Paolo Morazzoni

Relationship between rate and extent of catechin absorption and plasma antioxidant status.

Flavonoids are described to exert a large array of biological activities, which are mostly ascribed to their radical‐scavenging, metal chelating and enzyme modulation ability. Most of these evidences have been obtained by in vitro studies on individual compounds and at doses largely exceeding those dietary. Little is known about a possible relationship between rate and extent of the absorption and modifications of plasma antioxidants. To elucidate this aspect, human volunteers were supplemented with single doses of green tea catechins in free (Greense‐lect™) or phosphotipid complex form (Greenselect™ Phytosomer®) equivalent to 400 mg epigallocatechingallate (EGCg). EGCg was chosen as biomarker for green tea catechin absorption, and its time course plasma concentration was correlated to the subsequent percent variations of plasma ascorbate, total glutathione, α‐tocopherol, β‐carotene and Total Radical Antioxidant Parameter (TRAP). Green tea catechins were absorbed more extensively when administered as phospholipid complex rather than as free catechins. Single dose intake of both forms of catechins produced a transient decrease (10‐20%) of plasma ascorbate and total glutathione and an increase of plasma TRAP (16‐19%). These variations were consistent with the plasmatic levels of EGCg, ascorbate and total glutathione.

In vitro evaluation of newly developed chalcone analogues in human cancer cells.

Purpose: Among flavonoids, chalcones have been identified as interesting compounds having chemopreventive and antitumor properties. We studied a panel of newly developed chalcone analogues (S1–S10) using MDA-MB 231 and MCF-7 ADRr breast cancer cells and the T-leukemic Jurkat cell line. Quercetin was used as the reference compound. Methods: Antiproliferative activity was evaluated by cell counts performed after 72 h of exposure to the drugs. DNA analysis and redox activity were evaluated using flow cytometry. Apoptosis was assessed by morphological analysis, using YOYO-1 as DNA dye; p-glycoprotein function was ascertained by quantitating the efflux of rhodamine 123. Results: All cells were sensitive to chalcone analogues yielding IC50 in micromolar concentrations with the following order regardless of the multidrug resistance (MDR) status: S1 > S2 > quercetin. S1 and S2, the most active compounds, were selected to evaluate their effect on the cell cycle, apoptosis, redox activity, and modulation of the p-glycoprotein function. No significant perturbation in cell cycle was seen with concentration up to 1 μM after 24 h. After 72 h a slight increase in G2/M block and DNA fragmentation occurred at 10 μM. Morphological analysis of apoptosis showed that chalcone analogues induced apoptosis to a higher extent than quercetin. Redox analysis demonstrated that all substances were able to increase intracellular thiol levels, which returned to baseline value after 24 h for all drugs except quercetin. Production of reactive oxygen species was essentially unaffected by all compounds. Finally, in MDR-positive MCF-7 ADRr cells chalcone analogues were unable to modulate p-glycoprotein function while quercetin was able to. Conclusions: Newly developed S1 and S2 chalcones have a different but higher antitumor activity than quercetin and could be considered as potential new anticancer drugs.

The isothiocyanate produced from glucomoringin inhibits NF-kB and reduces myeloma growth in nude mice in vivo.

Glucosinolates (GLs), natural compounds extracted from Brassicaceae and precursors of isothiocyanates (ITCs), have been studied in the last decades mostly due to their chemopreventive activity and, more recently, for their potential use as novel chemotherapeutics. The aim of the present study was to investigate the in vitro and in vivo activity of glucomoringin (GMG), an uncommon member of the GLs family, and to compare it with glucoraphanin (GRA), one of the most studied GL. We have evaluated the potency of both compounds in inducing cell death, cell cycle perturbations, apoptosis, NF-kB inhibition and GST-pi activity in human carcinoma cells with different GST-pi contents as well as in human multiple myeloma and leukaemia cell lines. GMG-derived ITC (GMG-ITC) showed to be more effective compared to GRA-derived ITC (Sulforaphane), especially in inhibiting NF-kB activity and inducing apoptosis through a caspase-dependent pathway; these effects were more pronounced in myeloma cells, in which we could also observe a long lasting growth inhibitory effect, probably due to NF-kB inhibition, which is considered essential for myeloma cell survival. Both GLs were able to induce cell death in the muM range in all tested cell lines but caused cell cycle perturbations only in myeloma cells; they were also able to modulate the GST/GSH pathway by causing a 3-fold increase in GST-pi activity in MCF7 cells. In vivo study showed that pure GMG-ITC was only slightly active in a carcinoma mice model, whereas it had significant antitumoral activity in a myeloma model, causing little toxicity.

Decreased half life of cyclophosphamide in patients under continual treatment.

Abstract Plasma levels of cyclophosphamide (Cy) were measured in 16 cancer patients receiving 100 mg/day of Cy for over 1 yr . Oral and intravenous administrations gave similar AUC values, confirming that intestinal absorption is almost complete. When pharmacokinetics obtained at the first course of therapy were compared with pharmacokinetics measured after more than 6 months continual treatment, T 1 2 and Vd appeared significantly lower in the second population despite broad variability among patients.

Silybin and its bioavailable phospholipid complex (IdB 1016) potentiate in vitro and in vivo the activity of cisplatin

In this study we investigated whether the flavonoid silybin and its bioavailable derivative IdB 1016 (silipide) could enhance the antitumour activity of cisplatin (CDDP), the most commonly used drug in the treatment of gynaecological malignancies. Silybin alone up to 10 (M was unable to produce a relevant in vitro growth inhibition of A2780 cells, whereas CDDP was effective, giving an IC50 value of 0.5+/-0.14 microM. When silybin was combined with CDDP, a dose-dependent and statistically significant (p<0.05) increase of the CDDP activity was noticed, yielding IC50 values of 0.35+/-0.07 and 0.263+/-0.004 microM at silybin concentrations of 1 and 10 microM, respectively. The same trend was observed for in vivo experiments. IdB 1016 alone (1350 mg/kg) did not significantly affect tumour growth, whereas CDDP at the Maximum Tolerated Dose (12 mg/kg) produced a tumour weight inhibition (TWI%) of 80% and a log10 cell kill (LCK) of 0.7. Administration of both drugs resulted in a potentiation of the antitumour activity and TWI% and LCK increased to 90% and 1, respectively. Interestingly, mice receiving the combination recovered earlier in terms of body weight loss as compared to CDDP-treated mice. CDDP at 6 mg/kg yielded TWI of 44% and LCK of 0. The concomitant administration of IdB 1016 (1800 mg/kg) enhanced CDDP anti-tumour activity, with 68% TWI and 0.6 LCK. Finally, an antiangiogenic effect of IdB 1016 in an in vivo experimental model was demonstrated. Median haemoglobin value for the Matrigel from the vehicle-treated controls was 2.43 versus a value of 0.321 for the IdB 1016-treated animals.

Antitumour activity of the silybin-phosphatidylcholine complex, IdB 1016, against human ovarian cancer

This study aimed to assess, in an in vivo experimental model, the growth inhibitory effects of IdB 1016 (Silipide, a complex of silybin/phosphatidylcholine) when used as a single agent against human ovarian cancer. We also wanted to investigate the mechanism of the antiangiogenic action by assessing Vascular Endothelial Growth Factor (VEGF) levels and by using macroarray technology to evaluate the regulation of a panel of genes involved in angiogenesis. We also aimed to establish the plasma and tumour bioavailability of silybin after repeated administration of IdB 1016. Female nude mice bearing human ovarian cancer xenografts (A2780) received 450 mg/kg/day IdB 1016 daily by oral gavage until the end of the study. At sacrifice, blood and tumour specimens were collected and subsequently processed for the determination of silybin levels, VEGF levels or a gene expression profile. IdB 1016 was significantly active in inhibiting ovarian tumour growth. Treatment with 450 mg/kg/day for a total of 20 administrations produced a tumour weight inhibition (TWI%) of 78% and a Log10 Cell Kill (LCK) of 1.1. Free silybin levels were found to be 7.0+/-5.3 microg/ml and 183.5+/-85.9 ng/g tissue (mean+/-standard deviation (S.D.)) in the plasma and tumour samples, respectively. No significant differences were found in the concentration of human VEGF in xenografts from control and IdB 1016-treated mice. The array analysis suggested the downregulation of the VEGR receptor 3 and the upregulation of angiopoietin-2 as potential mechanisms for the antiangiogenic activity. In conclusion, these findings suggest IdB 1016 is a good candidate, with a relevant clinical potential, for use in the management of recurrent ovarian cancer. A phase II, non-randomised clinical study is now ongoing in our Institute aimed at evaluating the efficacy of daily administrations of IdB 1016 in the serological recurrence of ovarian cancer.

Topical anti-inflammatory activity of extracts and compounds from Hypericum perforatum L.

Three preparations of Hypericum perforatum L. (a hydroalcoholic extract, a lipophilic extract and an ethylacetic fraction) and the pure compounds hypericin, adhyperforin, amentoflavone, hyperoside, isoquercitrin, hyperforin dicyclohexylammonium (DHCA) salt and dicyclohexylamine were evaluated for their topical anti‐inflammatory activity. H. perforatum preparations provoked a dose‐dependent reduction of Croton‐oil‐induced ear oedema in mice, showing the following rank order of activity: lipophilic extract > ethylacetic fraction > hydroalcoholic extract (ID50 (dose that inhibited oedema by 50%) 220, 267 and >1000 μg cm−2, respectively). Amentoflavone (ID50 0.16μmol cm−2), hypericin (ID50 0.25μmol cm−2), hyperforin DHCA salt (ID50 0.25μmol cm−2) and adhyperofrin (ID50 0.30μmol cm−2) had anti‐inflammatory activity that was more potent or comparable to that of indometacin (ID50 0.26 μmol cm−2), whereas isoquercitrin and hyperoside were less active (ID50 about 1μmol cm−2). As dicyclohexylamine alone was inactive, the effect of hyperforin DHCA salt can be attributed completely to the phloroglucinol moiety. The pharmacological activity and phytochemical profile of the tested extracts and fraction suggest that different constituents are involved in the topical antiphlogistic property of H. perforatum in‐vivo.

Chemoprevention of DMBA-induced mammary cancer in rats by dietary soy

This study was designed to assess the potential chemopreventive effect of the administration of a standardized soy extract, SOYSELECTTM, on 7,12-Dimethylbenz[a]anthracene (DMBA)-induced mammary tumors in rats. Three groups, 24 females each, were used. Animals were fed either a phytoestrogen-free diet alone (control) or the same diet supplemented with 0.35% or 0.7% of soy extract. Treatment started at weaning and continued to the end of the study (24 weeks after DMBA administration). At day 50 of age all animals received via oral gavage 80 mg/kg DMBA. Only tumors subsequently classified as adenocarcinomas were considered for data evaluation. In rats on the soy diet, mammary tumors took a longer period of time to develop as compared to control rats. However, at the end of the study, no relevant difference in tumor incidence and multiplicity was observed among the groups. The most significant changes were seen between control and soy-treated groups when tumor dimension and results from histopathologic examination were considered. The latter, in fact, showed a dose-dependent reduction in the percentage of poorly differentiated tumors in treated animals. This change was statistically significant in animals receiving 0.7% soy. In addition, assessment of estrogen and progesterone receptor (ERα, PR) levels, revealed a significant reduction in the percentage of ERα and PR positive tumors in animals receiving 0.7% dietary soy, when compared to controls. Interestingly, genistein and daidzein plasma levels determined at the end of the study were within the range of those detected in people consuming large amounts of soyfoods.

Potential use of medicinal plants in the treatment of alcoholism

The present paper briefly reviews the most relevant experimental data on the reducing effect of some medicinal herbs on voluntary alcohol intake in animal models of alcoholism. Pueraria lobata, Tabernanthe iboga, Panax ginseng, Salvia miltiorrhiza and Hypericum perforatum proved to be effective in decreasing alcohol consumption. Reduction of alcohol absorption from the gastrointestinal system appears to be a common feature among most of the above plants. These data suggest that medicinal plants may constitute novel and effective pharmacotherapies for alcoholism.

Hypoglycemic effect of lupin seed γ-conglutin in experimental animals and healthy human subjects

A lupin seed γ-conglutin-enriched preparation was tested in a glucose overload trial with both murine models and adult healthy volunteers. The results with rats showed a dose-dependent significant decrease of blood glucose concentration, which confirmed previous findings obtained with the purified protein. Moreover, three test-product doses equivalent to 630, 315, and 157.5 mg γ-conglutin, orally administered 30 min before the carbohydrate supply, showed a relevant hypoglycemic effect in human trials. Insulin concentrations were not significantly affected. The general hematic parameters did not change at all. This is the first report on the glucose-lowering effect of lupin γ-conglutin in human subjects.