Complete chloroplast genome of endangered species Dipterocarpus retusus Blume (Dipterocarpaceae) and its phylogenetic implications.

Dipterocarpus retusus Blume is an endangered species on the IUCN Red List. In this study, we reported the complete chloroplast (cp) genome of D. retusus (GenBank accession number: OP271853). The cp genome was 154,303 bp long, with a large single-copy (LSC) region of 85,586 bp and a small single-copy (SSC) region of 20,273 bp separated by a pair of inverted repeats (IRs) of 24,222 bp. It encodes 128 genes, including 84 protein-coding genes, 36 tRNA genes, and eight ribosomal RNA genes. We also reconstructed the cp genome phylogeny of Dipterocarpus, which indicated D. retusus was closely related with the sympatric species D. gracilis. This study may contribute valuable information to the phylogenetic relationships within the genus Dipterocarpus.

Pickering Emulsion of Oleoresin from Dipterocarpus alatus Roxb. ex G. Don and Its Antiproliferation in Colon (HCT116) and Liver (HepG2) Cancer Cells.

Oleoresin of Dipterocarpus alatus Roxb. ex G. Don (DA) has been traditionally used for local medicinal applications. Several in vitro studies have indicated its pharmacological potential. However, the low water solubility hinders its use and development for pharmaceutical purposes. The study aimed to (1) formulate oil-in-water (o/w) Pickering emulsions of DA oleoresin and (2) demonstrate its activities in cancer cells. The Pickering emulsions were formulated using biocompatible carboxylated cellulose nanocrystal (cCNC) as an emulsifier. The optimized emulsion comprised 3% (F1) and 4% (v/v) (F2) of oleoresin in 1% cCNC and 0.1 M NaCl, which possessed homogeneity and physical stability compared with other formulations with uniform droplet size and low viscosity. The constituent analysis indicated the presence of the biomarker dipterocarpol in both F1 and F2. The pharmacological effects of the two emulsions were demonstrated in vitro against two cancer cell lines, HepG2 and HCT116. Both F1 and F2 suppressed cancer cell viability. The treated cells underwent apoptosis, as demonstrated by distinct nuclear morphological changes in DAPI-stained cells and Annexin V/PI-stained cells detected by flow cytometry. Our study highlights the prospect of Pickering emulsions for oleoresin, emphasizing enhanced stability and potential pharmacological advantages.

Stacked ensemble learning on HaCaT cytotoxicity for skin irritation prediction: A case study on dipterocarpol.

Skin irritation is an adverse effect associated with various substances, including chemicals, drugs, or natural products. Dipterocarpol, extracted from Dipterocarpus alatus, contains several skin benefits notably anticancer, wound healing, and antibacterial properties. However, the skin irritation of dipterocarpol remains unassessed. Quantitative structure-activity relationship (QSAR) is a recommended tool for toxicity assessment involving less time, money, and animal testing to access unavailable acute toxicity data. Therefore, our study aimed to develop a highly accurate machine learning-based QSAR model for predicting skin irritation. We utilized a stacked ensemble learning model with 1064 chemicals. We also adhered to the recommendations from the OECD for QSAR validation. Subsequently, we used the proposed model to explore the cytotoxicity of dipterocarpol on keratinocytes. Our findings indicate that the model displayed promising statistical quality in terms of accuracy, precision, and recall in both 10-fold cross-validation and test datasets. Moreover, the model predicted that dipterocarpol does not have skin irritation, which was confirmed by the cell-based assay. In conclusion, our proposed model can be applied for the risk assessment of skin irritation in untested compounds that fall within its applicability domain. The web application of this model is available at https://qsarlabs.com/#stackhacat.

Combinatory effects of Dipterocarpus alatus twig emulgel: Wound-restoring, antibacterial, and anti-inflammatory activities against methicillin-resistant Staphylococcus aureus-infected mouse superficial wounds.

Dipterocarpus alatus has been used for the treatment of infectious skin diseases and ulcerative wounds in Thai traditional medicine. A major pathogen in human superficial skin infections is methicillin-resistant Staphylococcus aureus (MRSA). This study determined the wound healing, antibacterial, and anti-inflammatory activities of D. alatus twig emulgel against MRSA-infected mouse superficial skin wounds. Ethyl acetate-methanol crude extract of D. alatus twig was incorporated into emulgel at concentrations of 20 and 40 mg/g (D20 and D40) and its activity was compared to tetracycline emulgel (160 µg/g, Tetra). MRSA-infected superficial wounds demonstrated decreased skin barrier strength, increased transepidermal water loss (TEWL), and mast cell accumulation. Expression of toll-like receptor 2 (TLR-2), NF-κß, TNFα, IL-1ß, IL-6 and IL-10 genes were induced after MRSA infection. Daily application of 100 µL of D20 or D40 for 9 days restored skin barrier strength and TEWL while reducing mast cell and MRSA numbers compared to the non-treated group (MRSA-NT). The wounds treated with D20 and D40 were entirely healed on day 9. Expression of TLR-2 and cytokine-related genes NF-κß, TNFα, IL-1ß, IL-6 and IL-10 were normalized by treatment with either D20 or D40. Therefore, emulgel containing 20 to 40 mg/g ethyl acetate-methanol crude D. alatus twig extract is a good candidate for development as a topical formulation for MRSA-infected ulcerated wounds.

Ultrasound-Assisted One-Pot Cloud Point Extraction for Iron Determination Using Natural Chelating Ligands from Dipterocarpus intricatus Dyer Fruit.

An ultrasound-assisted, one-pot cloud point extraction was developed for the determination of iron in vegetable samples by UV-Visible spectrophotometry. This method was based on the complexation of iron with an environmentally-friendly natural chelating agent extracted from Dipterocarpus intricatus Dyer fruit at pH 5.5 in the presence of Triton X-114. Reagent extraction, complexation, and preconcentration were performed simultaneously using ultrasound-assisted extraction at 45 °C. The surfactant-rich phase was diluted with ethanol and loaded through a syringe barrel packed with cotton that acted as a filter to trap the reagent powder. Analyte-entrapped on cotton was eluted using 0.1 mol·L-1 nitric acid solution. Filtrate and eluate solutions were measured absorbance of the dark-blue product at 575 nm. Influential parameters for the procedure were investigated. Under the optimum experimental conditions, the calibration curve was linear, ranging from 0.1 to 1.0 mg·L-1 with r2 = 0.997. Limits of detection and quantification were 0.03 and 0.09 mg·L-1, respectively while precision values of intra-day and inter-day were less than 5%. Recovery at 0.5 mg·L-1 ranged from 89.0 to 99.8%, while iron content in vegetable samples ranged from 2.45 to 13.36 mg/100 g. This method was cost-effective, reliable, eco-friendly, and convenient as a green analytical approach to determining iron content.

Novel role of Dipterocarpus tuberculatus as a stimulator of focal cell adhesion through the regulation of MLC2/FAK/Akt signaling pathway.

To investigate a novel function of Dipterocarpus tuberculatus on focal cell adhesion stimulation, alterations to the regulation of focal cell adhesion-related factors were analyzed in NHDF cells and a calvarial defect rat model after treatment with methanol extracts of D. tuberculatus (MED). MED contained gallic acid, caffeic acid, ellagic acid, and naringenin in high concentrations. The proliferation activity, focal cell adhesion ability, adhesion receptors-mediated signaling pathway in NHDF cells were increased by MED. Also, a dense adhered tissue layer and adherent cells on MED-coated titanium plate (MEDTiP) surfaces were detected during regeneration of calvarial bone. The results of the present study provide novel evidence that MED may stimulate focal cell adhesion in NHDF cells and a calvarial defect rat model.

Dipterocarpol in Oleoresin of Dipterocarpus alatus Attributed to Cytotoxicity and Apoptosis-Inducing Effect.

Dipterocarpus alatus Roxb. ex G. Don is widely found in Southeast Asia. Its oleo-resin has reportedly been used in biodiesel production. Two different biodiesel production processes produce resinous byproducts, namely degumming (DG) and distillation (DT). Gas chromatography-mass spectrometry identified sesquiterpenes and triterpenes in oleo-resin, DG, and DT; and long-chain hydrocarbons in oleo-resin. High-performance liquid chromatography detected dipterocarpol as a marker compound, with the highest to lowest amounts detected in DG, DT, and oleo-resin, respectively. Oleo-resin, DG, and DT exerted more cytotoxicity than dipterocarpol, and melphalan, a chemotherapeutic drug. Oleo-resin, DG, and DT exerted cytotoxicity to a different degree in T cell leukemia (Jurkat), cervical adenocarcinoma (HeLa), and human hepatocellular carcinoma (HepG2) cells, while the highest selectivity was found in the Jurkat cells compared to the non-cancer Vero cells. Dipterocarpol exhibited the highest cytotoxicity in HepG2 cells and the lowest cytotoxicity in Jurkat cells. Oleo-resin, DG, and DT induced apoptosis in Jurkat cells. In oleo-resin, DG, and DT, dipterocarpol and other compounds may act in synergy leading to cytotoxicity and an apoptosis-inducing effect. Oleo-resin, DG, and DT could be potential sources for anticancer agents. Dipterocarpol could serve as a biomarker for follow ups on the anticancer activity of a sample from D. alatus.

Promoting Effects of Titanium Implants Coated with Dipterocarpus tuberculatus Extract on Osseointegration.

Titanium (Ti) is the most commonly used biomaterial for dental implants. When inserting Ti implants into jawbones, the main issue is the lack of strong bonding between the Ti implant and the host bone (osseointegration). Inspired by the outstanding adhesion performance of natural phenolic compounds on metal substrates and promoting effect for cell adhesion, we coated a natural plant extract, Dipterocarpus tuberculatus (MED), on Ti implants. We tested three groups of Ti plates and screw-shaped fixtures: nontreated Ti as commercially produced, ozone-treated Ti as commonly used surface modification for dental implants, and MED-coated Ti. Interestingly, the MED coating on the Ti plate preserved the surface wetting property for 20 days, whereas the hydrophilic wetting of ozone-treated Ti was readily transformed to hydrophobic within a day. Computerized tomography and histopathological analysis revealed that MED coating enhanced new bone tissue formation and regeneration. The gene expression level of integrin as a bone cell adhesion receptor and its downstream key regulators was significantly increased than that of ozone-treated Ti. Therefore, we suggest considering MED-mediated cell signaling pathways in screening natural products for cell adhesion and osseointegration, and MED as a suitable coating agent for improving Ti implantation.

Therapeutic Effects of Dipterocarpus tuberculatus with High Antioxidative Activity Against UV-Induced Photoaging of NHDF Cells and Nude Mice.

To investigate the therapeutic effects of methanol extracts of Dipterocarpus tuberculatus Roxb. (MED) against UV-induced photoaging, we assessed for alterations in the antioxidant activity, anti-apoptotic effects, ECM modulation, skin appearances, and anti-inflammatory response in normal human dermal fibroblast (NHDF) cells and nude mice orally treated with MED. High levels of tannin content and high free radical scavenging activity to DPPH were determined in MED, while seven active components, namely, gallic acid, bergenin, ellagic acid, ε-viniferin, asiatic acid, oleanolic acid, and 2α-hydroxyursolic acid, were identified using LC-MS analyses. UV-induced alterations in the NO concentration, SOD activity, and Nrf2 expression were remarkably recovered in MED-treated NHDF cells. Moreover, the decreased number of apoptotic cells and G2/M phase arrest were observed in the UV + MED-treated groups. Similar recoveries were detected for ß-galactosidase, MMP-2/9 expression, and intracellular elastase activity. Furthermore, MED treatment induced suppression of the COX-2-induced iNOS mediated pathway, expression of inflammatory cytokines, and inflammasome activation in UV-radiated NHDF cells. The anti-photoaging effects observed in NHDF cells were subsequently evaluated and validated in UV + MED-treated nude mice through skin phenotypes and histopathological structure analyses. Taken together, these results indicate that MED exerts therapeutic effects against UV-induced photoaging and has the potential for future development as a treatment for photoaging.

Dipterocarpus tuberculatus Roxb. Ethanol Extract Has Anti-Inflammatory and Hepatoprotective Effects In Vitro and In Vivo by Targeting the IRAK1/AP-1 Pathway.

Dipterocarpus tuberculatus Roxb. has been used traditionally as a remedy for many diseases, especially inflammation. Therefore, we analyzed and explored the mechanism of the anti-inflammatory effect of a Dipterocarpus tuberculatus Roxb. ethanol extract (Dt-EE). Dt-EE clearly and dose-dependently inhibited the expression of pro-inflammatory cytokines such as IL-6, TNF-α, and IL-1ß in lipopolysaccharide (LPS)-treated RAW264.7 cells. Also, Dt-EE suppressed the activation of the MyD88/TRIF-mediated AP-1 pathway and the AP-1 pathway related proteins JNK2, MKK4/7, and TAK1, which occurred as a result of inhibiting the kinase activity of IRAK1 and IRAK4, the most upstream factors of the AP-1 pathway. Finally, Dt-EE displayed hepatoprotective activity in a mouse model of hepatitis induced with LPS/D-galactosamine (D-GalN) through decreasing the serum levels of alanine aminotransferase and suppressing the activation of JNK and IRAK1. Therefore, our results strongly suggest that Dt-EE could be a candidate anti-inflammatory herbal medicine with IRAK1/AP-1 inhibitory and hepatoprotective properties.

Efficacy of Dipterocarpus alatus oil combination with Rhinacanthus nasutus leaf and Garcinia mangostana pericarps against canine demodicosis.

BACKGROUND AND AIM: Canine demodicosis is a skin disease that is a major global health problem in dogs. Ivermectin is a drug of choice for treatment, but it may cause toxicity in dogs carrying multidrug resistance mutation-1 gene mutations. Hence, alternative herbal medicines are used instead of the drug, such as Dipterocarpus alatus oil (YN oil), Rhinacanthus nasutus leaf (WC), and Garcinia mangostana pericarps (MG) extracts. This study aimed to determine the efficacy of D. alatus oil, R. nasutus leaf, and G. mangostana pericarp extracts on canine demodicosis in vivo. MATERIALS AND METHODS: Twenty-five mixed-breed dogs with localized demodicosis were examined. Dogs were diagnosed with demodicosis through deep skin scraping and screened with the inclusion criteria. Five dogs of each group were treated in five treatment groups (ivermectin, YN oil, YN oil+WC, YN oil+MG, and YN oil+WC+MG) for 1 month. The individual dogs were clinically evaluated, and the dermatological lesions were monitored daily for 60 days. RESULTS: Dermatological lesion improvement was predominantly observed in the group of dogs treated with YN oil+WC. This was evidenced by the disappearance of the hyperpigmentation and lichenification on day 28 post-treatment and alopecia on day 56 post-treatment. Moreover, no allergic or clinical signs were observed during treatment. CONCLUSION: YN oil+WC is an alternative herbal medicine that could be used for the treatment of localized canine demodicosis.

Effects of the Ethanol Extract of Dipterocarpus alatus Leaf on the Unpredictable Chronic Mild Stress-Induced Depression in ICR Mice and Its Possible Mechanism of Action.

Treatment of the unpredictable chronic mild stress (UCMS) mice with the ethanol extract of Dipterocarpus alatus leaf attenuated anhedonia (increased sucrose preference) and behavioral despair (decreased immobility time in tail suspension test (TST) and forced swimming test (FST)). The extract not only decreased the elevation of serum corticosterone level and the index of over-activation of the hypothalamic-pituitary-adrenal (HPA) axis, caused by UCMS, but also ameliorated UCMS-induced up-regulation of serum- and glucocorticoid-inducible kinase 1 (SGK1) mRNA expression and down-regulation of cyclic AMP-responsive element binding (CREB) and brain-derived neurotrophic factor (BDNF) mRNAs in frontal cortex and hippocampus. In vitro monoamine oxidase (MAO) inhibition assays showed that the extract exhibited the partial selective inhibition on MAO-A. HPLC analysis of the extract showed the presence of flavonoids (luteolin-7-O-glucoside, kaempferol-3-glucoside, rutin) and phenolic acids (gallic acid, ferulic acid, and caffeic acid) as major constituents.

Chemical Composition, Antioxidant and Cytotoxicity Activities of Leaves, Bark, Twigs and Oleo-Resin of Dipterocarpus alatus.

Dipterocarpus alatus (Dipterocarpaceae) is a medicinal plant whose use is well known for the treatment of genito-urinary diseases. However, there is no report of its cytotoxic potential. In this study, the chemical composition, antioxidant and cytotoxic activities of extracts of the leaves, bark, twigs and oleo-resin from D. alatus are investigated. Cytotoxicity was measured by the neutral red (NR) assay against HCT116, SKLU1, SK-MEL2, SiHa and U937 cancer cell lines and antioxidant capacity was evaluated by DPPH, ABTS radical scavenging, and ferric reducing antioxidant power (FRAP) assays. The chemical composition was analyzed by gas chromatography-mass spectrometry (GC-MS). Leaf, bark and twig extracts exhibited stronger antioxidant activity than oleo-resin, with bark extract showing the highest antioxidant activity and the highest total phenolic content. All samples showed more cytotoxic activity against the U937 cell line than HCT116, SKLU1, SK-MEL2 and SiHa cells with oleo-resin being more cytotoxic than melphalan against U937 cells. Chemical composition analysis of oleo-resin by GC-MS showed that the major components were sesquiterpenes, namely α-gurjunene (30.31%), (-)-isoledene (13.69%), alloaromadendrene (3.28%), ß-caryophyllene (3.14%), γ-gurjunene (3.14%) and spathulenol (1.11%). The cytotoxic activity of oleo-resin can be attributed to the sesquiterpene content, whereas the cytotoxic and antioxidant activities of leaf, bark and twig extracts correlated to total phenolic content.

The complete chloroplast genome of Dipterocarpus turbinatus Gaertn. F.

Dipterocarpus turbinatus Gaertn. F., naturally distributes in Southern China, which is an elite natural tree with high economic and medicinal value. In study, all chloroplast (cp) genome of Dipterocarpus turbinatus Gaertn. F. was assembled and characterized based on Illumina pair-end sequencing data. The complete chloroplast genome length was 152,279 bp. It contained a large (LSC, 83,862 bp) and a small (SSC, 20,215 bp) single copy region, separated by a pair of inverted repeats of 24,101 bp (IRs). The overall GC content of genome was 37.3%, the corresponding values of LSC, SSC, and IR regions were 35.3, 31.6, and 43.2%, respectively. There were 128 genes in the genome including 84 protein-coding genes, 36 tRNA genes, and 8 rRNA genes. Among all genes, 14 genes contain a single intron and 1 gene has two introns. The result showed that Dipterocarpus turbinatus Gaertn. F. was closely related to Vatica mangachapoi.

Anti-hyperuricemic and anti-inflammatory actions of vaticaffinol isolated from Dipterocarpus alatus in hyperuricemic mice.

The present study was designed to examine the anti-hyperuricemic and anti-inflammatory effects and possible mechanisms of vaticaffinol, a resveratrol tetramer isolated from ethanol extracts of Dipterocarpus alatus, in oxonate-induced hyperuricemic mice. At 1 h after 250 mg·kg-1 potassium oxonate was given, vaticaffinol at 20, 40, and 60 mg·kg-1 was intragastrically administered to hyperuricemic mice once daily for seven consecutive days. Vaticaffinol significantly decreased serum uric acid levels and improved kidney function in hyperuricemic mice. It inhibited hepatic activity of xanthine dehydrogenase (XDH) and xanthine oxidase (XOD), regulated renal mRNA and protein levels of urate transporter 1 (URAT1), glucose transporter 9 (GLUT9), organic anion transporter 1 (OAT1), organic cation transporter 1 (OCT1), OCT2, organic cation/carnitine transporter 1 (OCTN1), and OCTN2 in hyperuricemic mice. Moreover, vaticaffinol markedly down-regulated renal protein levels of NOD-like receptor 3 (NLRP3), apoptosis-associated speck-like (ASC), and Caspase-1, resulting in the reduction of interleukin (IL)-1ß, IL-18, IL-6 and tumor necrosis factor-α (TNF-α) levels in this animal model. Additionally, HPLC and LC-MS analyses clearly testified the presence of vaticaffinol in the crude extract. These results suggest that vaticaffinol may be useful for the prevention and treatment of hyperuricemia with kidney inflammation.