Structural optimization, synthesis and in vitro synergistic anticancer activities of combinations of new N3-substituted dihydropyrimidine calcium channel blockers with cisplatin and etoposide.

T-type calcium channels are considered potential drug targets to combat cancer. Combining T-type calcium channel blockers with conventional chemotherapy drugs represents a promising strategy towards successful cancer treatment. From this perspective, we report in this study the design and synthesis of a novel series of N3-sustituted dihydropyrimidines (DHPMs) as anticancer adjuvants to cisplatin (Cis) and etoposide (Eto). Full spectral characterization of the new compounds was done using FT-IR, 1H NMR, 13C NMR, and HRMS. Structure elucidation was confirmed by 2D NMR 1H-H COSY, HSQC and NOESY experiments. Novel derivatives were tested for their Ca2+ channel blocking activity by employing the whole cell patch-clamp technique. Results demonstrated that most compounds were potential T-type calcium channel blockers with the triazole-based C12 and C13 being the most selective agents against CaV3.2 channel. Further electrophysiological studies demonstrated that C12 and C13 inhibited CaV3.2 currents with respective affinity of 2.26 and 1.27 µM, and induced 5 mV hyperpolarizing shifts in the half-inactivation potential. Subsequently, C12 and C13 were evaluated for their anticancer activities alone and in combination with Cis and Eto against A549 and MDA-MB 231 cancer cells. Interestingly, both compounds exhibited potential anticancer effects with IC50 values < 5 µM. Combination studies revealed that both compounds had synergistic effects (combination index CI < 1) on Cis and Eto through induction of apoptosis (p53 activation and up-regulation of BAX and p21 gene expression). Importantly, in silico physicochemical and ADMET assessment of both compounds revealed their potential drug-like properties with decreased risk of cardiac toxicity. Hence, C12 and C13 are promising anticancer adjuvants through inhibition of CaV3.2 T-type calcium channels, thereby serving as eminent leads for further modification.

Synthesis of some new C2 substituted dihydropyrimidines and their electrophysiological evaluation as L-/T-type calcium channel blockers.

Drugs targeting different calcium channel subtypes have strong therapeutic potential for future drug development for cardiovascular disorders, neuropsychiatric diseases and cancer. This study aims to design and synthesize a new series of C2 substituted dihydropyrimidines to mimic the structure features of third generation long acting dihydropyridine calcium channel blockers and dihydropyrimidines analogues. The target compounds have been evaluated as blockers for CaV1.2 and CaV3.2 utilizing the whole-cell patch clamp technique. Among the tested compounds, compound 7a showed moderate calcium channel blockade activity against CaV3.2. Moreover, the predicted physicochemical properties and pharmacokinetic profiles of the target compounds recommend that they can be considered as drug-like candidates. The results highlight some significant information for the future design of lead compounds as calcium channel blockers.

Design, synthesis and pharmacological evaluation of some substituted dihydropyrimidines with L-/T-type calcium channel blocking activities.

New dihydropyrimidines bearing various lipophilic pharmacophores and functionalities at position 3 were designed and synthesized. The basic framework of the new compounds was designed to maintain the main structural requirements for calcium channel blocking activity of the known dihydropyridines and dihydropyrimidines calcium channel blockers. The newly synthesized compounds were evaluated as antagonists for CaV1.2 and CaV3.2 using the whole-cell patch clamp technique. Seven compounds (4b, 4c, 6c, 9, 13c, 13e and 17b) showed promising dual calcium channel blocking activity and three compounds (13b, 14b and 17a) were selective against Cav3.2. Their drug-likeness has been assessed using Molinspiration and Molsoft softwares. Their physicochemical properties and pharmacokinetic profiles recommend that they can be considered as drug-like candidates.

Scarf versus long chevron osteotomies for the treatment of hallux valgus: A prospective randomized controlled study.

BACKGROUND: The aim of this study is to compare scarf osteotomy and long chevron osteotomy in treatment of hallux valgus deformity regarding operative time, power of correction and complications. DESIGN: A prospective randomized controlled comparative trial. METHODS: 48 cases with hallux valgus were divided randomly in 2 groups (21 treated by scarf and 22 treated by long chevron osteotomy and 5 were missed during follow up), average age 36 years, follow up time was average of 25.9 months. Patients were assessed clinically, radiologically, and functional scoring system of American College of Foot and ankle Surgeons (ACFAS)was used both pre and postoperatively. RESULTS: Operative time was 69min in scarf group compared to 63min to long chevron group, radiological correction showed no statistically significant difference between both groups while functional improvement in ACFAS score was in favour of long chevron group 69.1% compared to scarf group 57.5% CONCLUSIONS: Both osteotomies possess almost identical corrective power of the IMA (intermetatarsal angle) and similar clinical outcomes with slightly shorter operative time and subjective technical simplicity for the long chevron osteotomy.

Synthesis and biological evaluation of novel N3-substituted dihydropyrimidine derivatives as T-type calcium channel blockers and their efficacy as analgesics in mouse models of inflammatory pain.

Low-voltage-activated calcium channels are important regulators of neurotransmission and membrane ion conductance. A plethora of intracellular events rely on their modulation. Accordingly, they are implicated in many disorders including epilepsy, Parkinson's disease, pain and other neurological diseases. Among different subfamilies, T-type calcium channels, and in particular the CaV3.2 isoform, were shown to be involved in nociceptive neurotransmission. The role of CaV3.2 in pain modulation was supported by demonstrating selective antisense oligonucleotide-mediated CaV3.2 knockdown, in vivo antinociceptive effects of T-type blockers, and pain attenuation in CaV3.2 knockout formalin-induced pain model. These Emerging investigations have provided new insights into targeting T-type calcium channels for pain management. Within this scope, various T-type calcium channel blockers have been developed such as mibefradil and ethosuximide. Although being active, most of these molecules interact with other receptors as well. This addresses the need for T-selectivity. Few selective T-type channel blockers of diverse chemical classes were developed such as ABT-639 and TTA-P2. Interestingly, R(-) efonidipine which is a dihydropyridine (DHP) showed T-channel selectivity. Systematic modification of 1,4-dihydropyridine scaffold introduced novel derivatives with 40-fold T-type selectivity over L-type calcium channels. Along these lines, substitution of the DHP core with various analogues favored T-selectivity and may serve as novel pharmacophores. Several dihydropyrimidine (DHPM) mimics were introduced by Squibb as potential candidates. As a continuation of this approach, the current study describes the synthesis of Novel N3 substituted DHPMs with structure similarities to the active DHPs. Different functional groups were introduced to the N3 position through a spacer to gain more information about activity and selectivity. Furthermore, the spacer aims at improving the metabolic stability of the molecules. Initial screening data by whole patch clamp technique showed a robust inhibition of Cav3.2 T-type channels by eleven compounds. Interestingly, four compounds of these were efficient selective T-type blockers. Based on selectivity and efficiency, two compounds were selected for in vivo evaluation in mouse models of inflammatory pain. Results showed effective attenuation of nociception and mechanical hypersensitivity.

An ensemble multi-stream classifier for infant needs detection.

In this paper, we propose a novel multi-stream video classifier for infant needs detection. The proposed system is an ensemble-based system that combines several machine learning to improve the overall result of the state-of-the-art algorithms. It is a multi-stream in the sense that it combines the output predictions of both audio and images of infants from every single classifier employed in the system for a unified result. This produces better performance and results compared to the previous other research techniques, which relied on only one of these modalities. For training and testing the proposed system, from the Dunstan Baby Language video collection, we built three separate datasets for videos, images, and sounds encompassing the five primary infant needs that require predicting. These are: hunger, have wind, uncomfortable (require diaper change), wants to burp or tired, with a total of 3348 samples. We used four different ensemble algorithms for the best reachable performance. The proposed algorithm improves the overall accuracies of each single classifier from a low of 51% to a high of 99%. The proposed method also improves the accuracy of the classification process by about 9% compared to the state-of-the-art approaches, which was 90%.

Sarcophine-diol, a skin cancer chemopreventive agent, inhibits proliferation and stimulates apoptosis in mouse melanoma B16F10 cell line.

Sarcodiol (SD) is a semi-synthetic derivative of sarcophine, a marine natural product. In our previous work, we reported the significant chemopreventive effects of SD against non-melanoma skin cancer both in vitro and in vivo mouse models. In this investigation, we extended this work to study the effect of sarcodiol on melanoma development, the more deadly form of skin cancer, using the mouse melanoma B16F10 cell line. In this study we report that SD inhibits the de novo DNA synthesis and enhances fragmentation of DNA. We also evaluated the antitumor effect of SD on melanoma cell viability using several biomarkers for cell proliferation and apoptosis. SD inhibits the expression levels of signal transducers and activators of transcription protein (STAT-3) and cyclin D1, an activator of cyclin-dependent kinase 4 (Cdk4). SD treatment also enhances cellular level of tumor suppressor protein 53 (p53) and stimulates cleavage of the nuclear poly (ADP-ribose) polymerase (cleaved-PARP). SD also enhances cellular levels of cleaved Caspase-3, -8, -9 and stimulates enzymatic activities of Caspase-3, -8 and -9. These results, in addition to inhibition of cell viability, suggest that SD inhibits melanoma cell proliferation by arresting the cell-division cycle in a Go quiescent phase and activates programmed cell death (apoptosis) via extrinsic and intrinsic pathways. Finally, these studies demonstrate that SD shows a very promising chemopreventive effect in melanoma B16F10 tumor cells.

Sarcophine-diol inhibits expression of COX-2, inhibits activity of cPLA2, enhances degradation of PLA2 and PLC(γ)1 and inhibits cell membrane permeability in mouse melanoma B16F10 cells.

Sarcophine-diol (SD) is a semi-synthetic derivative of sarcophine with a significant chemopreventive effect against non-melanoma skin cancer both in vitro and in vivo. Recently, we have studied the effect of SD on melanoma development using the mouse melanoma B16F10 cell line. In this study, our findings show that SD suppresses cell multiplication and diminishes membrane permeability for ethidium bromide (EB), a model marker used to measure cell permeability for Ca²âº ions. SD also decreases protein levels of COX-2, and increases degradation of phospholipases PLA2 and PLC(γ)1 and diminishes enzymatic activity of the Ca²âº-dependent cPLA2. This lower membrane permeability for Ca²âº-ions, associated with SD, is most likely due to the diminished content of lysophosphosphatidylcholine (lysoPC) within cell membranes caused by the effect of SD on PLA2. The decrease in diacylglycerol (DAG) and inositol 1,4,5-triphosphate (IP3) due to inhibition of PLC(γ)1, leads to the downregulation of Ca²âº-dependent processes within the cell and also inhibits the formation of tumors. These findings support our previous data suggesting that SD may have significant potential in the treatment of melanoma.

Dose-response on the chemopreventive effects of sarcophine-diol on UVB-induced skin tumor development in SKH-1 hairless mice.

Sarcophine-diol (SD) is a lactone ring-opened analogue of sarcophine. It has shown chemopreventive effects on chemically-induced skin tumor development in female CD-1 mice, as well as in a UVB-induced skin tumor development model in hairless SKH-1 mice at a dose of 30 µg SD applied topically and 180 mJ/cm(2) UVB. The objective of this study was to determine the dose-response on the chemopreventive effects of SD on SKH-1 hairless mice when exposed to a UVB radiation dose of 30 mJ/cm(2). This UVB dose better represents chronic human skin exposure to sunlight leading to skin cancer than previous studies applying much higher UVB doses. Carcinogenesis was initiated and promoted by UVB radiation. Female hairless SKH-1 mice were divided into five groups. The control group was topically treated with 200 µL of acetone (vehicle), and the SD treatment groups were topically treated with SD (30 µg, 45 µg, and 60 µg dissolved in 200 µL of acetone) 1 h before UVB radiation (30 mJ/cm(2)). The last group of animals received 60 µg SD/200 µL acetone without UVB exposure. These treatments were continued for 27 weeks. Tumor multiplicity and tumor volumes were recorded on a weekly basis for 27 weeks. Weight gain and any signs of toxicity were also closely monitored. Histological characteristics and the proliferating cell nuclear antigen (PCNA) were evaluated in the mice skin collected at the end of the experiment. The dose-response study proved a modest increase in chemopreventive effects with the increase in SD dose. SD reduced the number of cells positively stained with PCNA proliferation marker in mice skin. The study also showed that SD application without UVB exposure has no effect on the structure of skin. The results from this study suggest that broader range doses of SD are necessary to improve the chemopreventive effects.

Thiazolopyrimidine Scaffold as a Promising Nucleus for Developing Anticancer Drugs: A Review Conducted in Last Decade.

The thiazolopyrimidine nucleus is a bioisosteric analog of purine and an important class of N-containing heterocycles. Thiazolopyrimidine scaffolds are considered a promising class of bioactive compounds that encompass diverse biological activities, such as antibacterial, antiviral, antifungal, anticancer, corticotrophin-releasing factor antagonists, anti-inflammatory, antituberculosis, and glutamic receptors antagonists. Despite the importance of thiazolopyrimidines from a pharmacological viewpoint, there is hardly a comprehensive review on this important heterocyclic nucleus. Throughout the years, those scaffolds have been studied extensively for its anticancer properties and several compounds were designed, synthesized, and evaluated for their anticancer effects with activity in the µM to nM range. However, there are hardly any reviews covering the anticancer effects of thiazolopyrimidines. In this review, an effort was made to compile literature covering the anticancer activity of thiazolopyrimidines reported in the last decade (2010-2020). Nearly thirty articles were reviewed and compounds with IC50 < 50 µM against at least 50% of the used cell lines were listed in this review. The best ten compounds (10a, 14b, 17g, 18, 25e, 25k, 34e, 41i, 49a and 49c) showing the best anticancer activity against the corresponding cell lines during the last 10 years are highlighted. By highlighting the most active compounds, this review article sheds light on the structural features associated with the strongest anticancer effects to provide guidance for future research aiming to develop anticancer molecules.

Design, synthesis, structural optimization, SAR, in silico prediction of physicochemical properties and pharmacological evaluation of novel & potent thiazolo[4,5-d]pyrimidine corticotropin releasing factor (CRF) receptor antagonists.

Corticotropin-releasing factor (CRF) is a 41-amino-acid neuropeptide secreted from the hypothalamus and is the main regulator of the hypothalamus-pituitary-adrenocortical (HPA) axis. CRF is the master hormone which modulates physiological and behavioral responses to stress. Many disorders including anxiety, depression, addictive disorders and others are related to over activation of the CRF system. This suggests that new molecules which can interfere with CRF binding to its receptors may be potential candidates for neuropsychiatric drugs to treat stress-related disorders. Previously, three series of pyrimidine and fused pyrimidine CRF1 receptor antagonists were synthesized by our group and specific binding assays, competitive binding studies and determination of the ability to antagonize the agonist-stimulated accumulation of cAMP (the second messenger for CRF receptors) were reported. In continuation of our efforts in this direction, in the current manuscript, we report the synthesis & biological evaluation of a new series of CRF1 receptor antagonists. Seven compounds showed promising binding affinity with the best two compounds (compounds 6 & 43) displaying a superior binding affinity to all of our previous compounds. Compounds 6 & 43 have only 4 times and 2 times less binding affinity than the standard CRF antagonist antalarmin, respectively. Thus, our two best lead compounds (compound 6 & 43) can be considered potent CRF receptor antagonists with binding affinity of 41.0 & 19.2 nM versus 9.7 nM for antalarmin.

Effects of magnolol on UVB-induced skin cancer development in mice and its possible mechanism of action.

BACKGROUND: Magnolol, a plant lignan isolated from the bark and seed cones of Magnolia officinalis, has been shown to have chemopreventive effects on chemically-induced skin cancer development. The objectives of this investigation are to study the anticarcinogenic effects of magnolol on UVB-induced skin tumor development in SKH-1 mice, a model relevant to humans, and determine the possible role of apoptosis and cell cycle arrest involved in the skin tumor development. METHODS: UVB-induced skin carcinogenesis model in SKH-1 mice was used for determining the preventive effects of magnolol on skin cancer development. Western blottings and flow cytometric analysis were used to study the effects of magnolol on apoptosis and cell cycle. RESULTS: Magnolol pretreated groups (30, 60 µ g) before UVB treatments (30 mJ/cm2, 5 days/week) resulted in 27-55% reduction in tumor multiplicity as compared to control group in SKH-1 mice. Magnolol pretreatment increased the cleavage of caspase-8 and poly-(-ADP-ribose) polymerase (PARP), increased the expression of p21, a cell cycle inhibitor, and decreased the expression of proteins involved in the G2/M phase of cell cycle in skin samples from SKH-1 mice.Treatment of A431 cells with magnolol decreased cell viability and cell proliferation in a concentration dependent manner. Magnolol induced G2/M phase cell cycle arrest in A431 cells at 12 h with a decreased expression of cell cycle proteins such as cyclin B1, cyclin A, CDK4, Cdc2 and simultaneous increase in the expression of Cip/p21, a cyclin-dependent kinase inhibitor. Magnolol induced apoptosis in vivo and in vitro with an increased cleavage of caspase-8 and PARP. Phospho-signal transducers and activators of transcription 3 (Tyr705), B-Raf, p-MEK, and p-AKT were down-regulated, whereas phosphorylation of ERK was induced by magnolol in A431 cells. CONCLUSIONS: Magnolol pretreatments prevent UVB-induced skin cancer development by enhancing apoptosis, causing cell cycle arrest at G2/M phase, and affecting various signaling pathways. Magnolol could be a potentially safe and potent anticarcinogenic agent against skin cancer.

Modified oblique high tibial osteotomy with minimal fixation for correction of adolescent tibia vara: a prospective case series study.

PURPOSE: To assess the reliability and efficacy of the modified oblique high tibial osteotomy for correction of complex deformity in adolescent tibia vara. METHODS: A total of 19 patients (25 legs) with adolescent tibia vara were enrolled in this study. There were 16 male (84.2%) and three female (15.8%) patients who had modified Rab oblique osteotomy with minimal fixation performed. The age of the patients at time of surgery ranged from 12 years to 30 years (mean 17.23 (sd 5.27)). The body mass index ranged from 22 kg/m2 to 42 kg/m2 (mean 32.05 (sd 6.13)). All patients were followed up for over two years (mean 3.4; 2 to 5). RESULTS: The femoro-tibial angle was improved from -34° to -12° (mean -20.04° (sd 5.24°) preoperatively and from -12° to 7°, postoperatively (mean 2.04° (sd 4.07)). Medial deviation of the mechanical axis corrected from 38 mm to 125 mm (mean 76.13 (sd 23.29)) preoperatively to 0 mm to 36 mm (mean 5.74 (sd 7.3)) postoperatively. The time needed to achieve union ranged from eight weeks to 16 weeks (mean 10.2 (sd 2.42)). According to the Lysholm functional knee score scale, there were 15 excellent (78.9%), two good (10.5%), one fair (5.2%) and one poor (5.2%) after correction of the deformity. CONCLUSION: Modified Rab osteotomy with minimal fixation by two or three screws shows promising results with good correction of varus deformity (coronal plane), internal torsion (axial plane) and procurvatum (sagittal plane), in management of adolescent tibia vara with minimal morbidity and complications. LEVEL OF EVIDENCE: IV.

Arthrodiastasis in the management of Perthes disease: a systematic review.

This systematic review explores the relevant literature to assess the efficacy of the use of arthrodiastasis in the management of Perthes disease. Until this moment, arthrodiastasis is not well established for its use in Perthes disease as opposed to other containment procedures. Furthermore, there are no clear indications for its use in this disease. Twelve articles were matched to the inclusion criteria and all articles were reviewed and radiological and clinical data were collected and compiled. As regards the hip flexion range of motion, the average preoperative flexion range of motion was 55.32°, while the postoperative was 90°. The average preoperative hip abduction range of motion was 12.28° and postoperative was 35.28°. Mean preoperative hip internal rotation range of motion was 8.69° and postoperatively was 24.93°. Mean preoperative external rotation range of motion was 21.73°, while the postoperative range was 33.71°. Final Stulberg classification was ascertained showing most patients ending with stages two and three. Complications were also assessed with most of which being superficial pin tract infections. The use of arthrodiastasis is a valid treatment option for Perthes disease; however, more articles need to be produced showing comparative data of arthrodiastasis versus other containment procedures. Level of evidence - level 1: systematic review.

Chemopreventive effects of sarcophine-diol on ultraviolet B-induced skin tumor development in SKH-1 hairless mice.

Sarcophine-diol (SD), one of the structural modifications of sarcophine, has shown chemopreventive effects on 12-dimethylbenz(a)anthracene-initiated and 12-O-tetradecanoylphorbol-13-acetate-promoted skin tumor development in female CD-1 mice. The objective of this study was to determine the chemopreventive effects of SD on UVB-induced skin tumor development in hairless SKH-1 mice, a model more relevant to human skin cancer, and to determine the possible mechanisms of action. Carcinogenesis was initiated and promoted by UVB radiation. Female hairless SKH-1 mice were divided into two groups having 27 mice in each group: control and SD treatment. The control group was topically treated with 100 microL acetone and SD treatment group was topically treated with SD (30 microg/100 microL in acetone) 1 hour before each UVB radiation for 32 weeks. Tumor counts were recorded on a weekly basis for 30 weeks. Effects of SD on the expression of caspases were investigated to elucidate the possible mechanism of action. The proteins from epidermal homogenates of experimental mice were used for SDS-PAGE and Western blotting using specific antibodies against caspase-3, caspase-8 and caspase-9 respectively. TUNEL assay was used for determining DNA fragmented apoptotic cells in situ. Results showed that at the end of experiment, tumor multiplicity in control and SD treatment groups was 25.8 and 16.5 tumors per mouse respectively. Furthermore, Topical treatment of SD induced DNA fragmented apoptotic cells by upgrading the expressions of cleaved caspase-3 and caspase-8. This study clearly suggested that SD could be an effective chemopreventive agent for UVB-induced skin cancer by inducing caspase dependent apoptosis.

Selective antagonism of CRF1 receptor by a substituted pyrimidine.

The corticotrophin-releasing factor (CRF) and its type 1 receptor (CRF1R) regulate the hypothalamic-pituitary-adrenal axis, as well as other systems, thus playing a crucial role in the maintenance of homeostasis. Non-peptide CRF1R-selective antagonists exert therapeutic effects on experimental animals with abnormal regulation of their homeostatic mechanisms. However, none of them is as yet in clinical use. In an effort to develop novel small non-peptide CRF1R-selective antagonists, we have synthesized a series of substituted pyrimidines described in a previous study. These small molecules bind to CRF1R, with analog 3 having the highest affinity. Characteristic structural features of analog 3 are a N,N-bis(methoxyethyl)amino group at position 6 and a methyl in the alkythiol group at position 5. Based on the binding profile of analog 3, we selected it in the present study for further pharmacological characterization. The results of this study suggest that analog 3 is a potent CRF1R-selective antagonist, blocking the ability of sauvagine, a CRF-related peptide, to stimulate cAMP accumulation in HEK 293 cells via activation of CRF1R, but not via CRF2R. Moreover, analog 3 blocked sauvagine to stimulate the proliferation of macrophages, further supporting its antagonistic properties. We have also constructed molecular models of CRF1R to examine the interactions of this receptor with analog 3 and antalarmin, a prototype CRF1R-selective non-peptide antagonist, which lacks the characteristic structural features of analog 3. Our data facilitate the design of novel non-peptide CRF1R antagonists for clinical use.

Chemopreventive effects of sarcophine-diol on skin tumor development in CD-1 mice.

The objective of this study was to determine the chemopreventive effects of sarcophine-diol (SD) on 7,12-dimethylbenz(a)anthracene initiated and 12-O-tetradecanoylphorbol-13-acetate promoted skin tumor development in mice and its possible mechanisms of action. SD pretreatment significantly (P<0.05) decreased skin papilloma development during promotion phase. SD significantly (P<0.05) increased caspase-3 and decreased cyclooxygenase-2 during initiation phase or promotion phase. SD significantly (P<0.05) increased caspase-8 during promotion phase. SD resulted in a 95% reduction in 12-O-tetradecanoylphorbol-13-acetate-induced DNA synthesis. SD could be an effective chemopreventive agent for skin cancer by enhancing apoptosis and decreasing cell proliferation.

Chemopreventive effects of sarcotriol on ultraviolet B-induced skin tumor development in SKH-1 hairless mice.

Sarcotriol (ST) has been shown to be chemopreventive on 7,12-dimethyl-benz(a)anthracene (DMBA) initiated and 12-O-tetradecanoylphorbol-13-acetate (TPA)-promoted skin tumor development in CD-1 mice in recent studies from our laboratory. The objective of this study was to determine the chemopreventive effects of ST on ultraviolet B (UVB)-induced skin tumor development in female SKH-1 hairless mice, an experimental model relevant to human skin cancer development, and its possible mechanisms of action. Female SKH-1 mice were divided into two groups: Control and ST treated. Control was topically treated with 100 microliter acetone and ST treated group administered with 30 microgram ST in 100 microliter acetone one hour before UVB exposure. For UVB-induced tumorigenesis, carcinogenesis was initiated and promoted by UVB (180 mJ/cm(2)). Group weights and tumor counts were taken once every week. After 30 weeks, mice were sacrificed and dorsal skin samples were collected. The proteins from the skin sample were further used for SDS-PAGE and Western blotting using specific antibodies against caspase-3, caspase-8, caspase-9 and p53. Tumor multiplicity was found 19.6, 5.2 in the control and ST treated groups respectively. Caspase-3, -8, -9 and p53 were significantly (P < 0.05) upregulated in ST treated group compared to Control group. Together, this study for the first time identifies the chemopreventive effects of ST in UVB-induced carcinogenesis possibly by inducing apoptosis and upregulating p53.

Structure and Function of Small Non-Peptide CRF Antagonists and their Potential Clinical Use.

Corticotropin-releasing factor (CRF) can be considered a very important hormone or a chemical mediator. It works closely with other systems to regulate the manner through which the body may respond to stress. Thus it affects many biological processes associated with stress. Dysfunction of this system has also been correlated with various diseases such as major depression, anxiety, drug addiction and eating disorders. Rationally, this means that interfering with binding of CRF to its intended receptors can be an attractive target for drug design aiming at developing new medications for many ailments that are associated with stress such as depression, anxiety and stress-induced relapse in drug addiction. Hundreds of accounts of small molecule antagonists have appeared in the literature and the preclinical and clinical pharmacology have been reported for many of these agents. Several classes of small molecule CRF receptor antagonists which belong to the non-peptide class have been developed with many being widely used for research purposes. Currently several major pharmaceutical companies are pursuing development of small non-peptide CRF1 receptor antagonists. In this review article we explain the importance of development of non-peptide CRF antagonists and their clinical relevance with emphasis on those members that showed great promise or those that were advanced to clinical trials.

Synthesis of 2-imino and 2-hydrazono thiazolo[4,5-d]pyrimidines as corticotropin releasing factor (CRF) antagonists.

Corticotropin-releasing factor (CRF) is an important neuropeptide hormone which controls the body's overall response to stress. It plays a crucial role in regulating the behavioral, cardiovascular, immune and gastrointestinal systems. Over-activation of the CRF system has been implicated in many disorders including anxiety, depression, drug addiction, hypertension, Irritable Bowel Syndrome (IBS), peptic ulcers, inflammation and others. Thus, binding of CRF to its receptors is an attractive target to develop new medications which aim at treating ailments associated with chronic stress. Numerous small-molecule non-peptide CRF receptor antagonists were developed and many are in various stages in clinical trials. Many showed great promise in treatment of anxiety, depression, peptic ulcers, inflammation, IBS and drug addiction. In our recent previous work, the development of two series of pyrimidine and fused pyrimidine CRF antagonists were described. In continuation of our efforts in this direction, in the current manuscript, the synthesis of a third series of CRF receptor antagonists is described. The binding affinities of select compounds for the type 1 receptor of CRF (CRF1R) were determined and compared to a standard CRF antagonist drug antalarmin. A lead compound was identified and further evaluated by measuring its effect on the inhibition of the agonist-stimulated accumulation of second messengers.