Self-assembled renewable nano-sized pentacyclic triterpenoid maslinic acids in aqueous medium for anti-leukemic, antibacterial and biocompatibility studies: An insight into targeted proteins-compound interactions based mechanistic pathway prediction through molecular docking.

Maslinic acid is a naturally occurring dihydroxy, mono-carboxy bioactive triterpenoid. Its bulky structure was the main hindrance in the path of biological activity. Sodium and potassium salts of nano-sized triterpenoid maslinic acid were prepared from maslinic acid and its self-assembly property was studied in aqueous and aqueous-organic binary liquid mixtures. Morphology of the compounds studied by Field Emission Scanning Electron Microscopy (FESEM), Atomic Force Microscopy (AFM), High Resolution Transmission Electron Microscopy (HRTEM), Optical Microscopy, Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction (XRD) revealed vesicular morphology of the self-assemblies. Selective cytotoxicity was performed in leukemic (K-562 and KG-1a) and PBMC cells. Among the three self-assemblies (maslinic acid 1, sodium maslinate 2 and potassium maslinate 3), sodium maslinate 2 showed better antileukemic efficacy. Sodium maslinate 2 induced apoptosis in leukemic cells by elevating ROS levels and disrupting the cellular antioxidant system. From the in-silico studies, it was confirmed that 2 interacted with extrinsic and intrinsic apoptotic proteins of leukemic cells and killed those cells by inducing apoptotic pathways. The compounds 1, 2 and 3 showed significant antibacterial efficacy against E.coli strain through binding with several periplasmic membrane fusion protein (MFP) and limiting the efflux system leading to arrestation of antimicrobial resistance.

Self-Assembled Maslinic Acid Attenuates Doxorobucin Induced Cytotoxicity via Nrf2 Signaling Pathway: An In Vitro and In Silico Study in Human Healthy Cells.

The clinical applications of some well-known chemotherapeutic drugs for cancer treatment have been restricted nowadays owing to their adverse effects on many physiological systems. In this experimental study, maslinic acid (MA) isolated from Olea europaea (Olive) fruit extract was used to mitigate the cytotoxicity induced by Doxorubicin (DOX) in human healthy peripheral blood mononuclear cells (hPBMCs). Self-assembled maslinic acid (SA-MA) was obtained in ethanol-water mixture (35.5 mM: 4:1 v/v). The morphology of SA-MA was analyzed by various physicochemical characterization techniques, which revealed its micro-metric vesicular architecture as well as nano-vesicular appearances. In this study, treatment of hPBMCs with DOX has been found to generate severe intracellular oxidative stress, which was significantly mitigated after pre-treatment with SA-MA. Alteration of hPBMC morphologies after DOX treatment was also restored notably by pre-treatment with SA-MA. Furthermore, pentoxifylline (TNF-α inhibitor) and indomethacin (COX-2 inhibitor) were used to investigate the responsible pathway by which SA-MA protected hPBMCs from DOX-induced cellular stress. Restoration of hPBMC viability above 92% in both cases confirmed that SA-MA protected the cells by inhibiting inflammatory pathways generated by DOX treatment. Subsequently, in molecular docking study, it was also evaluated that MA could successfully bind with the pocket region of Keap1, while Nrf2 was capable of upregulating cytoprotecting genes.

Garland, Flower, and Petals via a Hierarchical Self-Assembly of Ursane-Type Triterpenoid Uvaol.

Uvaol, a 6-6-6-6-6 pentacyclic dihydroxy ursane-type triterpenoid, is isolable from different parts of plants Plumeria rubra, Olea europaea, Nerium oleander, Lavandula pedunculta, and Malus domestica. It is also obtained by a one-step reduction of naturally occurring triterpenoid ursolic acid. Herein, we report the first self-assembly properties of uvaol in different neat organic liquids and aqueous organic binary liquid mixtures. Spontaneous self-assembly of uvaol in different neat liquids and binary liquid mixtures yielded garland, flower, and petal-like porous superstructures of nano- to micrometer dimensions. Utilization of self-assemblies has been demonstrated in generation of anticancer drug conjugates and the removal of carcinogenic and toxic chemicals.

Self-assembly of the monohydroxy triterpenoid lupeol yielding nano-fibers, sheets and gel: environmental and drug delivery applications.

Lupeol is a medicinally important naturally abundant triterpenoid having a 6-6-6-6-5 fused pentacyclic backbone and one polar secondary "-OH" group at the C3 position of the "A" ring. It was extracted from the dried outer bark of Bombax ceiba and its self-assembly properties were investigated in different neat organic as well as aquous-organic binary liquid mixtures. The triterpenoid having only one polar "-OH" group and a rigid lipophilic backbone self-assembled in neat organic non-polar liquids like n-hexane, n-heptane, n-octane and polar liquids like DMSO, DMF, DMSO-H2O, DMF-H2O, and EtOH-H2O yielding supramolecular gels via formation of nano to micrometre long self-assembled fibrillar networks (SAFINs). Morphological investigation of the self-assemblies was carried out by field emission scanning electron microscopy, high resolution transmission electron microscopy, atomic force microscopy, optical microscopy, concentration dependent FTIR and wide angle X-ray diffraction studies. The mechanical properties of the gels were studied by concentration dependent rheological studies in different solvents. The gels were capable of removing toxic micro-pollutants like rhodamine-B and 5,6-carboxyfluorescein as well as the toxic heavy metal Cr(vi) from contaminated water. Moreover release of the chemotherapeutic drug doxorubicin from a drug loaded gel in PBS buffer at pH 7.2 has also been demonstrated by spectrophotometry.

Flower- and Grass-like Self-Assemblies of an Oleanane-Type Triterpenoid Erythrodiol: Application in the Removal of Toxic Dye from Water.

Erythrodiol (3ß-olean-12-ene-3, 28-diol) (C30H50O2) 1 is a nanosized oleanane-type fused 6-6-6-6-6 pentacyclic triterpeneoid extractable from the dried leaves of olive (Olea europia). One step reduction of oleanolic acid extracted from Lantana camara also yields the same compound. The triterpenoid has one secondary -OH group attached at C3 of the "A" ring and one primary -OH group at C28 present at the junction of the "D" and "E" rings. Here, we report the spontaneous self-assembly of erythrodiol in different neat organic liquids and aqueous-organic liquid mixtures. The nanosized dihydroxy triterpenoid having an oleanane-type lipophilic rigid skeleton self-assembled in liquids, yielding nanosized fibrils, microsized flowers, and grass-like architectures via formation of densely assembled fibrils and petals or 2D sheets. The microstructures of the self-assemblies have been characterized by different techniques like optical microscopy, electron microscopy, atomic force microscopy, FTIR, and wide angle X-ray diffraction studies. The porous self-assemblies having a large surface area obtained from 1 were capable of adsorbing toxic fluorophores like rhodamine-B, rhodamine-6G, methylene blue, and crystal violet (CV). Moreover, removal of the aforementioned toxic pigments has also been demonstrated from their aqueous solutions by using UV-visible spectrophotometry and epifluorescence microscopy.

Self assembled arjunolic acid acts as a smart weapon against cancer through TNF- α mediated ROS generation.

Arjunolic acid (AA) a plant derived pentacyclic triterpenoid which showed effective anticancer activity against MCF-7 and HeLa cells as well as no significant toxic effect was observed against normal lymphocytes. In the current study the self assemble property of arjunolic acid gives an extra emphasis on anticancer activity which was proved by several fluorescence studies like ROS generation, EtBr/AO and DAPI staining. At a selected dose of 50µg/ml AA disrupt the redox balance inside the cancer cells by producing reactive oxygen species. The apoptotic event was mediated by two key regulator proteins TNF-α and NF-κß which was proved here. The increment of the pro-inflammatory cytokines indicates the ROS mediated pathway of cancer cell apoptosis.

Self-assembly of naturally occurring stigmasterol in liquids yielding a fibrillar network and gel.

Stigmasterol, a naturally occurring 6-6-6-5 monohydroxy phytosterol, was extracted from the leaves of Indian medicinal plant Roscoea purpurea, commonly known as Kakoli. In continuation of our studies on the self-assembly properties of naturally occurring terpenoids, herein, we report the first self-assembly properties of this phytosterol in different organic liquids. The molecule self-assembled in organic liquids yielding supramolecular gels in most of the liquids studied via the formation of fibers and belt-like architechtures of nano-to micrometer diameter. Characterization of the self-assemblies carried out by using scanning electron microscopy, transmission electron microscopy, atomic force microscopy, optical microscopy, FTIR and X-ray diffraction studies indicated fibrillar network and belt-like structures. A model for the self-assembly of stigmasterol has been proposed based on molecular modeling studies, X-ray diffraction data and FTIR studies. Rheology studies indicated that the gels were of high mechanical strength. Fluorophores such as rhodamine B, carboxy fluorescein including the anticancer drug doxorubicin could be loaded in the gels. Moreover, release of the loaded fluorophores including the drug has also been demonstrated from the gel phase into aqueous medium.

Green synthesis of Nerium oleander-conjugated gold nanoparticles and study of its in vitro anticancer activity on MCF-7 cell lines and catalytic activity.

The phytochemicals present in the stem bark extract of Nerium oleander (commonly known as Karabi) have been utilized for the green synthesis of stable gold-conjugated nanoparticles at room temperature under very mild conditions. The green synthesized gold-conjugated nanoparticles were characterized by surface plasmon resonance spectroscopy, High resolution transmission electron microscopy, X-ray diffraction studies and dynamic light scattering. A mechanism for the synthesis and stabilization of gold-conjugated nanoparticles (AuNPs) has been proposed. Anticancer activity of the stabilized AuNPs studied against MCF-7 breast cancer cell line revealed that the stabilized AuNPs were highly effective for the apoptosis of cancer cells selectively. The antioxidant activity of the stem bark extract of Nerium oleander has also been studied against a long lived 2,2-diphenylpicrylhydrazyl radical at room temperature. Moreover, the utilization of the stabilized AuNPs as a catalyst has also been demonstrated.

Self-assembly of Renewable Nano-sized Triterpenoids.

Studies on plant metabolites have gained renewed interest in recent years because these can serve as renewable chemicals for the development of a sustainable society. Among various plant secondary metabolites, terpenoids constitute the major component and triterpenoids are the 30C subset of it. In recent years, triterpenoids have drawn the attention of scientific community due to many of its potential and realized applications in medicine, drug delivery, thermochromic materials, pollutant capture, catalysis, liquid crystals, etc. In this personal review, we have discussed our computational results carried out on sixty representative naturally occurring triterpenoids demonstrating that all the triterpenoids are renewable functional nano-entities. Study of the self-assembly of several triterpenoids such as betulin, betulinic acid, oleanolic acid, glycyrrhetinic acid and arjunolic acid and their derivatives in different liquids have also been discussed. Moreover, the utilization of the resulting supramolecular architectures such as vesicles, spheres, flowers and fibrillar networks of nano- to micrometer dimensions and gels have also been discussed in the perspective of green, renewable and nanos.

Hierarchical Self-Assembly of a Renewable Nanosized Pentacyclic Dihydroxy-triterpenoid Betulin Yielding Flower-Like Architectures.

Betulin, a naturally occurring 6-6-6-6-5 pentacyclic dihydroxy-triterpenoid, is extractable from the bark of white birch (Betula papyrifera). We report the first self-assembly properties of betulin in different liquids. The molecule spontaneously self-assembled in different media, yielding flower-like architectures of nano- to micrometers diameters via the formation of fibrillar networks. The self-assemblies have been characterized by optical microscopy, scanning electron microscopy, transmission electron microscopy, dynamic light scattering, FTIR, and X-ray diffraction studies. The porous microstructure of the self-assemblies has been utilized for the entrapment of fluorophore such as rhodamine-B and the anticancer drug doxorubicin. Moreover, the removal of toxic dyes such as rhodamine 6G, crystal violet, methylene blue, and cresol red has also been demonstrated.

Self assembled nano fibers of betulinic acid: A selective inducer for ROS/TNF-alpha pathway mediated leukemic cell death.

The main complication in betulinic acid (BA) based drug delivery has been observed due to its bulk structure. The present study demonstrates the potential effects of self assembled nano size betulinic acid (SA-BA) by treating human leukemic cell lines (KG-1A and K562) and its normal counterpart. Self assembly property of BA was investigated using SEM and DLS study which showed that the BA forms fibrous structure having few nanometers in diameter. Selective anti-leukemic efficacy study of SA-BA was investigated by cell viability assay. Mode of leukemic cell death and probable pathway of apoptosis was monitored by measuring ROS level, pro and anti-inflammatory cytokine status and expression of caspase-8 and caspage-3 by immunocytochemistry. Higher efficacy of SA-BA over non-assemble BA was monitored toward cancer cells, with no relevant toxicity to normal blood cells. SA-BA facilitated reactive oxygen species (ROS) mediated leukemic cell death, confirmed by pre-treatment of N-acetyl-L-cysteine. Induction of apoptosis by SA-BA treatment increased pro-inflammatory cytokines, specifically potentiated TNF-α mediated cell death, confirmed by expression of caspase-8 and caspage-3 by immunocytochemistry. This study explored the better anti-leukemic efficacy of SA-BA over BA and this modification will enrich the use of BA in cancer therapy.

Self-assembled betulinic acid augments immunomodulatory activity associates with IgG response.

Studies relating to the adjuvanic role of self assembly, nanosized betulinic acid (SA-BA) are relatively limited. The concept of immunostimulatory activity of SA-BA is based on the activation of immune system against cancer antigen. This study showed that SA-BA, a pentacyclic triterpene isolated from the bark of the Ziziphus jujube tree, elevated the immunological functions of cancer antigen in anticancer immunotherapy. We found that, SA-BA pulsed human macrophages secreted elevated level of pro-inflammatory cytokines with an increased CD4(+) cell population. Pulse macrophages were also significantly arrested the KG-1A and K562 cell growth in vitro setup at 1:10 ratio for 48h. The use of TNF-α inhibitors confirmed the association between SA-BA with TNF-α function. SA-BA pulsed macrophages displayed substantial T cell allostimulatory capacity and promoted the generation of cytotoxic T lymphocytes (CTLs). The adjuvanticity of SA-BA was proved by the generation of in vivo IgG response. Collectively, these findings will enrich the biomedical applications of SA-BA as a potent immune stimulating agent. Moreover, the macrophage stimulating efficacy of SA-BA might be an effective way in the cancer immunotherapy.

Self-assembled betulinic acid protects doxorubicin induced apoptosis followed by reduction of ROS-TNF-α-caspase-3 activity.

Doxorubicin (DOX) is a well-known drug used to treat a wide range of solid tumor and hematological malignancies, but the use of this drug is now restricted owing to its severe side effects, including normal cellular toxicity. This study was conducted to evaluate the potency of self-assembled betulinic acid (SA-BA) against DOX induced chemotherapeutic toxicity in human peripheral blood lymphocytes (PBLs). The isolated betulinic acid from the bark of Ziziphus jujuba tree was purified by column chromatography and characterized by FT-IR, XRD, (1)H NMR and self-assembly property was investigated by SEM imaging. DOX treatment produced significant reduction of viability of PBLs mainly by lowering cellular anti-oxidant pool and elevating the reactive oxygen species level. Pre-treatment with SA-BA followed by DOX exposure for 24h protected the PBLs from DOX induced oxidative stress. Potent anti-apoptotic role of SA-BA was also confirmed by FACS analysis and western blot assay. Severe inflammation is one of the major concerns in DOX treatment. We found that pre-treatment with SA-BA on PBLs significantly protected the PBLs from DOX induced inflammation. Thus, our finding confirms that SA-BA can be used to ameliorate the cytotoxic effects of DOX, which can be a helpful strategy during DOX mediated chemotherapy in cancer patients.

First self-assembly study of betulinic acid, a renewable nano-sized, 6-6-6-6-5 pentacyclic monohydroxy triterpenic acid.

Self-assembly of betulinic acid, a renewable nano-sized 6-6-6-6-5 pentacyclic triterpenic acid studied in twenty two organic liquids and alcohol-water mixtures showed that it self-assembled in all the liquids studied affording strong gels in nineteen organic liquids and also in alcohol-water mixtures. Optical and electron microscopy and atomic force microscopy studies revealed fibrillar networks having fibers of nano- to micro-metre cross sections and micrometre lengths.

Eugenol protects nicotine-induced superoxide mediated oxidative damage in murine peritoneal macrophages in vitro.

The present work is aimed at evaluating the protective effect of eugenol against in vitro nicotine-induced toxicity in murine peritoneal macrophages, compared with N-acetylcysteine. Eugenol was isolated from Ocimum gratissimum and characterized by HPLC, FTIR, (1)H NMR. To establish most effective protective support, we used five different concentrations of eugenol (1, 5, 10, 15, and 20microg/ml) and N-acetylcysteine (0.25, 0.5, 1.0, 2.0, and 5.0microg/ml) against 10mM nicotine in mice peritoneal macrophages. A dose-dependent protective effect was observed with all doses of eugenol and N-acetylcysteine, as evidenced by decreased level of superoxide anion generation and malondialdehyde, and also increased level of reduced glutathione, and superoxide dismutase activity. Moreover, maximum protection was observed at the concentration of 15.0microg/ml eugenol (0.09nM) and 1.0microg/ml N-acetylcysteine (0.006nM). Further, eugenol (15.0microg/ml) and N-acetylcysteine (1.0microg/ml) were tested against nicotine (10mM) toxicity by analyzing the radical generation, lipid, protein, DNA damage, and endogenous antioxidant status. There was a significant increase in the level of radical generation, NADPH oxidase and myeloperoxidase activity, lipid, protein, DNA damage and oxidized glutathione level in nicotine-treated group, which were significantly reduced by eugenol and N-acetylcysteine supplementation. Antioxidant status was significantly depleted in the nicotine-treated group, which was effectively restored by eugenol and N-acetylcysteine supplementation. The protection by eugenol against nicotine toxicity was merely equal effective to that of N-acetylcysteine. These findings suggest the potential use and benefit of eugenol isolated from O. gratissimum as a modulator of nicotine-induced cellular damage and it may be used as an immunomodulatory drug against nicotine toxicity.

Donor-acceptor interaction promoted gelation: visual observation of color change.

An anthrylidene derivative of arjunolic acid could immobilize varieties of organic solvents at low concentrations in the presence of an electron-deficient guest. Gelation in the presence of picric acid in organic solvents could be observed visually with concomitant color change. Electron micrographs of the xerogels showed a fibrous structure having fibers of submicron diameters. [structure: see text].