Seaweed polysaccharide derived bioaldehyde nanocomposite: Potential application in anticancer therapeutics

5H-benzo[c]fluorene derivative exhibits antiproliferative activity via microtubule destabilization

Present study aimed at a single component cyclization of 2-benzylidene-1-tetralones for the preparation of 5H-benzo[c]fluorenes and their antiproliferative activity. This ring closure reaction underwent via reductive cyclization in the presence of a sodium borohydride-aluminium chloride system. Ten diverse 5H-benzo[c]fluorene derivatives were prepared and evaluated for antiproliferative activity against three human cancer cell lines by SRB assay. Four of these benzofluorenes exhibited significant antiproliferative effect with an IC50 < 10.75 µM. The best representative compound 21, exhibited IC50 against K562 leukemic cells at 3.27 µM in SRB assay and 7.68 µM in Soft agar colony assay. It exhibited a microtubule destabilization effect in tubulin kinetics and inhibited 82.9 % microtubule polymer mass at 10 µM concentration in Protein Sedimentation assay (Microtubule). Compound 21 exerted G0/G1 phase arrest in cell division cycle analysis in K562 cells. It also induced apoptosis in K562 cells via activation of Caspase cascade pathway. Furthermore, compound 21 also possessed anti-inflammatory activity by inhibiting TNF-α and IL-6 moderately. It exhibited significant in vivo efficacy and reduced K562 tumour in xenograft mice by 47 % at an 80 mg/kg oral dose. Further, it was found to be safe and well tolerable up to 1000 mg/kg in Swiss albino mice. Compound 21 needs to be optimized for better in vivo efficacy in rodent models for further development.

Selenium nanoparticles stabilized by Sargassum fusiforme polysaccharides: Synthesis, characterization and bioactivity

Selenium nanoparticles (SeNPs) are a potential tumor therapeutic drug and have attracted widespread attention due to their high bioavailability and significant anticancer activity. However, the poor water solubility and degradability of selenium nanoparticles severely limit their application. In this study, spherical selenium nanoparticles with a particle size of approximately 50 nm were prepared by using Sargassum fusiforme polysaccharide (SFPS) as a modifier and Tween-80 as a stabilizer. The results of in vitro experiments showed that Sargassum fusiforme polysaccharide-Tween-80-Selenium nanoparticles (SFPS-Tw-SeNPs) had a significant inhibitory effect on A549 cells, with an IC50 value of 6.14 μg/mL, and showed antitumor cell migration and invasion ability against A549 cells in scratch assays and cell migration and invasion assays (transwell assays). Western blot experiments showed that SFPS-Tw-SeNPs could inhibit the expression of tumor migration- and invasion-related proteins. These results suggest that SFPS-Tw-SeNPs may be potential tumor therapeutic agents, especially for the treatment of human lung cancer.

Updated Progress on Polysaccharides with Anti-Diabetic Effects through the Regulation of Gut Microbiota: Sources, Mechanisms, and Structure-Activity Relationships

Diabetes mellitus (DM) is a common chronic metabolic disease worldwide. The disturbance of the gut microbiota has a complex influence on the development of DM. Polysaccharides are one type of the most important natural components with anti-diabetic effects. Gut microbiota can participate in the fermentation of polysaccharides, and through this, polysaccharides regulate the gut microbiota and improve DM. This review begins by a summary of the sources, anti-diabetic effects and the gut microbiota regulation functions of natural polysaccharides. Then, the mechanisms of polysaccharides in regulating the gut microbiota to exert anti-diabetic effects and the structure-activity relationship are summarized. It is found that polysaccharides from plants, fungi, and marine organisms show great hypoglycemic activities and the gut microbiota regulation functions. The mechanisms mainly include repairing the gut burrier, reshaping gut microbiota composition, changing the metabolites, regulating anti-inflammatory activity and immune function, and regulating the signal pathways. Structural characteristics of polysaccharides, such as monosaccharide composition, molecular weight, and type of glycosidic linkage, show great influence on the anti-diabetic activity of polysaccharides. This review provides a reference for the exploration and development of the anti-diabetic effects of polysaccharides.

Cancer reduction in mice with Prakasine nanomedicine immunotherapy

In this study, non-toxic mercury nanoparticle Prakasine (PRK-NP) was synthesized as per 'Prakash theory of metal drugs' and nanoparticle's non toxicity has been demonstrated by employing in vitro MTT (dose = 320ug/ml), SBR (dose = 80ug/ml) and apoptosis assays (dose = 320ug/ml), and in vivo acute and chronic toxicity studies in mice (n = 12, dose = 900 mg/kg body weight oral), rat (n = 14, dose = 500 mg/kg body weight oral for 18 months), rabbit (n = 14, dose = 500 mg/kg body weight oral for 18 months) and dogs (n = 14, dose = 500 mg/kg body weight oral for 18 months). The MTT, SBR and apoptosis assays established no cytotoxicity, no genotoxicity and no cytolytic anticancer effects. The mice, rat, rabbit and dog studies also indicated nontoxicity. The PRK-NPs significantly reduced the breast cancer tumour in murine mammary tumour - C3H/HeJ model 35% and 43.7% in mice at doses of 200 mg/kg and 500 mg/kg respectively. Also, in xenograft mammary tumour mice model the tumour regressions are 25.7% and 83% in the doses of 500 mg/kg and 1000 mg/kg respectively, compared to standard positive control drugs without any adverse effects and toxicity. Thus, the current study beholds anticipation PRK-NPs may play a vital role in therapeutic.

Evaluation of cashew gum-polyvinyl alcohol (CG-PVA) electrospun nanofiber mat for scarless wound healing in a murine model

Modern-day treatment for burns and wounds demands scarless healing which is becoming a challenging clinical problem. Thus, to alleviate such issues, it becomes essential to develop biocompatible and biodegradable wound dressing material for skin tissue regeneration, which could heal the wound in a very short span leaving no scars. The present study focuses on the development of nanofiber of Cashew gum polysaccharide-Polyvinyl alcohol using electrospinning. The prepared nanofiber was optimized based on uniformity of fiber diameter (FESEM), mechanical property (Tensile Strength), and optical contact angle (OCA) and was subjected to evaluation of: antimicrobial activity against Streptococcus aureus and Escherichia coli, hemocompatibility, and in-vitro biodegradability. The nanofiber was also characterized using different analytical techniques including thermogravimetric analysis, Fourier-transform infrared spectroscopy, and X-ray diffraction. The cytotoxicity was also investigated on L929 fibroblast cells using an SRB assay. The in-vivo wound healing assay showed accelerated healing in comparison to untreated wounds. The in-vivo wound healing assay and histopathological slides of regenerated tissue confirmed that the nanofiber has the potential to accelerate healing properties.

Inhibition of H1N1 by Picochlorum sp. 122 via AKT and p53 signaling pathways

Influenza viruses cause a severe threat to global health, which can lead to annual epidemics and cause pandemics occasionally. However, the number of anti-influenza therapeutic agents is very limited. Polysaccharides, extracted from Picochlorum sp. (PPE), seaweed Polysaccharides, have exhibited antiviral activity and were expected to be used for influenza treatment. In our research, the capability of PPE to inhibit H1N1 infection was proved in MDCK cells. PPE could make MDCK cells avoid being infected with H1N1 and inhibited nuclear fragmentation and condensation of chromatin. PPE evidently inhibited the generation of reactive oxygen species in MDCK cells. Mechanism study revealed that PPE prevented MDCK cells from H1N1 infection through induction of apoptosis by stimulating AKT signaling pathway and suppressing p-p53 signaling pathway. In conclusion, PPE turns out to act as a prospective antiviral drug for H1N1 influenza.

Development of hyaluronic acid-anchored polycaprolactone nanoparticles for efficient delivery of PLK1 siRNA to breast cancer

PlK1 has a significant role in the development of breast cancer. Thus, silencing of PlK1 gene may arrest the growth of breast cancer. However, the in vivo stability of PlK1 siRNA after injection remains a challenge to target the specific site. The delivery of siPlK1 RNA via viral vector and amine group-terminated dendrimer is associated with immune reaction and cellular cytotoxicity. Thus, in the present study, hyaluronic acid-functionalized and -thiolated polycaprolactone nanoparticles (SH-HPP NPs) were developed for enhancing the targeting capabilities of siRNA towards human breast cancer cells. NPs displayed size in the range of 180-217 nm, and with sustain and pH-dependent release of siRNA up to 120 h. The in vitro treatments with siRNA-containing NPs showed the high number of necrotic cells and the cell cycle arrest at the G2/M phase. The gene expression analysis depicts the decrease of endogenous PLK1 siRNA expression on MCF-7 cells upon PLK1 NPs treatment. In vitro cytotoxicity experiments demonstrated effective anticancer properties against MCF-7. Finally, in vivo results showed that substantial tumor inhibition was achieved with PLK1 siRNA-containing SH-HPP NPs in comparison of the control group. Hence, HPP NPs have enormous potential for the selective delivery of siRNA, i.e., breast cancer cells.

Preparation and intrinsic kinetics study of the scale-up production of hydroxypropyl agar by heterogeneous hydroxypropylation reaction

Hydroxypropylation is effective in modifying the structure and properties of agar. So far, the industrial scale-up production of hydroxypropylated agar has not been evaluated. Therefore, the large-scale production of the hydroxypropylation of agar using a heterogeneous reaction system was evaluated in the present this study. The structures and properties of the hydroxypropyl agar (HPA) product were measured and the intrinsic kinetics of the heterogeneous reaction were determined and analyzed. The results showed that the large-scale HPA had good thermal stability, and lower viscosity, gelling temperature and melting temperature compared with those of agar. The SEM indicated that the improvement of solubility of HPA was not only due to the hydrophilic effect of hydroxypropyl group, but also due to the formation of cluster structure and grid structure. The characteristic of heterogeneous hydroxypropylation reaction were determined by preliminary kinetic experiments, which demonstrated that the reaction order of propylene oxide was 2, while that for agar was approximately 0. The reaction activation energy of heterogeneous hydroxypropylation reaction was calculated to be 83.50 kJ/mol using the Arrhenius formula. Taken together, the results would provide guidances for the industrialization of hydroxypropyl agar.

Inhibition of enterovirus 71 infection by polysaccharides extracted from Picochlorum sp. 122 via the AKT and ATM/ATR signaling pathways

Enterovirus 71 (EV71) poses a major threat to public health globally due to severe and even fatal hand, foot, and mouth disease (HFMD). However, no effective antiviral agents are available to treat HFMD caused by this virus. Polysaccharides have been shown to exhibit antiviral activity, and polysaccharides extracted from Picochlorum sp. 122 (PPE) could potentially be used to treat HFMD, but reports on their antiviral activity are limited. In this study, the antiviral activity of PPE against EV71 was verified in Vero cells. PPE was shown to limit EV71 infection, as demonstrated using an MTT assay and by observing the cellular cytopathic effect. In addition, a decrease in VP1 RNA and protein levels indicated that PPE effectively inhibits proliferation of EV71 in Vero cells. An annexin V affinity assay also indicated that PPE protects host cells from apoptosis through the AKT and ATM/ATR signalling pathways. These results demonstrate that PPE has potential as an antiviral drug to treat HFMD caused by EV71.

Bioinspired Nanomodification Strategies: Moving from Chemical-Based Agrosystems to Sustainable Agriculture

Agrochemicals have supported the development of the agricultural economy and national population over the past century. However, excessive applications of agrochemicals pose threats to the environment and human health. In the last decades, nanoparticles (NPs) have been a hot topic in many fields, especially in agriculture, because of their physicochemical properties. Nevertheless, the prevalent methods for fabricating NPs are uneconomical and involve toxic reagents, hindering their extensive applications in the agricultural sector. In contrast, inspired by biological exemplifications from microbes and plants, their extract and biomass can act as a reducing and capping agent to form NPs without any toxic reagents. NPs synthesized through these bioinspired routes are cost-effective, ecofriendly, and high performing. With the development of nanotechnology, biosynthetic NPs (bioNPs) have been proven to be a substitute strategy for agrochemicals and traditional NPs in heavy-metal remediation of soil, promotion of plant growth, and management of plant disease with less toxicity and higher performance. Therefore, bioinspired synthesis of NPs will be an inevitable trend for sustainable development in agricultural fields. This critical review will demonstrate the bioinspired synthesis of NPs and discuss the influence of bioNPs on agricultural soil, crop growth, and crop diseases compared to chemical NPs or agrochemicals.

Seaweed bioactive compounds: Promising and safe inputs for the green synthesis of metal nanoparticles in the food industry

Scientific research on developing and characterizing eco-friendly metal nanoparticles (NPs) is an active area experiencing currently a systematic and continuous growth. A variety of physical, chemical and more recently biological methods can be used for the synthesis of metal nanoparticles. Among them, reports supporting the potential use of algae in the NPs green synthesis, contribute with only a minor proportion, although seaweed was demonstrated to perform as a successful reducing and stabilizing agent. Thus, the first part of the present review depicts the up-to-date information on the use of algae extracts for the synthesis of metal nanoparticles, including a deep discussion of the certain advantages as well as some limitations of this synthesis route. In the second part, the available characterization techniques to unravel their inherent properties such as specific size, shape, composition, morphology and dispersibility are comprehensively described, to finally focus on the factors affecting their applications, bioactivity, potential toxic impact on living organisms and incorporation into food matrices or food packaging, as well as future prospects. The present article identifies the key knowledge gap in a systematic way highlighting the critical next steps in the green synthesis of metal NPs mediated by algae.

Optimization of Extraction and Purification of Polysaccharides from Veronicastrum axillare, and Evaluation of Their Biological Activities

Veronicastrum axillare polysaccharides (VAP) were isolated by cellulase-assisted digestion. The optimum conditions (2 % cellulase, 47 °C for 2.5 h, then, 95 °C for 2.5 h, pH 4.1, solid/liquid ratio 1 : 7.6) were identified by a combination of single factor optimization and response surface DOE (design of experiment) methods, and achieved a yield of 4.7 %. Treatment with 1 % TCA for 10 min, then, 2 % DEAE-cellulose removed protein and colored impurities. Purified VAP retained most of the radical-scavenging activities and GES-1 cell protection capability in vitro, indicating VAP were the key active components of V. axillare. Some molecular features were identified by FT-IR and NMR analyses. The molecular weight was estimated from DOSY NMR experiments to be around 21 kDa. There were 6.3 % uronic acid residues in the VAP. The constituent sugars after TFA hydrolysis were identified by HPLC to include glucose, arabinose, rhamnose, galactose, and xylose in a molar ratio of 405 : 259 : 82 : 42 : 1.