Mohammad Ajmal Ali

Silver nanoparticles synthesized from Adenium obesum leaf extract induced DNA damage, apoptosis and autophagy via generation of reactive oxygen species

Silver nanoparticles (AgNPs) are an important class of nanomaterial used for a wide range of industrial and biomedical applications. Adenium obesum is a plant of the family Apocynaceae that is rich in toxic cardiac glycosides; however, there is scarce information on the anticancer potential of its AgNPs. We herein report the novel biosynthesis of AgNPs using aqueous leaf extract of A. obesum (AOAgNPs). The synthesis of AOAgNPs was monitored by color change and ultraviolet-visible spectroscopy (425 nm). It was further characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). The FTIR spectra for the AOAgNPs indicated the presence of terpenoids, long chain fatty acids, secondary amide derivatives and proteins that could be responsible for the reduction and capping of the formed AOAgNPs. X-ray diffraction confirmed the crystallinity of the AgNPs. The TEM images revealed mostly spherical particles in the size range of 10-30 nm. The biological properties of novel AOAgNPs were investigated on MCF-7 breast cancer cells. Cell viability was determined by the MTT assay. Generation of reactive oxygen species (ROS), DNA damage, induction of apoptosis and autophagy were assessed. A dose-dependent decrease in the cell viability was observed. The IC50 value was calculated as 217 μg/ml. Both qualitative and quantitative evaluation confirmed about a 2.5 fold increase in the generation of ROS at the highest concentration of 150 μg/ml. A significant (p<0.05) increase in the DNA damage evaluated by comet assay was evident. Flow cytometry revealed an increase in the apoptotic cells (24%) in the AOAgNPs treated group compared to the control. Acridine orange staining of acidic vesicles in exposed cells confirmed the induction of autophagy. These findings suggest that AOAgNPs increased the level of ROS resulting in heightened the DNA damage, apoptosis and autophagy in MCF-7 cells.

In vitro cytotoxicity screening of wild plant extracts from Saudi Arabia on human breast adenocarcinoma cells

This study investigated the in vitro anticancer activities of a total of 14 wild angiosperms collected in Saudi Arabia. The cytotoxic activity of each extract was assessed against human breast adenocarcinoma (MCF-7) cell lines by using the MTT assay. Among the plants screened, the potential cytotoxic activity exhibited by the extract of Lavandula dentata (Lamiaceae) was identified, and we analyzed its anticancer potential by testing antiproliferative and apoptotic activity. Our results clearly show that ethanolic extract of L. dentata exhibits promising cytotoxic activity with an IC50 value of 39 μg/mL. Analysis of cell morphological changes, DNA fragmentation and apoptosis (using an Annexin V assay) also confirmed the apoptotic effect of L. dentata extract, and thus, our data call for further investigations to determine the active chemical constituent(s) and their mechanisms of inducing apoptosis.

Taxonomic significance of trichomes micromorphology in cucurbits.

Studies on trichomes micromorphology using Scanning Electron Microscope (SEM) were undertaken in 23 species with one variety under 13 genera of the family Cucurbitaceae (viz., Benincasa hispida (Thunb.) Cogn., Citrullus lanatus (Thunb.) Matsum. & Nakai, Cucumis melo var. agrestis Naudin, Cucumis sativus L., Diplocyclos palmatus (L.) C. Jeffrey, Edgaria dargeelingensis C.B. Clarke, Gynostemma burmanicum King ex Chakr., Gynostemma pentaphyllum (Thunb.) Makino, Gynostemma pubescens (Gagnep.) C.Y. Wu, Hemsleya dipterygia Kuang & A.M. Lu, Lagenaria siceraria (Molina) Standl., Luffa acutangula (L.) Roxb., Luffa cylindrica M. Roem., Luffa echinata Roxb., Melothria heterophylla (Lour.) Cogn., Melothria leucocarpa (Blume) Cogn., Melothria maderspatana (L.) Cogn., Sechium edule (Jacq.) Sw., Thladiantha cordifolia (Blume) Cogn., Trichosanthes cucumerina L., T. cucumerina var. anguina (L.) Haines, Trichosanthes dioica Roxb., Trichosanthes lepiniana (Naudin) Cogn. and T. tricuspidata Lour.). The trichomes in the family Cucurbitaceae vary from unicellular to multicellular, conical to elongated, smooth to ridges, with or without flattened disk at base and cyctolithic appendages, thin to thick walled, curved at apices to blunt. Trichomes micromorphology in the family Cucurbitaceae was found significant taxonomically.

Molecular phylogenetic relationships among members of the family Phytolaccaceae sensu lato inferred from internal transcribed spacer sequences of nuclear ribosomal DNA

The phylogeny of a phylogenetically poorly known family, Phytolaccaceae sensu lato (s.l.), was constructed for resolving conflicts concerning taxonomic delimitations. Cladistic analyses were made based on 44 sequences of the internal transcribed spacer of nuclear ribosomal DNA from 11 families (Aizoaceae, Basellaceae, Didiereaceae, Molluginaceae, Nyctaginaceae, Phytolaccaceae s.l., Polygonaceae, Portulacaceae, Sarcobataceae, Tamaricaceae, and Nepenthaceae) of the order Caryophyllales. The maximum parsimony tree from the analysis resolved a monophyletic group of the order Caryophyllales; however, the members, Agdestis, Anisomeria, Gallesia, Gisekia, Hilleria, Ledenbergia, Microtea, Monococcus, Petiveria, Phytolacca, Rivinia, Schindleria, Seguieria, Stegnosperma, and Trichostigma, which belong to the family Phytolaccaceae s.l., did not cluster under a single clade, demonstrating that Phytolaccaceae is polyphyletic.

Ethnomedicinal assessment of Irula tribes of Walayar valley of Southern Western Ghats, India

The present study was aimed to explore the traditional knowledge of Irula tribal people who are practicing herbal medicine in Walayar valley, the Southern Western Ghats, India. A total number of 146 species of plants distributed in 122 genera belonging to 58 families were identified as commonly used ethnomedicinal plants by them. Interestingly, 26 new claims were also made in the present study. Through the data obtained from Irula tribal healers, the herbs were mostly used for medicine (40.4%) followed by trees (26.7%) and climbers (18.5%). In addition leaves were highly used for medicinal purposes, collected from 55 species (38%) followed by multiple parts from 18 species (12%). Acorus calamus is the species of higher use value (1.80) assessed to be prescribed most commonly for the treatment of cough. High informant consensus factor (1.0) obtained for insecticidal uses and cooling agent indicates that the usage of Canarium strictum and Melia dubia, and Mimosa pudica and Sesamum indicum respectively for that purposes had obtained high degree of agreement among the healers in using these species for the respective purposes. The most commonly used method of preparation was decoction (63%) followed by raw form (23%), paste (12%) and powder (2%). Therefore, it is suggested to take-up pharmacological and phytochemical studies to evaluate the species to confirm the traditional knowledge of Irulas on medicinal plants.

Interactome analysis and design of inhibitors against selected protein targets of Ser/Thr protein kinase (STPK) signaling pathways in Mycobacterium tuberculosis H37Rv.

Tuberculosis continues to be a major cause of mortality worldwide despite significant advances in chemotherapy and development of the BCG vaccine. Although curable, the tuberculosis treatment period (6-9 months) presents many concerns, including patient noncompliance and the development of drug toxicity and drug resistance. This study aimed to understand the protein-protein interactions of key proteins involved in the Mycobacterium tuberculosis STPK signal transduction pathway (such as PknB, PknE, and PstP); in addition, we attempted to identify promising leads for the inhibition of protein-protein interactions. Interactome analyses revealed the interactions of these protein targets with several other proteins, including PknG and PbpA. Drug-like candidates were screened based on Lipinskis rule of five and the absorption digestion metabolism excretion toxicity. Molecular docking of the target proteins with the selected ligands identified cryptolepine HCl to be a common molecule interacting with all protein targets (with a good docking score). The generation of a pharmacophore model for cryptolepine HCl revealed three pharmacophoric regions: aromatic hydrocarbon, hydrogen bond acceptor, and hydrogen bond donor, which play important roles in its interaction with the protein targets. Therefore, cryptolepine HCl appears to be a promising drug candidate for further optimization and validation against M. tuberculosis.

Target fishing of glycopentalone using integrated inverse docking and reverse pharmacophore mapping approach

Glycopentalone isolated from Glycosmis pentaphylla (family Rutaceae) has cytotoxic and apoptosis inducing effects in various human cancer cell lines; however, its mode of action is not known. Therefore, target fishing of glycopentalone using a combined approach of inverse docking and reverse pharmacophore mapping approach was used to identify potential targets of glycopentalone, and gain insight into its binding modes against the selected molecular targets, viz., CDK-2, CDK-6, Topoisomerase I, Bcl-2, VEGFR-2, Telomere:G-quadruplex and Topoisomerase II. These targets were chosen based on their key roles in the progression of cancer via regulation of cell cycle and DNA replication. Molecular docking analysis revealed that glycopentalone displayed binding energies ranging from -6.38 to -8.35 kcal/mol and inhibition constants ranging from 0.758 to 20.90 μM. Further, the binding affinities of glycopentalone to the targets were in the order: Telomere:G-quadruplex > VEGFR-2 > CDK-6 > CDK-2 > Topoisomerase II > Topoisomerase I > Bcl-2. Binding mode analysis revealed critical hydrogen bonds as well as hydrophobic interactions with the targets. The targets were validated by reverse pharmacophore mapping of glycopentalone against a set of 2241 known human target proteins which revealed CDK-2 and VEGFR-2 as the most favorable targets. The glycopentalone was well mapped to CDK-2 and VEGFR-2 which involve six pharmacophore features (two hydrophobic centers and four hydrogen bond acceptors) and nine pharmacophore features (five hydrophobic, two hydrogen bond acceptors and two hydrogen bond donors), respectively. The present computational approach may aid in rational identification of targets for small molecules against large set of candidate macromolecules before bioassays validation.

The potential of antioxidant activity of methanolic extract of Coscinium fenestratum (Goetgh.) Colebr (Menispermaceae)

To explore the possible bioactive compounds and to study the antioxidant capacity of Coscinium fenestratum (Goetgh.) Colebr (Menispermaceae), the qualitative and quantitative phytochemical screening for various secondary metabolites were evaluated. Using the GC–MS analysis, a total number of 30 phytochemical compounds were predicted with their retention time, molecular weight, molecular formula, peak area, structure and activities. The most prevailing heterocyclic compound was Bis(2,4,6- triisopropylphenyl) phosphinicazide (6.70%). The antioxidant activity was evaluated by spectrophotometric methods using the reducing power assay and the DPPH• and ABTS•+ scavenging assays. The activity was determined to be increased in all the test samples with the increase in the volume of the extract. C. fenestratum possess a good source of many bioactive compounds that are used to prevent diseases linked with oxidative stress.

Molecular authentication of Anthemis deserti Boiss. (Asteraceae) based on ITS2 region of nrDNA gene sequence

The dried plant material of medicinally important Anthemis deserti Boiss. (family: Asteraceae) especially when it remains in the powdered form often look similar to Anthemis melampodina Del.; and therefore, difficult to distinguish, finally lead to chances of adulteration. The adulteration in medicinal plants effects on the efficacy of the drugs. The molecular authentication of herbal plant materials such as based on the internal transcribed spacer 2 (ITS2) sequences of nuclear ribosomal DNA (nrDNA) is considered as more reliable method compared to other the biochemical or histological methods. The present study aims to molecular authentication ofA. deserti based on molecular phylogenetic analyses of ITS2 gene sequence of nrDNA region. The ITS2 region of nrDNA of A. deserti were sequenced, and the molecular phylogenetic analyses were performed together with the GenBank sequences. The Maximum Parsimony tree revealed the close relationships of A. deserti with A. melampodina; however, the Neighbor-Joining and Maximum Likelihood tree clearly revealed that A. deserti is distinct from A. melampodina, which is also supported by the differences in nucleotides at five diffident positions (i.e. 22, 28, 87, 175 and 198) in the DNA sequence alignment.

The binding proximity of methyl β-lilacinobioside isolated from Caralluma retrospiciens with topoisomerase II attributes apoptosis in breast cancer cell line

The alterations in somatic genomes that controls the mechanism of cell division as a main cause of cancer, and then the drug that specifically toxic to the cancer cells further complicates the process of the development of the widely effective potential anticancer drug. The side effects of the drug as well as the radiotherapy used for the treatment of cancer is severe; therefore, the search of the natural products from the sources of wild plants having anticancer potential is become immense importance today. The ethno-medicinal survey undertaken in Al-Fayfa and Wadi-E-Damad region of southern Saudi Arabia revealed that the Caralluma retrospiciens (Ehrenb.) N.E.Br. (family Apocynaceae) is being used for the treatment of cancer by the native inhabitants. The biological evaluation of anticancer potential of bioassay-guided fractionations of methanolic extract of whole plant of C. retrospiciens against human breast adenocarcinoma cell line (MCF-7) followed by characterization using spectroscopic methods confirmed the presence of methyl β-lilacinobioside, a novel active constituent reported for the first time from C. retrospiciens, is capable of inhibition of cell proliferation and induction of apoptosis in MCF-7 cells by regulating ROS mediated autophagy, and thus validated the folkloric claim. Based on a small-scale computational target screening, Topoisomerase II was identified as the potential binding target of methyl β-lilacinobioside.