Diagnostic challenge: Secondary omental torsion misdiagnosed as acute appendicitis-A case report.

This case presents a diagnostic challenge in a 28-year-old male initially evaluated for severe abdominal pain, vomiting, and constipation, leading to the presumption of post-appendectomy complications. Clinical examination revealed abdominal distension, tenderness, and signs of peritonism, along with a reducible inguinal hernia. On subsequent CT scan, a large, inflamed area of omentum localized to the right abdomen extending up to the defect in the inguinal region with mild ascites was revealed. Upon exploration, it was discovered that the patient's initial surgery had focused solely on an appendix deemed mildly inflamed by the operating surgeon, while a concurrent diagnosis of secondary omental torsion was missed. This oversight underscores the challenges in diagnosing abdominal pathologies, with the initial misdiagnosis leading to ongoing patient distress. Meticulous adhesiolysis and omentectomy were performed, resulting in the resolution of the patient's symptoms.

Inhibiting Intracellular α2C-Adrenoceptor Surface Translocation Using Decoy Peptides: Identification of an Essential Role of the C-Terminus in Receptor Trafficking.

The G protein-coupled α2-adrenoceptor subtype C (abbreviated α2C-AR) has been implicated in peripheral vascular conditions and diseases such as cold feet-hands, Raynaud's phenomenon, and scleroderma, contributing to morbidity and mortality. Microvascular α2C-adrenoceptors are expressed in specialized smooth muscle cells and mediate constriction under physiological conditions and the occlusion of blood supply involving vasospastic episodes and tissue damage under pathological conditions. A crucial step for receptor biological activity is the cell surface trafficking of intracellular receptors, triggered by cAMP-Epac-Rap1A GTPase signaling, which involves protein-protein association with the actin-binding protein filamin-2, mediated by critical amino acid residues in the last 14 amino acids of the receptor carboxyl (C)-terminus. This study assessed the role of the C-terminus in Rap1A GTPase coupled receptor trafficking by domain-swapping studies using recombinant tagged receptors in transient co-transfections and compared with wild-type receptors using immunofluorescence microscopy. We further tested the biological relevance of the α2C-AR C-terminus, when introduced as competitor peptides, to selectively inhibit intracellular α2C-AR surface translocation in transfected as well as in microvascular smooth muscle cells expressing endogenous receptors. These studies contribute to establishing proof of principle to target intracellular α2C-adrenoceptors to reduce biological activity, which in clinical conditions can be a target for therapy.

Naturally Isolated Sesquiterpene Lactone and Hydroxyanthraquinone Induce Apoptosis in Oral Squamous Cell Carcinoma Cell Line.

Oral squamous cell carcinoma (OSCC) is one of the most prevalent cancers worldwide, especially in Asian countries. The emergence of its drug resistance and its side effects demands alternatives, to improve prognosis. Since the majority of cancer drugs are derived from natural sources, it provides a window to look for more biocompatible alternatives. In this study, two natural compounds, costunolide (CE) and aloe emodin (AE), were isolated from the stem of Lycium shawii. The compounds were examined for their anticancer and apoptotic potentials against OSCC (CAL 27) cells, using an in vitro analysis, such as a MTT assay, scratch assay, gene, and protein expressions. Both compounds, CE and AE, were found to be cytotoxic against the cancer cells with an IC50 value of 32 and 38 µM, respectively. Moreover, the compounds were found to be non-toxic against normal NIH-3T3 cells and comparable with the standard drug i.e., 5-fluorouracil (IC50 = 97.76 µM). These compounds were active against normal cells at higher concentrations. Nuclear staining displayed the presence of apoptosis-associated morphological changes, i.e., karyopyknosis and karyorrhexis in the treated cancer cells. Flow cytometry results further confirmed that these compounds induce apoptosis rather than necrosis, as the majority of the cells were found in the late apoptotic phase. Gene and protein expression analyses showed an increased expression of apoptotic genes, i.e., BAK, caspase 3, 6, and 9. Moreover, the compounds significantly downregulated the expression of the anti-apoptotic (BCL-2 L1), metastatic (MMP-2), and pro-inflammatory (COX-2) genes. Both compounds have shown promising anticancer, apoptotic, and anti-migratory activities against the OSCC cell line (i.e., CAL-27). However, further in vivo studies are required to explore these compounds as anticancer agents.

Comparative Study to Characterise the Pharmaceutical Potential of Synthesised Snake Venom Bradykinin-Potentiating Peptides In Vivo.

BACKGROUND: Bradykinin-potentiating peptides (BPPs) are snake venom peptides inhibiting the angiotensin-converting enzyme (ACE). ACE plays an important role in the regulation of blood pressure. BPPs lead to the development of ACE inhibitors for the treatment of hypertension. OBJECTIVE: The objective of the present work was to carry out a comprehensive comparative study of four synthesised snake venom BPPs in vivo. METHODS: Four synthesised snake venom BPPs were administered to rats via the intraperitoneal route for 15 days at a fixed dose. Lisinopril was used as a comparative standard. Thirty male albino rats were divided into six groups: A, B, C, D, E (lisinopril), and F (control). Group F was maintained as the control group and given only saline. After 15 days, blood samples and tissues were removed for the study of selective biochemical parameters and histomorphometric analysis. Statistical evaluation of all results was also performed. RESULTS: The results indicated that peptide I, with the sequence ZSAPGNEAIPP, was highly toxic and adversely affected all the biochemical and histological parameters studied in this work. Peptide II (ZNWPHPQIPP) and peptide IV (ZQWAQGRAPHPP) showed lower toxicity. None of the BPPs raised the serum creatinine level and exhibited nephroprotective effects. Although lisinopril raised the creatinine level, it showed a protective role towards the pancreas and lungs in parallel. CONCLUSION: The present work shows that although there is a high sequence similarity between the four BPPs, their in vivo activity varies. The sequences of peptide II and peptide IV can be used to improve the design of current ACE inhibitors used for hypertension treatment.

Natural products based crown ethers: synthesis and their anticancer potential.

Natural products based novel crown ethers have been prepared by employing biologically active natural structures including tetrahydroisoquinoline, chrysin and biochanin-A as the side arms. The resulting crown scaffolds were evaluated for their anticancer potential against two cancer cell lines i.e. NCI-H460 (non-small lung carcinoma), MCF-7 (breast adenocarcinoma). The comparative study showed that the addition of crown scaffold put marked effects on antiproliferative profile of parent natural precursors and is significant for lung carcinoma in particular. Biochanin-A derived crown ether showed three (03) folds higher antiproliferative activity (IC50 = 6.08 ± 0.07 µM) against lung carcinoma as compared to standard drug cisplatin (IC50 = 19.00 ± 1.24 µM). Cytotoxic trends for NIH-3T3 cell lines were also examined and found reduced as compared to parent natural structures. Hence, these findings could open a new pathway towards developing effective carcinostatic drugs.HIGHLIGHTSFour natural products based novel crown ethers have been developed.Comparative antiproliferative screening of crown ethers and natural precursors.Addition of crown showed marked effects on anticancer profile of natural products.Crown formation is significant for lung carcinoma potential in particular.Biochanin-A derived crown ether found three folds more active than standard drug.

Pharmacological Characterisation of Pseudocerastes and Eristicophis Viper Venoms Reveal Anticancer (Melanoma) Properties and a Potentially Novel Mode of Fibrinogenolysis.

Venoms are a rich source of potential lead compounds for drug discovery, and descriptive studies of venom form the first phase of the biodiscovery process. In this study, we investigated the pharmacological potential of crude Pseudocerastes and Eristicophis snake venoms in haematological disorders and cancer treatment. We assessed their antithrombotic potential using fibrinogen thromboelastography, fibrinogen gels with and without protease inhibitors, and colourimetric fibrinolysis assays. These assays indicated that the anticoagulant properties of the venoms are likely induced by the hydrolysis of phospholipids and by selective fibrinogenolysis. Furthermore, while most fibrinogenolysis occurred by the direct activity of snake venom metalloproteases and serine proteases, modest evidence indicated that fibrinogenolytic activity may also be mediated by selective venom phospholipases and an inhibitory venom-derived serine protease. We also found that the Pseudocerastes venoms significantly reduced the viability of human melanoma (MM96L) cells by more than 80%, while it had almost no effect on the healthy neonatal foreskin fibroblasts (NFF) as determined by viability assays. The bioactive properties of these venoms suggest that they contain a number of toxins suitable for downstream pharmacological development as candidates for antithrombotic or anticancer agents.

Synthesis and characterization of maltol capped silver nanoparticles and their potential application as an antimicrobial agent and colorimetric sensor for cysteine.

Maltol capped silver nanoparticles (McAgNPs) were synthesized using maltol (3-hydroxy-2-methyl-4-pyrone) as reducing and capping agent. McAgNPs were characterized by Visible and FTIR (Fourier transform infrared) spectroscopy, dynamic light scattering (DLS), and atomic force microscopy (AFM). Bright yellow color McAgNPs showed surface plasmon resonance (SPR) band at 436 nm, spherical shape and the average size between 35 to 50 nm. McAgNPs revealed higher stability against varying storage time, temperature, pH and salt concentrations. McAgNPs were successfully utilized for the selective and highly sensitive colorimetric detection of cysteine (Cys). Addition of Cys in a solution of McAgNPs, resulted a rapid change in color from yellow to orange because of the formation of nanoaggregates as confirmed by Visible/FTIR spectroscopy, DLS, and AFM studies. The estimated limit of detection (0.043 µM) was found to be more sensitive than previously reported other optical methods. The practical applicability of probe was also established by spiking the known concentrations of Cys in biological (blood plasma and urine) and environmental (tap and lake water) samples with significant recovery rates (92-104.6%). Despite being nontoxic to various tested cell lines, McAgNPs demonstrated potent antimicrobial, antibiofilm, and biofilm eradicating activities, thus potentially valuable in diagnostics and/or the synthesis of other nanocomposite material for broader applications.

Synthesis and sensitive detection of doxycycline with sodium bis 2-ethylhexylsulfosuccinate based silver nanoparticle.

The monitoring of residual antibiotics in the environment has gained a significant importance for the effective control, because of the high risk to human health. A simple strategy was designed for the green synthesis and detection of doxycycline (Dox) by using anionic surfactant sodium bis 2-ethylhexylsulfosuccinate based silver nanoparticles (AOT-AgNPs). The chemical reduction and capping of Ag+1 ions was achieved by sulfonyl and carbonyl functional groups of AOT molecule. The AOT-AgNPs were found to have excellent stability at variable environmental parameters (i.e. temperature, storage period, salt concentration and pH) possibly due to the strong emulsifying nature of the surfactant. Mechanism of interaction between the AOT-AgNPs and Dox was established with UV/visible, Fourier transform infrared (FTIR) spectroscopy, Atomic force microscopy (AFM) and Dynamic light scattering (DLS) techniques, which suggests the interaction via aggregates formation. The synthesize probe could detect the Dox within 15 min over a wide range of concentrations from 0.1 to 140µM with limit of detection (LOD) of 0.2 µM. As proof of strategy, we have illustrated that the AOT-AgNPs also detect Dox in biological and environmental samples with negligible interference and very significant recovery rates. Moreover, non-toxic nature against various tested cell lines (i.e. normal mouse fibroblast (NIH-3 T3) and cancerous non-small lung carcinoma (NCI-H460)) and significant antimicrobial, antibiofilm and biofilm eradicating potential of AOT-AgNPs were provide ideal nanomaterial for further applications.

The Scorpion Venom Peptide Smp76 Inhibits Viral Infection by Regulating Type-I Interferon Response.

Dengue virus (DENV) and Zika virus (ZIKV) have spread throughout many countries in the developing world and infect millions of people every year, causing severe harm to human health and the economy. Unfortunately, there are few effective vaccines and therapies available against these viruses. Therefore, the discovery of new antiviral agents is critical. Herein, a scorpion venom peptide (Smp76) characterized from Scorpio maurus palmatus was successfully expressed and purified in Escherichia coli BL21(DE3). The recombinant Smp76 (rSmp76) was found to effectively inhibit DENV and ZIKV infections in a dose-dependent manner in both cultured cell lines and primary mouse macrophages. Interestingly, rSmp76 did not inactivate the viral particles directly but suppressed the established viral infection, similar to the effect of interferon (IFN)-ß. Mechanistically, rSmp76 was revealed to upregulate the expression of IFN-ß by activating interferon regulatory transcription factor 3 (IRF3) phosphorylation, enhancing the type-I IFN response and inhibiting viral infection. This mechanism is significantly different from traditional virucidal antimicrobial peptides (AMPs). Overall, the scorpion venom peptide Smp76 is a potential new antiviral agent with a unique mechanism involving type-I IFN responses, demonstrating that natural AMPs can enhance immunity by functioning as immunomodulators.

Snake Venom Peptides: Tools of Biodiscovery.

Nature endowed snakes with a lethal secretion known as venom, which has been fine-tuned over millions of years of evolution. Snakes utilize venom to subdue their prey and to survive in their natural habitat. Venom is known to be a very poisonous mixture, consisting of a variety of molecules, such as carbohydrates, nucleosides, amino acids, lipids, proteins and peptides. Proteins and peptides are the major constituents of the dry weight of snake venoms and are of main interest for scientific investigations as well as for various pharmacological applications. Snake venoms contain enzymatic and non-enzymatic proteins and peptides, which are grouped into different families based on their structure and function. Members of a single family display significant similarities in their primary, secondary and tertiary structures, but in many cases have distinct pharmacological functions and different bioactivities. The functional specificity of peptides belonging to the same family can be attributed to subtle variations in their amino acid sequences. Currently, complementary tools and techniques are utilized to isolate and characterize the peptides, and study their potential applications as molecular probes, and possible templates for drug discovery and design investigations.

Hydration facilitates oxygenation of hemocyanin: perspectives from molecular dynamics simulations.

Molecular dynamics simulations were applied to deoxy- and oxy-hemocyanins using newly developed force field parameters for the dicopper site to evaluate their structural and dynamical properties. Data obtained from the simulations provided information of the oxygenation effect on the active site and overall topology of the protein that was analyzed by root-mean-square deviations, b-factors, and dicopper coordination geometries. Domain I of the protein was found to demonstrate higher flexibility with respect to domain II because of the interfacial rotation between domain I and II that was further endorsed by computing correlative domain movements for both forms of the protein. The oxygenation effect on the overall structure of the protein or polypeptide subunit was further explored via gyration radii evaluated for the metal-binding domain and for the whole subunit. The evaluation of hydration dynamics was carried out to understand the water mediated role of amino acid residues of the solvent tunnel facilitating the entry of oxygen molecule to the dicopper site of hemocyanin.

Quinazoline and quinazolinone as important medicinal scaffolds: a comparative patent review (2011-2016).

INTRODUCTION: Quinazoline and quinazolinone scaffolds represent an important class of biologically active nitrogen heterocyclic compounds. A variety of marketed drugs are based on these moieties. A diverse range of molecules with quinazoline/quinazolinone moieties have been reported to exhibit broad spectrum of biological activities. AREAS COVERED: This review covers recent efforts in the synthesis and biological screening of quinazoline/quinazolinone based compounds from 2011-2016. EXPERT OPINION: Quinazoline and quinazolinones represent a diverse class of biologically active nitrogen heterocyclic compounds with immense therapeutic potential. Their ease of synthetic accessibility, and flexibility in structural modifications and functionalization further adds to their appeal in medicinal chemistry. A number of currently available drugs are based on quinazoline/quinazolinone scaffold. It is interesting to note that, among the recent patents available, a lot of them focus on the promising anticancer activity of quinazoline and quinazolinone containing compounds. However their biological activity is certainly not limited to anticancer only, they are also known to elicit a number of other biological and physiological effects in vitro and in vivo respectively. The interest in quinazolines and quinazolinones is ever growing, since they offer a fairly diverse chemical space for exploration of medicinal potential.

Isolation and characterization of three new anti-proliferative Sesquiterpenes from Polygonum barbatum and their mechanism via apoptotic pathway.

BACKGROUND: The emergence of chemoresistant cancers and toxicity related to existing chemotherapeutic agents, demand the search for new pharmacophore with enhanced anti-cancer activity and least toxicity. For this purpose, three new sesquiterpenes were isolated from ethyl acetate fraction of the aerial parts of the plant Polygonum barbatum and evaluated for their anti-cancer potential. METHODS: The structural elucidation and characterization of the isolated compounds 1-3 were performed using various spectroscopic techniques such as mass, UV, IR, and extensive 1D/2D-NMR spectroscopy. Furthermore, the compounds 1-3 were subjected to screening of anti-cancer activity against different cell lines followed by brief analysis of apoptotic and anti-angiogenic potentials of the potent hit against non-small cell lung carcinoma cell line. RESULTS: All the compounds 1-3 were subjected to anti-proliferative potential against non-small cell lung carcinoma (NCI-H460), breast cancer (MCF-7), cervical cancer (HeLa) and normal mouse fibroblast (NIH-3 T3) cell lines. Among these, compound 3 was found to be more cytotoxic against NCI-H460 and MCF-7 cells (IC50 = 17.86 ± 0.72 and 11.86 ± 0.46 µM respectively). When compared with the standard drug cisplatin compound 3 was found to have more potent activity against NCI-H460 (IC50 = 19 ± 1.24 µM) as compared to MCF-7 cell lines (IC50 = 9.62 ± 0.5 µM). Compound 3 induced apoptosis in NCI-H460 cells in a dose dependent manner. It significantly downregulated, the expression of anti-apoptotic (BCL-2 L1 and p53) and increased the expression of pro-apoptotic (BAK and BAX) genes. Besides apoptosis, it also significantly reduced the cell migration and downregulated the angiogenic genes (i.e. VEGF and COX-2), thereby, inhibiting angiogenesis in NCI-H460 cells. CONCLUSION: Compound 3 possesses potent anti-proliferative potential as well as induced apoptosis and inhibited the cell migration of the cancerous cells by altering the gene expression, responsible for it.

Small molecules as activators in medicinal chemistry (2000-2016).

INTRODUCTION: From therapeutic point of view, it is often beneficial to enhance the expression of certain enzymes whose low expression is responsible for the observed ailment. Small molecules as activators of several enzymes have great biological potential as anti-microbial and anti-cancer agents, for the treatment of diabetes, obesity, metabolic disorders, and for the treatment of neurological disorders including Alzheimer's disease. This review covers patents describing small molecules as activators, and provides structural leads for the design of even more potent activators. Area covered: This review is focused on small molecules that have been explored as activators of enzymes in the last and current decade (2000-2016). Expert opinion: The ability to modulate activity of enzymes has long been a quest of medicinal chemistry. This has been the impetus behind the development of a plethora of drugs as enzyme inhibitors. However only a few enzyme activators as drugs have made it to the market. Disorders characterized by supressed enzyme activity can be treated by enhancing the activity of a specific enzyme.

Structure-Activity Relationship of Chlorotoxin-Like Peptides.

Animal venom (e.g., scorpion) is a rich source of various protein and peptide toxins with diverse physio-/pharmaco-logical activities, which generally exert their action via target-specific modulation of different ion channel functions. Scorpion venoms are among the most widely-known source of peptidyl neurotoxins used for callipering different ion channels, such as; Na⁺, K⁺, Ca⁺, Cl(-), etc. A new peptide of the chlorotoxin family (i.e., Bs-Tx7) has been isolated, sequenced and synthesized from scorpion Buthus sindicus (family Buthidae) venom. This peptide demonstrates 66% with chlorotoxin (ClTx) and 82% with CFTR channel inhibitor (GaTx1) sequence identities reported from Leiurus quinquestriatus hebraeus venom. The toxin has a molecular mass of 3821 Da and possesses four intra-chain disulphide bonds. Amino acid sequence analysis of Bs-Tx7 revealed the presence of a scissile peptide bond (i.e., Gly-Ile) for human MMP2, whose activity is increased in the case of tumour malignancy. The effect of hMMP2 on Bs-Tx7, or vice versa, observed using the FRET peptide substrate with methoxycoumarin (Mca)/dinitrophenyl (Dnp) as fluorophore/quencher, designed and synthesized to obtain the lowest Km value for this substrate, showed approximately a 60% increase in the activity of hMMP2 upon incubation of Bs-Tx7 with the enzyme at a micromolar concentration (4 µM), indicating the importance of this toxin in diseases associated with decreased MMP2 activity.

Structure-activity relationship of an alpha-toxin Bs-Tx28 from scorpion (Buthus sindicus) venom suggests a new alpha-toxin subfamily.

Scorpion venoms are among the most widely known source of peptidyl neurotoxins used for callipering different ion channels, e.g., for Na(+), K(+), Ca(+) or Cl(-). An alpha-toxin (Bs-Tx28) has been purified from the venom of scorpion Buthus sindicus, a common yellow scorpion of Sindh, Pakistan. The primary structure of Bs-Tx28 was established using a combination of MALDI-TOF-MS, LC-ESI-MS, and automated Edman degradation analysis. Bs-Tx28 consists of 65 amino acid residues (7274.3+/-2Da), including eight cysteine residues, and shows very high sequence identity (82-94%) with other long-chain alpha-neurotoxins, active against receptor site-3 of mammalian (e.g., Lqq-IV and Lqh-IV from scorpions Leiurus sp.) and insect (e.g., BJalpha-IT and Od-1 from Buthotus judaicus and Odonthobuthus doriae, respectively) voltage-gated Na(+) channels. Multiple sequence alignment and phylogenetic analysis of Bs-Tx28 with other known alpha- and alpha-like toxins suggests the presence of a new and separate subfamily of scorpion alpha-toxins. Bs-Tx28 which is weakly active in both, mammals and insects (LD(50) 0.088 and 14.3microg/g, respectively), shows strong induction of the rat afferent nerve discharge in a dose-dependent fashion (EC(50)=0.01microg/mL) which was completely abolished in the presence of tetrodotoxin suggesting the binding of Bs-Tx28 to the TTX-sensitive Na(+)-channel. Three-dimensional structural features of Bs-Tx28, established by homology modeling, were compared with other known classical alpha-mammal (AaH-II), alpha-insect (Lqh-alphaIT), and alpha-like (BmK-M4) toxins and revealed subtle variations in the Nt-, Core-, and RT-CT-domains (functional domains) which constitute a "necklace-like" structure differing significantly in all alpha-toxin subfamilies. On the other hand, a high level of conservation has been observed in the conserved hydrophobic surface with the only substitution of W43 (Y43/42) and an additional hydrophobic character at position F40 (L40/A/V/G39), as compared to the other mentioned alpha-toxins. Despite major differences within the primary structure and activities of Bs-Tx28, it shares a common structural and functional motif (e.g., transRT-farCT) within the RT-CT domain which is characteristic of scorpion alpha-mammal toxins.

Molecular mechanism of high altitude respiration: primary structure of a minor hemoglobin component from Tufted duck (Aythya fuligula, Anseriformes).

Avian hemoglobins have attracted much attention in view of the unique oxygen transport characteristics. The present study describes the primary structure of minor hemoglobin component HbD from Tufted duck (Aythya fuligula), a migratory bird seen in Pakistan during the winter season. Separation of the polypeptide subunits was achieved by ion exchange chromatography in the presence of 8M urea. Molecular masses of the intact protein as well as peptides obtained from chemical and enzymatic cleavages were determined by electrospray ionization mass spectrometry. The sequence was studied by automatic Edman degradation of the native chains and their tryptic/hydrolytic fragments in a gas-phase sequencer. Comparison of the hemoglobin sequence with the corresponding sequences of Anseriform representatives and other avian species shows residues like alpha(D)23 Asp, alpha(D)120 Asp as being specific to Tufted duck. The three-dimensional structure analyzed with the protein structure modeling package, WHAT IF, using the crystal structure coordinates of chicken hemoglobin (PDB code=1hbr) shows alpha(D)34 Val, alpha(D)38 Gln, and alpha(D)94 Asp as possible mediators offering alternate pathway for oxygen uptake and release thereby leading to distinct hypoxia tolerance in the Tufted ducks. Results are discussed with reference to function and evolution in the Anseriform representatives.