Triterpenoids from the fruits of Melia toosendan Sieb. et Zucc. with α-glucosidase inhibitory activities.

Four previously unreported tirucallane-type triterpenoids (1-4), together with four known analogues (5-8), were isolated from the fruits of Melia toosendan Sieb. et Zucc. Their planar structures were comprehensively elucidated by detailed analyses of HRESIMS, 1D and 2D NMR spectra data. The relative configurations of 1-4 were determined by NOESY experiments. The comparison of experimental and calculated electronic circular dichroism (ECD) spectra led to the establishment of the absolute configurations of new compounds. All isolated triterpenoids were evaluated for their α-glucosidase inhibitory activities in vitro. Compounds 4 and 5 showed moderate α-glucosidase inhibitory activities with IC50 values of 120.3 ± 5.8 and 104.9 ± 7.1 µM, respectively.

Copaiba oil and Neem extract can be a potential alternative for the behavioral control of Sitophilus zeamais.

Insects' ethology is an important factor when it is desired to carry out pest management. This knowledge makes it possible to manipulate behavioral activities, repel, or attract insects according to needs and interests. The maize weevil Sitophilus zeamais (Mots., 1855) (Coleoptera: Curculionidae), one of the main stored grain pests, has been the target of studies of behavioral changes studies through natural substances due to its resistance to different insecticidal classes. Thus, this study aimed to evaluate the effect of sublethal concentrations of neem extract and copaiba oil on the locomotor behavior of S. zeamais. The behavioral characteristic considered were walking activity, the frequency of contact of insects with the treated grain mass, and the time spent for this behavior. The walking activity of the S. zeamais increased with exposure to Neem extract and Copaiba oil. In general, the Neem extract and Copaiba oil-induced more contact with grain mass than the control, suggesting an attractive effect on the insect, however more significant for the Neem oil. The insect's behavior was altered, presenting a specific path due to Copaiba oil and Neem extract stimuli. These results indicate that Copaiba oil and Neem extract can be a potential alternative for controlling S. zeamais on stored products since changes in this pests' behavior can reduce qualitative and quantitative grain damage. Thus, the development of products based on Copaiba oil and Neem extract may be helpful for storage pest management.

Limonoids and unsaturated fatty acids present in Melia toosendan increase ceramide production in keratinocytes.

The skin barrier prevents moisture evaporation and the entry of foreign substances such as allergens. Ceramides are one of the most important factors for maintaining skin barrier function. Melia toosendan is a plant of the Meliaceae family, and its fruit extracts have been used in Traditional Chinese Medicine as analgesics and anthelmintics; however, its ability to increase ceramide levels has not been reported. In this study, we screened for compounds present in M. toosendan fruit extracts that increase ceramide levels in the skin. We fractionated the extracts based on their activity to identify the active components. Nimbolinins, limonoids such as toosendanin, and hydroxylated unsaturated fatty acids were found to be the major active components. The structure-activity relationship of toosendanin derivatives indicated that the sites around R4 and R5 contributed to the activity. To the best of our knowledge, this is the first report showing that limonoids promote ceramide production in skin cells. Therefore, M. toosendan fruit extracts may be used to develop products for improving the skin barrier function.

Identification of potential modulators of osteosarcoma metastasis by high-throughput cellular screening of natural products.

A high-throughput screening assay was developed and applied to a large library of natural product extract samples, in order to identify compounds which preferentially inhibited the in vitro 2D growth of a highly metastatic osteosarcoma cell line (MG63.3) compared to a cognate parental cell line (MG63) with low metastatic potential. Evaluation of differentially active natural product extracts with bioassay-guided fractionation led to the identification of lovastatin (IC50  = 11 µm) and the limonoid toosendanin (IC50  = 26 nm). Other statins and limonoids were then tested, and cerivastatin was identified as a particularly potent (IC50  < 0.1 µm) and selective agent. These compounds potently and selectively induced apoptosis in MG63.3 cells, but not MG63. Assays with other cell pairs were used to examine the generality of these results. Statins and limonoids may represent unexplored opportunities for development of modulators of osteosarcoma metastasis. As cerivastatin was previously approved for clinical use, it could be considered for repurposing in osteosarcoma, pending validation in further models.

Green route to synthesize Zinc Oxide Nanoparticles using leaf extracts of Cassia fistula and Melia azadarach and their antibacterial potential.

Development of plant based nanoparticles has many advantages over conventional physico-chemical methods and has various applications in medicine and biology. In present study, zinc oxide (ZnO) nanoparticles (NPs) were synthesized using leaf extracts of two medicinal plants Cassia fistula and Melia azadarach. 0.01 M zinc acetate dihydrate was used as a precursor in leaf extracts of respective plants for NPs synthesis. The structural and optical properties of NPs were investigated by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM), ultraviolet-visible spectrophotometer (UV-Vis) and dynamic light scattering (DLS). The antibacterial potential of ZnO NPs was examined by paper disc diffusion method against two clinical strains of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) based on the zone of inhibition and minimal inhibitory indices (MIC). Change in color of the reaction mixture from brown to white indicated the formation of ZnO NPs. UV peaks at 320 nm and 324 nm, and XRD pattern matching that of JCPDS card for ZnO confirmed the presence of pure ZnO NPs. FTIR further confirmed the presence of bioactive functional groups involved in the reduction of bulk zinc acetate to ZnO NPs. SEM analysis displayed the shape of NPs to be spherical whereas DLS showed their size range from 3 to 68 nm. The C. fistula and M. azadarach mediated ZnO NPs showed strong antimicrobial activity against clinical pathogens compared to standard drugs, suggesting that plant based synthesis of NPs can be an excellent strategy to develop versatile and eco-friendly biomedical products.

New meliacarpin-type (C-seco) and C-ring intact limonoids from the fruits of Melia toosendan.

Toosendansins E-I (1-5), five new limonoids together with nine known limonids(6-14), were isolated and identified from the fruits of Melia toosendan. Their skeletons were belonged to meliacarpins (1 and 2), nimbin (3), and vilasinins (4 and 5). All the isolates were identified using 1D & 2D NMR spectroscopic experiments, and the absolute configurations of 1 and 2 with 1,3-dicinnamoyl moieties were achieved by CD method. Compounds 1 and 4 showed moderate inhibitory activity against osteosarcoma cell line U-2 OS, and compound 4, ohchinolal (12), meliatoxin B1 (13) and 1,12-diacetyltrichichilin B (14) showed obvious reversal activity of multidrug resistance in MCF-7 cell line at 6.25 µM.

Characterization of Limonoids Isolated from the Fruits of Melia toosendan and Their Antifeedant Activity against Pieris rapae.

The fruits of Melia toosendan Sieb. et Zucc. (Meliaceae) are a source of bioactive limonoids that can be used as effective pesticides. In this study, two novel limonoids, 6-acetylsendanal and 6-ketocinamodiol, were isolated together with fourteen known compounds, namely four protolimonoids, six trichilin-class limonoids, and four C-seco limonoids. The structures of the new compounds were determined by extensive spectroscopic analyses (HR-ESI-MS, UV, IR, 1D and 2D NMR). The bioassay results revealed that eleven of the extracted limonoids exhibited interesting antifeedant activities against the larvae of Pieris rapae with AFC50 values in the range of 0.11-1.79 mm. Particularly, mesendanin H, with an AFC50 value of 0.11 mm, exhibited a higher activity than the positive control toosendanin. Information on new bioactive limonoids may provide further insight into M. toosendan as a source of bioactive components.

Effect of ethanolic extract of Melia dubia leaves on full-thickness cutaneous wounds in Wistar rats.

In recent years, the therapeutic effects of phyto-principles have been appreciated for their promising effects on wound healing. Melia dubia (Malabar neem) possesses anti-cancer, anti-diabetic, anti-tumor, anti-inflammatory, antioxidant, antibacterial, and fungicidal properties. Here, we studied the wound healing efficacy of ethanolic extract of M. dubia leaves on cutaneous wound healing for the first time. The ethanolic extract of M. dubia was applied topically on the wounds of the experimental rats until the wounds heal completely. Wounds of the control rats were treated with PBS. Granulation tissues formed on wound surfaces of the excision wound were harvested on days 4 and 8 and analyzed to determine the total collagen and hexosamine content. Total collagen and hexosamine were significantly (p < .001) higher in M. dubia treated rats compared to control. The rate of wound closure was significantly higher (p < .001) and period of epithelialization was shorter in M. dubia treated rats. Incision wound tissue was used for the tensile strength measurement. Tensile strength was improved in M. dubia treated wound tissues. Results concluded that the topical application of ethanolic extracts of M. dubia improved the rate of wound contraction and tensile strength by increased synthesis of collagen.

Meliacarpinin-Type Limonoids from the Bark of Melia toosendan.

Three new meliacarpinin-type limonoids, toosendanes A⁻C (1⁻3), along with three, known meliacarpinins (4⁻6) were isolated from the bark of Melia toosendan. Their structures, along with their absolute configurations, were elucidated, based on detailed analyses. These included HRESIMS and 1D/2D-NMR, modified Mosher's method, and electronic circular dichroism (ECD). Limonoids 2 and 3 showed moderate inhibitory activity on LPS-activated, RAW 264.7 macrophages.

Evaluation of in vitro antioxidant, antiglycation and antimicrobial potential of indigenous Myanmar medicinal plants.

OBJECTIVE: Myanmar has a long history of using medicinal plants for treatment of various diseases. To the best of our knowledge there are no previous reports on antiglycation activities of medicinal plants from Myanmar. Therefore, this study was aimed to evaluate the antioxidant, antiglycation and antimicrobial properties of 20 ethanolic extracts from 17 medicinal plants indigenous to Myanmar. METHODS: In vitro scavenging assays of 2,2-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO), superoxide (SO) radicals were used to determine the antioxidant activities. Folin-Ciocalteu's method was performed to determine the total phenolic content. Antiglycation and antimicrobial activities were detected by bovine serum albumin-fluorescent assay and agar well diffusion method. RESULTS: Terminalia chebula Retz. (Fruit), containing the highest total phenolic content, showed high antioxidant activities with inhibition of 77.98% ±â€¯0.92%, 88.95% ±â€¯2.42%, 88.56% ±â€¯1.87% and 70.74%±â€¯2.57% for DPPH, NO, SO assays and antiglycation activity respectively. It also showed the antimicrobial activities against Staphylococcus aureus, Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans with inhibition zone of 19, 18, 17, 25 and 15 mm, respectively. Garcinia mangostana Linn. showed the strongest activities for SO and antiglycation assays with inhibition of 93.68% ±â€¯2.63% and 82.37% ±â€¯1.78%. Bark of Melia sp. was the best NO radical scavenger with inhibition rate of 89.39%±â€¯0.60%. CONCLUSION: The results suggest that these plants are potential sources of antioxidants with free radical-scavenging and antiglycation activities and could be useful for decreasing the oxidative stress and glycation end-product formation in glycation-related diseases.

Fructose furoic acid ester: An effective quorum sensing inhibitor against uropathogenic Escherichia coli.

Uropathogenic Escherichia coli (UPEC) are the most common cause of UTI, accounting for more than 90% infections in the normal and unobstructed urinary tracts. Multi-drug resistance (MDR) is an emerging threat to the mankind and hence, there is an urge to develop alternative therapies. Targeting quorum sensing (QS), a cell-cell communication process regulates various biofilm and virulence factors would be a most promising alternate which curbs the pathogenesis without killing the bacteria, unlike antibiotics. SdiA, a quorum regulator is well-known to control the behavioural changes of UPEC in establishing biofilm and virulence. Therefore, we have hypothesized that the SdiA-selective inhibitors derived from the plant, Melia dubia using the molecular docking would be a remarkable therapeutic candidate to down regulate the UPEC biofilm and virulence phenotypes. In this study, we have designed, synthesized and characterized the fructose-furoic acid ester by NMR and ESI-MS. In vitro studies revealed that the QSI-MD selectively inhibits UPEC adherence and confocal laser scanning microscopy (CLSM) analysis showed the effectiveness of QSI-MD to inhibit the UPEC biofilm. Genetic studies using qRT-PCR revealed the down-regulation of quorum sensing regulated genes (fimA, csgA, espA). Based on the findings, we could propose that the QSI-MD could possibly act through SdiA and show target-specific inhibition of biofilm and virulence. It is notable that more than 70 bacterial species execute their communication through the SdiA homologues (LuxIR system). Hence, the QSI-MD could be further developed as a broad-spectrum anti-infective drug.

New triterpenoids with diverse side-chains from the barks of Melia Toosendan.

Nine new euphane- and apotirucallane-type triterpenoids (Toosendines A-I; 1-9), along with three known tirucallane-type compounds were isolated from the barks of Melia toosendan. Their structures were elucidated based on detailed spectroscopic analyses (HRESIMS, 1D/2D-NMR) and circular dichroism spectra. Results of bioactivities screening exhibited that compounds 1, 4 and 5 showed remarkable NO inhibitory activities in LPS-activated RAW 264.7 macrophages, meanwhile, compounds 1 and 4 showed moderate cytotoxicities against U2OS human cancer cell line.

New limonoids isolated from the bark of Melia toosendan.

Two new limonoids, 12-ethoxynimbolinins G and H (compounds 1 and 2), and one known compound, toosendanin (Chuanliansu) (compound 3), were isolated from the bark of Melia toosendan. Their structures were elucidated by spectroscopic analysis and X-ray techniques. The absolute configuration of toosendanin (3) was established by single-crystal X-ray diffraction. Compounds 1-3 were evaluated for their cytotoxicity against five tumor cell lines.

Synthesis of ZnO nanoparticles using Melia dubia leaf extract and its characterisation.

The present work deals with the synthesis of zinc oxide (ZnO) nanoparticles (Nps) using the biocompounds extracted from Melia dubia leaves (MD L.) and zinc acetate as precursors. The choice of the precursors was based on the intention to use the synthesised ZnO Nps for the healthcare applications. In this line, the antimicrobial property of ethanolic extract of MD L., uncalcined ZnO Nps and calcined ZnO Nps has been assessed and compared. The prepared particles have been characterised by comparing their Fourier transform infrared spectrum, X-ray diffraction (XRD) diffractogram and TEM images. The presence of ZnO has been confirmed using IR spectrum. The crystal structure and crystallite size have been found out using XRD diffractogram, and the obtained crystallite size was confirmed using TEM images. Finally, an attempt has been made to correlate the structure with the antimicrobial property of the material.

[Chromatographic fingerprint analysis of Toosendan Fructus by HPLC-CAD coupled with chemometrics methods].

A new method was developed for the chromatographic fingerprint analysis of Toosendan Fructus by HPLC coupled with the charged aerosol detector (CAD) in the present study. Samples were well separated on an Agilent ZOBAX SB C18 column (4.6 mm × 250 mm, 5 µm) by gradient elution using acetonitrile and water containing 0.1 % formic acid (v/v) at the flow rate of 1.0 mL·min−1. The column temperature was 30 ℃ and the injection volume was 5 µL. The nitrogen inlet pressure of the charged aerosol detector (CAD) was 35 psi, and the nebulizer chamber temperature was 35 ℃. In addition, the method of the chromatographic fingerprints combined with multivariate statistical analysis was effective and reasonable lead to an accurate classification of 20 batches of samples from different locations. The results showed that 28 common peaks were observed in the fingerprint and the samples were classified into three clusters. The established method was well validated, and showed high precision, good repeatability, and satisfactory stability. It may serve in the quality control and evaluation of Toosendan Fructus.

Two new limonoids isolated from the fuits of Melia toosendan.

In the present study, two new limonoids, 1α, 7α-dihydroxyl-3α-acetoxyl-12α-ethoxylnimbolinin (1) and 1α-tigloyloxy-3α-acetoxyl-7α-hydroxyl-12ß-ethoxylnimbolinin (2), together with other four known limonoids (3-6), were isolated from the fruits of Melia toosendan. Their structures were elucidated by means of extensive spectroscopic analyses (NMR and ESI-MS) and comparisons with the data reported in the literature. The isolated compounds were evaluated for their antibacterial activities. Compound 4 exhibited significant antibacterial activity against an oral pathogen, Porphyromonas gingivalis ATCC 33277, with an MIC value of 15.2 µg·mL(-1). Compound 2 was also active against P. gingivalis ATCC 33277, with an MIC value of 31.25 µg·mL(-1). In conlcusion, our resutls indicate that these compounds may provide a basis for future development of novel antibiotics.

Green-synthesised nanoparticles from Melia azedarach seeds and the cyclopoid crustacean Cyclops vernalis: an eco-friendly route to control the malaria vector Anopheles stephensi?

The impact of green-synthesised mosquitocidal nanoparticles on non-target aquatic predators is poorly studied. In this research, we proposed a single-step method to synthesise silver nanoparticles (Ag NP) using the seed extract of Melia azedarach. Ag NP were characterised using a variety of biophysical methods, including UV-vis spectrophotometry, scanning electron microscopy, energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. In laboratory assays on Anopheles stephensi, Ag NP showed LC50 ranging from 2.897 (I instar larvae) to 14.548 ppm (pupae). In the field, the application of Ag NP (10 × LC50) lead to complete elimination of larval populations after 72 h. The application of Ag NP in the aquatic environment did not show negative adverse effects on predatory efficiency of the mosquito natural enemy Cyclops vernalis. Overall, this study highlights the concrete possibility to employ M. azedarach-synthesised Ag NP on young instars of malaria vectors.

Antimicrobial compounds from root, stem bark and seeds of Melia volkensii.

Three compounds, toosendanin (1), kulactone (2) and scopoletin (3), were isolated from either the root bark and/or the stem bark of Melia volkensii. Their structures were determined on the basis of spectroscopic data generated and by comparison with data from the literature. 1 and 2, isolated for the first time from M. volkensii, exhibited significant (p < 0.05) activity against Escherichia coli with minimum inhibitory concentration of 12.5 µg/mL, close to that of neomycin (6.25 µg/mL). The compounds also exhibited high activity against Aspergillus niger (MIC 6.25 µg/mL compared to 2.5 µg/mL for clotrimazole). Dichloromethane and methanol seed, hexane stem bark and methanol root bark extracts exhibited activities towards Escherichia coli, Staphylococcus aureus, Aspergillus niger and Plasmodium falciparum, respectively. Antimicrobial activity of the plant towards A. niger, P. falciparum and S. aureus is reported for the first time in the current work.

Anticancer effects of crude extract from Melia toosendan Sieb. et Zucc on hepatocellular carcinoma in vitro and in vivo.

OBJECTIVE: To investigate the anti-cancer effects of crude extract from Melia toosendan Sieb. et Zucc and its possible molecular mechanisms in vitro and in vivo. METHODS: Transonic alcohol-chloroform extraction method was used to extract toosendanin from the bark of Melia toosendan Sieb. et Zucc, and the content of toosendanin in the crude extract was measured by high performance liquid chromatography (HPLC). Anti-cancer effects of crude extract from Melia toosendan Sieb. et Zucc were investigated in in vivo and in vitro studies. In the in vitro experiment, human hepatocellular carcinoma cell lines SMMC-7721 and Hep3B were co-incubated with toosendanin crude extract of different concentrations, respectively. In the in vivo experiment, BALB/c mice were subcutaneously inoculated with mouse hepatocellular carcinoma H22 cells and treated with crude extract. RESULTS: HPLC revealed the content of toosendanin was about 15%. Crude extract from Melia toosendan Sieb. et Zucc inhibited cancer cells growth in a dose- and time-dependent manner. The 50% inhibitory concentration (IC50, 72 h) was 0.6 mg/L for SMMC-7721 cells and 0.8 mg/L for Hep3B cells. Both high-dose [0.69 mg/(kg d)] and low-dose [0.138 mg/(kg d)] crude extract could markedly suppress cancer growth, and the inhibition rate was greater than 50%. Hematoxylin and eosin staining showed necrotic area in cancers and transmission electron microscopy displayed necrotic and apoptotic cancer cells with apoptotic bodies. Immunohistochemistry showed that the expression of Bax and Fas increased and the expression of Bcl-2 reduced. CONCLUSIONS: Toosendanin extract has potent anti-cancer effects via suppressing proliferation and inducing apoptosis of cancer cells in vivo and in vitro. The mechanism of apoptosis involves in mitochondrial pathway and death receptor pathway.

Lignans from the Fruits of Melia toosendan and Their Agonistic Activities on Melatonin Receptor MT1.

Investigation on the fruits of Melia toosendan afforded seven new lignans (1-7), along with seventeen known compounds (8-24). The structures of the new compounds, involving four neo-lignans (1-4), two sesquilignans (5-6), and a nor-lignan (7), were elucidated based on extensive spectroscopic analyses (high-resolution electrospray ionization mass spectra, ultraviolet, infrared, one-dimensional and two-dimensional nuclear magnetic resonance). Compound 24 exhibited activity on melatonin receptor type 1 with an agonistic rate of 57.77% at 1.02 mM according to the assay on HEK293 cell lines in vitro.