Silvia Di Giacomo

Curcumin and Resveratrol in the Management of Cognitive Disorders: What is the Clinical Evidence?

A growing body of in vitro and in vivo evidences shows a possible role of polyphenols in counteracting neurodegeneration: curcumin and resveratrol are attractive substances in this regard. In fact, epidemiological studies highlight a neuroprotective effect of turmeric (rhizome of Curcuma longa L.), the main source of curcumin. Moreover, the consumption of red wine, the main source of resveratrol, has been related to a lower risk of developing dementia. In this review, we analyzed the published clinical trials investigating curcumin and resveratrol in the prevention or treatment of cognitive disorders. The ongoing studies were also described, in order to give an overview of the current search on this topic. The results of published trials (five for curcumin, six for resveratrol) are disappointing and do not allow to draw conclusions about the therapeutic or neuroprotective potential of curcumin and resveratrol. These compounds, being capable of interfering with several processes implicated in the early stages of dementia, could be useful in preventing or in slowing down the pathology. To this aim, an early diagnosis using peripheral biomarkers becomes necessary. Furthermore, the potential preventive activity of curcumin and resveratrol should be evaluated in long-term exposure clinical trials, using preparations with high bioavailability and that are well standardized.

Genotoxicity assessment of some cosmetic and food additives

α-Hexylcinnamaldehyde (HCA) and p-tert-butyl-alpha-methylhydrocinnamic aldehyde (BMHCA) are synthetic aldehydes, characterized by a typical floral scent, which makes them suitable to be used as fragrances in personal care (perfumes, creams, shampoos, etc.) and household products, and as flavouring additives in food and pharmaceutical industry. The aldehydic structure suggests the need for a safety assessment for these compounds. Here, HCA and BMHCA were evaluated for their potential genotoxic risk, both at gene level (frameshift or base-substitution mutations) by the bacterial reverse mutation assay (Ames test), and at chromosomal level (clastogenicity and aneuploidy) by the micronucleus test. In order to evaluate a primary and repairable DNA damage, the comet assay has been also included. In spite of their potential hazardous chemical structure, a lack of mutagenicity was observed for both compounds in all bacterial strains tested, also in presence of the exogenous metabolic activator, showing that no genotoxic derivatives were produced by CYP450-mediated biotransformations. Neither genotoxicity at chromosomal level (i.e. clastogenicity or aneuploidy) nor single-strand breaks were observed. These findings will be useful in further assessing the safety of HCA and BMHCA as either flavour or fragrance chemicals.

1H NMR-based urinary metabolic profiling reveals changes in nicotinamide pathway intermediates due to postnatal stress model in rat

The maternal separation protocol in rodents is a widely recognized model of early life stress allowing acute and chronic physiological consequences to be studied. An (1)H NMR-based metabolomic approach was applied to urines to evaluate the systemic metabolic consequences of maternal separation stress in female rats after the beginning of weaning and 4 weeks later when the rats were reaching adulthood. Furthermore, because maternal separation is considered as a model mimicking the inflammatory bowel syndrome, the lactulose/mannitol test was used to evaluate the influence of postnatal maternal separation on gut permeability and mucosal barrier function by (1)H NMR spectroscopy analysis of urine. The results showed no statistical differences in gut permeability due to maternal separation. The application of ANOVA simultaneous component analysis allowed the contributions of physiological adaptations to the animals development to be separated from the metabolic consequences due to postnatal stress. Systemic metabolic differences in the maternally separated pups were mainly due to the tryptophan/NAD pathway intermediate levels and to the methyladenosine level. Urinary NMR-based metabolic profiling allowed us to disentangle the metabolic adaptive response of the rats to postnatal stress during the animals growth, highlighting the metabolic changes induced by weaning, gut closure, and maturity.

Mutagenicity of cigarette butt waste in the bacterial reverse mutation assay: The protective effects of β-caryophyllene and β-caryophyllene oxide

Cigarette filters pose a serious litter and toxic waste disposal problem, because of their not biodegradability and to the leaching of toxins in the environment. Therefore, cigarette butts need to be manipulated as special waste, with potential risks to human health and environment. In the present study, the genotoxic potential of a methanol extract from commonly discharged cigarette butts (CBE) was evaluated in the bacterial reverse mutation assay on Salmonella typhimurium TA98 and TA100 and Escherichia coli WP2uvrA strains, both in the absence and presence of the S9 exogenous metabolic activator. Furthermore, the ability of the natural sesquiterpenes β‐caryophyllene (CRY) and β‐caryophyllene oxide (CRYO) to inhibit the mutagenicity of CBE was studied as a possible preventive strategy. In order to identify the potential antimutagenic mechanisms, three different protocols (pretreatment, cotreatment, and posttreatment) were applied. CBE showed to increase the number of revertant colonies in all the strains tested in presence of S9, so resulting mutagenic. In the antimutagenicity assay, both CRY and CRYO significantly reduced the revertant colonies induced by CBE, although with different potency and specificity. For both sesquiterpenes, the antimutagenicity was strong in all experimental conditions, except for the cotreatment of CRY with CBE in WP2uvrA, which produced a moderate inhibition. Both desmutagenic and bioantimutagenic mechanisms seem to be involved in the antimutagenicity of the test substances. Taking into account the potential genotoxicity of cigarette butts, CRY and CRYO appear as possible further candidates as environmental decontaminants against this hazardous waste.

Antimutagenic Thio Compounds from Sisymbrium officinale

Glucoputranjivin (1) and isopropyl isothiocyanate (2) were isolated from an aqueous dry extract of Sisymbrium officinale and were identified by spectroscopic analysis. The antimutagenic activity of these compounds was evaluated in a bacterial reverse mutation assay using E. coli WP2, WP2uvrA, and WP2uvrA/pKM101 strains, in comparison with the extract. In the absence of the exogenous metabolic activation system S9, the thio compounds exerted antimutagenic activity against the direct-acting mutagen methyl methanesulfonate, in all strains. In the presence of S9, both thio compounds were active against the indirect mutagens 2-aminoanthracene, in WP2uvrA, and 2-aminofluorene, in WP2. The antimutagenicity seems to be due to specific mechanisms, such as the induction of the adaptive response or the excision repair system. Conversely, the inhibition of the CYP450-mediated activation of mutagens was not supported by the present results. An antimutagenic effect was also observed for the S. officinale aqueous extract against the arylamines 2AA and 2AF, but not against MMS. These results suggest that both thio compounds are involved in the antimutagenicity of S. officinale. The antimutagenicity of glucosinolate 1 is reported for the first time.

Chemoresistance and chemosensitization in cholangiocarcinoma

One of the main difficulties in the management of patients with advanced cholangiocarcinoma (CCA) is their poor response to available chemotherapy. This is the result of powerful mechanisms of chemoresistance (MOC) of quite diverse nature that usually act synergistically. The problem is often worsened by altered MOC gene expression in response to pharmacological treatment. Since CCA includes a heterogeneous group of cancers their genetic signature coding for MOC genes is also diverse; however, several shared traits have been defined. Some of these characteristics are shared with other types of liver cancer, namely hepatocellular carcinoma and hepatoblastoma. An important goal in modern oncologic pharmacology is to develop novel strategies to overcome CCA chemoresistance either by increasing drug specificity, such as in targeted therapies aimed to inhibit receptors with tyrosine kinase activity, or to increase the amounts of active agents inside CCA cells by enhancing drug uptake or reducing efflux through export pumps. This article is part of a Special Issue entitled: Cholangiocytes in Health and Diseaseedited by Jesus Banales, Marco Marzioni, Nicholas LaRusso and Peter Jansen.

Sisymbrium Officinale (L.) Scop. and its Polyphenolic Fractions Inhibit the Mutagenicity of Tert-Butylhydroperoxide in Escherichia Coli WP2uvrAR Strain.

One Sisymbrium officinale (L.) Scop. aqueous dry extract (SOE) and its polyphenolic fractions (Fb, Fc, Fd and Fe) were evaluated for their ability to inhibit the oxidative mutagenicity of tert‐butylhydroperoxide in the Ames test. The possible involvement of desmutagenic and/or bioantimutagenic mechanisms was evaluated by applying a three‐time based protocol (pre‐treatment, co‐treatment and post‐treatment). Furthermore, some protective antioxidant mechanisms were investigated. The total polyphenol and flavonol amount was also determined, and the fingerprint was outlined by high‐performance thin‐layer chromatography and densitometry. SOE, Fb and Fe exhibited strong antimutagenicity against tert‐butylhydroperoxide in all treatment protocols, this suggesting the involvement of both desmutagenic and bioantimutagenic mechanisms. These samples also showed antioxidant properties, including neutralization of the superoxide anion, lipid peroxidation inhibition and chelation and reduction of iron. Fb and Fe were rich in polyphenols and flavonols, so suggesting a possible role of these compounds in the antimutagenicity. Taking into account that oxidative stress is responsible for the damage of various environmental toxicants, particularly tobacco smoke, present results can support the traditional use of hedge mustard by smokers to restore the vocal cord function affected by the oxidative damage and suggest a possible application of SOE and its fractions as food supplements. Copyright

α-Hexylcinnamaldehyde inhibits the genotoxicity of environmental pollutants in the bacterial reverse mutation assay.

The antimutagenicity of α-hexylcinnamaldehyde (1), a semisynthetic and more stable derivative of cinnamaldehyde, was evaluated against common environmental pollutants in the bacterial reverse mutation assay. The pre-, co-, and post-treatment protocols were applied to assess the involvement of desmutagenic and/or bioantimutagenic mechanisms. Compound 1 (9-900 μM) produced a strong antimutagenicity (>40% inhibition) in the Salmonella typhimurium TA98 strain against the nitroarenes 2-nitrofluorene and 1-nitropyrene in almost all experimental conditions. A strong inhibition was also reached against the nitroarene 1,8-dinitropyrene and the arylamine 2-aminoanthracene in the cotreatment at the highest concentrations tested. In order to evaluate if an inhibition of bacterial nitroreductase (NR) and O-acetyltransferase (OAT) could be involved in the antimutagenicity of 1 against nitroarenes, the substance was further tested against 1-nitropyrene (activated by both NR and OAT) in TA98NR and TA98 1,8-DNP strains (lacking the NR and OAT enzymes, respectively). Although both desmutagenic and bioantimutagenic mechanisms appear mostly involved in the antimutagenicity of 1, based on data obtained in the TA98NR strain, applying the pretreatment protocol, compound 1 seems to act as an inhibitor of the OAT-mediated mutagen bioactivation. These results provide justification for further studies on 1 as a possible chemopreventive agent.

Chelidonium majus L. does not potentiate the hepatic effect of acetaminophen

AIM The present study assessed the ability of Chelidonium majus to potentiate the hepatic effect of a sub-toxic dose of acetaminophen, in rats. RESULTS C. majus, when administered alone, did not alter the liver function parameters in male, whereas an increase in fibrinogen level was found in female rats. Moreover, it did not affect the hepatic histomorphology in both male and female rats. The sub-toxic dose of acetaminophen induced: a significant increase in activated partial thromboplastin time in both genders, a focal hepatocellular necrosis with minor lymphocytes infiltrate and a slight but significant increase in total bilirubin, AST, and ALT in male rats, and in prothrombin time in female rats. The co-administration of C. majus did not increase the effects induced by acetaminophen, in both genders. CONCLUSIONS C. majus does not modify the hepatic effects of acetaminophen in our in vivo experimental model.

Antiviral and Antioxidant Activity of a Hydroalcoholic Extract from Humulus lupulus L.

A hydroalcoholic extract from female inflorescences of Humulus lupulus L. (HOP extract) was evaluated for its anti-influenza activity. The ability of the extract to interfere with different phases of viral replication was assessed, as well as its effect on the intracellular redox state, being unbalanced versus the oxidative state in infected cells. The radical scavenging power, inhibition of lipoperoxidation, and ferric reducing activity were assayed as antioxidant mechanisms. A phytochemical characterization of the extract was also performed. We found that HOP extract significantly inhibited replication of various viral strains, at different time from infection. Viral replication was partly inhibited when virus was incubated with extract before infection, suggesting a direct effect on the virions. Since HOP extract was able to restore the reducing conditions of infected cells, by increasing glutathione content, its antiviral activity might be also due to an interference with redox-sensitive pathways required for viral replication. Accordingly, the extract exerted radical scavenging and reducing effects and inhibited lipoperoxidation and the tBOOH-induced cytotoxicity. At phytochemical analysis, different phenolics were identified, which altogether might contribute to HOP antiviral effect. In conclusion, our results highlighted anti-influenza and antioxidant properties of HOP extract, which encourage further in vivo studies to evaluate its possible application.