Effect of Boswellia Serrata Extract on Acute Inflammatory Parameters and Tumor Necrosis Factor-α in Complete Freund's Adjuvant-Induced Animal Model of Rheumatoid Arthritis.

CONTEXT: The worldwide prevalence of rheumatoid arthritis (RA) is about 1%, whereas in India, it is approximately 0.75%. The current therapy for RA includes nonsteroidal anti-inflammatory drugs corticosteroids, disease-modifying anti-rheumatic drugs and some recently developed biologic agents, but all of these are associated with adverse effects. Some herbal drugs, such as Boswellia serrata, have been reported to possess anti-inflammatory activity. AIMS: The aim of this study is to evaluate the anti-arthritic activity of Boswellia serrata extract (BSE) in complete Freund's adjuvant (CFA)-induced arthritis in rats. MATERIALS AND METHODS: Thirty-six Wistar rats were divided into six equal groups. RA was induced by intradermal injection of 0.1 ml CFA in hind paw. Body weight, ankle diameter, paw volume, arthritic index, tumor necrosis factor-α (TNF-α), and histopathological examination were assessed. The experimental data were statistically assessed by one-way analysis of variance (ANOVA). STATISTICAL ANALYSIS USED: The recorded data were analyzed using paired t-test and ANOVA test using SPSS. The data were analyzed and represented as mean difference. Value of P < 0.05 was considered statistically significant. RESULTS: BSE at dose 180 mg/kg showed statistically significant improvement in body weight and decrease in ankle diameter and arthritic index (P < 0.05); however, there was insignificant change in paw volume (P = 0.056). This improvement was comparable with Indomethacin. The level of TNF-α did not show any statistically significant change (P = 0.076). Histopathological results also exhibited a reduction in inflammatory parameters. CONCLUSIONS: BSE might have usefulness as an adjunct to conventional therapy of RA.

A comparative assessment of intranasal and oral dexmedetomidine for procedural sedation in pediatric dental patients.

OBJECTIVES: The objective of this study was to assess the safety and efficacy of intranasal and oral dexmedetomidine for procedural sedation in pediatric dental patients. MATERIALS AND METHODS: Forty-four uncooperative American Society of Anesthesiologists Grade-I children, requiring dental treatment were randomly divided into four groups who received different doses of dexmedetomidine through intranasal and oral routes. The vital signs were monitored continuously during each visit. RESULTS: In this study, significant (P < 0.05) differences were found in the onset of sedation, duration, and recovery time between intranasal and oral groups. All vital signs were within normal physiological limits with no significant adverse effects in either of the groups. CONCLUSION: Dexmedetomidine is a safe and effective agent for procedural sedation in pediatric dental patients with intranasal route having distinct advantages over oral route.

Curcuma longa extract reduces inflammatory and oxidative stress biomarkers in osteoarthritis of knee: a four-month, double-blind, randomized, placebo-controlled trial.

BACKGROUND AND PURPOSE: Curcuma longa L. (CL), an Indian herb, has been used to treat many disorders because of its wide spectrum of pharmacological activities. It has been shown to exhibit anti-oxidant and anti-inflammatory properties, and is being used as herbal remedy since ancient times. Osteoarthritis of knee (KOA) is a chronic painful disorder in which prolong use of non-steroidal anti-inflammatory drugs (NSAIDs) or steroids may result into many serious side effects; hence, there is a need to develop herbal drugs, having good analgesia without side effects. Therefore, we planned to evaluate the efficacy of CL in KOA. METHODS: The study was designed as a randomized, double-blind, placebo-controlled trial in patients of KOA. After obtaining ethical clearance and written informed consent, a total of 160 patients of KOA were randomly enrolled into two groups to receive either CL extract or placebo along with the standard drug regimen. The patients were assessed on day 0, day 60, and day 120. On the days of their visit, the clinical prognosis was assessed by visual analog scale (VAS) and Western Ontario and McMaster Universities (WOMAC) Osteoarthritis index. On these days, the radiographs were also taken for Kellgren and Lawrence grading and blood samples were collected for assessing the changes in levels of IL-1ß and biomarkers of oxidative stress, such as reactive oxygen species and malondialdehyde (MDA). RESULTS: Over all significant improvement was observed in the patients of CL extract group as compared to placebo group. Clinically, the VAS and WOMAC scores became better, and simultaneously, the levels of biomarkers, viz., IL-1ß, ROS, and MDA, were also significantly (p < 0.05) improved. CONCLUSION: It may be concluded that on chronic administration, CL suppresses inflammation and brings clinical improvement in patients of KOA, which may be observed by decreased level of IL-1ß and VAS/WOMAC scores, respectively. At the same time, CL decreases the oxidative stress also.

A comparative evaluation of analgo-sedative effects of oral dexmedetomidine and ketamine: a triple-blind, randomized study.

BACKGROUND: Use of sedative agents for difficult to manage children during dental procedures has been indicated for years, but neither the agent nor the route has been found to be ideal. OBJECTIVES: The aim of the study was to evaluate and compare the efficacy and safety of oral dexmedetomidine (D) and ketamine (K) in producing moderate sedation among uncooperative pediatric dental patients. METHODS: This prospective, triple-blind, randomized comparative study included 112 ASA grade I children of both sexes aged 3-10 years, who satisfied all the inclusion criteria. They were randomly divided into four groups and ketamine 8 mg·kg(-1) (K) or dexmedetomidine 3 µg·kg(-1) (D1), 4 µg·kg(-1) (D2) and 5 µg·kg(-1) (D3) were given orally. Similar dental procedures were performed in these patients, and effects of these drugs were assessed in terms of changes in vital signs, onset and duration of sedation, analgesia, and amnesia. Secondary outcomes such as level of sedation, behavior, adverse effects, and overall success were also measured. RESULTS: The onset of sedation was significantly rapid with K and D3 as compared to D1 and D2. Recovery from sedation was fastest in group D1. Intra- and postoperative analgesia and anterograde amnesia were highest with K and least with D1, while D3 produced analgesia comparable to K. In K treated group, vomiting was observed in five patients and two patients exhibited emergence phenomenon. Overall, highest success rate was observed in D3 group. CONCLUSIONS: Given by oral route, the novel sedative dexmedetomidine provides dose-dependent effective analgo-sedation, comparable to ketamine, with less adverse effects.

The introduction of P4 substituted 1-methylcyclohexyl groups into Boceprevir: a change in direction in the search for a second generation HCV NS3 protease inhibitor.

In the search for a second generation HCV protease inhibitor, molecular modeling studies of the X-ray crystal structure of Boceprevir1 bound to the NS3 protein suggest that expansion into the S4 pocket could provide additional hydrophobic Van der Waals interactions. Effective replacement of the P4 tert-butyl with a cyclohexylmethyl ligand led to inhibitor 2 with improved enzyme and replicon activities. Subsequent modeling and SAR studies led to the pyridine 38 and sulfone analogues 52 and 53 with vastly improved PK parameters in monkeys, forming a new foundation for further exploration.

A facile and efficient synthesis of 3,3-dimethyl isopropylidene proline from (+)-3-carene.

A highly efficient and practical route to 3,4-isopropylidene proline I, starting from (+)-3-carene, was developed. The three continuous stereocenters were constructed using the inherent chirality of the starting natural product 2. The overall yield for the 12-step synthesis is 34%. The optimized sequence leading to 1 has been successfully applied on a multigram scale, thereby establishing the practicality of this route.

Discovery of Narlaprevir (SCH 900518): A Potent, Second Generation HCV NS3 Serine Protease Inhibitor.

Boceprevir (SCH 503034), 1, a novel HCV NS3 serine protease inhibitor discovered in our laboratories, is currently undergoing phase III clinical trials. Detailed investigations toward a second generation protease inhibitor culminated in the discovery of narlaprevir (SCH 900518), 37, with improved potency (∼10-fold over 1), pharmacokinetic profile and physicochemical characteristics, currently in phase II human trials. Exploration of synthetic sequence for preparation of 37 resulted in a route that required no silica gel purification for the entire synthesis.

Toward the back-up of boceprevir (SCH 503034): discovery of new extended P4-capped ketoamide inhibitors of hepatitis C virus NS3 serine protease with improved potency and pharmacokinetic profiles.

Hepatitis C is the most prevalent liver disease. Viral hepatitis C (HCV), a small (+)-RNA virus, infects chronically an estimated 300 million people worldwide. Results of Phase I clinical studies with our first generation HCV inhibitor Boceprevir, SCH 503034 (1), presented at the 56th Annual Meeting of the American Association for the Study of Liver Diseases (AASLD) were encouraging, and thus, additional human clinical studies are underway. In view of the positive data from our first generation compound, further work aimed at optimizing its overall profile was undertaken. Herein, we report that extension of our earlier inhibitor to the P(4) pocket and optimization of the P(1)' capping led to the discovery of new ketoamide inhibitors of the HCV NS3 serine protease with improved in vitro potency. In addition to being potent inhibitors of HCV subgenomic RNA replication, some of the new P(4)-capped inhibitors were also found to have improved PK profile.

Toward second generation hepatitis C virus NS3 serine protease inhibitors: discovery of novel P4 modified analogues with improved potency and pharmacokinetic profile.

Hepatitis C virus (HCV) infection is a global health crisis leading to liver cirrhosis, hepatocellular carcinoma, and liver failure in humans. Recently, we disclosed the discovery of Boceprevir, SCH 503034 (1), a novel, potent, selective, orally bioavailable NS3 protease inhibitor that is currently undergoing phase III clinical trials. Our efforts toward a second generation HCV NS3 serine protease inhibitor were directed at improving the overall profile of the inhibitor. This article will elaborate on our studies leading to the discovery of new P4 modified inhibitors with enhanced potency and improved oral bioavailability. Thus, introduction of ether and carbamate-derived P4 moieties resulted in improving the replicon potency significantly. Incorporation of the P' secondary amide residue afforded significant improvement in pharmacokinetic properties. Combining the preferred moieties, identified from comprehensive SAR studies, resulted in inhibitors that displayed superior potency and very good oral as well as target organ exposure in rats.

Key steps in the structure-based optimization of the hepatitis C virus NS3/4A protease inhibitor SCH503034.

The structures of both native and S139A holo-HCV NS3/4A protease domain were solved to high resolution. Subsequently, structures were determined for a series of ketoamide inhibitors in complex with the protease. The changes in the inhibitor potency were correlated with changes in the buried surface area upon binding the inhibitor to the active site. The largest contributions to the binding energy arise from the hydrophobic interactions of the P1 and P2 groups as they bind to the S1 and S2 pockets. This correlation of the changes in potency with increased buried surface area contributed directly to the design of a potent tripeptide inhibitor of the HCV NS3/4A protease, which is currently in clinical trials.

Characterization of resistance mutations against HCV ketoamide protease inhibitors.

An issue of clinical importance in the development of new antivirals for HCV is emergence of resistance. Several resistance loci to ketoamide inhibitors of the NS3/4A protease have been identified (residues V36, T54, R155, A156, and V170) by replicon and clinical studies. Using SCH 567312, a more potent protease inhibitor derived from SCH 503034 (boceprevir) series, we identified two new positions (Q41 and F43) that confer resistance to the ketoamide class. The catalytic efficiency of protease enzymes was not affected by most resistance mutations, whereas replicon fitness varied with specific mutations. SCH 503034 and another ketoamide inhibitor, VX-950 (telaprevir), showed moderate losses of activity against most resistance mutations (< or =10-fold); the highest resistance level was conferred by mutations at A156 locus. Although SCH 503034 and VX-950 bind similarly to the active site, differences in resistance level were observed with specific mutations. Changes at V36 and R155 had more severe impact on VX-950, whereas mutations at Q41, F43 and V170 conferred higher resistance to SCH 503034. Structural analysis of resistance mutations on inhibitor binding is discussed.

Posaconazole (Noxafil, SCH 56592), a new azole antifungal drug, was a discovery based on the isolation and mass spectral characterization of a circulating metabolite of an earlier lead (SCH 51048).

Posaconazole (SCH 56592) is a novel triazole antifungal drug that is marketed in Europe and the United States under the trade name 'Noxafil' for prophylaxis against invasive fungal infections. SCH 56592 was discovered as a possible active metabolite of SCH 51048, an earlier lead. Initial studies have shown that serum concentrations determined by a microbiological assay were higher than those determined by HPLC from animals dosed with SCH 51048. Subsequently, several animals species were dosed with (3)H-SCH 51048 and the serum was analyzed for total radioactivity, SCH 51048 concentration and antifungal activity. The antifungal activity was higher than that expected based on SCH 51048 serum concentrations, confirming the presence of active metabolite(s). Metabolite profiling of serum samples at selected time intervals pinpointed the peak that was suspected to be the active metabolite. Consequently, (3)H-SCH 51048 was administered to a large group of mice, the serum was harvested and the metabolite was isolated by extraction and semipreparative HPLC. LC-MS/MS analysis suggested that the active metabolite is a secondary alcohol with the hydroxyl group in the aliphatic side chain of SCH 51048. All corresponding monohydroxylated diastereomeric mixtures were synthesized and characterized. The HPLC retention time and LC-MS/MS spectra of the diastereomeric secondary alcohols of SCH 51048 were similar to those of the isolated active metabolite. Finally, all corresponding individual monohydroxylated diasteriomers were synthesized and evaluated for in vitro and in vivo antifungal potencies, as well as pharmacokinetics. SCH 56592 emerged as the candidate with the best overall profile.

Discovery of the HCV NS3/4A protease inhibitor (1R,5S)-N-[3-amino-1-(cyclobutylmethyl)-2,3-dioxopropyl]-3- [2(S)-[[[(1,1-dimethylethyl)amino]carbonyl]amino]-3,3-dimethyl-1-oxobutyl]- 6,6-dimethyl-3-azabicyclo[3.1.0]hexan-2(S)-carboxamide (Sch 503034) II. Key steps in structure-based optimization.

The structures of both the native holo-HCV NS3/4A protease domain and the protease domain with a serine 139 to alanine (S139A) mutation were solved to high resolution. Subsequently, structures were determined for a series of ketoamide inhibitors in complex with the protease. The changes in the inhibitor potency were correlated with changes in the buried surface area upon binding the inhibitor to the active site. The largest contribution to the binding energy arises from the hydrophobic interactions of the P1 and P2 groups as they bind to the S1 and S2 pockets [the numbering of the subsites is as defined in Berger, A.; Schechter, I. Philos. Trans. R. Soc. London, Ser. B 1970, 257, 249-264]. This correlation of the changes in potency with increased buried surface area contributed directly to the design of a potent tripeptide inhibitor of the HCV NS3/4A protease that is currently in clinical trials.

In vitro antiviral activity of SCH446211 (SCH6), a novel inhibitor of the hepatitis C virus NS3 serine protease.

BACKGROUND: Current hepatitis C virus (HCV) therapies may cure approximately 60% of infections. They are often contraindicated or poorly tolerated, underscoring the need for safer and more effective drugs. A novel, alpha-ketoamide-derived, substrate-based inhibitor of the HCV serine protease (SCH446211) was developed. Compared with earlier reported inhibitors of similar chemical class, it has a P1'-P2' extension which provides extended interaction with the protease active site. The aim of this study was to evaluate the in vitro antiviral activity of SCH446211. METHODS: Binding constant of SCH446211 to HCV NS3 protease was measured with the chromogenic substrate in vitro cleavage assay. Cell-based activity of SCH446211 was evaluated in replicon cells, which are Huh-7 hepatoma cells stably transfected with a subgenomic HCV RNA as reported previously. After 72 h of incubation with SCH446211, viral transcription and protein expression were measured by real-time RT-PCR (TaqMan), quantitative in situ hybridization, immunoblot and indirect immunofluorescence. RESULTS: The binding constant of SCH446211 to HCV NS3 protease was 3.8 +/- 0.4 nM. HCV replication and protein expression were inhibited by SCH446211 in replicon cells as consistently shown by four techniques. In particular, based on quantitative real-time RT-PCR measurements, the IC50 and IC90 of SCH446211 were estimated to be 40 +/- 20 and 100 +/- 20 nM (n = 17), respectively. Long-term culture of replicon cells with SCH446211 reduced replicon RNA to <0.1 copy per cell. SCH446211 did not show cellular toxicity at concentrations up to 50 microM. CONCLUSIONS: SCH446211 is a potent inhibitor of HCV protease in vitro. Its extended interaction with the HCV NS3 protease active site is associated with potent in vitro antiviral activity. This observation is potentially a useful guide for development of future potent inhibitors against HCV NS3 protease.

Discovery of (1R,5S)-N-[3-amino-1-(cyclobutylmethyl)-2,3-dioxopropyl]- 3-[2(S)-[[[(1,1-dimethylethyl)amino]carbonyl]amino]-3,3-dimethyl-1-oxobutyl]- 6,6-dimethyl-3-azabicyclo[3.1.0]hexan-2(S)-carboxamide (SCH 503034), a selective, potent, orally bioavailable hepatitis C virus NS3 protease inhibitor: a potential therapeutic agent for the treatment of hepatitis C infection.

Hepatitis C virus (HCV) infection is the major cause of chronic liver disease, leading to cirrhosis and hepatocellular carcinoma, which affects more than 170 million people worldwide. Currently the only therapeutic regimens are subcutaneous interferon-alpha or polyethylene glycol (PEG)-interferon-alpha alone or in combination with oral ribavirin. Although combination therapy is reasonably successful with the majority of genotypes, its efficacy against the predominant genotype (genotype 1) is moderate at best, with only about 40% of the patients showing sustained virological response. Herein, the SAR leading to the discovery of 70 (SCH 503034), a novel, potent, selective, orally bioavailable NS3 protease inhibitor that has been advanced to clinical trials in human beings for the treatment of hepatitis C viral infections is described. X-ray structure of inhibitor 70 complexed with the NS3 protease and biological data are also discussed.

Discovery of SCH446211 (SCH6): a new ketoamide inhibitor of the HCV NS3 serine protease and HCV subgenomic RNA replication.

Introduction of various modified prolines at P(2) and optimization of the P(1) side chain led to the discovery of SCH6 (24, Table 2), a potent ketoamide inhibitor of the HCV NS3 serine protease. In addition to excellent enzyme potency (K(i)*= 3.8 nM), 24 was also found to be a potent inhibitor of HCV subgenomic RNA replication with IC(50) and IC(90) of 40 and 100 nM, respectively. Recently, antiviral activity of 24 was demonstrated with inhibition of the full-length genotype 2a HCV genome. In addition, 24 was found to restore the responsiveness of the interferon regulatory factor 3 (IRF-3) in cells containing HCV RNA replicons.

Depeptidization efforts on P3-P2' alpha-ketoamide inhibitors of HCV NS3-4A serine protease: effect on HCV replicon activity.

Depeptidization efforts of the P(3)-P(2) region of P(3) capped alpha-ketoamide inhibitor of HCV NS3 serine protease 1 are reported. We clearly established that N-methylation of the P(2) nitrogen and modification of the P(2)' carboxylic acid terminus were essential for activity in the replicon assay.

Mutations conferring resistance to SCH6, a novel hepatitis C virus NS3/4A protease inhibitor. Reduced RNA replication fitness and partial rescue by second-site mutations.

Drug resistance is a major issue in the development and use of specific antiviral therapies. Here we report the isolation and characterization of hepatitis C virus RNA replicons resistant to a novel ketoamide inhibitor of the NS3/4A protease, SCH6 (originally SCH446211). Resistant replicon RNAs were generated by G418 selection in the presence of SCH6 in a dose-dependent fashion, with the emergence of resistance reduced at higher SCH6 concentrations. Sequencing demonstrated remarkable consistency in the mutations conferring SCH6 resistance in genotype 1b replicons derived from two different strains of hepatitis C virus, A156T/A156V and R109K. R109K, a novel mutation not reported previously to cause resistance to NS3/4A inhibitors, conferred moderate resistance only to SCH6. Structural analysis indicated that this reflects unique interactions of SCH6 with P'-side residues in the protease active site. In contrast, A156T conferred high level resistance to SCH6 and a related ketoamide, SCH503034, as well as BILN 2061 and VX-950. Unlike R109K, which had minimal impact on NS3/4A enzymatic function, A156T significantly reduced NS3/4A catalytic efficiency, polyprotein processing, and replicon fitness. However, three separate second-site mutations, P89L, Q86R, and G162R, were capable of partially reversing A156T-associated defects in polyprotein processing and/or replicon fitness, without significantly reducing resistance to the protease inhibitor.

Hydroxylated analogues of the orally active broad spectrum antifungal, Sch 51048 (1), and the discovery of posaconazole [Sch 56592; 2 or (S,S)-5].

As part of a detailed study, the syntheses, biological activities, and pharmacokinetic properties of hydroxylated analogues of the previously described broad spectrum antifungal agents, Sch 51048 (1), Sch 50001 (3), and Sch 50002 (4), are described. Based on an overall superior profile, one of the alcohols, Sch 56592 (2), was selected for clinical studies.

Novel inhibitors of the hepatitis C virus NS3 proteinase.

The hepatitis C virus proteinase inhibitor 4-methyl-1-(phenylmethyl)-2,6-pyridinedione 1 undergoes a novel autoxidation process, on silica gel, leading to the dimer 2 as the major product, a relatively more potent inhibitor of the enzyme.