Analysis of Usnea fasciata crude extracts with antineoplastic activity

Different fractions, isolated from the lichen Usnea fasciata, were analyzed by PC, TLC, and RP-HPLC. Analysis of the organic phases, mainly containing phenolics, revealed that usnic acid is the main product from secondary metabolites, whereas the polysaccharides isolichenin and raffinose are the most abundant water-soluble carbohydrates. Fractions containing usnic acid, as well as those containing isolichenin, showed moderate activity against sarcoma 180 and Ehrlich tumor cells. High antitumoral activity, near 90% inhibition, was found associated with the fraction containing raffinose.

Antitumor activity of patulin and structural analogs

A comparison between the cytotoxicity and the antitumor activity of patulin and five structural analogs (isopatulin, dehydroisopatulin, dimethylisopatulin, trimethylisopatulin and isopropylisopatulin) has been established. In vitro assays using L 1210 and P 388 cells showed that the structure of the pyranic ring as well as the nature of the substituents influenced the observed activities. Among the five structural analogs of patulin assayed in vivo against Ehrlich carcinoma, L 1210 and P 388 leukemias, dehydroisopatulin was the only one to be active on all 3 types of tumors at a dose of 100 mg.kg-1.d-1. The ratio between the LD50 in mice and the active dose was 5 while with patulin it was 10. It can be assumed that the lactone function is not solely responsible for the activity of patulin and its structural analogs.

In vitro and in vivo antitumoral activity of free, and encapsulated taxol

The anti-tumoral activity of taxol encapsulated either in liposomes or in nanocapsules was compared with that of free taxol, using the P388 and L1210 leukaemia test systems. The in vitro inhibition of cell growth was measured after 48 h and 96 h exposure to various concentrations of taxol. With P388 cells, the inhibitory activities of the three forms of the drug were similar. With the L1210 cells, however, the concentrations required for a 50 per cent inhibition of cell growth (IC50) after 48 h exposure to the drug were greater for nanocapsules than for liposomes or free taxol, the values being 0.060, 0.043 and 0.035 micrograms ml-1, respectively. However, a greater efficiency of nanocapsules was observed after 96 h exposure. Using cytomorphometric analysis, no difference was found between L1210 cells treated either with free or encapsulated taxol. In vivo, mice bearing P388 leukaemia, and treated either with taxol solubilized with 5 per cent DMSO + 5 per cent cremophor in saline solution, or with taxol encapsulated in liposomes (IP daily dose of 12.5 mg Kg-1 body weight x 4 days) showed ILS values of 65.8% and 67.9% respectively. Nanocapsules proved to be toxic, apparently due to their composition: this problem is currently under investigation.

Diels-Alder reactions between dienamides and quinones: stereochemistry of the cycloadditions and cytotoxic activity of the adducts

Tetrahydronaphthoquinones and tetrahydroanthraquinones bearing an amido group have been prepared by Diels-Alder reactions between (E)-1-(N-carbobenzyloxyamino)-1,3-butadiene (2) or (E)-1-(N-benzoyl-N-benzylamino)-1,3-butadiene (5) and benzoquinone or 5-substituted naphthoquinones. The stereochemistry of the cycloadditions was investigated. A high regioselectivity was observed in the reaction of the diene carbamate 2 with 5-methoxy and 5-acetoxy naphthoquinones. This latter gave the unexpected 1,8-regioisomer 3d. The cycloadditions of the dienamide 5 with naphthoquinones 1 (R = OH, OMe, OAc) are regiospecific. Assignment of the structure of the tetrahydroanthraquinone 6b is in good agreement with the known directing effect of the 5-hydroxy group of juglone 1b in analogous Diels-Alder reactions. With 5-methoxy and 5-acetoxy naphthoquinones, the opposite regiochemistry observed is consistent with the electron-donating influence of the methoxy or acetoxy group, making the C-3 carbon atom more electron deficient. Aromatization of the adducts 6b and 7c was accompanied by an unusual elimination of the amido moiety. Thus, 1-hydroxy and 1-methoxy anthraquinones were obtained. Reactions of the dienes 2 and 5 with benzoquinone gave the tetrahydronaphthoquinones 9 and 10 with an endo stereospecificity. Oxidation of 9 by activated manganese dioxide gave the naphthoquinone 11. These compounds were submitted to in vitro cytotoxic assays towards murine L 1210 leukemia cells and clonogenic human tumor cell line MDA-MB 231. The naphthoquinone derivatives 9, 10 and 11 had significant activities with IC50 less than or equal to 0.4 microgram/ml towards these two tumor cell systems.

Clinical value of an amplified electrophoretic determination of enolase isoenzymes in small cell lung carcinoma patients

Neurone specific enolase (NSE); alpha gamma and gamma gamma isoenzymes of the glycolytic enzyme enolase, is found in considerable quantity in serum of patients with small cell lung cancer (SCLC). The spectrophotometric measurement of serum enolase activity, plus the electrophoretic separation of isoenzymes (alpha alpha, alpha gamma and gamma gamma) using an amplification reaction constitute a simple method, the application of which has not yet been demonstrated. In patients, serum values of higher than 25 U/l of total enolase activity, with more than 10% NSE, were considered to be positive. Seventy patients diagnosed as SCLC were classified before treatment as having either limited (LD) or extensive (ED) disease, and after chemotherapy as being in complete (CR) or partial remission (PR), stable state (SS) or in relapse (R). The levels of enolase activity and NSE (M +/- SE) in these patients (enolase: 67 +/- 7 U/l, NSE 27 +/- 2%) were different from those in a control group of 19 patients with non-small cell lung cancer (enolase: 29 +/- 2 U/l, NSE: 7 +/- 1%) (p less than 0.001) at the time of diagnosis. Mean enolase and NSE levels in patients with SCLC were seen to differ significantly according to the clinical stage. The results of those patients with ED differed from those of patients with LD (p less than 0.001). The results of the group of patients that achieved remission differed from that of patients during relapse (p less than 0.0001). Serial measurements demonstrated a good correlation between enolase and NSE serum levels and the progression of the disease. The usefulness of this method in the early assessment of treatment was also demonstrated. The clinical usefulness of the dosage of NSE with that of two other tumour markers CKBB and mitochondrial CK was compared.

Isoenzyme pattern of enolase in human lung tumor xenografts in nude mice

A simple method is described which allows easy determination of neuroendocrine (NE) differentiation in human broncho-pulmonary tumor models grown in heterotransplanted nude mice. Enolase (EC 4.2.1.11) isoenzyme composition is studied using the electrophoretic method in xenograft tumor homogenates. The relatively large amount of alpha gamma and gamma gamma isoenzymes (neuron-specific enolase (NSE] is indicative of the neuroendocrine differentiation level of these tumors. The gamma gamma isoenzyme is present at a high level (M +/- SE: 10 +/- 2%) in all NE tumor models and absent in non NE tumor models. The alpha gamma isoenzyme is found in a significantly higher proportion in NE tumor models (30 +/- 2%) than in non NE tumor models (9 +/- 2%) (p less than 0.001). Moreover it is possible to discriminate between human and mice isoenzymes to estimate the proportion of mouse tissue hat is present in the xenograft.

Isoenzyme pattern of enolase in the diagnosis of neuroendocrine bronchopulmonary tumors

Electrophoretic separation of enolase isoenzymes and the measurement of enolase activity were performed in 25 lung tumor extracts. In 13 neuroendocrine (NE) tumors (nine small cell lung carcinoma [SCLC], three atypical NE tumors, and one carcinoid tumor), the NE differentiation was assessed by ultrastructural determination of neurosecretory granule (NSG) density. Twelve non-NE lung tumors also were studied (three adenocarcinomas, four epidermoid, two composite, two large cell undifferentiated carcinomas, and one lymphoma). Four normal lung tissues and 1 human brain were used as controls. The gamma gamma isoenzyme was present at a high level (mean +/- SE, 12 +/- 3%) in all NE carcinomas and consistently absent in all non-NE tumors as well as in normal lung. The alpha gamma isoenzyme was found in significantly higher proportion in NE carcinomas (mean +/- SE, 29 +/- 2%) than in non-NE tumors (mean +/- SE, 8 +/- 1%) (P less than 0.0001), despite an equally high level of total enolase activity in both groups of tumor. The separation of alpha gamma and gamma gamma isoenzymes of enolase allows for the accurate diagnosis of NE tumors and NE components of atypical NE carcinomas, and the gamma gamma isoenzyme, in contrast to gamma chain detection by immunoassay, can be considered to be a specific marker in itself of NE differentiation in lung neoplasms.

Therapeutic response to taxol of six human tumors xenografted into nude mice

To test the antineoplastic activity of taxol, a natural product isolated from yew (Taxus baccata L.), six human tumors transplanted into athymic mice were used (primary tumors of breast, endometrium, ovary, brain, lung and a recurrence of tongue tumor). While the growth rates varied with the histopathological characteristics of different tumor types, all mice were treated at a mean tumor volume of 200 +/- 8 mm3. Taxol was given SC at a dose level of 12.5 mg/kg per injection per day for 5 consecutive days out of 7 over a period of 3 weeks. With this schedule antitumor responses were obtained in all of the six neoplasms xenografted into nude mice. In the case of the ductal carcinoma of the breast total tumor regressions were observed in four of the five treated animals. In the five other experimental models taxol produced significant growth delays. We believe that the results of these initial tests on the nude mouse--human tumor xenograft system are convincing and justify clinical assessment of this drug.

Influence of the diet on the plasma kinetics of 8-methoxypsoralen

The plasma kinetics of 8-methoxypsoralen (8-MOP) have been determined in 103 patients treated by PUVA in the routine conditions in which PUVA therapy is carried out in hospital. 8-MOP is taken with breakfast; four types of breakfast were available, which differed by their lipid content; this study showed that the diet has no influence on the bioavailability of 8-MOP.

[Action of taxol on human tumors transplanted in athymic mice]

In order to study the antitumour activity of taxol (a diterpene of the taxane type) isolated from Yew: Taxus baccata L. (Taxacae), human tumours implanted as xenografts in athymic Mice were used. Swiss nude mice were treated subcutaneously (12.5 mg/kg/injection/day for 5 consecutive days out of 7, over a period of 3 weeks). Treatment by taxol of a liver metastasis of a breast tumour, a tongue primary tumour and a skin metastasis of bronchial carcinoma gave statistically significant results (0,01 greater than P greater than 0,001 and P less than 0,001). However, taxol showed a very moderate antitumour activity against a transplanted primary tumour of the colon.

Comparison between plasma levels of 8-methoxypsoralen and skin photosensitivity: the interest of pharmacokinetic studies during photochemotherapy of psoriasis

The present work compares the time course of 8-methoxypsoralen (8-MOP) plasma levels with that of induced skin photosensitivity. The value of plasma assay as a reflexion of cutaneous concentration of 8-MOP has been definitively demonstrated. This study also shows the importance of pharmacokinetics in the therapy management of ‘poor responders’ to PUVA.

[Tamoxifen fluorescence as a marker of hormone-dependence: physicochemical aspects]

In acid solutions, Tamoxifen is protonized and forms with eosin a fluorescent ionic association (lambda exc 480 nm, lambda em 565 nm). This reaction is quantitatively linked to the concentration of Tamoxifen. Thus the Tamoxifen induced fluorescence observed in hormone-dependent malignant breast tumor cells after Papanicolaou staining procedure, appears as a consequence of the binding of Tamoxifen to eosin.