Preferentially Cytotoxic Constituents of Andrographis paniculata and their Preferential Cytotoxicity against Human Pancreatic Cancer Cell Lines.

In the course of our search for anticancer agents based on a novel anti-austerity strategy, we found that the 70% EtOH extract of the crude drug Andrographis Herba (aerial parts of Andrographis paniculata), used in Japanese Kampo medicines, killed PANC-1 human pancreatic cancer cells preferentially in nutrient-deprived medium (NDM). Phytochemical investigation of the 70% EtOH extract led to the isolation of 21 known compounds consisting of six labdane-type diterpenes (11, 15, 17-19, 21), six flavones (5, 7, 10, 12, 14, 20), three flavanones (2, 6, 16), two sterols (3, 8), a fatty acid (1), a phthalate (4), a triterpene (9), and a monoterpene (13). Among them, 14-deoxy-11,12-didehydroandrographolide (17) displayed the most potent preferential cytotoxicity against PANC-1 and PSN-1 cells with PC50 values of 10.0 µM and 9.27 µM, respectively. Microscopical observation, double staining with ethidium bromide (EB) and acridine orange (AO), and flow cytometry with propidium iodide/annexin V double staining indicated that 14-deoxy-11,12-didehydroandrographolide (17) triggered apoptosis-like cell death in NDM with an amino acids and/or serum-sensitive mode.

Anti-austeritic Constituents of the Congolese Medicinal Plant Aframomum melegueta.

In the course of our search for anticancer agents based on a novel anti-austerity strategy, we found that the CHCl3 extract of the roots of Aflamomum melegueta (Zingiberaceae), collected in the Democratic Republic of Congo, killed PANC-1 human pancreatic cancer cells preferentially in nutrient-deprived medium (NDM). Phytochemical investigation of the CHCl3 extract led to the isolation of seven known compounds [(-)-buplerol (1), (-)-arctigenin (2), (E)-14-hydroxy-15-norlabda-8(17),12-dien-16-al (3), labda-8(17),12-dien-15,16-dial (4), 16-oxo-8(17),12(E)-labdadien-15-oic acid (5), 5-hydroxy-7-methoxyflavone (6), and apigenin (7)]. In addition to the previously reported preferentially cytotoxic compound, (-)-arctigenin (2, PC50 0.5 µM), (-)-buplerol (1) also displayed potent preferential cytotoxicity with a PC50 value of 8.42 µM and triggered apoptosis-like PANC-1 cell death in NDM.

A new polyoxygenated cyclohexane and other constituents from Kaempferia rotunda and their cytotoxic activity.

The isolation of secondary metabolites from a methanolic extract of Kaempferia rotunda yielded 12 compounds (1-12), including a new polyoxygenated cyclohexane compound, (-)-3-acetyl-4-benzoyl-1-benzoyloxymethyl-1,6-diepoxycyclohexan-2,3,4,5-tetrol (1). The structures of the isolated compounds were determined based on their spectroscopic data and comparison with references. All of the isolated compounds were tested for their cytotoxic activity against pancreatic (PSN-1) and breast (MDA-MB231) cancer cell lines. Compound 12 showed moderate cytotoxic activity against PSN-1 and MDA-MB231 without showing any cytotoxicity against the normal cell line, TIG-3.

New guaian-type sesquiterpene from Wikstroemia indica.

From a MeOH extract of powdered roots of Wikstroemia indica, we isolated a new guaian-type sesquiterpene (1) and two known guaian-type sesquiterpenes [oleodaphnal (2), 1alpha,7alpha,10alphaH-guaia-4,11-dien-3-one (3)], together with twelve known compounds: (+)-arctigenin, (+)-matairesinol, (+)-trachelogenin, (+)-nortrachelogenin, (+)-hinokinin, (+)-kusunokinin, 7-methoxycoumarin, 7-hydroxycoumarin (umbelliferone), daphnogitin, daphnoretin, salicifoliol, and (-)-pinoresinol. The structure of compound 1 was determined to be 4,10,11-guaiatrien-3-one-14-oic acid, by the analyses of spectral data.

Antiausterity activity of arctigenin enantiomers: importance of (2R,3R)-absolute configuration.

From a MeOH extract of powdered roots of Wikstroemia indica, six dibenzyl-gamma-butyrolactone-type lignans with (2S,3S)-absolute configuration [(+)-arctigenin (1), (+)-matairesinol (2), (+)-trachelogenin (3), (+)-nortrachelogenin (4), (+)-hinokinin (5), and (+)-kusunokinin (6)] were isolated, whereas three dibenzyl-gamma-butyrolactone-type lignans with (2R,3R)-absolute configuration [(-)-arctigenin (1*), (-)-matairesinol (2*), (-)-trachelogenin (3*)] were isolated from Trachelospermum asiaticum. The in vitro preferential cytotoxic activity of the nine compounds was evaluated against human pancreatic PANC-1 cancer cells in nutrient-deprived medium (NDM), but none of the six lignans (1-6) with (2S,3S)-absolute configuration showed preferential cytotoxicity. On the other hand, three lignans (1*-3*) with (2R,3R)-absolute configuration exhibited preferential cytotoxicity in a concentration-dependent manner with PC50 values of 0.54, 6.82, and 5.85 microM, respectively. Furthermore, the effect of (-)- and (+)-arctigenin was evaluated against the activation of Akt, which is a key process in the tolerance to nutrition starvation. Interestingly, only (-)-arctigenin (1*) strongly suppressed the activation of Akt. These results indicate that the (2R,3R)-absolute configuration of (-)-enantiomers should be required for the preferential cytotoxicity through the inhibition of Akt activation.

Heptaoxygenated xanthones as anti-austerity agents from Securidaca longepedunculata.

In a course of our search for anticancer agent based on a novel anti-austerity strategy, we found that the CHCl3 extract of the roots of Securidaca longepedunculata (Polygalaceae), collected at Democratic Republic of Congo, killed PANC-1 human pancreatic cancer cells preferentially in nutrient-deprived medium (NDM). Phytochemical investigation on the CHCl3 extract led to the isolation of 28 compounds including five new polymethoxylated xanthones [1,6,8-trihydroxy-2,3,4,5-tetramethoxyxanthone (1), 1,6-dihydroxy-2,3,4,5,8-pentamethoxyxanthone (2), 8-hydroxy-1,4,5,6-tetramethoxy-2,3-methylenedioxyxanthone (3), 4,6,8-trihydroxy-1,2,3,5-tetramethoxyxanthone (4), 4,8-dihydroxy-1,2,3,5,6-pentamethoxyxanthone (5)] and a new benzyl benzoate [benzyl 3-hydroxy-2-methoxybenzoate (6)]. Among them, 1,6,8-trihydroxy-2,3,4,5-tetramethoxyxanthone (1) and 1,6-dihydroxy-2,3,4,5,8-pentamethoxyxanthone (2) displayed the potent preferential cytotoxicity with PC50 of 22.8 and 17.4 µM, respectively. They triggered apoptosis-like PANC-1 cell death in NDM with a glucose-sensitive mode.

Anti-austeric activity of phenolic constituents of seeds of Arctium lappa.

From seeds of Arctium lappa L. (Asteraceae) we obtained arctigenin (1), arctiin (2), chlorogenic acid (3), 4,5-dicaffeoylquinic acid (4), 3,5-dicaffeoylquinic acid (5), 3,4-dicaffeoylquinic acid (6), matairesinol (11), isolappaol A (12), lappaol F (14), and lappaol B (15), together with 1:1 mixtures of isolappaol C (7) and lappaol C (8), arctignan E (9) and arctignan D (10), and 12 and lappaol A (13), while 3,3',4'-tri-O-demethylarctigenin (16), 3,3'-di-O-demethyl-4'-dehydroxyarctigenin (17), and 3-O-demethylarctigenin (18) were obtained by anaerobic microbiological metabolism of 1. Then, we evaluated the in vitro preferential cytotoxic activity of these pure compounds and 1:1 mixtures, together with enterodiol (19) and enterolactone (20), against human pancreatic cancer PANC-1 cells in nutrient-deprived medium (NDM). Among them, 1 and 18 showed potent activity, with PC50 values of 1.75 and 4.38 microM, respectively, while 11, 15, and 17 showed mild activity with PC50 values of 31.1, 30.9, and 38.7 microM, respectively. By comparing their structures and PC50 values, the following structural moieties could be concluded to be important for the preferential cytotoxicity of 1: 1) the 3-hydroxy-4-methoxyphenyl group at the 2-position on the gamma-butyrolactone ring, 2) the less polar substituent at the 3-position on the gamma-butyrolactone ring, and 3) the gamma-butyrolactone ring.

[Stump recurrence after pulmonary metastasectomy from colorectal cancer].

Pulmonary metastasectomy with wedge resection is an ideal procedure in terms of less invasiveness and preservation of respiratory function, while local recurrence is a major problem. The goal of this study was to verify risk factors of stump recurrence after pulmonary metastasectomy from colorectal cancer. Pulmonary metastasectomies including 112 operations for 131 lesions in 85 patients with colorectal cancer were performed in our department since March, 2005 until the end of 2010. In our cases, stump recurrence significantly occurred in patients who underwent wedge resection than segmentectomy or lobectomy. Stump recurrence developed in 14 operations among 62 wedge resections (recurrence rate: 23%). Diameter more than 10 mm and distance between pleura and deepest end of the tumor (depth value) more than 14 mm were risk factors as stump recurrence. Tumor diameter and depth value can be a decisional factor for wedge resection in pulmonary metastasectomy in the colorectal cancer patients.

Synthesis and antitumor evaluation of arctigenin derivatives based on antiausterity strategy.

A series of new (-)-arctigenin derivatives with variably modified O-alkyl groups were synthesized and their preferential cytotoxicity was evaluated against human pancreatic cancer cell line PANC-1 under nutrient-deprived conditions. The results showed that monoethoxy derivative 4i (PC(50), 0.49 µM), diethoxy derivative 4h (PC(50), 0.66 µM), and triethoxy derivative 4m (PC(50), 0.78 µM) showed the preferential cytotoxicities under nutrient-deprived conditions, which were identical to or more potent than (-)-arctigenin (1) (PC(50), 0.80 µM). Among them, we selected the triethoxy derivative 4m and examined its in vivo antitumor activity using a mouse xenograft model. Triethoxy derivative 4m exhibited also in vivo antitumor activity with the potency identical to or slightly more than (-)-arctigenin (1). These results would suggest that a modification of (-)-arctigenin structure could lead to a new drug based on the antiausterity strategy.

Dipasperoside A, a novel pyridine alkaloid-coupled iridoid glucoside from the roots of Dipsacus asper.

A new pyridine alkaloid-coupled iridoid glucoside, dipasperoside A (1), and 20 known compounds (2­21) were isolated from a water extract of Dipsacus asper roots. Compound 1 possessed a unique structural feature with a nicotinic acid nucleus coupled through C-5 with C-7 of a secoiridoid/iridoid glucoside dimer, and esterified with a C-7 hydroxyl group of an iridoid glucoside monomer. All isolates were evaluated for their inhibitory activity against nitric oxide (NO) production in a lipopolysaccharide (LPS)-activated murine macrophage cell line, RAW264.7.

Potential anti-tumor effect of IFN-λ2 (IL-28A) against human lung cancer cells.

Interferon (IFN)-λs (IL-28A/IL-28B/IL-29) classified as type III IFNs, are the latest members identified of the interferon family. As with type I IFNs such as IFN-α, type III IFNs share antiviral and antitumor activity and may have fewer side effects due to a more selective receptor distribution. Therefore, type III IFNs may be clinically useful for human viral and malignant diseases. Here we demonstrate the potential anti-tumor effect of IFN-λ2 (IL-28A) against human lung cancer cells. All lung cancer cell lines that we examined expressed both IFN-λ receptors (IL-28R1 and IL-10R2). Lung cancer cells with epidermal growth factor receptor (EGFR) mutations were more sensitive to IFN-λ2 treatment compared with cells with KRAS mutations. HCC827 cells with an EGFR mutation treated with IFN-λ2 underwent growth suppression and apoptotic cell death by STAT1 phosphorylation. Administration of neutralizing antibodies to IFN-λ inhibited caspase-3/7 activity induced by IFN-λ2. Finally, in vivo luminescent imaging also demonstrated the anti-tumor effect of IFN-λ2 in a cancer cell transplant animal model. Taken together, IFN-λ2 would be a new therapeutic agent for clinical lung cancers with EGFR mutations.

Anti-austerity agents from Rhizoma et Radix Notopterygii (Qianghuo).

During a search for potent anticancer agents from natural products based on an anti-austerity strategy, we found that a CHCl3 extract of Rhizoma et Radix Notopterygii (Qianghuo), a Chinese crude drug, exhibited strong cytotoxicity against PANC-1 human pancreatic cancer cells, with a PC50 value of 17.5 µg/mL. Further fractionation and purification of this bioactive extract led to the isolation of 19 known compounds. The in vitro preferential cytotoxicity of the isolates was evaluated against two human pancreatic cancer cell lines, PANC-1 and PSN-1. Among the compounds isolated, ostruthin displayed the most potent activity against both PANC-1 (PC50, 7.2 µM) and PSN-1 (PC50, 7.8 µM) cells in nutrient-deprived medium (NDM) and may have induced necrotic nutrient-deprived PANC-1 cell death.

Damnacanthal from the Congolese medicinal plant Garcinia huillensis has a potent preferential cytotoxicity against human pancreatic cancer PANC-1 cells.

Screening of eight Congolese medicinal plants showed that the CHCl(3) and MeOH extracts of Aframomum melegueta (PC(50) = 47.8 µg/mL and 13.8 µg/mL, respectively) and CHCl(3) extracts of Garcinia huillensis (PC(50) = 17.8 µg/mL) and Securidaca longepedunculata (PC(50) = 23.4 µg/mL) had preferential cytotoxicity against human pancreatic cancer PANC-1 cells under nutrient-deprived conditions. The active constituents of the CHCl(3) extract of G. huillensis were examined and 12 known anthraquinones were identified. Among them, damnacanthal (1) caused preferential necrotic cell death of PANC-1 and PSN-1 cells under nutrient-deprived and serum-sensitive conditions (PC(50) = 4.46 µm and 3.77 µm, respectively).

[Clinicopathological study of small lung cancer (diameter of 2 cm or less) by uptake value of 18F-fluorodeoxyglucose].

18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) for lung cancer may be a biomarker for malignancy as well as a useful tool for detection of nodal involvement and distant metastasis. The goal of this study was to clarify a relationship between clinicopathological findings and maximum standardized uptake value( SUVmax) obtained by preoperative PET in patients with non-small cell lung cancer in diameter of 2 cm or less. Between January 2008 and April 2011, 124 patients( 54 men and 70 women) with non-small cell lung cancer in diameter of 2 cm or less undergoing lobectomy or segmentectomy were enrolled. The relationship between SUVmax and clinicopathological findings as tumor diameter, histological type, pleural invasion, vascular invasion, lymphatic permeation and nodal involvement were analyzed. Correlation between SUVmax and findings such as vascular invasion and lymphatic permeation showed relatively strong in the patients with adenocarcinoma, on the contrary to the correlation in the patients with non-adenocarcinoma. No tumor showing SUVmax of 2 or less showed vascular invasion and/or lymphatic permeation as well as nodal involvement in any patients with adenocarcinoma. SUVmax of the primary tumor in diameter of 2 cm or less, can be a useful biomarker which indicates a surgical candidate for sublobar pulmonary resection as well as mediastinal nodal dissection, especially in patients with adenocarcinoma.

[Clinical outcome after video-assisted thoracic surgery (VATS) for clinical stage I lung cancer with pathologically nodal involvement].

The lymph node dissection with video-assisted thoracic surgery( VATS) was technically feasible and the remnant lymph nodes and tissues were 2% to 3%, which seems acceptable for clinical stage I lung cancer. Surgical outcome after VATS for clinical stage I lung cancer with pathologically nodal involvement, however, remains unclear. Medical records of 72 patients who had clinical stage I non small cell lung cancer with pathologically nodal involvement( pN1:21 patients, pN2:51 patients) and underwent VATS lobectomy or segmentectomy with mediastinal dissection between January 2005 and December 2010, were retrospectively reviewed. Postoperative recurrence and survival were studied. Remnant nodal recurrence occurred in 8 patients with pN1 (recurrence rate 38%) and 15 patients with pN2 (recurrence rate 29%). The 1- and 3-year disease free survival rate was 87% and 68%. The 1- and 3-year survival rate was 100% and 79%. This study suggested that VATS is acceptable for patients with clinical stage I lung in terms of survival rate, cancer with pN1. In a view point of remnant nodal recurrence, a more skillful dissection procedure is required.

Two new cytotoxic phenylallylflavanones from Mexican propolis.

Two new phenylallylflavanones, (2R,3R)-6-[1-(4'-hydroxy-3'-methoxyphenyl)prop-2-en-1-yl]pinobanksin (1) and (2R,3R)-6-[1-(4'-hydroxy-3'-methoxyphenyl)prop-2-en-1-yl]pinobanksin 3-acetate (2) were isolated from a methanolic extract of Mexican propolis. Their structures were elucidated with spectroscopic analysis. Both compounds (1, 2) exhibited preferential cytotoxic activity against PANC-1 human pancreatic cancer cells in a nutrient-deprived medium with the concentration at which 50% cells died preferentially in NDM (PC50) values of 17.9 µM and 9.1 µM, respectively.

[Stump consolidation after video-assisted thoracoscopic segmentectomy].

Pulmonary segmentectomy by video-assisted thoracic surgery (VATS) is used for minimally invasive surgery for removal of small lung neoplasms, and stump consolidation is one of the potential postoperative complications. The objective of the present study is to clarify the incidence of stump consolidation and its predictive factors by assessing patients who underwent VATS segmentectomy in our department. Stump consolidation was defined as atelectatic lesions along the surgical stump with >10 mm thickness in horizontal sectional view by computed tomography, at least 3 months after surgery. Between February 2007 and September 2010, 70 patients (38 men and 32 women) with primary lung cancer (43 patients) and metastatic pulmonary tumor (27 patients) underwent VATS segmentectomy. Stump consolidations were seen in 7 patients. Univariate analysis showed the significant difference for the period of performed operation. Left-sided operation, especially segmentectomy of left S(1+2), was another predictive factor, though not significant. Stump consolidation after VATS segmentectomy can be deueloped by conbined workspace for stapling and misidentification of intersegmental plane. When division of the intersegmental plane is difficult, open thoracotomy should be undertaken to prevent such compliance.

Identification of chrysoplenetin from Vitex negundo as a potential cytotoxic agent against PANC-1 and a panel of 39 human cancer cell lines (JFCR-39).

Human pancreatic cancer is known to be the most deadly disease with the lowest 5-year survival rate and is resistant to well known conventional chemotherapeutic drugs in clinical use. Screening of medicinal plants from Myanmar utilizing antiausterity strategy led to the identification of Vitex negundo as one of the medicinal plants having potent preferential cytotoxic activity against PANC-1 human pancreatic cancer cells. Bioactivity-guided phytochemical investigation led to the isolation of chrysoplenetin (1) and chrysosplenol D (2) as the active constituents with a PC(50) value of 3.4 µg/mL and 4.6 µg/mL, respectively, against PANC-1 cells. Both these compounds induced apoptosis-like morphological changes in PANC-1 cells. Chrysoplenetin was further tested against a panel of 39 human cancer cell lines (JFCR-39) at the Japanese Foundation for Cancer Research, and 25 cell lines belonging to lung, breast, CNS, colon, melanoma, ovarian, prostate cancer and stomach cancer cell lines were found to be highly sensitive to chrysoplenetin at a submicromolar range. In the JFCR-39 panel, lung NCI-H522, ovarian OVCAR-3 and prostate PC-3 cells were found to be most sensitive with GI(50) of 0.12, 0.18 and 0.17 µm, respectively. The COMPARE analysis suggested that the molecular mode of action of chrysoplenetin was unique compared with the existing anticancer drugs.

Extrapulmonary hamartoma.

We describe a rare case of extrapulmonary hamartoma. A 65-year-old man underwent video-assisted thoracic surgery to obtain a histological diagnosis of a tumor with an irregular shape in the subpleural region of the right apical segment. Thoracoscopy showed a chondromatous tumor in the extrapleural region. The tumor resection was uneventful. Pathology study showed a hamartoma outside the visceral pleura.

Cytochrome P450 3A4 inhibitory constituents of the wood of Taxus yunnanensis.

From the aqueous extract of the wood of Taxus yunnanensis, which showed cytochrome P450 3A4 (CYP3A4) inhibition, a new isoflavan [(3S,4R)-4'-hydroxy-6,3'-dimethoxyisoflavan-4-ol (1)], a new degraded lignan [2,3-bis(hydroxymethyl)-7-hydroxy-6-methoxy-1-tetralone (2)], and a new lignan [(7R)-7-hydroxytaxiresinol (3)] were isolated, together with nine known lignans. Among the isolates obtained, α-conidendrin (12) showed strong CYP3A4 inhibition with an IC(50) value of 0.2 µM.