Cordycepin Nanoencapsulated in Poly(Lactic-Co-Glycolic Acid) Exhibits Better Cytotoxicity and Lower Hemotoxicity Than Free Drug.

PURPOSE: Cordycepin, a natural product isolated from the fungus Cordyceps militaris, is a potential candidate for breast cancer therapy. However, due to its structural similarity with adenosine, cordycepin is rapidly metabolized into an inactive form in the body, hindering its development as a therapeutic agent. In the present study, we have prepared cordycepin as nanoparticles in poly(lactic-co-glycolic acid) (PLGA) and compared their cellular uptake, cytotoxicity and hemolytic potential with free cordycepin. MATERIALS AND METHODS: Cordycepin-loaded PLGA nanoparticles (CPNPs) were prepared by the double-emulsion solvent evaporation method. Physico-chemical characterization of the nanoparticles was done by zetasizer, transmission electron microscopy (TEM) and reverse-phase high-pressure liquid chromatography (RP-HPLC) analyses. Cellular uptake and cytotoxicity of CPNPs and free drug were tested in human breast cancer cells (MCF7). Hemolytic potential of both of these forms was evaluated in rat red blood cells (RBCs). RESULTS: Physico-chemical characterization revealed that CPNPs were spherical in shape, possessed a size range of 179-246 nm, and released the encapsulated drug sustainably over a period of 10 days. CPNPs exhibited a high level of cellular uptake and cytotoxicity than the free drug in MCF-7 cells. While CPNPs were not toxic to rat RBCs even at high concentrations, free cordycepin induced hemolysis of these cells at relatively low concentration. CONCLUSION: Our results reveal that delivery as CPNPs could enhance the clinical efficacy of cordycepin substantially.

Correction: Marslin, G., et al. Secondary Metabolites in the Green Synthesis of Metallic Nanoparticles. Materials 2018, 11, 940.

The authors have overlooked a few mistakes when rearranging the Table 1 and Table 2 and references at the final stages, which were carried-over to the published version of the review [...].

Elicitation as a tool to improve the profiles of high-value secondary metabolites and pharmacological properties of Hypericum perforatum.

OBJECTIVES: In this review, we aim at updating the available information on the improvement of the Hypericum perforatum L. (Hypericaceae) phytochemical profile and pharmacological properties via elicitation. KEY FINDINGS: Hypericum perforatum seedlings, shoots, roots, calli and cell suspension cultures were treated with diverse elicitors to induce the formation of secondary metabolites. The extracts of the elicitor-treated plant material containing naphthodianthrones, phloroglucinols, xanthones, flavonoids and other new compounds were quantitatively analysed and tested for their bioactivities. While hypericins were mainly produced in H. perforatum cultures containing dark nodules, namely shoots and seedlings, other classes of compounds such as xanthones, phloroglucinols and flavonoids were formed in all types of cultures. The extracts obtained from elicitor-treated samples generally possessed better bioactivities compared to the extract of control biomass. SUMMARY: Although elicitation is an excellent tool for the production of valuable secondary metabolites in H. perforatum cell and tissue cultures, its exploitation is still in its infancy mainly due to the lack of reproducibility and difficulties in scaling up biomass production.

Prediction and elucidation of factors affecting solubilisation of imatinib mesylate in lipids.

The physico-chemical properties of lipids influencing the solubilisation of imatinib mesylate (IM) in lipid matrix were evaluated and a statistical model to predict the same has been derived in the present study. After experimental quantification of IM solubility in various lipids, Hansen Hildebrand's total solubility parameters were calculated in order to study the role of various forces connected to lipid-drug interaction. To develop a relationship between the various descriptors of the lipids and experimental solubility of IM in lipids (% w/w), quantitative structure-solubility relationship (QSSR) was used. To generate equations that can predict the solubility of IM in lipids (%w/w), multiple linear regression was used. Amongst the various lipids tested, glyceryl monostearate and behenic acid solubilised the highest (6.19 ± 0.22%) and lowest (0.01 ± 0.01%) amounts of IM respectively. Our results suggested that alkyl chain length, polarity of the lipids, index of cohesive interaction in solids, estimated number of hydrogen bonds that would be accepted by the solute from water molecules in an aqueous solution, estimated number of hydrogen bonds that would be donated by the solute to water molecules in an aqueous solution and solvent accessible surface area collectively play a significant role in solubilising IM in the lipids. The equation developed could predict the solubility of IM in lipids with good accuracy (R2pred = 0.912).

Secondary Metabolites in the Green Synthesis of Metallic Nanoparticles.

The ability of organisms and organic compounds to reduce metal ions and stabilize them into nanoparticles (NPs) forms the basis of green synthesis. To date, synthesis of NPs from various metal ions using a diverse array of plant extracts has been reported. However, a clear understanding of the mechanism of green synthesis of NPs is lacking. Although most studies have neglected to analyze the green-synthesized NPs (GNPs) for the presence of compounds derived from the extract, several studies have demonstrated the conjugation of sugars, secondary metabolites, and proteins in these biogenic NPs. Despite several reports on the bioactivities (antimicrobial, antioxidant, cytotoxic, catalytic, etc.) of GNPs, only a handful of studies have compared these activities with their chemically synthesized counterparts. These comparisons have demonstrated that GNPs possess better bioactivities than NPs synthesized by other methods, which might be attributed to the presence of plant-derived compounds in these NPs. The ability of NPs to bind with organic compounds to form a stable complex has huge potential in the harvesting of precious molecules and for drug discovery, if harnessed meticulously. A thorough understanding of the mechanisms of green synthesis and high-throughput screening of stabilizing/capping agents on the physico-chemical properties of GNPs is warranted to realize the full potential of green nanotechnology.

Oral Delivery of Curcumin Polymeric Nanoparticles Ameliorates CCl4-Induced Subacute Hepatotoxicity in Wistar Rats.

Curcumin is the major bioactive compound of Curcuma longa, an important medicinal plant used in traditional herbal formulations since ancient times. In the present study, we report that curcumin nanoparticles (ηCur) protects Wistar rats against carbon tetrachloride (CCl4)-induced subacute hepatotoxicity. Nanoparticles of sizes less than 220 nm with spherical shape were prepared using PLGA and PVA respectively as polymer and stabilizer. Test animals were injected via intraperitoneal route with 1 mL/kg CCl4 (8% in olive oil) twice a week over a period of 8 weeks to induce hepatotoxicity. On the days following the CCl4 injection, test animals were orally administered with either curcumin or its equivalent dose of ηCur. Behavioural observation, biochemical analysis of serum and histopathological examination of liver of the experimental animals indicated that ηCur offer significantly higher hepatoprotection compared to curcumin.

Solid Lipid Nanoparticles of Albendazole for Enhancing Cellular Uptake and Cytotoxicity against U-87 MG Glioma Cell Lines.

Albendazole (ABZ) is an antihelminthic drug used for the treatment of several parasitic infestations. In addition to this, there are reports on the anticancer activity of ABZ against a wide range of cancer types. However, its effect on glioma has not yet been reported. In the present study, cytotoxicity of ABZ and ABZ loaded solid lipid nanoparticles (ASLNs) was tested in human glioma/astrocytoma cell line (U-87 MG). Using glyceryl trimyristate as lipid carrier and tween 80 as surfactant spherical ASLNs with an average size of 218.4 ± 5.1 nm were prepared by a combination of high shear homogenization and probe sonication methods. A biphasic in vitro release pattern of ABZ from ASLNs was observed, where 82% of ABZ was released in 24 h. In vitro cell line studies have shown that ABZ in the form of ASLNs was more cytotoxic (IC50 = 4.90 µg/mL) to U-87 MG cells compared to ABZ in the free form (IC50 = 13.30 µg/mL) due to the efficient uptake of the former by these cells.

Nanoparticles Alter Secondary Metabolism in Plants via ROS Burst.

The particles within the size range of 1 and 100 nm are known as nanoparticles (NPs). NP-containing wastes released from household, industrial and medical products are emerging as a new threat to the environment. Plants, being fixed to the two major environmental sinks where NPs accumulate - namely water and soil, cannot escape the impact of nanopollution. Recent studies have shown that plant growth, development and physiology are significantly affected by NPs. But, the effect of NPs on plant secondary metabolism is still obscure. The induction of reactive oxygen species (ROS) following interactions with NPs has been observed consistently across plant species. Taking into account the existing link between ROS and secondary signaling messengers that lead to transcriptional regulation of secondary metabolism, in this perspective we put forward the argument that ROS induced in plants upon their interaction with NPs will likely interfere with plant secondary metabolism. As plant secondary metabolites play vital roles in plant performance, communication, and adaptation, a comprehensive understanding of plant secondary metabolism in response to NPs is an utmost priority.

Curcumin Encapsulated into Methoxy Poly(Ethylene Glycol) Poly(ε-Caprolactone) Nanoparticles Increases Cellular Uptake and Neuroprotective Effect in Glioma Cells.

Curcumin is a natural polyphenolic compound isolated from turmeric (Curcuma longa) with well-demonstrated neuroprotective and anticancer activities. Although curcumin is safe even at high doses in humans, it exhibits poor bioavailability, mainly due to poor absorption, fast metabolism, and rapid systemic elimination. To overcome these issues, several approaches, such as nanoparticle-mediated targeted delivery, have been undertaken with different degrees of success. The present study was conducted to compare the neuroprotective effect of curcumin encapsulated in poly(ε-caprolactone) and methoxy poly(ethylene glycol) poly(ε-caprolactone) nanoparticles in U251 glioblastoma cells. Prepared nanoparticles were physically characterized by laser doppler anemometry, transmission electron microscopy, and X-ray diffraction. The results from laser doppler anemometry confirmed that the size of poly(ε-caprolactone) and poly(ethylene glycol) poly(ε-caprolactone) nanoparticles ranged between 200-240 nm for poly(ε-caprolactone) nanoparticles and 30-70 nm for poly(ethylene glycol) poly(ε-caprolactone) nanoparticles, and transmission electron microscopy images revealed their spherical shape. Treatment of U251 glioma cells and zebrafish embryos with poly(ε-caprolactone) and poly(ethylene glycol) poly(ε-caprolactone) nanoparticles loaded with curcumin revealed efficient cellular uptake. The cellular uptake of poly(ethylene glycol) poly(ε-caprolactone) nanoparticles was higher in comparison to poly(ε-caprolactone) nanoparticles. Moreover, poly(ethylene glycol) poly(ε-caprolactone) di-block copolymer-loaded curcumin nanoparticles were able to protect the glioma cells against tBHP induced-oxidative damage better than free curcumin. Together, our results show that curcumin-loaded poly(ethylene glycol) poly(ε-caprolactone) di-block copolymer nanoparticles possess significantly stronger neuroprotective effect in U251 human glioma cells compared to free curcumin and curcumin-loaded poly(ε-caprolactone) nanoparticles.

Quillaja saponin: A prospective emulsifier for the preparation of solid lipid nanoparticles.

Quillaja saponin (QS) is a non-ionic amphiphilic surfactant of natural origin. In the present study, we evaluated its potential to form solid lipid nanoparticles (SLNs) in the presence of stearic acid (SA) as a lipid carrier and imatinib mesylate (IM) as a model drug. IM loaded solid lipid nanoparticles (IMSLNs) were prepared using the hot homogenisation method. Characterisation of IMSLNs revealed that they were quasi-spherical in shape, neutrally charged and 143.5-641.9nm in size. Haemolysis, a toxicity issue of QS was not observed in SLNs. Comparative in vitro cytotoxicity analyses performed in human breast cancer cell line MCF7 revealed that IMSLNs were more toxic than IM. On the other hand, in vitro viability studies in the RAW264.7 cell line did not show any sign of toxicity by IMSLNs. Our results indicate that QS hold great potential in nano drug delivery as an emulsifier.

A brief perspective on the diverging theories of lymphatic targeting with colloids.

For targeted delivery of colloids to the lymphatic system, the colloids should efficiently reach and remain in the lymphatics for a considerable period of time. As per the current knowledge, diffusion and phagocytosis are the two mechanisms through which colloids reach the lymphatic system. Several parameters including particle size and charge have been shown to affect the direct uptake of colloids by the lymphatic system. Although many researchers attached ligands on the surface of colloids to promote phagocytosis-mediated lymphatic delivery, another school of thought suggests avoidance of phagocytosis by use of carriers like polyethylene glycol (PEG)ylated colloids to impart stealth attributes and evade phagocytosis. In this perspective, we weigh up the paradoxical theories and approaches available in the literature to draw conclusions on the conditions favorable for achieving efficient lymphatic targeting of colloids.

Antimicrobial activity of cream incorporated with silver nanoparticles biosynthesized from Withania somnifera.

We report on the antimicrobial activity of a cream formulation of silver nanoparticles (AgNPs), biosynthesized using Withania somnifera extract. Aqueous extracts of leaves promoted efficient green synthesis of AgNPs compared to fruits and root extracts of W. somnifera. Biosynthesized AgNPs were characterized for their size and shape by physical-chemical techniques such as UV-visible spectroscopy, laser Doppler anemometry, transmission electron microscopy, scanning electron microscopy, atomic force microscopy, X-ray diffraction, and X-ray energy dispersive spectroscopy. After confirming the antimicrobial potential of AgNPs, they were incorporated into a cream. Cream formulations of AgNPs and AgNO3 were prepared and compared for their antimicrobial activity against human pathogens (Staphylococcus aureus, Pseudomonas aeruginosa, Proteus vulgaris, Escherichia coli, and Candida albicans) and a plant pathogen (Agrobacterium tumefaciens). Our results show that AgNP creams possess significantly higher antimicrobial activity against the tested organisms.

PEGylated ofloxacin nanoparticles render strong antibacterial activity against many clinically important human pathogens.

The rise of bacterial resistance against important drugs threatens their clinical utility. Fluoroquinones, one of the most important classes of contemporary antibiotics has also reported to suffer bacterial resistance. Since the general mechanism of bacterial resistance against fluoroquinone antibiotics (e.g. ofloxacin) consists of target mutations resulting in reduced membrane permeability and increased efflux by the bacteria, strategies that could increase bacterial uptake and reduce efflux of the drug would provide effective treatment. In the present study, we have compared the efficiencies of ofloxacin delivered in the form of free drug (OFX) and as nanoparticles on bacterial uptake and antibacterial activity. Although both poly(lactic-co-glycolic acid) (OFX-PLGA) and methoxy poly(ethylene glycol)-b-poly(lactic-co-glycolic acid) (OFX-mPEG-PLGA) nanoformulations presented improved bacterial uptake and antibacterial activity against all the tested human bacterial pathogens, namely, Escherichia coli, Proteus vulgaris, Salmonella typhimurium, Pseudomonas aeruginosa, Klebsiella pneumoniae and Staphylococcus aureus, OFX-mPEG-PLGA showed significantly higher bacterial uptake and antibacterial activity compared to OFX-PLGA. We have also found that mPEG-PLGA nanoencapsulation could significantly inhibit Bacillus subtilis resistance development against OFX.

Delivery as nanoparticles reduces imatinib mesylate-induced cardiotoxicity and improves anticancer activity.

Clinical effectiveness of imatinib mesylate in cancer treatment is compromised by its off-target cardiotoxicity. In the present study, we have developed physically stable imatinib mesylate-loaded poly(lactide-co-glycolide) nanoparticles (INPs) that could sustainably release the drug, and studied its efficacy by in vitro anticancer and in vivo cardiotoxicity assays. MTT (methylthiazolyldiphenyl-tetrazolium bromide) assay revealed that INPs are more cytotoxic to MCF-7 breast cancer cells compared to the equivalent concentration of free imatinib mesylate. Wistar rats orally administered with 50 mg/kg INPs for 28 days showed no significant cardiotoxicity or associated changes. Whereas, increased alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase levels, and reduced white blood cell, red blood cell, and hemoglobin content were observed in the animals administered with free drug. While the histological sections from hearts of animals that received INPs did not show any significant cardiotoxic symptoms, loss of normal architecture and increased cytoplasmic vacuolization were observed in the heart sections of animals administered with free imatinib mesylate. Based on these results, we conclude that nano-encapsulation of imatinib mesylate increases its efficacy against cancer cells, with almost no cardiotoxicity.

Poly (ɛ-caprolactone) nanoparticles of carboplatin: Preparation, characterization and in vitro cytotoxicity evaluation in U-87 MG cell lines.

Carboplatin is a platinum based drug used in the treatment of several malignancies. Due to poor cellular uptake, generally, a larger dose of drug is administered to achieve therapeutic levels, causing harmful side-effects such as hematologic toxicity. In order to enhance the cellular uptake of carboplatin, we have developed carboplatin loaded nanoparticles using the biodegradable polymer poly (ɛ-caprolactone) (PCL). Nanoparticles ranging from the size of 23.77±1.37 to 96.73±2.79 nm with positive zeta potential and moderate entrapment efficiency (54.21±0.98%) were obtained. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) confirmed the spherical morphology and smooth surface of all nanoformulations. The concentrations of PCL and the stabilizer (DMAB) are found to play a role in determining the size and the entrapment efficiency of the nanoparticles. Drug release from nanoparticles followed a biphasic pattern with an initial burst release followed by a sustained release for 10h. Results of in vitro cellular uptake and cytotoxicity studies revealed that carboplatin in the form of PCL-nanoparticles were efficiently up taken and displayed profound cytotoxicity to U-87 MG (human glioma) cells than the free drug. Importantly, unlike the free carboplatin, carboplatin in the form of PCL nanoparticles did not present any haemolytic activity in rat erythrocytes, a major side effect of this chemotherapeutic drug. This suggests that poly (ɛ-caprolactone) nanoencapsulation of carboplatin might be an efficient approach to treat cancer, while reducing carboplatin induced haemolysis.

Test anxiety levels of board exam going students in Tamil Nadu, India.

The latest report by the National Crime Records Bureau has positioned Tamil Nadu as the Indian state with highest suicide rate. At least in part, this is happening due to exam pressure among adolescents, emphasizing the imperative need to understand the pattern of anxiety and various factors contributing to it among students. The present study was conducted to analyze the level of state anxiety among board exam attending school students in Tamil Nadu, India. A group of 100 students containing 50 boys and 50 girls from 10th and 12th grades participated in the study and their state anxiety before board exams was measured by Westside Test Anxiety Scale. We found that all board exam going students had increased level of anxiety, which was particularly higher among boys and 12th standard board exam going students. Analysis of various demographic variables showed that students from nuclear families presented higher anxiety levels compared to their desired competitive group. Overall, our results showing the prevalence of state anxiety among board exam going students in Tamil Nadu, India, support the recent attempt taken by Tamil Nadu government to improve student's academic performance in a healthier manner by appointing psychologists in all government schools.

Evaluation of the analgesic activity of ethyl acetate, methanol and aqueous extracts of Pleurotus eous mushroom.

OBJECTIVE: To evaluate the analgesic activity of the ethyl acetate, methanol and aqueous extracts of Pleurotus eous (P. eous) mushroom. METHODS: The dried fruiting bodies were extracted with ethyl acetate, methanol and water. The analgesic effect of extracts of P. eous were investigated at doses 250,500 and 1,000 mg/kg body weight, using acetic-acid induced writhing, hot-plate, tail immersion and tail-clip tests. RESULTS: P. eous extracts produced significant reduction in number of writhes induced by intraperitoneal injection of acetic-acid (P<0.05). Moreover, in hot-plate and tail immersion test, all the three extracts significantly raised the pain threshold at different time of observation (0-60 min) in comparison with control (P<0.05). In tail-clip test the extracts also caused a significant inhibition of pain at both the doses used (P<0.05). CONCLUSIONS: The results of present study suggest that extracts of P. eous possess potent analgesic property and could serve as a base for future drugs.

Poly(D,L-lactic-co-glycolic acid) nanoencapsulation reduces Erlotinib-induced subacute toxicity in rat.

Erlotinib-HCl is a quinazoline derivative used as a drug in the therapy of non-small-cell lung cancer. The present study was conducted to compare the subacute toxicity induced by Erlotinib-HCl delivered to rats as nanoparticles and as free drug. Wistar rats were orally administered with a daily dosage of 200 mg kg(-1) Erlotinib-HCl either as free drug or as Poly(D,L-lactic-co-glycolic acid) (PLGA) encapsulated nanoparticles. After four weeks of treatment, the animals were analyzed for toxicological changes. Although nanoparticulate form of the drug did not induce any toxicity, free drug significantly reduced the levels of white blood cells (WBC), red blood cells (RBC) and haemoglobin, while increasing the levels of neutrophils and corpuscular haemoglobin. Moreover, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were significantly increased in the animals administered with free drug. Histopathological studies confirmed significant damage to the internal organs of animals treated with free drug. Whereas, the internal organs of animals treated with the drug encapsulated in PLGA nanoparticles were more or less similar to the healthy organs. Our results show that Erlotinib-HCl delivered in the form of nanoparticles has less toxic effect than the free drug in experimental rats.