Adriana Garozzo

Antioxidant enzymatic systems in neuronal and glial cell-enriched fractions of rat brain during aging.

The activities of Cu,Zn superoxide dismutase, glutathione peroxidase, catalase and glutathione reductase in neuronal and glial cell-enriched fractions obtained from the cerebral cortex of rat brain during aging (15, 30, 90, 350, 750 days of age) were assayed. Our results showed that glutathione peroxidase, catalase and glutathione reductase activities varied little during the examined periods. Only the Cu,Zn superoxide dismutase activity decreased notably from 15th to 750th day of age in both neuronal and glial cells, moreover the activities of all enzymes studied were always detected at lower levels in neuronal cells with respect to glial cells. In agreement with diminished SOD activity, the lipid peroxidation showed an elevated increase with aging; this fact is more evident in neuronal than in glial cells. In conclusion our data show that Cu,Zn superoxide dismutase is the most affected antioxidant enzymatic system of brain aging and it could be responsible for the increased lipid peroxidation in both cell types examined.

Human obesity relationship with Ad36 adenovirus and insulin resistance.

Objectives:Infection with specific pathogens may lead to increased adiposity: a specific adiposity-promoting effect of Ad36 human adenovirus, without the involvement of neurological mechanisms, was reported. The aim of this study is to investigate whether non-diabetic patients with earlier Ad36 infection show greater degrees of overweight obesity, of Insulin Resistance (IR), assessed by homoeostasis-model assessment (HOMA), and/or of other related factors. Moreover, the relationship, if any, among these factors and an earlier Ad36 infection, and the hypothesis of a mechanism involving IR are investigated.Subjects:Ad36 seropositivity is assessed in 68 obese and 135 non-obese subjects, along with body composition, HOMA and laboratory investigations.Results:Age, body mass index (BMI), waist–hip ratio, blood pressure, insulin, HOMA and triglycerides are significantly greater in the Ad36 seropositive group. Ad36 seropositivity, along with HOMA and total cholesterol, explains BMI variance. No Ad36 seropositivity effect to HOMA could be envisaged by the same statistical model.Conclusion:A significant association of Ad36 seropositivity with obesity and with essential hypertension in human beings is suggested by our study; this association is mostly significant in women. Our results do not support that any Ad36 adipogenic adenovirus effect is operating in human obesity through an insulin-resistance-related mechanism. Ad36 seropositive status could also be a hallmark of a clinical-metabolic profile possibly preceding obesity and diabetes in non-obese patients.

Ad36 adipogenic adenovirus in human non-alcoholic fatty liver disease

Aims: Infection with specific pathogens may lead to increased adiposity. The human adenovirus 36 (Ad36) is a relatively new factor in promoting adipogenesis. It seems to improve the metabolic profile, expanding adipose tissue and enhancing insulin sensitivity in animal models. The aim of this study was to investigate whether any association or predictor effect of Ad36 seropositivity is present in non‐alcoholic fatty liver disease (NAFLD), a condition associated with obesity and insulin resistance (IR).

In vitro antiviral activity of Melaleuca alternifolia essential oil

Aims:  To investigate the in vitro antiviral activity of Melaleuca alternifolia essential oil (TTO) and its main components, terpinen‐4‐ol, α‐terpinene, γ‐terpinene, p‐cymene, terpinolene and α‐terpineol.

Anti-rhinovirus activity of 3-methylthio-5-aryl-4-isothiazolecarbonitrile derivatives

A series of 3-methylthio-5-aryl-4-isothiazolecarbonitriles has been evaluated as anti rhinovirus agents against a panel of 17 representative human rhinovirus (HRV) serotypes, belonging to both A and B groups. No anti rhinovirus activity was detected for 3-methylthio-5-phenyl-4-isothiazolecarbonitrile (IS-2). Isothiazole derivatives with bulky substituents (O-Bn or O-But groups) on the para position of the phenyl ring were the most effective compounds of this series. In fact, a reduction in virus-induced cytopathogenicity was demonstrated for the O-Bn substituted IS-50 compound against the majority (88%) of the rhinoviruses tested, whereas the compound with an O-Ts group (IS-44) was found to be a specific inhibitor of group B serotypes, exhibiting the lowest IC(50) against HRVs type 2, 85 and 89. Our studies on the mechanism of action of IS-44 demonstrated that it prevents the thermal inactivation of HRV 2 infectivity, probably due to a conformational shift in the viral capsid and a decrease in affinity for the cellular receptor, resulting in an inhibition of attachment of the virions.

Synthesis of new 3-methylthio-5-aryl-4-isothiazolecarbonitriles with broad antiviral spectrum.

The isothiazole derivative 3-methylthio-5-(4-OBn-phenyl)-4-isothiazolecarbonitrile, coded IS-50, which in previous studies had exhibited a broad antipicornavirus spectrum of action, was selected as the model for the synthesis of a new series of 3-methylthio-5-aryl-4-isothiazolecarbonitriles. These compounds were prepared in good yield (from 66 to 82%) by alkylation of 3-methylthio-5-(4-hydroxyphenyl)-4-isothiazolecarbonitrile with suitable bromides in the presence of acetone; only the 4-cyanophenoxy derivatives were obtained in a yield of less than 30%. All the compounds were screened against a panel of 17 representative human rhinovirus (HRV) serotypes belonging to both A and B groups, enteroviruses polio 1, ECHO 9 and Coxsackie B1, cardiovirus EMC, measles virus, and herpes simplex virus type 1 (HSV-1). Our results demonstrate that HRV 86 (group A) and HRVs 39 and 89 (group B) are the rhinovirus serotypes more susceptible to the action of these compounds. Isothiazole derivatives with a longer intermediate alkyl chain exhibited good activity against polio 1 and ECHO 9. The compound bearing a butyl group between the two phenoxy rings showed the lowest IC(50) against Coxsackie B1 and measles viruses. No activity against HSV-1 was detected with any of the compounds screened.

Synthesis of new 3,4,5-trisubstituted isothiazoles as effective inhibitory agents of enteroviruses.

The synthesis and evaluation of 3,4,5-trisubstituted isothiazoles as antiviral agents led to the discovery of several compounds effective in vitro against enteroviruses polio 1 and ECHO 9. Structure-activity relationship studies revealed that a short thioalkyl chain in the 3-position and a methyl ester group in the 4-position are the structural components that, to a large extent, contribute to the positive biological profile in terms of both selectivity and low cytotoxicity. Under one-step growth conditions, methyl 3-methylthio-5-phenyl-4-isothiazolecarboxilate caused the greatest activity if added within 1 h after poliovirus adsorption. These data suggest interference with early events of viral replication.

Synthesis and antiviral activity of a new series of 4-isothiazolecarbonitriles

A series of 4-isothiazolecarbonitriles was synthesized and screened for in vitro antiviral activity. The effect of various substituents on the phenyl ring, as well as the substitution of the phenyl for other aromatic and heteroaromatic rings, was examined to establish the requirements for optimum activity. The most active member of the series, 3methylthio-5-phenyl-4-isothiazolecarbonitrile, exhibited a high level of activity against enteroviruses polio 1 and ECHO 9. Preliminary studies on its mechanism of action indicated that this compound had an effect on an early event in the replication of poliovirus type 1.

Obesity-independent association of human adenovirus Ad37 seropositivity with nonalcoholic fatty liver disease.

Objective: Adenoviruses Ad36 and Ad37 increase adiposity in animals and are associated with obesity in humans; effects on the liver have been reported. The association of Adenovirus Ad36 seropositivity (Ad36+) with obesity but not with the severity of nonalcoholic fatty liver disease (NAFLD) has been previously shown. We investigate whether nondiabetic Ad37+ patients show a different prevalence of NAFLD and ultrasound Bright Liver score. Patients: A total of 268 adult nondiabetic patients (146 men, 122 women) were included after lifestyle counseling including a personalized Mediterranean diet, increase in physical activity, and smoking withdrawal. After an Ad37+/Ad36+ assay, overweight obesity, insulin resistance, C-reactive protein, and bright liver prevalence and severity were compared according to Ad37+. Results: Sixty-five of 268 patients were Ad37+ and 82/268 patients were both Ad37 seronegative (Ad37−) and Ad36−. The prevalence of obesity, defined as body mass index≥30, was not significantly different in Ad37+ (11/65; 16.9%) vs. Ad37− (15/82; 18.2%) patients; Bright Liver was present in 22/65 (33.8%) Ad37+ patients vs. 13/82 (15.8%) Ad37− patients (P<0.019). By odds ratio (OR), a consistent risk for NAFLD was associated with Ad37+, greater insulin resistance, and C-reactive protein. By a predictive multiple linear regression model, 40.0% of variance toward NAFLD and 50.4% toward the severity of Bright Liver score was explained significantly and independently by Ad37+ and by body mass index. Conclusions: Ad37+ status in nondiabetic patients on an appropriate diet is significantly associated with NAFLD; because fatty liver improves even without weight loss by a “healthy” diet, and not only by lower food caloric intake, Ad37+ may be an adjunctive hallmark of an unfavorable clinical-metabolic profile, if not a causative factor of NAFLD.

Effects on adhesiveness and hydrophobicity of sub-inhibitory concentrations of netilmicin

The effect of sub-inhibitory concentrations (SICs) of netilmicin on bacterial hydrophobicity and adhesiveness to conjunctival cells was investigated. One strain each of Pseudomonas aeruginosa, Pseudomonas spp., Staphylococcus aureus and S. epidermidis was investigated for its susceptibility to netilmicin, its adherence to conjunctival cells and to the effect of hydrocarbon hexadecane before and after treatment with SIC of netilmicin. All of the bacteria tested were susceptible to netilmicin except for Pseudomonas spp. which showed intermediate resistance. Netilmicin-treated Pseudomonas strains exhibited a lower level of hydrophobicity towards n-hexadecane compared with non-treated strains, while netilmicin-treated S. epidermidis and S. aureus showed a slight increase of hydrophobicity. Adherence of the two Pseudomonas strains to conjunctival cells was significantly reduced after growth in the presence of netilmicin, while the adherence of the two staphylococci was only slightly reduced.