Mammea Siamensis Research Articles

Prediction of Protein-Drug Interactions, Pharmacophore Modeling, and Toxicokinetics of Novel Leads for Type 2 Diabetes Treatment.

Small heterocyclic compounds have been crucial in pioneering advances in type 2 diabetes treatment. There has been a dramatic increase in the pharmacological development of novel heterocyclic derivatives aimed at stimulating the activation of Glucokinase (GK). A pharmaceutical intervention for diabetes is increasingly targeting GK as a legitimate target. Diabetes type 2 compromises Glucokinase's function, an enzyme vital for maintaining the balance of blood glucose levels. Medicinal substances strategically positioned to improve type 2 diabetes management are used to stimulate the GK enzyme using heterocyclic derivatives. The research endeavor aimed to craft novel compounds, drawing inspiration from the inherent coumarin nucleus found in nature. The goal was to evoke the activity of the glucokinase enzyme, offering a tailored approach to mitigate the undesired side effects typically associated with conventional therapies employed in the treatment of type 2 diabetes. Coumarin, sourced from nature's embrace, unfolds as a potent and naturally derived ally in the quest for innovative antidiabetic interventions. Coumarin was extracted from a variety of botanical origins, including Artemisia keiskeana, Mallotus resinosus, Jatropha integerrima, Ferula tingitana, Zanthoxylum schinifolium, Phebalium clavatum, and Mammea siamensis. This inclusive evaluation was conducted on Muybridge's digital database containing 53,000 hit compounds. The presence of the coumarin nucleus was found in 100 compounds, that were selected from this extensive repository. Utilizing Auto Dock Vina 1.5.6 and ChemBioDraw Ultra, structures generated through this process underwent docking analysis. Furthermore, these compounds were accurately predicted online log P using the Swiss ADME algorithm. A predictive analysis was conducted using PKCSM software on the primary compounds to assess potential toxicity. Using Auto Dock Vina 1.5.6, 100 coumarin derivatives were assessed for docking. Glucokinase (GK) binding was significantly enhanced by most of these compounds. Based on superior binding characteristics compared with Dorzagliatin (standard GKA) and MRK (co-crystallized ligand), the top eight molecules were identified. After further evaluation through ADMET analysis of these eight promising candidates, it was confirmed that they met the Lipinski rule of five and their pharmacokinetic profile was enhanced. The highest binding affinity was demonstrated by APV16 at -10.6 kcal/mol. A comparison between the APV16, Dorzagliatin and MRK in terms of toxicity predictions using PKCSM indicated that the former exhibited less skin sensitization, AMES toxicity, and hepatotoxicity. Glucokinase is most potently activated by 100 of the compound leads in the database of 53,000 compounds that contain the coumarin nucleus. APV12, with its high binding affinity, favorable ADMET (adjusted drug metabolic equivalents), minimal toxicity, and favorable pharmacokinetic profile warrants consideration for progress to in vitro testing. Nevertheless, to uncover potential therapeutic implications, particularly in the context of type 2 diabetes, thorough investigations and in-vivo evaluations are necessary for benchmarking before therapeutic use, especially experiments involving the STZ diabetic rat model.

Comparative discriminant analysis of Mesua ferrea L. and its adulterants

The Uygur medicinal material Mesua ferrea L. has different plant sources in the market. The flower bud of Mammea siamensis T. Anders, which originated from Myanmar and Thailand, is actually used in the dosage room of Uygur hospitals and pharmaceutical enterprises in Xinjiang Region. On the contrary, flowers of Mesua ferrea L. are less frequently used. In this study, the taxonomic characteristics, liquid chromatography-mass spectrometry (LC/MS) and liquid chromatography (HPLC) were used to compare the similarities and differences between the two species. The results showed that the flowers of the two plants were significantly different in morphology, but the similarity of chemical components was high. At the same time, the study also found that Mesua ferrea L. and Mammea siamensis T. Anders contain a large amount of vitexin and isovitexin, which can be used for qualitative and quantitative research. This study provides a reference for the identification, development and utilization of Mesua ferrea L medicinal materials and the revision of quality standards.

In vivo antimalarial effect of 1-hydroxy-5,6,7-trimethoxyxanthone isolated from Mammea siamensis T. Anders. flowers: pharmacokinetic and acute toxicity studies

BackgroundThe potent antiplasmodial activity of 1-hydroxy-5,6,7-trimethoxyxanthone (HTX), isolated from Mammea siamensis T. Anders. flowers, has previously been demonstrated in vitro. However, its in vivo activity has not been reported. Therefore, this study aimed to investigate the antimalarial activity and acute toxicity of HTX in a mouse model and to evaluate the pharmacokinetic profile of HTX following a single intraperitoneal administration.MethodsThe in vivo antimalarial activity of HTX was evaluated using a 4-day suppressive test. Mice were intraperitoneally injected with Plasmodium berghei ANKA strain and given HTX daily for 4 days. To detect acute toxicity, mice received a single dose of HTX and were observed for 14 days. Additionally, the biochemical parameters of the liver and kidney functions as well as the histopathology of liver and kidney tissues were examined. HTX pharmacokinetics after intraperitoneal administration was also investigated in a mouse model. Liquid chromatography triple quadrupole mass spectrometry was used to quantify plasma HTX and calculate pharmacokinetic parameters with the PKSolver software.ResultsHTX at 10 mg/kg body weight significantly suppressed parasitemia in malaria-infected mice by 74.26%. Mice treated with 3 mg/kg HTX showed 46.88% suppression, whereas mice treated with 1 mg/kg displayed 34.56% suppression. Additionally, no symptoms of acute toxicity were observed in the HTX-treated groups. There were no significant alterations in the biochemical parameters of the liver and kidney functions and no histological changes in liver or kidney tissues. Following intraperitoneal HTX administration, the pharmacokinetic profile exhibited a maximum concentration (Cmax) of 94.02 ng/mL, time to attain Cmax (Tmax) of 0.5 h, mean resident time of 14.80 h, and elimination half-life of 13.88 h.ConclusionsHTX has in vivo antimalarial properties against P. berghei infection. Acute toxicity studies of HTX did not show behavioral changes or mortality. The median lethal dose was greater than 50 mg/kg body weight. Pharmacokinetic studies showed that HTX has a long elimination half-life; hence, shortening the duration of malaria treatment may be required to minimize toxicity.

A new genus, new species and new record of eriophyoid mites (Acari: Diptilomiopidae) from Thailand

Saraphia siamensis gen. nov. & sp. nov. (Acari: Eriophyoidea) from Mammea siamensis (Miq.) T. Anderson in Thailand is described, illustrated. We provide a geometric morphometric analysis based on different geoghraphic populations. Additionally, we report Vasates spondiasi Boczek & Chandrapatya, 1989, a new record from M. siamensis. No visible damaging symptom was observed for both eriophyoid mite species, indicating that they are vagrants on the underside of leaves.

GC-MS and Bioassay-Guided Isolation of Xanthones from <i>Mammea siamensis</i>

Mammea siamensis (Miq.) T. Anders. (Calophyllaceae) plants have long been employed as an active integral composition in Thai traditional medicine. Additionally, phenylcoumarins and triterpenes were reported as major components in phytochemical research. This work explored the various parts of M. siamensis; barks, flowers, twigs, leaves, and young leaves; to determine their bioactive compounds. By using the GC-MS and bioassay guidance, two xanthones, 6-deoxyisojacareubin (1) and 1,5-dihydroxyxanthone (2), together with a mixture of phenylcoumarins, mammea A/AA cyclo D (3) and mammea A/AB cyclo D (4) have been isolated from the methanolic extract of young leaves. Their structures were identified by means of spectroscopic technique and by comparison with literature data. In particular, the current study was the first exposed report of xanthones 1 and 2 from the genus Mammea. Furthermore, compounds 1 and 2 and the methanolic young leaf extract had high antioxidant efficiency on DPPH and ABTS assays. The young leaf extract provided mild toxicity on the brine shrimp lethality test (BSLT) with LC50 value of 93.11 ± 1.37 µg/mL. In addition, the isolated compounds 1 and 2 were non-toxicity in BSLT assay. Therefore, the young leaf extract and the purified constituents 1 and 2 should be further studied and developed for using in pharmaceutical industries.

Preclinical evaluation of antimalarial activity of CPF-1 formulation as an alternative choice for the treatment of malaria

BackgroundKheaw Hom remedy is a traditional Thai medicine used to treat fever. Some plants used in the Kheaw Hom remedy show promising in vitro antimalarial activity. This study prepared novel formulations of plants from the Kheaw Hom remedy and evaluated their antimalarial and toxicological activities.MethodsSeven new formulations were prepared by combining at least three herbs of six selected plants from the Kheaw Hom remedy, namely Mammea siamensis Kosterm., Mesua ferrea L., Dracaena loureiroi Gagnep., Pogostemon cablin (Blanco) Benth., Kaempferia galanga L, and Eupatorium stoechadosmum Hance. In vitro antimalarial activities of each formulation’s aqueous and ethanolic extracts were evaluated using the parasite lactate dehydrogenase (pLDH) assay. Cytotoxicity in Vero and HepG2 cells was assessed using the MTT assay. An extract with good antimalarial potency and selectivity index (SI) was selected for in vivo antimalarial activity using Peter’s 4-day suppressive test and acute oral toxicity test in mice. In addition, bioactive compounds were identified using Gas chromatography-mass spectrometry (GC-MS) analysis.ResultsAmong the seven new formulations, ethanolic extracts of CPF-1 (Formulation 1) showed the highest activity with an IC50 value of 1.32 ± 0.66 µg/ml, followed by ethanolic extracts of Formulation 4 and Formulation 6 with an IC50 value of 1.52 ± 0.28 µg/ml and 2.48 ± 0.34 µg/ml, respectively. The highest SI values were obtained for the ethanolic extract of CPF-1 that was selected to confirm its in vivo antimalarial activity and toxicity. The results demonstrated a significant dose-dependent reduction in parasitemia. Maximum suppressive effect of the extract (72.01%) was observed at the highest dose administered (600 mg/kg). No significant toxicity was observed after the administration of 2000 mg/kg. Using GC-MS analysis, the most abundant compound in the ethanolic extract of CPF-1 was ethyl p-methoxycinnamate (14.32%), followed by 2-propenoic acid, 3-phenyl-, ethyl ester, (E)- (2.50%), and pentadecane (1.85%).ConclusionThe ethanolic extract of CPF-1 showed promising in vitro and in vivo antimalarial efficacy, with no toxic effects at a dose of 2000 mg/kg, suggesting that the ethanolic extract of CPF-1 may serves as a new herbal formulation for the treatment of malaria. Additional research is required for safety and clinical pharmacology studies.

Structures of Mammeasins P and Q, Coumarin-Related Polysubstituted Benzofurans, from the Thai Medicinal Plant Mammea siamensis (Miq.) T. Anders.: Anti-Proliferative Activity of Coumarin Constituents against Human Prostate Carcinoma Cell Line LNCaP.

A methanol extract of the flowers of Mammea siamensis (Miq.) T. Anders. (Calophyllaceae) showed anti-proliferative activity against human prostate carcinoma LNCaP cells (IC50 = 2.0 µg/mL). Two new coumarin-related polysubstituted benzofurans, mammeasins P (1) and Q (2), and a known polysubstituted coumarin mammea B/AC cyclo F (39) were isolated from the extract along with 44 previously reported polysubstituted coumarin constituents (3-38 and 40-47). The structures of two new compounds (1 and 2) were determined based on their spectroscopic properties derived from the physicochemical evidence including NMR and MS analyses and taking the plausible generative pathway into account. Among the coumarin constituents, mammeasins A (3, IC50 = 1.2 µM) and B (4, 0.63 µM), sugangin B (18, 1.5 µM), kayeassamins E (24, 3.0 µM) and G (26, 3.5 µM), and mammeas E/BA (40, 0.88 µM), E/BB (41, 0.52 µM), and E/BC (42, 0.12 µM) showed relatively potent anti-proliferative activity.

Natural Compounds with BMI1 Promoter Inhibitory Activity from Mammea siamensis and Andrographis paniculata.

A new coumarin derivative (1) and 30 known compounds were isolated from Mammea siamensis and Andrographis paniculata, guided by B cell-specific Moloney murine leukemia virus insertion region 1 (BMI1) promoter inhibitory activity. Among the isolated compounds, 15 compounds showed BMI1 promoter inhibitory activity, and five compounds were found to be cytotoxic. 14-Deoxy-11,12-dehydroandrographolide (18) was highly cytotoxic to DU145 cells with an IC50 value of 25.4 µM. Western blotting analysis of compound 18 in DU145 cells suggested that compound 18 suppresses BMI1 expression.

Antimalarial potential of compounds isolated from Mammea siamensis T. Anders. flowers: in vitro and molecular docking studies

Background:The emergence of antimalarial drug resistance encourages the search for new antimalarial agents. Mammea siamensis belongs to the Calophyllaceae family, which is a medicinal plant that is used in traditional Thai preparations. The hexane and dichloromethane extracts of this plant were found to have potent antimalarial activity. Therefore, this study aimed to isolate active compounds from M. siamensis flowers and evaluate their antimalarial potential and their interactions with Plasmodium falciparum lactate dehydrogenase (PfLDH).Methods:The compounds from M. siamensis flowers were isolated by chromatographic techniques and evaluated for their antimalarial activity against chloroquine (CQ)-resistant P. falciparum (K1) strains using a parasite lactate dehydrogenase (pLDH) assay. Interactions between the isolated compounds and the PfLDH enzyme were investigated using a molecular docking method.Results:The isolation produced the following thirteen compounds: two terpenoids, lupeol (1) and a mixture of β-sitosterol and stigmasterol (5); two mammea coumarins, mammea A/AA cyclo D (6) and mammea A/AA cyclo F (7); and nine xanthones, 4,5-dihydroxy-3-methoxyxanthone (2), 4-hydroxyxanthone (3), 1,7-dihydroxyxanthone (4), 1,6-dihydroxyxanthone (8), 1-hydroxy-5,6,7-trimethoxyxanthone (9), 3,4,5-trihydroxyxanthone (10), 5-hydroxy-1-methoxyxanthone (11), 2-hydroxyxanthone (12), and 1,5-dihydroxy-6-methoxyxanthone (13). Compound 9 exhibited the most potent antimalarial activity with an IC50 value of 9.57 µM, followed by 10, 1, 2 and 13 with IC50 values of 15.48, 18.78, 20.96 and 22.27 µM, respectively. The molecular docking results indicated that 9, which exhibited the most potent activity, also had the best binding affinity to the PfLDH enzyme in terms of its low binding energy (-7.35 kcal/mol) and formed interactions with ARG109, ASN140, and ARG171.Conclusion:These findings revealed that isolated compounds from M. siamensis flowers exhibited antimalarial activity. The result suggests that 1-hydroxy-5,6,7-trimethoxyxanthone is a possible lead structure as a potent inhibitor of the PfLDH enzyme.

Phytochemicals with Chemopreventive Activity Obtained from the Thai Medicinal Plant Mammea siamensis (Miq.) T. Anders.: Isolation and Structure Determination of New Prenylcoumarins with Inhibitory Activity against Aromatase.

With the aim of searching for phytochemicals with aromatase inhibitory activity, five new prenylcoumarins, mammeasins K (1), L (2), M (3), N (4), and O (5), were isolated from the methanolic extract of Mammea siamensis (Miq.) T. Anders. flowers (fam. Calophyllaceae), originating in Thailand. The stereostructures of 1–5 were elucidated based on their spectroscopic properties. Among the new compounds, 1 (IC50 = 7.6 µM) and 5 (9.1 µM) possessed relatively strong inhibitory activity against aromatase, which is a target of drugs already used in clinical practice for the treatment and prevention of estrogen-dependent breast cancer. The analysis through Lineweaver–Burk plots showed that they competitively inhibit aromatase (1, Ki = 3.4 µM and 5, 2.3 µM). Additionally, the most potent coumarin constituent, mammea B/AB cyclo D (31, Ki = 0.84 µM), had a competitive inhibitory activity equivalent to that of aminoglutethimide (0.84 µM), an aromatase inhibitor used in therapeutics.

Anti-proliferative activities of coumarins from the Thai medicinal plant Mammea siamensis (Miq.) T. Anders. against human digestive tract carcinoma cell lines

Geranylated coumarins named mammeasins G–J (1–4) were isolated from the methanol extract of the flowers of Mammea siamensis (Miq.) T. Anders. (Calophyllaceae) originating in Thailand. Their structures were established based on detailed spectroscopic analyses. The isolates, including previously reported coumarin constituents (5–28), exhibited anti-proliferative activities against human carcinoma cell lines HSC-2, HSC-4, MKN-45, and MCF-7. Mammeasin A (7, IC50 = 13.6 μM) and surangin B (15, 15.2 μM), both consisting of the geranyl group, were found to show relatively strong activities against HSC-4 cells and their mechanisms of action were found to involve apoptotic cell death.

Southeast Asian Medicinal Plants with Angiotensin Converting Enzyme (ACE) Inhibition Properties

Introduction: This article aims to provide a summary of medicinal plants in the Southeast Asian countries that have an angiotensin-converting enzyme (ACE) inhibitory activity that is therapeutically useful for treating hypertension. Methods: This review paper is a result of extensive searches via electronic database platforms, including Pubmed, Google Scholar, Scopus, and Science Direct with the keyword search terms: ACE enzyme, Southeast Asia countries, plants, and extracts. Results: Thirty-four articles on ACE inhibition activity of 76 Southeast Asian medicinal plants were found and further reviewed. Several plants from Malaysia (Chassalia curviflora, Citrus hystrix, Murraya koenigii, Senna garrettiana), Indonesia (Gnetum Gnemon, Momordica charantia, Nasturtium officinale, Peperomia pellucida, Pereskia saccharose), and Thailand (Mammea siamensis) were found to exhibit strong ACE inhibitory activity in vitro. Bioactive compounds such as 3’,4’, dihydroxy-3-5 dimethoxy flavone-7-O-β-rhamnose and quercetin-3-O-glucoside showed the highest potency in exhibiting the ACE inhibition activity in this review. Conclusions: This review suggests for an in-depth investigation on the potent crude extracts for the potential development of complementary herbal medicines as well as on the potent ACE inhibitor compounds for further development as new ACE inhibitor candidates for hypertension therapy.

Geranylated Coumarins From Thai Medicinal Plant Mammea siamensis With Testosterone 5α-Reductase Inhibitory Activity

Geranylated coumarin constituents, kayeassamin I (1) and mammeasins E (2) and F (3) were newly isolated from the methanol extract of the flowers of Mammea siamensis (Calophyllaceae) originating in Thailand, along with five known isolates, such as mammea E/BC (23), deacetylmammea E/AA cyclo D (31), deacetylmammea E/BB cyclo D (32), mammea A/AA cyclo F (34), and mammea A/AC cyclo F (35). These compounds (1–3) were obtained as an inseparable mixture (ca. 1:1 ratio) of the 3″R and 3″S forms, respectively. Among the isolated coumarins from the extract, mammeasins E (2, 22.6 μM), A (4, 19.0 μM), and B (5, 24.0 μM), kayeassamins E (9, 33.8 μM), F (10, 15.9 μM), and G (11, 17.7 μM), surangin C (13, 5.9 μM), and mammeas A/AA (17, 19.5 μM), E/BB (22, 16.8 μM), and A/AA cyclo F (34, 23.6 μM), were found to inhibit testosterone 5α-reductase.

Acute toxicity and histopathological changes in livers of frog tadpoles (Hoplobatrachus rugulosus) exposed to bioinsecticides derived from Azadirachta indica A. Juss., Stemona curtisii Hook.F., and Mammea siamensis

Azadirachta indica A. Juss., Stemona curtisii Hook.F., and Mammea siamensis are popularly used as bioinsecticides by Thai farmers. To evaluate their safety on frog (Hoplobatrachus rugulosus) tadpoles, the ecologically and economically important species of Thailand, an acute static toxicity test was performed. The tadpoles (n = 10 per treatment group) were exposed to the bioinsecticides from A. indica (NSAI 5, 10, 15, 20, and 25 g/l) and the mixture of S. curtisii and M. siamensis (SCMS 0.8, 1.2, 1.6, 2.0, and 2.4 mg/l). It was found that the median lethal concentration (LC50) values at 96 h of the NSAI and the SCMS were 11.81 and 1.44 mg/l respectively. Hepatic failures were observed in tadpoles exposed to the NSAI and the SCMS. Histopathological changes included vacuolation, leukocyte infiltration, necrotic cell, and blood congestion. These lesions were more severe in the tadpoles treated with the NSAI or the SCMS at the high concentrations. Additionally, necrosis of bile duct epithelium, karyolysis, and sinusoidal dilation were apparently found in the tadpole exposed to 25 g/l of the NSAI, while the degeneration of bile duct was noted in the 1.6–2.4 mg/l of the SCMS-treated groups. However, the tadpoles exposed to 5 g/l of the NSAI showed only mild pathological changes in their livers. From a higher value of LC50 of the NSAI than the SCMS together with the mild histopathological changes in the tadpoles exposed to the low concentrations, thus the NSAI is less toxic to H. rugulosus tadpoles than the SCMS.

Total syntheses of the aromatase inhibitors, mammeasins C and D, from Thai medicinal plant Mammea siamensis

The first total syntheses of the geranylated pyranocoumarins, mameasins C (1) and D (2), aromatase inhibitors isolated from the flowers of Mammea siamensis, were accomplished in five steps, starting from phloroglucinol 3. In this strategy, the characteristic pyran ring-fused coumarin core of 1 and 2 was effectively constructed by Friedel-Crafts acylation of 3, followed by Reformatsky reaction of the resultant ketone to give a key coumarin intermediate 9. Compound 9 was converted to targets 1 and 2 in a stepwise manner by successive C-acylation and O-geranylation, followed by a [1,3]-sigmatropic geranyl shift. Furthermore, screening of intermediates obtained in the synthetic pathway to 1 and 2 revealed that de-geranylated pyranocoumarins (10 and 11) show superior aromatase inhibitory activity as compared to the natural products 1 and 2.

EFFECT OF THAI SARAPHI FLOWER EXTRACTS ON WT1 AND BCR/ABL PROTEIN EXPRESSION IN LEUKEMIC CELL LINES.

Background:Saraphi (Mammea siamensis) is a Thai traditional herb. In this study, the cytotoxic effects of crude ethanolic and fractional extracts including hexane, ethyl acetate, and methanol fractions from M. siamensis flowers were investigated in order to determine their effect on WT1 expression in Molt4 and K562 cells and Bcr/Abl expression in K562 cells.Materials and Methods:The flowers of M. siamensis were extracted using ethanol. The ethanol flower extract was further fractionated with hexane, ethyl acetate, and methanol. Cytotoxic effects were measured by the MTT assay. Bcr/Abl and WT1 protein levels after treatments were determined by Western blotting. The total cell number was determined via the typan blue exclusion method.Results:The hexane fraction showed the strongest cytotoxic activity on Molt4 and K562 cells, with IC50 values of 2.6 and 77.6 μg/ml, respectively. The hexane extract decreased Bcr/Abl protein expression in K562 cells by 74.6% and WT1 protein expressions in Molt4 and K562 cells by 68.4 and 72.1%, respectively. Total cell numbers were decreased by 66.2 and 48.7% in Molt4 and K562 cells, respectively. Mammea E/BB (main active compound) significantly decreased both Bcr/Abl and WTlprotein expressions by 75 and 49.5%, respectively when compared to vehicle control.Conclusion:The hexane fraction from M. siamensis flowers inhibited cell proliferation via the suppression of WT1 expression in Molt4 and K562 cells and Bcr/Abl expression in K562 cells. The active compound may be mammea E/BB. Extracts from M. siamensis flowers show promise as naturally occurring anti-cancer drugs.

Down-regulatory mechanism of mammea E/BB from Mammea siamensis seed extract on Wilms' Tumor 1 expression in K562 cells.

BackgroundWilms’ tumor 1 (WT1) is a biological marker for predicting leukemia progression. In this study, mammea E/BB, an active compound from Saraphi (Mammea siamensis) seed extract was examined for its effect on down-regulatory mechanism of WT1 gene expression, WT1 protein and mRNA stability, and cell proliferation in K562 cell line.MethodsM. siamensis seeds were obtained from the region of Chiang Mai (North of Thailand). Mammea E/BB was extracted from seeds of M. siamensis. WT1 protein expression and stability were evaluated by Western blot analysis. WT1 mRNA stability was assessed by qRT-PCR. WT1-DNA binding and WT1 promoter activity were assayed by ChIP assay and luciferase-reporter assay, respectively. Cell cycle arrest was studied by flow cytometry.ResultsTreatment with mammea E/BB led to down-regulation of WT1 expression. The suppression of WT1 expression did not involve protein and mRNA degradation. Rather, WT1 protein was down-regulated through disruption of transcriptional auto-regulation of the WT1 gene. Mammea E/BB inhibited WT1-DNA binding at the WT1 promoter and decreased luciferase activity. It also disrupted c-Fos/AP-1 binding to the WT1 promoter via ERK1/2 signaling pathway and induced S phase cell cycle arrest in K562 cells.ConclusionMammea E/BB had pleotropic effects on kinase signaling pathways, resulting in inhibition of leukemia cell proliferation.Electronic supplementary materialThe online version of this article (doi:10.1186/s12906-016-1107-z) contains supplementary material, which is available to authorized users.

Kayeassamin A Isolated from the Flower of Mammea siamensis Triggers Apoptosis by Activating Caspase-3/-8 in HL-60 Human Leukemia Cells.

Background:Mammea siamensis (Miq.) T. Anders. is used as a medicinal plant in Thailand and has several traditional therapeutic properties. In a previous study, we isolated eight compounds from the flower of M. siamensis and demonstrated that kayeassamin A (KA) exhibited potent antiproliferative activity against human leukemia and stomach cancer cell lines.Objective:In this study, we investigated the effect of KA on cell viability and apoptotic mechanisms in HL-60 human leukemia cells.Materials and Methods:Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Nuclear morphology and DNA fragmentation were observed using Hoechst 33258 staining and agarose gel electrophoresis, respectively. The sub-G1 phase of cells was analyzed by flow cytometry after the cellular DNA had been stained with propidium iodide. The protein levels of poly (ADP-ribose) polymerase (PARP) and caspases were determined by Western blotting.Results:KA exhibited a significant cytotoxic effect in a dose- and time-dependent manner, and induced chromatin condensation, DNA fragmentation, and sub-G1 phase DNA content, known as molecular events associated with the induction of apoptosis. In addition, KA strongly induced the activation of PARP and caspase-3 and -8, with weak caspase-9 activation. Furthermore, KA-induced DNA fragmentation was abolished by pretreatment with z-VAD-FMK (a broad caspase inhibitor), z-DEVD-FMK (a caspase-3 inhibitor), and z-IETD-FMK (a caspase-8 inhibitor), but not by z-LEHD-FMK (a caspase-9 inhibitor) pretreatment.Conclusion:These results indicate that KA triggers apoptotic cell death by activation of caspase-3 and -8 in HL-60 cells.SUMMARY Kayeassamin A (KA) isolated from the flower of Mammea siamensis exhibited a significant cytotoxic effect in HL-60 human leukemia cells. KA triggers apoptotic cell death by activating caspase-3/-8. Abbreviations Used: KA: Kayeassamin A; MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; PARP: Poly (ADP-ribose) polymerase; PI: Propidium iodide; CA: Corosolic acid

Aromatase Inhibitory Activity of Geranylated Coumarins, Mammeasins C and D, Isolated from the Flowers of Mammea siamensis.

A methanol extract of the flowers of Mammea siamensis (Calophyllaceae) was found to inhibit enzymatic activity against aromatase (IC50=16.5 µg/mL). From the extract, two new geranylated coumarins, mammeasins C (1) and D (2), were isolated together with seven coumarins: 8-hydroxy-5-methyl-7-(3,7-dimethyl-octa-2,6-dienyl)-9-(2-methyl-1-oxobutyl)-4,5-dihydropyrano[4,3,2-de]chromen-2-one (9), 8-hydroxy-5-methyl-7-(3,7-dimethyl-octa-2,6-dienyl)-9-(3-methyl-1-oxobutyl)-4,5-dihydropyrano[4,3,2-de]chromen-2-one (10), mammeas A/AA (14), A/AB (15), A/AA cyclo D (18), E/BA (23), and E/BC cyclo D (25). The structures of 1 and 2 were elucidated on the basis of spectroscopic evidence. Among the isolates including 17 previously reported coumarins, 1 (IC50=2.7 µM), 2 (3.6 µM), and mammea B/AB cyclo D (21, 3.1 µM) showed relatively strong inhibitory activities comparable to the activity of the synthetic nonsteroidal aromatase inhibitor aminoglutethimide (2.0 µM).

Inhibitory effect of mammea E/BB from Mammea siamensis seed extract on Wilms' tumour 1 protein expression in a K562 leukaemic cell line

Mammea siamensis is used in traditional Thai medicine. This study was designed to extract and isolate an active compound from the M. siamensis seeds and to investigate its activity on Wilms' tumour 1 (WT1) protein expression in K562 cells. WT1 is a transcription factor that stimulates cell proliferation. The ethanol saraphi seed (ESS) extract was fractionated using n-hexane, ethyl acetate, n-butanol and water to obtain n-hexane saraphi seed (HSS), ethyl acetate saraphi seed (EASS), n-butanol saraphi seed (BSS), and water saraphi seed (WSS) extracts, respectively. The ESS, HSS and EASS extracts had strong cytotoxic effects on K562 cells in the MTT assay. All three fractions decreased WT1 protein levels and decreased total cell numbers. The HSS extract decreased the WT1 protein levels in a time- and dose-dependent manner. HPLC and NMR analyses indicated that the active compound of HSS was mammea E/BB. M. siamensis seeds are thus identified as a promising source of bioactive compounds for potential inhibition of WT1 protein expression.