Anti-inflammatory effects of the Thai herbal remedy Yataprasen and biflavonoids isolated from Putranjiva roxburghii in RAW264.7 macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Yataprasen is a topical Thai herbal remedy for the treatment of musculoskeletal pain and is included in Kumpe Thart Phra Narai, the first Thai textbook of traditional medicine. The herbal preparation is made from a hydroethanolic extract of a mixture of 13 medicinal plants, of which Putranjiva roxburghii Wall. leaves are the major ingredient.

AIM OF THE STUDY

In this study, we investigated the underlying mechanism of action for the anti-inflammatory effects of the Yataprasen remedy, its main ingredients, and the phytochemicals isolated from P. roxburghii leaves.

MATERIALS AND METHODS

The anti-inflammatory effects of the Yataprasen remedy, along with its main ingredients, including the leaves of Baliospermum solanifolium (Burm.) Suresh, Melia azedarach L., P. roxburghii, Senna siamea (Lam.) Irwin & Barneby, and Tamarindus indica L. were determined by measuring prostaglandin E2 (PGE2) secretion, nitric oxide (NO) production, and the synthesis of inflammatory biomarkers in lipopolysaccharide (LPS)-treated RAW264.7 macrophage cells. The active ingredients of the P. roxburghii leaves were separated by chromatography and spectroscopic measurements were used to identify their chemical structures.

RESULTS

Ethanol extracts of the Yataprasen remedy and some of its ingredients significantly suppressed LPS-induced PGE2 secretion and NO production in a dose-dependent manner. Treatment of RAW264.7 cells with ethanolic extracts of the Yataprasen remedy (50 μg/mL) significantly inhibited LPS-induced mRNA expression of TNF-α, COX-2, iNOS, and NF-κB. Among the plant ingredient extracts, P. roxburghii leaf extract exhibited the highest inhibitory effects on LPS-induced TNF-α and iNOS expression. Moreover, T. indica leaf extract showed the highest activity on the inhibition of LPS-induced COX-2 and NF-κB expression. Putraflavone, podocarpusflavone A, and amentoflavone were isolated biflavonoids from P. roxburghii leaf extract and showed the inhibitory effects on LPS-induced PGE2 secretion and NO synthesis in RAW264.7 cells. Of the isolated biflavonoids, amentoflavone exhibited the strongest anti-inflammatory activity by inhibiting the expression of TNF-α, COX-2, and iNOS.

CONCLUSION

The results support reported the anti-inflammatory effects of the Yataprasen remedy, which are associated with the downregulation of proinflammatory mediators. P. roxburghii, along with its biflavonoids, are the impact components that contribute to the anti-inflammatory effects of the herbal remedy.

Kombucha Beverages Produced from Fruits, Vegetables, and Plants: A Review on Their Pharmacological Activities and Health Benefits

Kombucha is a traditional health beverage produced by fermenting sweetened tea with a symbiotic culture of bacteria and yeasts. Consumption of kombucha beverages has been growing and there is kombucha commercially available worldwide as one of the most famous low-alcohol beverages. Kombucha beverages have been claimed to have beneficial effects on human health because they contain a variety of bioactive compounds that possess various functional properties. At present, several kinds of raw material (e.g., milk, fruit, vegetables, and herbs) have been fermented with kombucha consortium and consumed as kombucha beverages. Although several studies have been written regarding the biological activities of kombucha and raw materials, there is however little information available on the characterization of their components as well as the biological activities of fermented kombucha from many raw material mixtures. Several pharmacological activities were reviewed in the scientific literature, describing their potential implications for human health. In addition, the adverse effects and toxicity of kombucha consumption were also reviewed. In this study, we focused on the main and latest studies of the pharmacological effects of kombucha beverages produced from various kinds of raw materials, including antioxidant, anti-inflammatory, immunomodulatory, antimicrobial, anticancer, antidiabetic, antihypertensive, and antihyperlipidemic effects in in vitro and in vivo studies.

Establishment of Afgekia mahidolae B.L. Burtt & Chermsir in vitro culture and effect of elicitation on its bioactive compounds

Afgekia mahidolae is a rare plant species that possesses antioxidant, antimicrobial, and wound healing properties. This study aimed to establish the in vitro culture of A. mahidolae and investigate the effects of elicitors on their phenolic and flavonoid production, including the antioxidant activities. The established callus was prepared in the form of cell suspension cultures to determine the effect of elicitors. After elicitation for 3 days, A. mahidolae cell suspension cultures treated by 5 µM salicylic acid or 100 mg/L yeast extract exhibited significantly higher levels of total phenolic and total flavonoid content than untreated cultures, which correlated to the antioxidant activities. In addition, the profiles of phenolic and flavonoid compounds in the callus and intact leaves of A. mahidolae were determined by LC-MS, which showed different phytochemicals. The findings of this study may encourage more sustainable development of A. mahidolae cultivation.

Mass spectral analysis of secondary metabolites from Zingiber montanum rhizome extract using UHPLC-HR-ESI-QTOF-MS/MS

INTRODUCTION

Zingiber montanum (J.Koenig) Link ex A.Dietr. is a popular medicinal plant in Thailand. Its rhizomes have been used as an ingredient in various Thai traditional medicine formulas. While many reports have focused on the chemical constituents and biological activities of this plant, a comprehensive study on secondary metabolite profiling using tandem mass spectrometry has, to this point, never been documented.

OBJECTIVE

To analyze the chemical constituents in Z. montanum rhizomes using ultra-high performance liquid chromatography coupled with ultra-high-resolution electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC-HR-ESI-QTOF-MS/MS) analyses and to utilize the characteristic fragmentation patterns of these compounds to facilitate their identification.

METHODOLOGY

UHPLC-HR-ESI-QTOF-MS/MS in positive ion mode was used for chemical identification of secondary metabolites from the ethanolic extract of the plant material. MS/MS data of some known reference compounds, together with detailed fragmentation pattern information of several compounds obtained from the crude extract, were used to elucidate their chemical structures.

RESULTS

In this work, one benzaldehyde, ten phenylbutenoid monomers, six curcuminoids, and nine phenylbutenoid dimers were assigned based on their characteristic fragment ions. Among these compounds, 2-(3,4-dimethoxystyryl)oxirane was tentatively suggested as a potential new compound. Several characteristic fragment ions from these compounds were assigned and the relative ion abundance of these was also used to differentiate the chemical structures of compounds having the same molecular mass.

CONCLUSIONS

The results will benefit future high-throughput screening of bioactive compounds and method development for the quality control of raw materials and herbal drugs derived from Z. montanum rhizome extracts.

Gambogic Acid Inhibits Wnt/β-catenin Signaling and Induces ER Stress-Mediated Apoptosis in Human Cholangiocarcinoma

Objective:

Gambogic acid (GA) has been reported to induce apoptosis in cholangiocarcinoma (CCA) cell lines. However, the molecular mechanisms underlying its anti-cancer activity remain poorly understood. This study was aimed to investigate GA’s effect on human CCA cell lines, KKU-M213 and HuCCA-1, and its associated mechanisms on Wnt/β-catenin signaling pathway.

Methods:

Cell viability, apoptosis, and cell cycle analysis were conducted by MTT and flow cytometry. The effect of GA mediated Wnt/β-catenin and ER stress were determined by luciferase-reporter assay, qRT-PCR, and western blot analysis.

Results:

GA exhibited potent cytotoxicity in CCA cells which was associated with significantly inhibited cell proliferation, promoted G1 arrest, and activated caspase 3 mediated-apoptosis. GA attenuated β-catenin transcriptional levels, decreased β-catenin protein, and suppressed the expression of c-Myc, a downstream target gene of Wnt/β-catenin signaling. GA activated genes involved in ER stress mechanism in KKU-M213 and enhanced CCA’s sensitivity to gemcitabine.

Conclusion:

Our findings reveal that the molecular mechanism underpinning anti-cancer effect of GA is partially mediated through the inhibition of Wnt/β-catenin signaling pathway and induction of ER stress induced-apoptosis. GA may serve as a promising therapeutic modality for amelioration of gemcitabine-induced toxicity in CCA.

Antioxidant and Anticholinesterase Activities of Extracts and Phytochemicals of Syzygium antisepticum Leaves

Bioassay-guided separation of young leaves extracts of Syzygium antisepticum (Blume) Merr. & L.M. Perry led to the isolation of four triterpenoids (betulinic acid, ursolic acid, jacoumaric acid, corosolic acid) and one sterol glucoside (daucosterol) from the ethyl acetate extract, and three polyphenols (gallic acid, myricitrin, and quercitrin) from the methanol (MeOH) extract. The MeOH extract of S. antisepticum and some isolated compounds, ursolic acid and gallic acid potentially exhibited acetylcholinesterase activity evaluated by Ellman’s method. The MeOH extract and its isolated compounds, gallic acid, myricitrin, and quercitrin, also strongly elicited DPPH radical scavenging activity. In HEK-293 cells, the MeOH extract possessed cellular antioxidant effects by attenuating hydrogen peroxide (H₂O₂)-induced ROS production and increasing catalase, glutathione peroxidase-1 (GPx-1), and glutathione reductase (GRe). Furthermore, myricitrin and quercitrin also suppressed ROS production induced by H₂O₂ and induced GPx-1 and catalase production in HEK-293 cells. These results indicated that the young leaves of S. antisepticum are the potential sources of antioxidant and anticholinesterase agents. Consequently, S. antisepticum leaves are one of indigenous vegetables which advantage to promote the health and prevent diseases related to oxidative stress.

Cytotoxic compounds from the leaves and stems of the endemic Thai plant Mitrephora sirikitiae

Context: Mitrephora sirikitiae Weeras., Chalermglin & R.M.K. Saunders (Annonaceae) is a plant endemic to Thailand. Its constituents and their biological activities are unknown.Objective: Isolation and identification of the compounds in the leaves and stems of M. sirikitiae and determination of their cytotoxicity.Materials and methods: Methanol extracts of the leaves and stems of M. sirikitiae were separated by chromatography, and spectroscopic methods were used to determine the structures of the components. The cytotoxicity of the extracts and pure compounds was evaluated using the sulforhodamine B assay with several cell lines. The cells were treated with the compounds at concentrations of 0.16-20 µg/mL for 48 or 72 h.Results: The investigation of the extracts of M. sirikitiae leaves and stems resulted in the isolation of a new lignan, mitrephoran, and 15 known compounds. Among these compounds, 2-(3,4-dimethoxyphenyl)-6-(3,5-dimethoxyphenyl)-3,7-dioxabicyclo[3.3.0]octane, ciliaric acid, 6-methoxymarcanine A, and stepharanine were isolated from this genus for the first time. The alkaloids liriodenine and oxoputerine exhibited strong cytotoxicity against all tested cells (IC₅₀ values of 6.59-11.02 µM). In contrast, magnone A, 3',4-O-dimethylcedrusin, and 6-methoxymarcanine A inhibited the growth of some of the tested cells (IC₅₀ values of 2.03-19.73 µM). Magnone A and 6-methoxymarcanine A showed low toxicity for Hek 293 cells (IC₅₀ >20 µM).Discussion and conclusions: M. sirikitiae is a source of cytotoxic lignans and alkaloids. Among the cytotoxic compounds, magnone A and 6-methoxymarcanine A are potentially useful lead compounds for the further development of anticancer agents because of their selective inhibitory effects on cancer cell lines.

Synergistic Effect of Forbesione From Garcinia hanburyi in Combination with 5-Fluorouracil on Cholangiocarcinoma

Background: Chemotherapy for advanced cholangiocarcinoma (CCA) is largely ineffective; thus innovative combinations of chemotherapeutic agents and natural compounds represent a promising strategy. This study aimed to investigate the synergistic effects of forbesione combined with 5-fluorouracil (5-FU) in hamster cholangiocarcinoma (Ham-1) cells both in vitro and in vivo. The anti-tumor effects of 5-FU combined with forbesione in vitro were determined using the Sulforhodamine B (SRB) assay and the effects in vivo were assessed in transplanted Ham-1 allograph models. Using ethidium bromide/acridine orange (EB/AO) staining, the morphological changes of apoptotic cells was investigated. The expressions of apoptosis-related molecules after combined treatment with forbesione and 5-FU were determined using real-time RT-PCR and western blot analysis. Forbesione or 5-FU alone inhibited proliferation of Ham-1 cells in a dose-dependent manner and their combination showed a synergistic proliferation inhibitory effect in vitro. In vivo studies, forbesione in combination with 5-FU exhibited greater inhibition of the tumor in the hamster model compared with treatment using either drug alone. Forbesione combined with 5-FU exerted stronger apoptotic induction in Ham-1 cells than did single drug treatment. The combination of drugs strongly suppressed the expression of B-cell lymphoma 2 (Bcl-2) and procaspase-3 while enhancing the expression of p53, Bcl-2-associated X protein (Bax), apoptotic protease activating factor-1 (Apaf-1), caspase-9 and caspase-3, compared with single drug treatments. These results explained the decreased expression of cytokeratin 19 (CK19) positive cells and proliferation cell nuclear antigen (PCNA) positive cells in Ham-1 cell tumor tissues of the treated hamsters. There was no apparent systemic toxicity observed in the treated animals compared with the control groups. Forbesione combined with 5-FU strongly induced apoptosis in Ham-1 cells. The growth inhibitory effect of combined treatment using these two drugs was much greater than treatment with either drug alone, both in vitro and in vivo.

Inhibition of Oxidative Stress through the Induction of Antioxidant Enzymes of Pigmented Rice Bran in HEK-293 Cells

The cellular antioxidant enzymes play an essential role on the protection of oxidative stress. Pigmented rice bran is the major sources of phytochemicals and elicits antioxidant property. However, the effects of pigmented rice bran on the upregulation of cellular antioxidant enzymes are incompletely understood. In this study, we demonstrated that treatment of HEK-293 cells with pigmented rice bran extracts (200 μg/mL) from Red Hawm, Red Rose, Black Sukhothai-II, and Kum Doisaket strains significantly inhibited H2O2-induced intracellular ROS production. These pigmented rice bran extracts induced mRNA expression of glutathione peroxidase-1 (GPx-1), glutathione reductase and catalase. Additionally, treatment with these rice bran extract also increased protein expression of GPx-1 and catalase. Thus, these pigmented rice bran extracts exert the cellular antioxidant effects by decreasing ROS generation as well as increasing the production of antioxidant enzymes.

Thai Fruits Exhibit Antioxidant Activity and Induction of Antioxidant Enzymes in HEK-293 Cells

The cellular antioxidant enzymes play the important role of protecting the cells and organisms from the oxidative damage. Natural antioxidants contained in fruits have attracted considerable interest because of their presumed safety and potential nutritional value. Even though antioxidant activities of many fruits have been reported, the effects of phytochemicals contained in fruits on the induction of antioxidant enzymes in the cells have not been fully defined. In this study, we showed that extracts from Antidesma ghaesembilla, Averrhoa bilimbi, Malpighia glabra, Mangifera indica, Sandoricum koetjape, Syzygium malaccense, and Ziziphus jujuba inhibited H2O2-induced intracellular reactive oxygen species production in HEK-293 cells. Additionally, these Thai fruit extracts increased the mRNA and protein expressions of antioxidant enzymes, catalase, glutathione peroxidase-1, and manganese superoxide dismutase. The consumption of Thai fruits rich in phenolic compounds may reduce the risk of oxidative stress.

Antitumor effect of forbesione isolated from Garcinia hanburyi on cholangiocarcinoma in vitro and in vivo

Cholangiocarcinoma (CCA) is a malignancy with no effective therapy and poor prognosis. Forbesione, a caged xanthone isolated from Garcinia hanburyi, has been reported to inhibit proliferation and to induce apoptosis in human CCA cell lines. The present study aimed to further explore the potential anticancer properties of forbesione by testing its effects against the hamster CCA cell line Ham-1 in vitro and in vivo. It was observed that forbesione inhibited the growth of Ham-1 cells in vitro and suppressed Ham-1 growth as allograft in hamsters by inducing cell cycle arrest at the S phase. This was mediated by decreasing the protein expression of cyclin E, cyclin A and cyclin-dependent kinase 2. In addition, increased expression of p21 and p27 was detected, which could possibly explain the reduced expression of proliferating cell nuclear antigen and of the bile duct cell marker cytokeratin 19 observed in forbesione-treated Ham-1 cells in vitro and in tumor tissues of forbesione-treated hamsters. Furthermore, forbesione induced apoptosis through multiple pathways. The death receptor pathway was activated by increased expression of Fas, Fas-associated death domain and activated caspase-3, along with decreased expression of procaspase-8 and procaspase-3. The mitochondrial pathway was driven by increased expression of B-cell lymphoma (Bcl)-2-like protein 4, activated caspase-9 and inhibitor of κB-α, along with decreased expression of Bcl-2, survivin, procaspase-9 and nuclear factor-κB/p65. The endoplasmic reticulum pathway was stimulated by increased expression of activated caspase-12 and decreased expression of procaspase-12. No side effects or toxicity were observed in forbesione-treated hamsters. Thus, forbesione is a potential drug candidate for cancer therapy that deserves further investigation.

Bioactivity-guided Separation of the Active Compounds in Acacia pennata Responsible for the Prevention of Alzheimer's Disease

The objective of this study was to evaluate the health benefits of plants used in Thai food, specifically Acacia pennata Willd., in Alzheimer's prevention. A. pennata twigs strongly inhibited β-amyloid aggregation. Bioactivity-guided separation of the active fractions yielded six known compounds, tetracosane (1), 1-(heptyloxy)-octadecane (2), methyl tridecanoate (3), arborinone (4), confertamide A (5) and 4-hydroxy-1-methyl-pyrrolidin-2-carboxylic acid (6). The structures were determined by spectroscopic analysis. Biological testing revealed that tetracosane (1) was the most potent inhibitor of β-amyloid aggregation, followed by 1-(heptyloxy)-octadecane (2) with IC50 values of 0.4 and 12.3 μM. Methyl tridecanoate (3), arborinone (4) and 4-hydroxy-1-methyl-pyrrolidin-2-carboxylic acid (6) moderately inhibited β-amyloid aggregation. In addition, tetracosane (1) and methyl tridecanoate (3) weakly inhibited acetylcholinesterase (AChE). These results suggested that the effect of A. pennata on Alzheimer's disease was likely due to the inhibition of β-amyloid aggregation. Thus A. pennata may be beneficial for Alzheimer's prevention.

Biological Activity of Dolichandrone Serrulata Flowers and Their Active Components

Dolichandrone serrulata (DC.) Seem flowers are widely used as vegetables in northern and eastern Thailand. Biological studies of the methanolic extract of these flowers have shown promising antioxidant activity. Biological-guided separation of D. serrulata flowers yielded six compounds, identified as hallerone, protocatechuic acid, rengyolone, cleroindicin B, ixoside, and isomaltose. This is the first report on hallerone, protocatechuic acid, rengyolone, cleroindicin B, and isomaltose in D. serrulata. Protocatechuic acid was the most potent scavenger of 2,2-diphenyl-l-picrylhydrazyl and hydroxyl radicals with IC50 values of 25.6 ± 0.6 and 29.6 ± 0.4 μM, respectively. Hallerone and rengyolone showed moderate scavenging action on superoxide radicals and inhibited H2O2 induced reactive oxygen species production in HEK-293 cell. In addition, the other isolated compounds showed weak activity.

Bioactivity-guided Separation of the Active Compounds in Acacia Pennata Responsible for the Prevention of Alzheimer's Disease

The objective of this study was to evaluate the health benefits of plants used in Thai food, specifically Acacia pennata Willd., in Alzheimer's prevention. A. pennata twigs strongly inhibited β-amyloid aggregation. Bioactivity-guided separation of the active fractions yielded six known compounds, tetracosane (1), 1-(heptyloxy)-octadecane (2), methyl tridecanoate (3), arborinone (4), confertamide A (5) and 4-hydroxy-1-methyl-pyrrolidin-2-carboxylic acid (6). The structures were determined by spectroscopic analysis. Biological testing revealed that tetracosane (1) was the most potent inhibitor of β-amyloid aggregation, followed by 1-(heptyloxy)-octadecane (2) with IC50 values of 0.4 and 12.3 μM. Methyl tridecanoate (3), arborinone (4) and 4-hydroxy-1-methyl-pyrrolidin-2-carboxylic acid (6) moderately inhibited β-amyloid aggregation. In addition, tetracosane (1) and methyl tridecanoate (3) weakly inhibited acetylcholinesterase (AChE). These results suggested that the effect of A pennata on Alzheimer's disease was likely due to the inhibition of β-amyloid aggregation. Thus A. pennata may be beneficial for Alzheimer's prevention.

Biological Activity of Dolichandrone serrulata Flowers and Their Active Components

Dolichandrone serrulata (DC.) Seem flowers are widely used as vegetables in northern and eastern Thailand. Biological studies of the methanolic extract of these flowers have shown promising antioxidant activity. Biological-guided separation of D. serrulata flowers yielded six compounds, identified as hallerone, protocatechuic acid, rengyolone, cleroindicin B, ixoside, and isomaltose. This is the first report on hallerone, protocatechuic acid, rengyolone, cleroindicin B, and isomaltose in D. serrulata. Protocatechuic acid was the most potent scavenger of 2,2-diphenyl-l-picrylhydrazyl and hydroxyl radicals with IC50 values of 25.6 +/- 0.6 and 29.6 +/- 0.4 microM, respectively. Hallerone and rengyolone showed moderate scavenging action on superoxide radicals and inhibited H202 induced reactive oxygen species production in HEK-293 cell. In addition, the other isolated compounds showed weak activity.

Polyphenolic Compounds and Antioxidant Activities of the Leaves of Glochidion hypoleucum

Bioassay-guided fractionation of the methanol extract of Glochidion hypoleucum (Miq.) Boerl leaves led to the isolation of five polyphenol compounds, methyl gallate, gallic acid, apigenin-8- C-β-D-glucopyranoside (vitexin), luteolin-8- C-β-D-glucopyranoside (orientin), and luteolin-6- C-β-D-glucopyranoside (isoorientin). The chemical structures of the isolated compounds were determined using spectroscopic (NMR, UV-Vis, IR) and mass spectrometric techniques. The antioxidative properties of the methanol extract and isolated polyphenols were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) for radical scavenging activity and 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) to measure the level of reactive oxygen species (ROS). With the exception of vitexin, the crude methanol extract and the polyphenol compounds inhibited DPPH radicals with IC50 values ranging from 2.46 ± 0.05 to 40.0 ± 0.3 μg/mL. In addition, the crude methanol extract attenuated H2O2-induced intracellular ROS production in a dose-dependent manner in HEK-293 cells. Gallic acid and isoorientin significantly reduced the ROS level in HEK-293 cells at a concentration of 20 μM.

Polyphenolic compounds and antioxidant activities of the leaves of Glochidion hypoleucum

Bioassay-guided fractionation of the methanol extract of Glochidion hypoleucum (Miq.) Boerl leaves led to the isolation of five polyphenolic compounds, methyl gallate, gallic acid, apigenin-8-C-β-D-glucopyranoside (vitexin), luteolin-8-C-β-D-glucopyranoside (orientin), and luteolin-6-C-β-D-glucopyranoside (isoorientin). The chemical structures of the isolated compounds were determined using spectroscopic (NMR, UV-Vis, IR) and mass spectrometric techniques. The antioxidative properties of the methanol extract and isolated polyphenols were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) for radical scavenging activity and 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) to measure the level of reactive oxygen species (ROS). With the exception of vitexin, the crude methanol extract and the polyphenolic compounds inhibited DPPH radicals with IC50 values ranging from 2.46 ± 0.05 to 40.0 ± 0.3 μg/mL. In addition, the crude methanol extract attenuated H202-induced intracellular ROS production in a dose-dependent manner in HEK-293 cells. Gallic acid and isoorientin significantly reduced the ROS level in HEK-293 cells at a concentration of 20 μM.

Synergistic effects of isomorellin and forbesione with doxorubicin on apoptosis induction in human cholangiocarcinoma cell lines

BACKGROUND

Chemotherapy for advanced cholangiocarcinoma (CCA) is largely ineffective, but innovative combinations of chemotherapeutic agents and natural compounds represent a promising strategy. In our previous studies, isomorellin and forbesione, caged xanthones isolated from Garcinia hanburyi, were found to induce cell cycle arrest and apoptosis in CCA cell lines. The subject of our inquiry is the synergistic effect(s) of these caged xanthones with doxorubicin on growth inhibition and apoptosis induction in human CCA cell lines.

METHODS

KKU-100, KKU-M139 and KKU-M156 cell lines and Chang cells were treated with either isomorellin or forbesione alone or in combination with doxorubicin. Cell viability was determined using the sulforhodamine B assay. The combined effects of plant compounds with doxorubicin were analyzed using the isobologram and combination index method of Chou-Talalay. Apoptosis was determined by ethidium bromide/acridine orange staining. Protein expressions were determined by Western blot analysis.

RESULTS

Isomorellin or forbesione alone inhibited the growth of these CCA cell lines in a dose-dependent manner and showed selective cytotoxicity against CCA cells but not against Chang cells. Isomorellin/doxorubicin combination showed a synergistic growth inhibitory effect on KKU-M139 and KKU-M156 cells, while the forbesione/doxorubicin combination showed a synergistic growth inhibitory effect on KKU-100 and KKU-M139 cells. The percentages of apoptotic cells were significantly higher in the combined treatments than in the respective single drug treatments. The combined treatments strongly enhanced the expression of Bax/Bcl-2, activated caspase-9 and caspase-3, while suppressing the expression of survivin, procaspase-9 and procaspase-3, compared with single drug treatments. The degree of suppression of NF-κB activation mediated by a decrease in the expression of NF-κB/p65, a reduction of the pIκB-α level and an increase in the IκB-α protein level, was significantly higher in the combined treatment groups than in the single drug treatment groups. The degree of suppression of MRP1 protein expression was also significantly higher in the combined treatment than in the single drug treatment groups.

CONCLUSION

The combinations of isomorellin/doxorubicin and forbesione/doxorubicin showed significant synergistic effects on the growth inhibition and apoptosis induction in KKU-M156 and KKU-100 cells. Caged xanthones may be useful adjunct treatments with chemotherapy for Opisthorchis viverrini (OV)-associated CCA.

Involvement of p53 and nuclear factor-kappaB signaling pathway for the induction of G1-phase cell cycle arrest of cholangiocarcinoma cell lines by isomorellin

Cell cycle arrest is closely linked to apoptosis. Isomorellin-a caged xanthone isolated from Garcinia hanburyi-induced apoptosis in cholangiocarcinoma (CCA) cell lines. To elucidate potential anticancer mechanisms, we investigated the effects of isomorellin on the growth, cell cycle progression, cell cycle regulated protein expression and nuclear factor-kappa B (NF-κB) activation of KKU-100 and KKU-M156 CCA cell lines; using sulforhodamine B assay, flow cytometry and Western blot analysis. The growth of both CCA cell lines was significantly inhibited by isomorellin treatment in a time- and dose-dependent manner. The respective IC(50) value of isomorellin for KKU-100 cells was 6.2±0.13, 5.1±0.11 and 3.5±0.25 µM at 24, 48 and 72 h. By comparison, the respective IC(50) value for KKU-M156 cells was 1.9±0.22, 1.7±0.14 and 1.5±0.14 µM at 24, 48 and 72 h. The growth inhibition of CCA cells by isomorellin was through the G0/G1 phase arrest mediated by inhibition of NF-κB activation, up-regulation of p53, p21 and p27 and down-regulation of cyclin D1, cyclin E, Cdk4 and Cdk2 protein levels. Our research suggests that isomorellin induces cell cycle arrest and apoptosis in CCA cell lines through p53 and the NF-κB-signaling pathway. The growth inhibitory potential of isomorellin was comparable to that of gambogic acid. Isomorellin shows potential as a therapeutic agent against human cholangiocarcinoma.

Prenylated caged xanthones: chemistry and biology

CONTEXT

Prenylated caged xanthones are "privileged structure" characterized by the presence of the unusual 4-oxo-tricyclo[4.3.1.0(3,7)]dec-8-en-2-one scaffold. The natural sources of these compounds confines mainly in the Garcinia genus in the family of Guttiferae. Gambogic acid is the most abundant substance and most of the studies have been done on this compound, particularly as a new potential antitumor agent. The history, sources, structural diversity, and biological activities of these compounds are covered.

OBJECTIVE

This review is written with the intention to provide additional aspects from what have been published of prenylated caged xanthones, including history, sources, structural diversity, and biological activities.

METHODS

This review has been compiled using information from a number of reliable references mainly from major databases including SciFinder, ScienceDirect, and PubMed.

RESULTS

More than 120 prenylated caged xanthones have been found in the plant genera Garcinia, Cratoxylum, and Dascymaschalon. These compounds exhibited various potentially useful biological activities such as anticancer, anti-HIV-1, antibacterial, anti-inflammatory, and neurotrophic activities.

CONCLUSIONS

Prenylated caged xanthones, both naturally occurring and synthetic analogues, have been identified as promising bioactive compounds, especially for anticancer agents. Gambogic acid has been demonstrated to be a highly valuable lead compound for antitumor chemotherapy. The structure activity relationship (SAR) study of its analogues is still the subject of intensive research. Apoptosis cytotoxic mechanism has been identified as the major pathway. Research on the delineation of the in-depth mechanism of action is still on-going. Analogues of gambogic acid had been identified to be effective against a rare and special form of liver cancer, cholangiocarcinoma for which currently there is no chemotherapeutic treatment available.

Apoptotic activity of caged xanthones from Garcinia hanburyi in cholangiocarcinoma cell lines

AIM: To investigate the growth inhibitory mechanism of four caged xanthones from Garcinia hanburyi in cholangiocarcinoma (CCA) KKU-100 and KKU-M156 cells.

METHODS: Four caged xanthones, selected on the basis of their anticancer potency and chemical structure diversities (i.e. isomorellin, isomorellinol, forbesione and gambogic acid) were used in this study. Growth inhibition of these caged xanthones was determined using the sulforhodamine B assay. Induction of apoptosis was assessed by observing cell morphology, ethidium bromide and acridine orange staining and DNA fragmentation assay. Levels of apoptotic-related gene and protein expressions were determined by a real-time reverse transcriptase polymerase chain reaction and Western blotting analysis, respectively.

RESULTS: The compounds were found to inhibit growth of both cell lines in a dose-dependent manner and also showed selective cytotoxicity against the cancer cells when compared with normal peripheral blood mononuclear cells. Growth suppression by these compounds was due to apoptosis, as evidenced by the cell morphological changes, chromatin condensation, nuclear fragmentation, and DNA ladder formation. At the molecular level, these compounds induced down-regulation of Bcl-2 and survivin proteins with up-regulation of Bax and apoptosis-inducing factor proteins, leading to the activation of caspase-9 and -3 and DNA fragmentation. The functional group variations did not appear to affect the anticancer activity with regard to the two CCA cell lines; however, at a mechanistic level, isomorellinol exhibited the highest potency in increasing the Bax/Bcl-2 protein expression ratio (120 and 41.4 for KKU-100 and KKU-M156, respectively) and in decreasing survivin protein expression (0.01 fold as compared to control cells in both cell lines). Other activities at the molecular level indicate that functional groups on the prenyl side chain may be important.

CONCLUSION: Our findings for the first time demonstrate that four caged xanthones induce apoptosis in CCA cells which is mediated through a mitochondria-dependent signaling pathway.

Anti-HIV-1 and anti-inflammatory lupanes from the leaves, twigs, and resin of Garcinia hanburyi

Two new lupanes, 2 alpha-acetoxy-3 beta-hydroxy-19 beta-hydrogen-lup-20(29)-en-28-oic acid (2-acetoxyalphitolic acid) ( 1) and 2 alpha-hydroxy-3 beta-acetoxy-19 beta-hydrogen-lup-20(29)-en-28-oic acid (3-acetoxyalphitolic acid) ( 2), together with the known betulinic acid ( 3), betulin ( 4), and stimasterol-3- O- beta- D-glucopyranoside ( 5), were isolated from the leaves and twigs of GARCINIA HANBURYI. Compounds 1- 3 were also isolated from the resin of this plant. The structure of 2 was confirmed by single-crystal X-ray diffraction analysis. All of the lupanes ( 1- 4) displayed anti-HIV-1 activities in the anti-HIV-1 reverse transcriptase (IC (50) values 16.3-116.9 microg/mL) and syncytium assays (EC (50) 5.6-73.6 microg/mL, SI 1.7-3.3). Moreover compounds 1- 4 exhibited anti-inflammatory activity in an ethyl phenylpropiolate (EPP)-induced ear edema model.

Anti-inflammatory, analgesic and antipyretic activities of the extract of gamboge from Garcinia hanburyi Hook f

In Thai folklore medicine, gamboge, the yellow gum-resin secreted from Garcinia hanburyi, is used for infected wound, pain and edema The ethyl acetate extract from Garcinia hanburyi (GH5763) was assessed for anti-inflammatory, analgesic and antipyretic activities using experimental animal models. It was found that GH5763 possessed inhibitory activity on acute phase of inflammation as seen in ethyl phenylpropiolate-induced ear edema and carrageenin-induced hind paw edema in rats. However, GH5763 did not elicit any inhibitory effect on arachidonic acid-induced hind paw edema. In subchronic inflammatory model, GH5763 provoked a significant reduction of both transudative and proliferative phase when tested on cotton pellet-induced granuloma model. GH5763 also reduced the alkaline phosphatase activity in serum of rats in this animal model. In the analgesic test, GH5763 elicited inhibitory activity on acetic acid-induced writhing response and on both the early and the late phase of formalin test. Moreover, GH5763 also possessed an excellent antipyretic effect when tested in yeast-induced hyperthermic rats. It is postulated that the anti-inflammatory, analgesic and antipyretic activities of GH5763 are caused by the inhibition of the prostaglandin biosynthesis.

Cytotoxic and anti-HIV-1 caged xanthones from the resin and fruits of Garcinia hanburyi

Three new caged xanthones, 7-methoxydesoxymorellin (1), 2-isoprenylforbesione (2) and 8,8a-epoxymorellic acid (3), together with nine known caged xanthones were isolated from the EtOAc extracts of resin and fruits of Garcinia hanburyi. The structures were determined by spectroscopic methods. Most of the isolated compounds showed significant cytotoxicities against a panel of mammalian cancer cell lines. Compound 3, together with the known compounds desoxymorellin, morellic acid, gambogic acid, hanburin, forbesione and dihydroisomorellin, exhibited anti-HIV-1 activity in the reverse transcriptase (RT) assay while the known compounds desoxygambogenin and dihydroisomorellin were found moderately active in the syncytium assay. This work represents the first report on the anti-HIV-1 activities of caged xanthones.

Fine Tuning the Production of Nanosized β-Carotene Particles Using Spinning Disk Processing

Nanoparticles of trans-beta-carotene are accessible using spinning disk processing (SDP), by varying the reaction conditions and the choice of surfactant, macrocyclic amphiphiles, sulfonato-calix[4,5,6,8]arenes, and alpha,beta-cyclodextrins. SDP ensures rapid mixing and fast kinetics, and nanoparticles of the carotene formed in the presence of the calixarenes are stable with respect to extraction of the carotene into an organic solvent, unlike in the presence of the cyclodextrins. Insight into the supramolecular structure of the carotene nanoparticles has also been established. The mean particle sizes (dynamic light scattering, DLS) have been optimized at 40(2) and 56(1) nm and 71.4(6) and 82(1) nm, respectively, for each sulfonato-calix[5,6 and 4,8]arene, whereas the cyclodextrins form nanoparticles with a mean diameter of 71(1) and 68.5(6) nm, respectively. Zeta-potential studies show stability of all the colloidal dispersions at pH > 4 with values below -30 mV. UV-visible spectroscopy shows a blue shift indicative of H-aggregates of the carotene within the nanoparticles. The surface area derived from BET studies is 39.12 m(2)/g corresponding to particles of 76.7(5) nm in diameter, in agreement with sizes obtained from DLS and TEM measurements.