Determination and structural characterization of ravidasvir metabolites by LC coupled to triple quadrupole linear ion trap MS: Application to pharmacokinetics and phase I metabolism in rats.

Hepatitis C virus (HCV) is an infectious disease that has become a global clinical issue because of its significant morbidity and mortality. Novel anti-hepatitis C drugs are continuously developed to decrease the pervasiveness of the infection globally. A synthetic ravidasvir, benzimidazole-naphthylene-imidazole derivatives, has been used as an anti-HCV drug. This study determined the metabolites of ravidasvir and its pharmacokinetics in rats using information-dependent acquisition and multiple reaction monitoring scanning modes in linear ion trap LC-MS/MS instrument, respectively. Two time-programming linear-gradient chromatographic methods were employed using a Kinetex C18 column (50 × 3 mm, 2.6 µm) and a Luna HILIC column (100 × 4.6 mm, 3 µm) for the qualitative and quantitative determination of ravidasvir and its metabolites, respectively. In silico prediction where sites in a molecule are susceptible to metabolism by cytochrome P450 was implemented, which helped in proposing the metabolic pathway of ravidasvir. The most dominant metabolite in rat liver microsomal samples was oxidative ravidasvir, where one O-demethylated metabolite and eight isomers of the oxidative ravidasvir metabolites were identified. The study provides essential data for proposing the metabolic pathway and successfully applied it to determine the pharmacokinetics of ravidasvir in rat plasma.

Investigation of the Immunomodulatory effect of Berberis vulgaris on core-pulsed dendritic cell vaccine.

BACKGROUND: Virus-induced dendritic cells (DCs) functional deficiency leads to sub-optimal initiation of adaptive immune responses and consequently chronic infection establishment. The present study reports an advanced hepatitis C virus (HCV) therapeutic vaccine model based on In vivo enrichment of DCs with barberry ethanolic crude extract (BCE) then pulsing them with HCV core protein. METHODS: DCs were enriched by BCE intravenous injection in BALB/c mice. Vaccine efficiency was assessed by flow cytometric analysis of splenocytes of immunized mice, cytokine profiling, cytotoxic T lymphocyte assay, and humoral immune response assessment. RESULTS: There was no significant difference in surface phenotypic characterization of splenocytes from mice immunized with non-BCE-enriched-core-pulsed DCs (iDcs-core) compared to those from mice injected with RPMI-1640 medium. However, splenocytes from mice immunized with BCE-enriched-core-pulsed DCs showed 197 % increase in CD16+ population, 33 % increase in MHCII(+) population, and 43 % decrease in CD3(+) population. In iDCs-core group, 57.9 % greater anti-core cytotoxic T lymphocyte activity, up-regulation in interferon gamma and interleukin (IL) -12 expression, and down-regulation in IL-4 and IL-10 were recorded. Moreover, sustained specific anti-core antibodies were detected only in sera of the same group. CONCLUSIONS: results indicate that BCE-enriched-core-transduced DCs may serve as a new model for immunotherapy of HCV chronic infection.

In vitro biological assessment of Berberis vulgaris and its active constituent, berberine: antioxidants, anti-acetylcholinesterase, anti-diabetic and anticancer effects.

BACKGROUND: Berberis vulgaris is a well known plant with traditional herbal medical history. The aims of this study was to bioscreen and compare the in vitro biological activity (antioxidant, cholinergic, antidaibetic and the anticancer) of barberry crude extract and berberine active compound. METHODS: The effect of B. vulgaris extract and berberine chloride on cellular thiobarbituric acid reactive species (TBARS) formation, diphenyle-α-picrylhydrazyl (DPPH) oxidation, cellular nitric oxide (NO) radical scavenging capability, superoxide dismutase (SOD), glutathione peroxidase (GPx), acetylcholinesterase (AChE) and α-gulcosidase activities were spectrophotometrically determined. On the other hand, the effect of extract and berberine as anticancer was estimated on three different cell lines which were MCF-7, HepG-2, and Caco-2 cells by using neutral red uptake assay which compared with control normal cells (PBMC). RESULTS: Our results showed that barberry crude extract contains 0.6 mg berberine/mg crude extract. Barberry extract showed potent antioxidative capacity through decreasing TBARS, NO and the oxidation of DPPH that associated with GPx and SOD hyperactivation. Inhibitory effect of berberis crude extract on α-glucosidase was more potent than that of berberine chloride, while both had the same AChE inhibitory effect. Besides, different concentrations of both berberine chloride and barberry ethanolic extract showed to have no growth inhibitory effect on normal blood cells (PBMC). Otherwise, both berberine chloride and barberry ethanolic extract showed to have inhibitory effect on the growth of breast, liver and colon cancer cell lines (MCF7, HepG2 and CACO-2, respectively) at different incubation times starting from 24 hrs up to 72 hrs and the inhibitory effect increased with time in a dose dependent manner. CONCLUSION: This work demonstrates the potential of the barberry crude extract and its active alkaloid, berberine, on suppressing lipid peroxidation, suggesting a promising use in the treatment of hepatic oxidative stress, Alzheimer and idiopathic male factor infertility. Beside, berberis vulgaris ethanolic extract is safe non-toxic extract as it was not inhibit the growth of PBMC that can induce cancer cell death that could return to its powerful antioxidant activity.

Preparation, physicochemical characterization, and bioactivity evaluation of berberine-entrapped albumin nanoparticles.

Berberine (BBR) is an isoquinoline alkaloid with several clinical therapeutic applications. Its low water solubility, absorption, and cellular bioavailability diminish BBR's therapeutic efficacy. In this study, BBR was encapsulated into bovine serum albumin nanoparticles (BSA NPs) core to reduce BBR limitations and enhance its clinical therapeutic properties. Several physicochemical characterization tools, such as Dynamic Light Scattering and Ultraviolet-Visible spectroscopic measurements, field emission transmission electron microscopy surface morphology, Fourier transforms infrared spectroscopy, thermal stability analysis, and releasing studies, were used to evaluate the BBR-BSA NPs. Compared to BBR, BBR-BSA nanoparticles demonstrated superior free radical scavenging and antioxidant capacities, anti-hemolytic and anticoagulant efficacies, and antimicrobial activities, as demonstrated by the findings of the in vitro studies. Furthermore, a stressed pancreatic rat model was induced using a high-fat, high-sucrose diet plus carbon tetrachloride injection. The in vivo results revealed that BBR-BSA NPs substantially restored peripheral glucose metabolism and insulin sensitivity. Oral administration of BBR-BSA NPs also improved pancreatic ß-cells homeostasis, upregulated pancreatic antioxidant mechanisms, inhibited oxidants generation, and attenuated oxidative injury in the stressed pancreatic tissues. In conclusion, our in vitro and in vivo results confirmed that BBR-BSA NPs demonstrated more potent antioxidant properties and restored pancreatic homeostasis compared to BBR.

Characterization, in-silico, and in-vitro study of a new steroid derivative from Ophiocoma dentata as a potential treatment for COVID-19.

The medicinal potential of marine invertebrates' bioactive components that may act as anti-COVID-19 demonstrated promising results. Ophiocoma dentata, which is common in the Red Sea, is one such source. Therefore, this study aimed to isolate a new compound from the brittle star, Ophiocoma dentata, and evaluate its efficacy as anti-COVID-19 in-silico and in-vitro. Standard procedures were followed in order to assess the isolated compound's preliminary toxicity and anti-inflammatory properties. Computer virtual screening technology through molecular docking and ADMET studies was conducted as well as a new steroid derivative was isolated for the first time, named 5α-cholesta-4(27), 24-dien-3ß, 23 ß-diol. Investigation of the Anti-Covid-19 activity of the isolated compound using a Plaque reduction assay revealed 95% inhibition at a concentration of 5 ng/µl (12.48 µM). Moreover, this compound showed an IC50 of 11,350 ± 1500 ng/ml against the normal fibroblast cells, indicating its safety. Interestingly, this compound exhibited anti-inflammatory activity with an IC50 of 51.92 ± 0.03 µg/ml compared to a reference drug's IC50 of 53.64 ± 0.01 µg/ml, indicating that this compound is a potent anti-inflammatory. In silico data have proved that the isolated compound is a promising viral inhibitor against SARS-CoV2 and is thus recommended as a future nature preventive and curative antiviral drug.

Phytochemical and pharmacological appraisal of the aerial parts of Lotus corniculatus L. growing in Egypt.

Lotus corniculatus L. (Fabaceae) is widely grown in Egypt. It has a great history of folkloric medicinal uses. All fractions of aerial parts of L. corniculatus L. showed significant antioxidant and immunostimulant activities and could strongly induce lymphoproliferation. However, the light petrol fraction had antifungal activity against C. neoformans with IC50 value (<8 µg/mL) and exhibited strongest in-vitro antiprotozoal activity against protozoan parasites belonging to the genera Trypanosoma with IC50 value (0.98 µg/mL) and Plasmodium (with 100% inhibition using a sample concentration of 15866.7 ng/mL). This is the first study of the immunostimulant and antiprotozoal activities of genus Lotus. By this approach, it was possible to isolate eight compounds (-)-7,2'-dihydroxy-4'-methoxyisoflavan (vestitol) (1), kaempferol (2), kaempferol 3-O-α-L-rhamnoside (afzelin) (3), kaempferol 3, 7-O-α-L-dirhamnoside (kaempferitin) (4), kaempferol-3-O-[ß-D-xylopyranosyl (1″'→2″)-ß-D-galactopyranoside] (5), 3-O-[ß-D-glucuronopyranosyl] soyasapogenol B (6), kaempferol-3-O-[ß-D-xylopyranosyl (1″'→2″)-ß-D-galactopyranoside]-7-O-α-L-rhamnopyranoside (7) and 3-O-[α-L-rhamnopyranosyl (1″'→2″)-ß-D-galactopyranosyl-(1″→2')-ß-D-glucuronopyranosyl] soyasapogenol B (soyasaponin І) (8).

Potential therapeutic and pharmacological strategies for SARS-CoV2.

BACKGROUND: At the end of 2019, the new Coronavirus disease 2019 (COVID-19) strain causing severe acute respiratory syndrome swept the world. From November 2019 till February 2021, this virus infected nearly 104 million, with more than two million deaths and about 25 million active cases. This has prompted scientists to discover effective drugs to combat this pandemic. AREA COVERED: Drug repurposing is the magic bullet for treating severe acute respiratory syndrome coronavirus 2 (SARS-CoV2). Therefore, several drugs have been investigated in silico, in vitro, as well as through human trials such as anti-SARS-CoV2 agents, or to prevent the complications resulting from the virus. In this review, the mechanisms of action of different therapeutic strategies are summarized. According to the WHO, different classes of drugs can be used, including anti-malarial, antiviral, anti-inflammatory, and anti-coagulant drugs, as well as angiotensin-converting enzyme inhibitors, antibiotics, vitamins, zinc, neutralizing antibodies, and convalescent plasma therapy. Recently, there are some vaccines which are approved against SARS-CoV2. EXPERT OPINION: A complete understanding of the structure and function of all viral proteins that play a fundamental role in viral infection, which contribute to the therapeutic intervention and the development of vaccine in order to reduce the mortality rate. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40005-021-00520-4.

Prolonged overnutrition with fructose or fat induces metabolic derangements in rats by disrupting the crosstalk between the hypothalamus and periphery: Possible amelioration with fenofibrate.

Metabolic Syndrome (MetS) increases the risk of developing type 2 diabetes mellitus and cardiovascular complications. The crosstalk between the hypothalamus and periphery is vital for regulating food intake and energy homeostasis. However, it is impaired during MetS. The present study aimed to compare the distinct central and peripheral metabolic derangements induced by a high-fructose drink or high-fat diet, as well as the possible intervention by fenofibrate. Rats were divided into five groups: standard chow diet (SCD) group, high-fructose group (FR), high-fat group (HF), FR plus fenofibrate group (FR-F), and HF plus fenofibrate group (HF-F). FR and HF groups showed hyperglycemia, hyperinsulinemia, hypertriglyceridemia, hyperleptinemia, steatosis, and adipocyte hypertrophy. This was associated with elevated circulating levels of proinflammatory cytokines and free fatty acids (FFAs). The latter mediators are involved in the hypothalamic inflammation and dysregulation of signaling cascades that control food intake and glucose homeostasis. The effects were more pronounced in the HF group than FR group, which were matched with the observed higher levels of plasma FFAs and cytokines. Fenofibrate administration improved not only the peripheral metabolic disturbances, but also the central disturbances associated with insulin resistance induced by FR or HF diet. This study sheds light on the pivotal role of the hypothalamus in diet-induced MetS. Furthermore, the study suggests the utmost importance of developing a standardized model of metabolic syndrome in place of the great diversity between available models, which can induce different effects and negatively impact the validity of prospective studies.

Ipriflavone and Ipriflavone loaded albumin nanoparticles reverse lipopolysaccharide induced neuroinflammation in rats.

BACKGROUND: Neuroinflammation causes neurodegenerative conditions like Alzheimer's disease (AD). Ipriflavone (IP), therapeutic compound to postmenopausal osteoporosis, has limited estrogenic activity and is accounted as AChE inhibitor. The developing of drug delivery systems to enable drug targeting to specific sites increases the drug therapeutic effect. OBJECTIVE: The aim of the present study was to formulate and evaluate ipriflavone loaded albumin nanoparticles (IP-Np) along with free ipriflavone against lipopolysaccharide (LPS) induced neuroinflammation in rats. METHODS: Neuroinflammation was induced by intra-peritoneal (i.p) injection of LPS (250 µg/kg rat body weight) then treatments were conducted with (1) ipriflavone at two doses 50 mg/kg and 5 mg/kg, (2) IP-Np (5 mg ipriflavone/kg) or (3) IP-Np coated with polysorbate 80 (IP-Np-T80) (5 mg ipriflavone/kg). The alteration of the inflammatory response in male adult Wistar rats' brain hippocampus was investigated by examining associated indices using biochemical and molecular analyses. RESULTS: A significant upsurge in inflammatory mediators and decline in antioxidant status were observed in LPS-induced rats. In one hand, ipriflavone (50 mg/kg), IP-Np and IP-Np-T80 ameliorated LPS induced brain hippocampal inflammation where they depreciated the level of pro-inflammatory cytokines (TNF-α, IL-6, IL-1ß) and enhanced antioxidant status. In another hand, ipriflavone at dose (5 mg/kg) didn't show the same therapeutic effect. CONCLUSION: The current study provides evidence for the potential neuroprotective effect of ipriflavone (50 mg/kg) against LPS-induced neuroinflammation in rats through its anti-inflammatory and antioxidant activities. Moreover, nanoparticles significantly attenuated neuroinflammation in concentration lower than the effective therapeutic dose of free drug ten times.

Antibacterial activity of Centaurea pumilio L. root and aerial part extracts against some multidrug resistant bacteria.

BACKGROUND: In the context of searching for potent, safe, natural antimicrobial agents to combate the global antimicrobial resistance (AMR) phenomenon, the current study evaluates for the first time ever, the broad-spectrum antimicrobial activity of essential oil (EO) and extracts from the rare wild plant Centaurea pumilio L.. It has tremendous ethnomedicinal values; its dried root is used as a fattening agent, a treatment for bad breath and diabetes, and screened for schistosomicidal activity. METHODS: C. pumilio EO was extracted by hydrodistillation using a Clevenger apparatus. Chemical constituents of aerial part were extracted using a sequential solvent/solvent procedure employing four solvents with increasing polarities in the following order: petroleum ether, chloroform, ethyl acetate, and n-butanol. The chemical constituents were identified by GC-MS. Fifty-two microbial strains were used; twenty-six multidrug resistant (MDR), sixteen clinical, and ten reference strains. The identification of the microbial strains was performed by MALDI-TOF-MS. The antimicrobial activity of the EO and the aerial part and the root extracts was assessed through disc diffusion assay. A minimum inhibitory concentration (MIC) of the EO and extracts was determined using the broth micro-dilution method. RESULTS: The growth of reference and clinical strains was inhibited by EO, methanol, chloroform, and ethyl acetate aerial part extracts and chloroform root extract. The MDR strains growth, however, was inhibited only by EO and chloroform aerial part extract. GC-MS identified for the first time eighteen constituents from aerial part EO and chloroform extract each. EO showed antimicrobial activity against the reference, clinical, and MDR strains with MIC values of 31.25-125, 31.25-125, and 62.50-250 µg/mL, respectively. Methanol aerial part extract exhibited high antimicrobial activities with MIC values of 62.50-250 µg/mL against reference and clinical strains. Chloroform root extract displayed strong antimicrobial activity against reference and clinical strains recording MIC values of 62.50-250 µg/mL and 62.50-125 µg/mL, respectively. The chloroform aerial part extract demonstrated potent antimicrobial activity against the reference, clinical, and MDR strains with 31.25, 31.25, and 15.62 µg/mL MIC values, respectively. CONCLUSIONS: Present data unravel the C. pumilio pharmacological magnitude to discover eco-friendly potent antimicrobial agents to fight AMR phenomenon.

New pyrimidines and triazolopyrimidines as antiproliferative and antioxidants with cyclooxygenase-1/2 inhibitory potential.

Aim: Cyclooxygenase-2 (COX-2) inhibition and scavenging-free radicals are important targets in cancer treatment. Materials & methods: Sulfanylpyrimidines and triazolopyrimidines were synthesized and evaluated as anticancer and antioxidant COX-1/2 inhibitors. Results: Compound 7 showed the same growth inhibitory activity as 5-fluorouracil against MCF-7. Compound 6f displayed broad-spectrum anticancer activity against the four tested cancer cell lines. Compounds 5b, 6a, 6c, 6d and 8 were found to be more active antioxidants than trolox. Compounds 6a, 6c, 6f and 8 revealed high COX-2 inhibitory activity and selectivity, which was confirmed by docking studies. Conclusion: Compound 6f could be considered as promising anticancer and antioxidant structural lead with COX-2 inhibition that deserve further derivatization and investigation.

Dual inhibitors of hepatitis C virus and hepatocellular carcinoma: design, synthesis and docking studies.

AIM: Simultaneous inhibition of hepatitis C virus (HCV) and hepatocellular carcinoma (HCC) may enhance anti-HCV effects and reduce resistance and side effects. RESULTS/METHODOLOGY: Novel hybrid derivatives were designed and synthesized to exhibit dual activity against HCV and its associated major complication, HCC. The synthesized compounds were screened for their potential activity against HCV and HCC. Compounds 5f, 5j, 5l, 5p, 5q, 5r, 6c and 6d exhibited potential in vitro anticancer activity against HCC cell line HepG2, while compounds 5a, 5l, 5p and 5v showed in vitro anti-HCV activity. Docking studies suggested that the newly synthesized compounds could suppress HCC through VEGFR2 tyrosine kinase inhibition. CONCLUSION: Compounds 5l and 5p exhibited dual activity against HCV and HCC in vitro.

Flavonoids of Alcea rosea L. and their immune stimulant, antioxidant and cytotoxic activities on hepatocellular carcinoma HepG-2 cell line.

Alcea rosea L. is widely cultivated in gardens of Egypt as an ornamental plant and it has a great history of folkloric medicinal uses. In the present work, phytochemical investigation of the alcoholic extract of the flowers of A. rosea L. led to the isolation of six flavonoids (1-6). Dihydrokaempferol-4'-O-ß-d-glucopyranoside (1), dihydrokaempferol (2), kaempferol-3-O-[6″-(E-coumaroyl)]-ß-d-glucopyranoside (3), kaempferol-3-O-ß-d-glucopyranoside (4), Apigenin (5) and kaempferol-3-O-α-l-rhamnopyranosyl-(1'″→6″)-ß-d-glucopyranoside (6). Four of the isolated compounds were evaluated for their antioxidant, immunostimulant and cytotoxic activities against HepG-2 cell line. Compound (3) showed potent cytotoxic activity against HepG-2 cell line with high selectivity towards hepatocellular carcinoma in vitro (with IC50 = 3.8 µg/mL). Compounds 1 and 2 exhibited significant antioxidant activity and compound 4 showed a significant immune stimulant activity. Compound 1 is isolated for the first time from genus Alcea and this is the first report for its biological investigation.

Neuroprotective effect of ipriflavone against scopolamine-induced memory impairment in rats.

BACKGROUND: Alzheimer's disease is an age-related neurodegenerative disorder characterized clinically by a progressive loss of memory and cognitive functions resulting in severe dementia. Ipriflavone (IPRI) is a non-hormonal, semi-synthetic isoflavone, clinically used in some countries for the treatment and prevention of postmenopausal osteoporosis. Moreover, ipriflavone is a non-peptidomimetic small molecule AChE inhibitor with an improved bioavailability after systemic administration, due to its efficient blood-brain barrier permeability in comparison with peptidomimetic inhibitors. OBJECTIVE: The present study aimed to evaluate the possible enhancing effects of IPRI on memory impairments caused by scopolamine administration. METHODS: Male rats were administered IPRI (50 mg/kg, oral) 2 h before scopolamine injection (2 mg/kg, intraperitoneally injected) daily for 4 weeks. Effects of IPRI on acetylcholinesterase activity, amyloid-ß precursor processing, and neuroplasticity in the rats' hippocampus were investigated. RESULTS: Daily administration of IPRI reverted memory impairment caused by scopolamine as measured by the reduction of the escape latency. IPRI significantly alleviated the oxidative stress and restored the mRNA expression of both cAMP-response element-binding protein and brain-derived neurotrophic factor in the hippocampus. Furthermore, it significantly increased the expression of ADAM10 and ADAM17 (two putative α-secretase enzymes) and phosphorylated extracellular signal-regulated kinase 1/2 (pERK1/2) that associated with decreased expression of ß-secretase (BACE) in the hippocampus. Finally, both the amyloid-ß (Aß) and Tau pathologies were reduced. CONCLUSIONS: IPRI showed promising neuroprotective effects against scopolamine-induced memory dysfunction in rats. These findings contributed to the stimulation of α-secretase enzymes, the activation of MAPK/ERK1/2, and the alleviation of oxidative stress.

Berberine Reduces Neurotoxicity Related to Nonalcoholic Steatohepatitis in Rats.

Berberine is a plant alkaloid that has several pharmacological effects such as antioxidant, antilipidemic, and anti-inflammatory effects. Nonalcoholic steatohepatitis (NASH) triggers different aspects of disorders such as impaired endogenous lipid metabolism, hypercholesterolemia, oxidative stress, and neurotoxicity. In this study, we examined the mechanism by which NASH induces neurotoxicity and the protective effect of berberine against both NASH and its associated neurotoxicity. NASH induced rats showed significant impairments in lipid metabolism with increased serum triglycerides, cholesterol, and low-density lipoprotein (LDL). The NASH induced group also demonstrated a significant oxidative stress which is characterized by increased TBARs level and decreased antioxidant capacity such as GSH and SOD levels. Moreover, the NASH induction was associated with inflammation which was demonstrated by increased TNFα and nitric oxide levels. Hyperglycemia and hyperinsulinemia were observed in the NASH induced group. Also, our results showed a significant increase in the expression of the acetylcholine esterase (AChE) and amyloid beta precursor protein (AßPP). These changes were significantly correlated with decreased insulin degrading enzyme (IDE) and beta-amyloid40 (Aß 40) and increased beta-amyloid42 (Aß 42) in the hippocampal region. Daily administration of berberine (50 mg/kg) for three weeks ameliorated oxidative stress, inflammation, hyperlipidemia, hyperglycemia, hyperinsulinemia, and the observed neurotoxicity.

Synthetic peptide-based immunoassay as a supplemental test for HCV infection.

INTRODUCTION: Hepatitis C virus (HCV) is a single strand RNA hepatotrophic virus infecting 170 millions around the world and 20% of Egyptian blood donors. Although there has been significant improvement in the enzyme immunoassays (EIAs) in population screening of HCV infection, the development of a low variability, easy to automate and inexpensive supplemental test to support the current immunoassays was of a major concern to several laboratories. OBJECTIVES: In the current study, we embarked on a systematic study to analyze by DNA sequencing several HCV isolates to identify conserved core protein sequences and perform explorative analysis of five synthetic peptides from the core/E1 region in anti-HCV antibody assays. METHODS: We designed four synthetic-core specific peptides and an E1-specific peptide. These peptides were used to screen HCV antibodies in sera of 100 HCV positive patients and 100 HCV negative subjects and compared the results with those obtained by the commercial systems based on second and third generation enzyme-linked immunosorbent assays. RESULTS: Our results showed that all peptides detect HCV antibodies in infected sera to varying degrees. The synthetic peptide (a.a. 21-40) of the core protein had 99% sensitivity, 100% specificity and was highly reproducible. CONCLUSION: The above findings make this core peptide a candidate product for developing a supplemental test for chronic HCV infection in the Egyptian population.

Polysubstituted pyrazoles, part 5. Synthesis of new 1-(4-chlorophenyl)-4-hydroxy-1H-pyrazole-3-carboxylic acid hydrazide analogs and some derived ring systems. A novel class of potential antitumor and anti-HCV agents.

A novel series of 1-(4-chlorophenyl)-4-hydroxy-1H-pyrazole-3-carboxylic acid hydrazide analogs and some derived 4-substituted-1,2,4-triazolin-3-thiones, 2-substituted-1,3,4-thiadiazole and 2-substituted-1,3,4-oxadiazoles has been synthesized. Ten of the newly synthesized compounds were selected by the National Cancer Institute (NCI)-in vitro-disease oriented antitumor screening to be evaluated for their antitumor activity. Seven compounds, namely 7a-c, 9, 11, 13 and 14, exhibited potential and broad spectrum antitumor activity against most of the tested subpanel tumour cell lines (GI50<100 microM). Compounds 14 (GI50, TGI, and LC50 MG-MID values of 0.08, 15.8 and 64.6 microM, respectively) and 11 (GI50, TGI, and LC50 MG-MID values of 0.20, 11.7 and 87.1 microM, respectively) proved to be the most active members in this study with potential activity against all the tested subpanel tumour cell lines and particular effectiveness on the leukaemia subpanel at both the GI50 (0.03 and 0.09 microM, respectively) and the TGI levels (35.2 and 28.1 microM, respectively). Moreover, compound 14 exhibited a super sensitivity profile towards about 26 different cancer cell lines with GI50 values lying in the nanomolar concentration range (GI50 values<0.01 microM). In addition, compounds 2-5, 6a-d, 7a, 8-11, 12a, 13, 14 were investigated for their in vitro effect on the replication of hepatitis-C virus (HCV) in HepG2 hepatocellular carcinoma cell line infected with the virus using the reverse transcription-polymerase chain reaction (RT-PCR) technique. The results revealed that compounds 2 and 5 were capable of inhibiting the replication of both the HCV RNA (+) and (-) strands at 10-100 microg mL(-1) concentration range.

PI3K/Akt-independent NOS/HO activation accounts for the facilitatory effect of nicotine on acetylcholine renal vasodilations: modulation by ovarian hormones.

We investigated the effect of chronic nicotine on cholinergically-mediated renal vasodilations in female rats and its modulation by the nitric oxide synthase (NOS)/heme oxygenase (HO) pathways. Dose-vasodilatory response curves of acetylcholine (0.01-2.43 nmol) were established in isolated phenylephrine-preconstricted perfused kidneys obtained from rats treated with or without nicotine (0.5-4.0 mg/kg/day, 2 weeks). Acetylcholine vasodilations were potentiated by low nicotine doses (0.5 and 1 mg/kg/day) in contrast to no effect for higher doses (2 and 4 mg/kg/day). The facilitatory effect of nicotine was acetylcholine specific because it was not observed with other vasodilators such as 5'-N-ethylcarboxamidoadenosine (NECA, adenosine receptor agonist) or papaverine. Increases in NOS and HO-1 activities appear to mediate the nicotine-evoked enhancement of acetylcholine vasodilation because the latter was compromised after pharmacologic inhibition of NOS (L-NAME) or HO-1 (zinc protoporphyrin, ZnPP). The renal protein expression of phosphorylated Akt was not affected by nicotine. We also show that the presence of the two ovarian hormones is necessary for the nicotine augmentation of acetylcholine vasodilations to manifest because nicotine facilitation was lost in kidneys of ovariectomized (OVX) and restored after combined, but not individual, supplementation with medroxyprogesterone acetate (MPA) and estrogen (E2). Together, the data suggests that chronic nicotine potentiates acetylcholine renal vasodilation in female rats via, at least partly, Akt-independent HO-1 upregulation. The facilitatory effect of nicotine is dose dependent and requires the presence of the two ovarian hormones.

Cyanoacetic acid hydrazones of 3-(and 4-)acetylpyridine and some derived ring systems as potential antitumor and anti-HCV agents.

Two new acetylpyridinehydrazones derived from cyanoacetic acid hydrazide have been synthesized namely: cyanoacetic acid (1-pyridin-3 or 4-yl-ethylidene) hydrazides (1a,b). and some derived ring systems: 2-imino or 2-oxo-2H-chromenes (2a,b and 3a,b), substituted 2-thioxo-2,3-dihydrothiazoles (4a-d), substituted 2-thioxo-2,3-dihydro-6H-thiazolo[4,5-d]pyrimidin-7-ones (5a-d), substituted dihydrothiazoles (7a,b), and substituted 2-oxo-1,2-dihydropyridines (8a-d and 9a,b). Fifteen compounds were evaluated for their anticancer activity using the USA-NCI in-vitro screening program. Among the tested compounds, 8d exhibited a high value of percent tumor growth inhibition at concentrations of 10(-5) to 10(-7) M in all cancer cell lines, while 8b exhibited a significant value of percent tumor growth inhibition at concentration <10(-8 )M against non-small cells lung HOP-92. In addition, nine compounds were investigated for their in-vitro effect on the replication of hepatitis-C virus (HCV) in HepG2 hepatocellular carcinoma cell line infected with the virus using the reverse transcription polymerase chain reaction technique. Six compounds were capable of inhibiting the replication of both the HCV RNA (+)- and (-)-strands at 5-100 microg/mL concentration range. The activity order was 7b > 1b = 3a > 4c > 7a > 5c.

Immune response to Schistosoma mansoni calreticulin in schistosomiasis resistant individuals.

The major strategy to reduce the impact of schistosomiasis is the development of a defined antigen vaccine. It has recently been reported that the 62-kDa antigen known as S. mansoni calreticulin (SmCaR), is a good T- and B-cell antigen and represents a potential vaccine candidate. In the present study the immune response to SmCaR was evaluated in individuals resistant to schistosomiasis. Lymphoproliferative response and cytokine production to SmCaR was assessed in 30 schistosomiasis resistant and healthy individuals. Only 10% of the schistosomiasis resistant individuals showed significant proliferative response to SmCaR while all of them showed significant proliferative response to soluble adult warm antigen (SAWA). On the other hand, 20-30% of the schistosomiasis resistant individuals showed detectable levels of IL-2, IL-4 and IFN-gamma after stimulation with SmCaR, and 59% of them showed had anti SmCaR IgM specific antibodies. These findings suggest that SmCaR might be a potential vaccine antigen.