Potential drug candidates as P-glycoprotein inhibitors to reverse multidrug resistance in cancer: an in silico drug discovery study

The failure of chemotherapy in the treatment of carcinoma is mainly due to the development of multidrug resistance (MDR), which is largely caused by the overexpression of P-glycoprotein (P-gp/ABCB1/MDR1). Until recently, the 3D structure of the P-gp transporter has not been experimentally resolved, which restricted the discovery of prospective P-gp inhibitors utilizing in silico techniques. In this study, the binding energies of 512 drug candidates in clinical or investigational stages were assessed as potential P-gp inhibitors employing in silico methods. On the basis of the available experimental data, the performance of the AutoDock4.2.6 software to predict the drug-P-gp binding mode was initially validated. Molecular docking and molecular dynamics (MD) simulations combined with molecular mechanics-generalized Born surface area (MM-GBSA) binding energy computations were subsequently conducted to screen the investigated drug candidates. Based on the current results, five promising drug candidates, namely valspodar, dactinomycin, elbasvir, temsirolimus, and sirolimus, showed promising binding energies against P-gp transporter with ΔGbinding values of -126.7, -112.1, -111.9, -102.9, and -101.4 kcal/mol, respectively. The post-MD analyses revealed the energetical and structural stabilities of the identified drug candidates in complex with the P-gp transporter. Furthermore, in order to mimic the physiological conditions, the potent drugs complexed with the P-gp were subjected to 100 ns MD simulations in an explicit membrane-water environment. The pharmacokinetic properties of the identified drugs were predicted and demonstrated good ADMET characteristics. Overall, these results indicated that valspodar, dactinomycin, elbasvir, temsirolimus, and sirolimus hold promise as prospective P-gp inhibitors and warrant further invitro/invivo investigations.

A Comprehensive Review of Performance of Next-Generation Sequencing Platforms

Background

Next-generation sequencing methods have been developed and proposed to investigate any query in genomics or clinical activity involving DNA. Technical advancement in these sequencing methods has enhanced sequencing volume to several billion nucleotides within a very short time and low cost. During the last few years, the usage of the latest DNA sequencing platforms in a large number of research projects helped to improve the sequencing methods and technologies, thus enabling a wide variety of research/review publications and applications of sequencing technologies.

Objective

The proposed study is aimed at highlighting the most fast and accurate NGS instruments developed by various companies by comparing output per hour, quality of the reads, maximum read length, reads per run, and their applications in various domains. This will help research institutions and biological/clinical laboratories to choose the sequencing instrument best suited to their environment. The end users will have a general overview about the history of the sequencing technologies, latest developments, and improvements made in the sequencing technologies till now.

Results

The proposed study, based on previous studies and manufacturers' descriptions, highlighted that in terms of output per hour, Nanopore PromethION outperformed all sequencers. BGI was on the second position, and Illumina was on the third position.

Conclusion

The proposed study investigated various sequencing instruments and highlighted that, overall, Nanopore PromethION is the fastest sequencing approach. BGI and Nanopore can beat Illumina, which is currently the most popular sequencing company. With respect to quality, Ion Torrent NGS instruments are on the top of the list, Illumina is on the second position, and BGI DNB is on the third position. Secondly, memory- and time-saving algorithms and databases need to be developed to analyze data produced by the 3rd- and 4th-generation sequencing methods. This study will help people to adopt the best suited sequencing platform for their research work, clinical or diagnostic activities.

Unusual chalcogen⋯chalcogen interactions in like⋯like and unlike YCY⋯YCY complexes (Y = O, S, and Se)

Chalcogen⋯chalcogen interactions were investigated within four types of like⋯like and unlike YCY⋯YCY complexes (where Y = O, S, or Se). A plethora of quantum mechanical calculations, including molecular electrostatic potential (MEP), surface electrostatic potential extrema, point-of-charge (PoC), quantum theory of atoms in molecules (QTAIM), noncovalent interaction (NCI), and symmetry-adapted perturbation theory-based energy decomposition analysis (SAPT-EDA) calculations, were executed. The energetic findings revealed a preferential tendency of the studied chalcogen-bearing molecules to engage in type I, II, III, or IV chalcogen⋯chalcogen interactions. Notably, the selenium-bearing molecules exhibited the most potent ability to favorably participate in all the explored chalcogen⋯chalcogen interactions. Among like⋯like complexes, type IV interactions showed the most favorable negative binding energies, whereas type III interactions exhibited the weakest binding energies. Unexpectedly, oxygen-containing complexes within type IV interactions showed an alien pattern of binding energies that decreased along with an increase in the chalcogen atomic size level. QTAIM analysis provided a solo BCP, via chalcogen⋯chalcogen interactions, with no clues as to any secondary ones. SAPT-EDA outlined the domination of the explored interactions by the dispersion forces and indicated the pivotal shares of the electrostatic forces, except type III σ-hole⋯σ-hole and di-σ-hole interactions. These observations demonstrate in better detail all the types of chalcogen⋯chalcogen interactions, providing persuasive reasons for their more intensive use in versatile fields related to materials science and drug design.

Effect of External Electric Field on Tetrel Bonding Interactions in (FTF3···FH) Complexes (T = C, Si, Ge, and Sn)

A quantum chemical study was accomplished on the σ-hole interactions of the barely explored group IV elements, for the first time, in the absence and presence of the positively and negatively directed external electric field (EEF). The analyses of molecular electrostatic potential addressed the occurrence of the σ-hole on all the inspected tetrel atoms, confirming their salient versatility to engage in σ-hole interactions. MP2 energetic findings disclosed the occurrence of favorable σ-hole interactions within the tetrel bonding complexes. The tetrel bonding interactions became stronger in the order of C < Si < Ge < Sn for F-T-F3···FH complexes with the largest interaction energy amounting to -19.43 kcal/mol for the optimized F-Sn-F3···FH complex under the influence of +0.020 au EEF. The interaction energy conspicuously evolved by boosting the magnitude of the positively directed EEF value and declining the negatively directed EEF one. The decomposition analysis for the interaction energies was also executed in terms of symmetry-adapted perturbation theory, illuminating the dominant electrostatic contribution to all the studied complexes' interactions except carbon-based interactions controlled by dispersion forces. The outcomes that emerged from the current work reported significantly how the direction and strength of the EEF affect the tetrel-bonding interactions, leading to further improvements in the forthcoming studies of supramolecular chemistry and materials science.

In Silico Targeting Human Multidrug Transporter ABCG2 in Breast Cancer: Database Screening, Molecular Docking, and Molecular Dynamics Study

ABCG2 is a substantial member of the ABC transporter superfamily that plays a significant role in multidrug resistance in cancer. Until recently, the 3D structure of ABCG2 has not been resolved, which resulted in the limitation of developing potential ABCG2 inhibitors using structure-based drug discovery. Herein, eMolecules, ChEMBL, and ChEBI databases, containing >25 million compounds, were virtually screened against the ABCG2 transporter in homodimer form. Performance of AutoDock4.2.6 software to predict inhibitor-ABCG2 binding mode and affinity were validated on the basis of available experimental data. The explored databases were filtered based on docking scores. The most potent hits with binding affinities higher than that of experimental bound ligand (MZ29) were then selected and subjected to molecular mechanics minimization, followed by binding energy calculation using molecular mechanics-generalized Born surface area (MM-GBSA) approach. Furthermore, molecular dynamics simulations for 50 ns, followed by MM-GBSA binding energy calculations, were performed for the promising compounds, unveiling eight potential inhibitors with binding affinities <-55.8 kcal/mol. Structural and energetic analyses demonstrated the stability of the eight identified inhibitors over the 50 ns MD simulation. This research sheds light on the potentiality of the identified ABCG2 inhibitors as a therapeutic approach to overcome multidrug resistance cancer therapy.

Gastroprotection against Rat Ulcers by Nephthea Sterol Derivative

Different species belonging to the genus Nephthea (Acyonaceae) are a rich resource for bioactive secondary metabolites. The literature reveals that the gastroprotective effects of marine secondary metabolites have not been comprehensively studied in vivo. Hence, the present investigation aimed to examine and determine the anti-ulcer activity of 4α,24-dimethyl-5α-cholest-8β,18-dihydroxy,22E-en-3β-ol (ST-1) isolated from samples of a Nephthea species. This in vivo study was supported by in silico molecular docking and protein-protein interaction techniques. Oral administration of ST-1 reduced rat stomach ulcers with a concurrent increase in gastric mucosa. Molecular docking calculations against the H+/K+-ATPase transporter showed a higher binding affinity of ST-1, with a docking score value of -9.9 kcal/mol and a pKi value of 59.7 nM, compared to ranitidine (a commercial proton pump inhibitor, which gave values of -6.2 kcal/mol and 27.9 µM, respectively). The combined PEA-reactome analysis results revealed promising evidence of ST-1 potency as an anti-ulcer compound through significant modulation of the gene set controlling the PI3K signaling pathway, which subsequently plays a crucial role in signaling regarding epithelialization and tissue regeneration, tissue repairing and tissue remodeling. These results indicate a probable protective role for ST-1 against ethanol-induced gastric ulcers.

Anti-Viral and Immunomodulatory Properties of Propolis: Chemical Diversity, Pharmacological Properties, Preclinical and Clinical Applications, and In Silico Potential against SARS-CoV-2

Propolis, a resin produced by honeybees, has long been used as a dietary supplement and folk remedy, and more recent preclinical investigations have demonstrated a large spectrum of potential therapeutic bioactivities, including antioxidant, antibacterial, anti-inflammatory, neuroprotective, immunomodulatory, anticancer, and antiviral properties. As an antiviral agent, propolis and various constituents have shown promising preclinical efficacy against adenoviruses, influenza viruses, respiratory tract viruses, herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), human immunodeficiency virus (HIV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Over 300 chemical components have been identified in propolis, including terpenes, flavonoids, and phenolic acids, with the specific constituent profile varying widely according to geographic origin and regional flora. Propolis and its constituents have demonstrated potential efficacy against SARS-CoV-2 by modulating multiple pathogenic and antiviral pathways. Molecular docking studies have demonstrated high binding affinities of propolis derivatives to multiple SARS-CoV-2 proteins, including 3C-like protease (3CLpro), papain-like protease (PLpro), RNA-dependent RNA polymerase (RdRp), the receptor-binding domain (RBD) of the spike protein (S-protein), and helicase (NSP13), as well as to the viral target angiotensin-converting enzyme 2 (ACE2). Among these compounds, retusapurpurin A has shown high affinity to 3CLpro (ΔG = -9.4 kcal/mol), RdRp (-7.5), RBD (-7.2), NSP13 (-9.4), and ACE2 (-10.4) and potent inhibition of viral entry by forming hydrogen bonds with amino acid residues within viral and human target proteins. In addition, propolis-derived baccharin demonstrated even higher binding affinity towards PLpro (-8.2 kcal/mol). Measures of drug-likeness parameters, including metabolism, distribution, absorption, excretion, and toxicity (ADMET) characteristics, also support the potential of propolis as an effective agent to combat COVID-19.

On the Potentiality of X-T-X3 Compounds (T = C, Si, and Ge, and X = F, Cl, and Br) as Tetrel- and Halogen-Bond Donors

The versatility of the X-T-X3 compounds (where T = C, Si, and Ge, and X = F, Cl, and Br) to participate in tetrel- and halogen-bonding interactions was settled out, at the MP2/aug-cc-pVTZ level of theory, within a series of configurations for (X-T-X3)2 homodimers. The electrostatic potential computations ensured the remarkable ability of the investigated X-T-X3 monomers to participate in σ-hole halogen and tetrel interactions. The energetic findings significantly unveil the favorability of the tetrel···tetrel directional configuration with considerable negative binding energies over tetrel···halogen, type III halogen···halogen, and type II halogen···halogen analogs. Quantum theory of atoms in molecules and noncovalent interaction analyses were accomplished to disclose the nature of the tetrel- and halogen-bonding interactions within designed configurations, giving good correlations between the total electron densities and binding energies. Further insight into the binding energy physical meanings was invoked through using symmetry-adapted perturbation theory-based energy decomposition analysis, featuring the dispersion term as the most prominent force beyond the examined interactions. The theoretical results were supported by versatile crystal structures which were characterized by the same type of interactions. Presumably, the obtained findings would be considered as a solid underpinning for future supramolecular chemistry, materials science, and crystal engineering studies, as well as a fundamental linchpin for a better understanding of the biological activities of chemicals.

Blue Biotechnology: Computational Screening of Sarcophyton Cembranoid Diterpenes for SARS-CoV-2 Main Protease Inhibition

The coronavirus pandemic has affected more than 150 million people, while over 3.25 million people have died from the coronavirus disease 2019 (COVID-19). As there are no established therapies for COVID-19 treatment, drugs that inhibit viral replication are a promising target; specifically, the main protease (Mpro) that process CoV-encoded polyproteins serves as an Achilles heel for assembly of replication-transcription machinery as well as down-stream viral replication. In the search for potential antiviral drugs that target Mpro, a series of cembranoid diterpenes from the biologically active soft-coral genus Sarcophyton have been examined as SARS-CoV-2 Mpro inhibitors. Over 360 metabolites from the genus were screened using molecular docking calculations. Promising diterpenes were further characterized by molecular dynamics (MD) simulations based on molecular mechanics-generalized Born surface area (MM-GBSA) binding energy calculations. According to in silico calculations, five cembranoid diterpenes manifested adequate binding affinities as Mpro inhibitors with ΔGbinding < -33.0 kcal/mol. Binding energy and structural analyses of the most potent Sarcophyton inhibitor, bislatumlide A (340), was compared to darunavir, an HIV protease inhibitor that has been recently subjected to clinical-trial as an anti-COVID-19 drug. In silico analysis indicates that 340 has a higher binding affinity against Mpro than darunavir with ΔGbinding values of -43.8 and -34.8 kcal/mol, respectively throughout 100 ns MD simulations. Drug-likeness calculations revealed robust bioavailability and protein-protein interactions were identified for 340; biochemical signaling genes included ACE, MAPK14 and ESR1 as identified based on a STRING database. Pathway enrichment analysis combined with reactome mining revealed that 340 has the capability to re-modulate the p38 MAPK pathway hijacked by SARS-CoV-2 and antagonize injurious effects. These findings justify further in vivo and in vitro testing of 340 as an antiviral agent against SARS-CoV-2.

Prospective Drug Candidates as Human Multidrug Transporter ABCG2 Inhibitors: an In Silico Drug Discovery Study

Breast cancer resistance protein (ABCG2) is a human ATP-binding cassette (ABC) that plays a paramount role in multidrug resistance (MDR) in cancer therapy. The discovery of ABCG2 inhibitors could assist in designing unprecedented therapeutic strategies for cancer treatment. There is as yet no approved drug targeting ABCG2, although a large number of drug candidates have been clinically investigated. In this work, binding affinities of 181 drug candidates in clinical-trial or investigational stages as ABCG2 inhibitors were inspected using in silico techniques. Based on available experimental data, the performance of AutoDock4.2.6 software was first validated to predict the inhibitor-ABCG2 binding mode and affinity. Combined molecular docking calculations and molecular dynamics (MD) simulations, followed by molecular mechanics-generalized Born surface area (MM-GBSA) binding energy calculations, were then performed to filter out the studied drug candidates. From the estimated docking scores and MM-GBSA binding energies, six auspicious drug candidates-namely, pibrentasvir, venetoclax, ledipasvir, avatrombopag, cobicistat, and revefenacin-exhibited auspicious binding energies with value < -70.0 kcal/mol. Interestingly, pibrentasvir, venetoclax, and ledipasvir were observed to show even higher binding affinities with the ABCG2 transporter with binding energies of < -80.0 kcal/mol over long MD simulations of 100 ns. The stabilities of these three promising candidates in complex with ABCG2 transporter were demonstrated by their energetics and structural analyses throughout the 100 ns MD simulations. The current study throws new light on pibrentasvir, venetoclax, and ledipasvir as curative options for multidrug resistant cancers by inhibiting ABCG2 transporter.

In Silico Mining of Terpenes from Red-Sea Invertebrates for SARS-CoV-2 Main Protease (Mpro) Inhibitors

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent for the COVID-19 pandemic, which generated more than 1.82 million deaths in 2020 alone, in addition to 83.8 million infections. Currently, there is no antiviral medication to treat COVID-19. In the search for drug leads, marine-derived metabolites are reported here as prospective SARS-CoV-2 inhibitors. Two hundred and twenty-seven terpene natural products isolated from the biodiverse Red-Sea ecosystem were screened for inhibitor activity against the SARS-CoV-2 main protease (Mpro) using molecular docking and molecular dynamics (MD) simulations combined with molecular mechanics/generalized Born surface area binding energy calculations. On the basis of in silico analyses, six terpenes demonstrated high potency as Mpro inhibitors with ΔGbinding ≤ -40.0 kcal/mol. The stability and binding affinity of the most potent metabolite, erylosides B, were compared to the human immunodeficiency virus protease inhibitor, lopinavir. Erylosides B showed greater binding affinity towards SARS-CoV-2 Mpro than lopinavir over 100 ns with ΔGbinding values of -51.9 vs. -33.6 kcal/mol, respectively. Protein-protein interactions indicate that erylosides B biochemical signaling shares gene components that mediate severe acute respiratory syndrome diseases, including the cytokine- and immune-signaling components BCL2L1, IL2, and PRKC. Pathway enrichment analysis and Boolean network modeling were performed towards a deep dissection and mining of the erylosides B target-function interactions. The current study identifies erylosides B as a promising anti-COVID-19 drug lead that warrants further in vitro and in vivo testing.

Rutin and flavone analogs as prospective SARS-CoV-2 main protease inhibitors: In silico drug discovery study

Coronavirus disease 2019 (COVID-19) is a new pandemic characterized by quick spreading and illness of the respiratory system. To date, there is no specific therapy for Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2). Flavonoids, especially rutin, have attracted considerable interest as a prospective SARS-CoV-2 main protease (M^pro) inhibitor. In this study, a database containing 2017 flavone analogs was prepared and screened against SARS-CoV-2 M^pro using the molecular docking technique. According to the results, 371 flavone analogs exhibited good potency towards M^pro with docking scores less than −9.0 kcal/mol. Molecular dynamics (MD) simulations, followed by molecular mechanics-generalized Born surface area (MM/GBSA) binding energy calculations, were performed for the top potent analogs in complex with M^pro. Compared to rutin, PubChem-129-716-607 and PubChem-885-071-27 showed better binding affinities against SARS-CoV-2 M^pro over 150 ns MD course with ΔG_binding values of −69.0 and −68.1 kcal/mol, respectively. Structural and energetic analyses demonstrated high stability of the identified analogs inside the SARS-CoV-2 M^pro active site over 150 ns MD simulations. The oral bioavailabilities of probable SARS-CoV-2 M^pro inhibitors were underpinned using drug-likeness parameters. A comparison of the binding affinities demonstrated that the MM/GBSA binding energies of the identified flavone analogs were approximately three and two times less than those of lopinavir and baicalein, respectively. In conclusion, PubChem-129-716-607 and PubChem-885-071-27 are promising anti-COVID-19 drug candidates that warrant further clinical investigations.

Carotane sesquiterpenes from Ferula vesceritensis: in silico analysis as SARS-CoV-2 binding inhibitors

Two sesquiterpenes, 8α-anisate-dauc-4-ene-3,9-dione (webiol anisate) (1) and 10α-acetoxy-6α-benzoate-jaeschkeanadiol (2) as well as, ten known analogues (3-10), and two sesquiterpene coumarins (11-12) were isolated from an organic root extract of Ferula vesceritensis (Fam. Apiaceae). Chemical structures were elucidated based on IR, 1D- and 2D-NMR and HRMS, spectroscopic analyses. With molecular overlap observed between two protease inhibitors that are being examined as anti-COVID-19 drugs, and sesquiterpenes isolated here, metabolite molecular docking calculations were made using the main protease (Mpro), which is required for viral multiplication as well as RNA-dependent RNA polymerase (RdRp). In silico binding-inhibition analysis predicted that select F. vesceritensis sesquiterpenes can bind to these enzymes required for viral replication. Structures of the isolated constituents were also consistent with the chemo-systematic grouping of F. vesceritensis secondary metabolites with other Ferula species.

Prosopis juliflora leave extracts induce cell death of MCF-7, HepG2, and LS-174T cancer cell lines

Prosopis juliflora (P. juliflora) is a widespread phreatophytic tree, which belongs to the Fabaceae family. The goal of the present study is to investigate the potential anti-cancer effect of P. juliflora leave extracts and to identify its chemical composition. For this purpose, MCF-7 (breast), HepG2 (liver), and LS-174T (colorectal) cancer cell lines were cultivated and incubated with various concentrations of P. juliflora leave extracts, and its impact on cell viability, proliferation, and cell cycle stages was investigated. P. juliflora leave extracts induced concentration-dependent cytotoxicity against all tested cancer cell lines. The calculated IC₅₀ was 18.17, 33.1 and 41.9 μg/ml for MCF-7, HePG2 and LS-174T, respectively. Detailed analysis revealed that the cytotoxic action of P. juliflora extracts was mainly via necrosis but not apoptosis. Moreover, DNA content flow cytometry analysis showed cell-specific anti-proliferative action and cell cycle stages arrest. In order to identify the anti-cancer constituents of P. juliflora, the ethyl extracts were analyzed by liquid chromatography-mass spectrometry. The major constituents identified in the ethyl extracts of P. juliflora leaves were hydroxymethyl-pyridine, nicotinamide, adenine, and poly-(methyl methacrylate) (PMMA). In conclusion, P. juliflora ethyl acetate extracts have a potential anti-cancer effect against breast adenocarcinoma, hepatocellular carcinoma, and colorectal adenocarcinoma, and is enriched with anti-cancer constituents. See also Figure 1(Fig. 1).

Variations in genetic and chemical constituents of Ziziphus spina-christi L. populations grown at various altitudinal zonation up to 2227 m height

Altitudinal gradient-defined specific environmental conditions could lead to genetics and chemical variations among individuals of the same species. By using RAPD, ISSR, GC-MS and HPLC analysis, the genetic and chemical diversity of Ziziphus spina-christi plants at various altitudinal gradient namely; Abha (2227.86 m), Dala Valley (1424 m), Rakhma Valley (1000 m), Raheb Valley (505 m) and Al-Marbh (147 m) were estimated. RAPD markers revealed that the highest similarity value (40.22%) was between Raheb Valley and Al-Marbh while the lowest similarity (10.08%) was between Abha and Raheb Valley. Based on ISSR markers the highest similarity value (61.54%) was also between Raheb Valley and Al-Marbh, while the lowest similarity (26.84%) was between Abha and Rakhma Valley. GC-MS results showed the presence of various phytochemical constituents in each population. The dendrogram based on chemical compounds separated the Z. spina-christi grown at the highest elevations (Abha) from the populations in lower elevations. HPLC analysis showed that the leaves of Z. spina-christi plant contain considerable amount of vitamins including B1, B12, B2 and folic acid. In conclusion, there is a close relation between altitudinal gradients, genetic diversity and chemical constituents of the leaves of Z. spina-christi plants.

Differential-display reverse transcription-PCR (DDRT-PCR): a new technology for molecular detection and studying one of the antagonistic factors of Bacillus endophyticus strain SA against Staphylococcus aureus (MRSA)

Differential Display (DDRT-PCR) is a powerful technique for analyzing differences in gene expression. In-vivo expression technologies and differential display RT-PCR are providing new approaches to further examine a microbe's response to experimental conditions which more closely resemble natural microbial associations and habitats. In this study, Bacillus endophyticus strain SA isolated from the inner tissue of the stem of the cultivated plant (Salvadora persica, Asir, Kingdom of Saudi Arabia) produces an antagonistic factor. This factor has a broad spectrum of activity against Gram-positive and specifically against Staphylococcus aureus (MRSA). The antagonistic factor was isolated from the bacterial culture medium and purified by thin layer chromatography technique, then analyzed by GC-MS analysis. Identification of the producer strain was performed using the partial nucleotide sequence of 16S rRNA gene, which indicated that this strain is identical to B. endophyticus with 99 % similarity. The sequence of this strain was deposited at NCBI GenBank under accession number KF011545. Application of differential display RT-PCR revealed that the isolate was able to up-regulate a gene with serine protease like protein. The protein is well known as antimicrobial agent and was reported to be produced by plants, animals and insects. Serine protease is also known to be produced by bacteria for purposes oth er than bacterial-bacterial antagonistic effect, which has been confirmed by this study.

Neuroprotective role of thymoquinone against 1-methyl-4-phenylpyridinium-induced dopaminergic cell death in primary mesencephalic cell culture

OBJECTIVE

To investigate potential mechanisms mediating the neuroprotective effect of thymoquinone (TQ) on dopaminergic neurons.

METHODS

This study was conducted in the Chemistry and Biochemistry Institute, University of Veterinary Medicine, Vienna, Austria between June and August 2013. Primary cultures were prepared from embryonic mouse mesencephala (OFI/SPF) at gestation day 14. Four sets of cultures were kept untreated, treated with TQ on the eighth day in vitro (DIV) for 4 days, treated with 1-methyl-4-phenylpyridinium (MPP+) on the tenth DIV for 48 hours and co-treated with thymoquinone and MPP+. On the twelfth DIV, cultures were subjected to immunohistochemistry against tyrosine hydroxylase and fluorescent staining using LysoTracker Deep Red, 5,5`,6,6`-tetrachloro-1,1`,3,3`-tetraethylbenzimidazolylcarbocyanine (JC-1) and 4`,6-diamidino-2-phenylindole stains.

RESULTS

The MPP+ decreased the number of dopaminergic neurons by 40%, and increased the release of lactate dehydrogenase (LDH) into the culture medium. The TQ significantly rescued dopaminergic neurons and decreased the release of LDH at the concentrations of 0.1 and 1 uM. The TQ significantly shifted the red fluorescent intensity of the LysoTracker Deep Red, increased the mitochondrial membrane potential as it increased the red:green florescent ratio of JC-1, and decreased MPP+-induced apoptotic cell death.

CONCLUSION

The TQ protects dopaminergic neurons in primary mesencephalic culture by enhancing lysosomal degradation that clears damaged mitochondria and inhibits mitochondria-mediated apoptotic cell death.

Antimicrobial properties of 3 medicinal plants from Saudi Arabia against some clinical isolates of bacteria

OBJECTIVE

To examine the in vitro antibacterial activity of the ethanol extract of fresh fruits of Solanum incanum L., fresh leaves of Ricinus communis L. and Allium ampeloprasum var. porrum L., and to determine and quantify the phenol compounds of the investigated plant parts.

METHODS

This study was carried out at the Faculty of Science, King Khalid University, Abha, Kingdom of Saudi Arabia from July 2011 to September 2011. Nine clinical strains of bacteria and 3 ethanol extracts of 3 plant species were used for the antimicrobial study. Thirty grams of each sample was ground, filtrated, and each filtrate mixed with 100 ml ethanol and placed in a shaker for 48 hours. The ethanol was evaporated from the sample, weighed, and subjected to an antibacterial activity test using the agar diffusion method. The high-performance liquid chromatography was used to identify and quantify the phenols extracts of investigated samples.

RESULTS

Ethanol extract of the investigated plant parts showed antibacterial activities against different pathogenic bacteria. Leaf extracts of Ricinus communis showed the highest antibacterial activity, followed by the leaves of Allium ampeloprasum var. porrum, while the fruits of Solanum incanum showed the least activity. The amounts of main phenols detected in Ricinus communis leaves were higher than those of Solanum incanum fruits and Allium ampeloprasum var. porrum leaves.

CONCLUSION

The ethanol extract of the tested plants could be considered as an alternative source of new antibacterial drugs.

Antibacterial activity of the latex of Argemone ochroleuca Sweet

OBJECTIVE

To investigate the antibacterial effect of the crude latex of Argemone ochroleuca (A. ochroleuca) as antibacterial potential against a range of human pathogenic bacteria.

METHODS

This study was carried out at King Khalid University, Abha, Kingdom of Saudi Arabia from January to March 2010. Seventeen ml of fresh latex from A. ochroleuca Sweet was collected, and the antibacterial activity of crude and diluted latex were examined using one ml of standardized inoculum suspension, and using the agar diffusion method test against Bacillus subtilis, Enterobacter aerogenes, Micrococcus luteus, Escherichia coli, and Staphylococcus aureus. All inoculated plates were incubated aerobically at 290C for 48 hours. The diameter of the zones of inhibition was measured to the nearest mm.

RESULTS

The crude latex of A. ochroleuca exhibited a potent antibacterial effect on all bacterial strains examined. The zones of inhibition against the tested bacteria were found in the range of 9.30 - 40.3 mm along with their respective minimum inhibitory concentration values 100 ul/ml.

CONCLUSION

The observable inhibition on selected bacteria by latex of A. ochroleuca makes it a promising alternative as a potential source of natural antibacterial.