membrane potentials; both effects were partially reversed by Nec-1. Brazilin induced physiological and morphological changes in T24 cells and RIP1/RIP3/MLKL-mediated necroptosis might be involved. In conclusion, the results confirm the involvement of necroptosis in brazilin-induced cell death and suggest that brazilin could be explored as an anticancer agent against bladder cancer.

Brazilin Inhibits the Invasion and Metastasis of Breast Cancer.

This study aimed to determine the effect of brazilin on the invasion and metastasis of breast cancer. The breast cancer MDA-MB-231 and 4T1 cells were treated with brazilin to investigate proliferation and invasion using cell proliferation assay, wound healing assay, transwell assay. BALB/C mice were randomized into normal, model, positive control, and Sappan L. extract groups (n = 6/group). The mice were injected with 4T1 cells via caudal veins to establish a lung metastasis model and via subcutaneous injection to establish a xenograft model. Metastatic nodules on the lung surface, survival rates and visceral indices were evaluated. Subcutaneous tumor volumes and weights were measured. Brazilin inhibited the proliferation of breast cancer cells and significantly inhibited the wound healing, migration, and invasion of MDA-MB-231 and 4T1 cells. Compared with the normal group, the average survival days and spleen index in the model group were significantly decreased, but the lung index and number of pulmonary metastatic nodules were significantly increased. Compared with the model group, the average survival and spleen index of dose groups were significantly increased, and the lung index, the number of pulmonary metastatic nodules, and tumor volume and weight were significantly decreased. Brazilin significantly inhibits the proliferation and metastasis of breast cancer. This study might suggest a new therapeutic agent for breast cancer.

Brazilian Red Propolis Presents Promising Anti-H. pylori Activity in In Vitro and In Vivo Assays with the Ability to Modulate the Immune Response.

Helicobacter pylori is a Gram-negative, microaerophilic, curved-rod, flagellated bacterium commonly found in the stomach mucosa and associated with different gastrointestinal diseases. With high levels of prevalence worldwide, it has developed resistance to the antibiotics used in its therapy. Brazilian red propolis has been studied due to its biological properties, and in the literature, it has shown promising antibacterial activities. The aim of this study was to evaluate anti-H. pylori from the crude hydroalcoholic extract of Brazilian red propolis (CHEBRP). For this, in vitro determination of the minimum inhibitory and bactericidal concentration (MIC/MBC) and synergistic activity and in vivo, microbiological, and histopathological analyses using Wistar rats were carried out using CHEBRP against H. pylori strains (ATCC 46523 and clinical isolate). CHEBRP presented MIC/MBC of 50 and 100 µg/mL against H. pylori strains (ATCC 43526 and clinical isolate, respectively) and tetracycline MIC/MBC of 0.74 µg/mL. The association of CHEBRP with tetracycline had an indifferent effect. In the stomach mucosa of rats, all treatments performed significantly decreased the number of H. pylori, and a concentration of 300 mg/kg was able to modulate the inflammatory response in the tissue. Therefore, CHEBRP showed promising anti-H. pylori in in vitro and in vivo assays.

Protective role of Caesalpinia sappan extract and its main component brazilin against blue light-induced damage in human fibroblasts.

BACKGROUND: Ultraviolet (UV) radiation is a well-known factor that causes skin aging. Recently, with the development of technology, the skin has been exposed to not only the UV radiation but also the blue light from electronic devices. Blue light is a high-energy visible light that penetrates deep into the dermal layer, producing reactive oxygen species (ROS) and resulting in skin aging. In this study, we searched for candidate materials that can inhibit blue light-induced skin aging and found Caesalpinia sappan extract (CSE) to be effective. METHODS: Human dermal fibroblasts (HDFs) were treated with various concentrations of CSE and brazilin and exposed to blue light. We measured that antioxidant activity, MMP-1 levels using MMP-1 ELISA, changes in collagen type 1, collagen type 3, MMP-1, and MMP-3 mRNA expressions, and ROS generation. RESULTS: We confirmed that CSE has high absorption of blue light and antioxidant activity. Blue light irradiation at 30 J/cm2 decreased the expression of collagen types 1 and 3, increased the expression of matrix metalloproteinase (MMP)-1 and 3, and decreased the production of ROS in human dermal fibroblasts as compared to those of the nonirradiated group. However, pretreatment with CSE protected against the damage caused by the blue light. Brazilin, a major constituent of C. sappan, had high absorbance in the blue light region and antioxidant activities. Pretreatment with brazilin also inhibited the damage caused by the blue light in the cells. CONCLUSION: CSE and brazilin are potential agents for inhibiting skin aging caused by blue light-induced damage.

Antibacterial Activity against Foodborne Pathogens and Inhibitory Effect on Anti-Inflammatory Mediators' Production of Brazilin-Enriched Extract from Caesalpinia sappan Linn.

Caesalpinia sappan L. heartwood was collected from Mae Chaem District, Chiang Mai Province, Thailand. Crude extracts were prepared by Soxhlet's extraction using 50, 60, and 70% of ethanol (EtOH) at 50, 60, and 70 °C, and the brazilin content was measured using reversed-phase high performance liquid chromatography (RP-HPLC). The antibacterial activity against foodborne pathogens and anti-inflammatory aspects were investigated. C. sappan, prepared from 70% EtOH at 70 °C (E70T70), significantly (p < 0.05) exhibited the highest amount of brazilin (7.90 ± 0.50% w/w). All extracts were investigated for anti-inflammatory activity through an inhibition effect on nitric oxide (NO) and inducible nitric oxide synthase (iNOS) production in RAW264.7 mouse macrophage cells. The inhibitory effect on cyclooxygenase-2 (COX-2) production in HT-29 and HCT116 was also studied. All the extracts inhibited NO, iNOS, and COX-2 production induced by combined lipopolysaccharide and interferon-γ, especially E70T70, indicating the highest inhibition effect among other extracts. Additionally, E70T70 was selected to determine the antibacterial activity against foodborne pathogens, including Staphylococcus aureus, Escherichia coli, Salmonella enteritidis, and Vibrio parahaemolyticus. The result showed that 200 µg/mL extract reduced all test pathogens 100% at 24 h. These results suggested the potential of using C. sappan L. extract as a natural preservative in food and a natural active pharmaceutical ingredient.

Sappanwood-derived polyphenolic antidote of amyloidal toxins achieved detoxification via inhibition/reversion of amyloidal fibrillation.

The formidable virulence of methicillin-resistant staphylococcus aureus (MRSA) have thrown great challenges to biomedicine, which mainly derives from their autocrine phenol-soluble modulins (PSMs) toxins, especially the most toxic member termed phenol-soluble modulins α3 (PSMα3). PSMα3 cytotoxicity is attributed to its amyloidal fibrillation and subsequent formation of cross-α sheet fibrils. Inspired by the multiple biological activity of Sappanwood, herein, we adopted brazilin, a natural polyphenolic compound originated from Caesalpinia sappan, as a potential antidote of PSMα3 toxins, and attempted to prove that the regulation of PSMα3 fibrillation was an effective alexipharmic way for MRSA infections. In vitro results revealed that brazilin suppressed PSMα3 fibrillation and disassembled preformed amyloidal fibrils in a dose-dependent manner, in which molar ratio (brazilin: PSMα3) of efficient inhibition and disassembly were both 1:1. These desired regulations dominated by brazilin benefited from its bonding to core fibrils-forming residues of PSMα3 monomers urged by hydrogen bonding and pi-pi stacking, and such binding modes facilitated brazilin-mediated inhibition or disruption of interactions between neighboring PSMα3 monomers. In this context, these inhibited and disassembled PSMα3 assemblies could not easily insert into cell membrane and subsequent penetration, and thus alleviating the membrane disruption, cytoplasmic leakage, and reactive oxygen species (ROS) generation in normal cells. As such, brazilin dramatically decreased the cytotoxicity borne by toxic PSMα3 fibrils. In addition, in vivo experiments affirmed that brazilin relieved the toxicity of PSMα3 toxins and thus promoted the skin wound healing of mice. This study provides a new antidote of PSMα3 toxins, and also confirms the feasibility of the assembly-regulation strategy in development of antidotes against supramolecular fibrillation-dependent toxins.

Brazilin Isolated from Caesalpina Sappan Wood Induces Intrinsic Apoptosis on A549 Cancer Cell Line by Increasing p53, caspase-9, and caspase-3.

OBJECTIVE: Lung cancer is the leading cause of death among cancer patients. The majority of lung cancer is the Non-Small Lung Carcinoma (NSLC). This study evaluated the potency of brazilin isolated from Caesalpinia sappan wood to induce apoptosis on non-small lung carcinoma cell line, A549, by examining the expression of p53, caspase-9, and caspase-3. METHODS: Brazilin was isolated from Caesalpinia sappan wood following a guided assay and it was determined by using Brazilin®SIGMA as standard. The activity of brazilin on the growth of A549 cell line was analysed by MTT assay and the apoptosis was evaluated by flowcytometer following Annexin V (FITC) and PI staining. The expression of p53, caspase-9, and caspase-3 was examined by immunocytochemistry. RESULT: The IC50 of brazilin on A549 cell line was 43µg/mL. Cell treatment with 20 µg/mL and 40 µg/mL of brazilin significantly increased early apoptosis (p<0.001). Cell treatment with 40 µg/mL  of Brazilin significantly increased late apoptosis (p<0.001). Brazilin significantly increased the expression of p53, Caspase-9, and caspase-3 (p<0.001). CONCLUSION: This study showed evidence of the activity of brazilin to induce intrinsic apoptosis on a NSLC cell line A549.

Molecular docking of brazilin and its analogs to barrier-to-autointegration factor 1 (BAF1).

The tetracyclic phenolic compound brazilin, derived from the wood of Caesalpinia sappan, has been shown to bind to the chromatin protein BAF1 (barrier-to-autointegration factor 1), a protein essential to maintain integrity of the nuclear envelope in cells. BAF1 plays a role in cancer development. Using molecular docking, we have located the binding site for brazilin on the surface of the BAF1 monomer and compared its binding to that of four analogs. The oxidized product brazilein (ΔE = -57.7 kcal/mol) exhibits a higher affinity for BAF1 compared to the reduced form brazilin (ΔE = -38.2 kcal/mol). Incorporation of a 4-hydroxyl substituent on the indenochromene unit affords hematoxylin and hematein. In silico analysis predicts that the oxidized form hematein (ΔE = -66.2 kcal/mol) displays a higher affinity for BAF1 than the reduced form hematoxylin (ΔE = -42.2 kcal/mol). In contrast, the atypical bis-lactone product brazilide A cannot form good complexes with BAF1. The analysis points to the formation of more stable BAF1 complexes with the oxidized molecules compared to the reduced ones, but the position of the binding site on the protein cavity is different for brazilin/hematoxylin compared to brazilein/hematein. Our study may be useful to guide the design of BAF1 ligands.