Valorization of Kappaphycus alvarezii through extraction of high-value compounds employing green approaches and assessment of the therapeutic potential of κ-carrageenan.

This study utilizes different emerging green extraction technologies to recover maximum value-added products from Kappaphycus alvarezii and evaluate their bio-functional properties. Using the supercritical fluid extraction (SFE) method, the total lipid yield of 0.21 ± 0.2 % was obtained from the biomass. Linoleic acid, eicosapentaenoic acid, arachidonic acid, γ-linolenic acid, and docosahexaenoic acid were present in higher concentrations (9.12 %) in the lipid extracted with SFE as compared to hexane (5.5 %). Using an ultrasonication assisted approach, ~56 % of κ-carrageenan was recovered from SFE residual biomass, which contains 28.5 ± 1.9 % sulfate content. It exhibited a monosaccharide content of 3,6-anhydrogalactose (~24 %) and galactose (~53 %), as well as rheological properties within FAO limitations that can be explored for food-grade applications. ~58 % of the total protein (12.5 %) from SFE residual biomass was recovered using subcritical water hydrolysis method. The effectiveness of κ-carrageenan in suppressing the 3CLpro of SARS-CoV-2 using in vitro and in silico approaches was investigated. κ-Carrageenan effectively inhibited the main protease by up to 93 % at 1.6 mg mL-1. In silico results revealed that κ-carrageenan successfully binds to the active site of the main protease while retaining the structural integrity and stability of protein-ligand complexes.

Deciphering the role of fucoidan from brown macroalgae in inhibiting SARS-CoV-2 by targeting its main protease and receptor binding domain: Invitro and insilico approach.

The current study investigated the role of fucoidan from Padina tetrastromatica and Turbinaria conoides against 3-chymotrypsin like protease (3CLpro) and receptor binding domain (RBD) spike protein of SARS-CoV-2 using an invitro and computational approach. The 3CLpro and RBD genes were successfully cloned in pET28a vector, expressed in BL-21DE3 E. coli rosetta cells and purified by ion exchange affinity and size exclusion chromatography. Fucoidan extracted from both biomass using green approach, subcritical water, was found to inhibit 3CLpro of SARS-CoV-2 with an IC50 value of up to 0.35 mg mL-1. However, fucoidan was found to be inactive against the RBD protein. Molecular docking studies demonstrated that fucoidan binds to the active sites of 3CLpro with an affinity of -5.0 kcal mol-1. In addition, molecular dynamic simulations recorded stabilized interactions of protein-ligand complexes in terms of root mean square deviation, root mean square fluctuation, the radius of gyration, solvent accessible surface area and hydrogen bond interaction. The binding energy of fucoidan with 3CLpro was determined to be -101.821 ± 12.966 kJ mol-1 using Molecular Mechanic/Poisson-Bolt-Boltzmann Surface Area analysis. Fucoidan satisfies the Absorption, Distribution, Metabolism, and Excretion (ADME) properties, including Lipinski's rule of five, which play an essential role in drug design. According to the toxicity parameters, fucoidan does not exhibit skin sensitivity, hepatotoxicity, or AMES toxicity. Therefore, this work reveals that fucoidan from brown macroalgae could act as possible inhibitors in regulating the function of the 3CLpro protein, hence inhibiting viral replication and being effective against COVID-19.

Uncovering the phytochemicals of root exudates and extracts of lead (Pb) tolerant Chrysopogon zizanioides (L.) Roberty in response to lead contamination and their effect on the chemotactic behavior of rhizospheric bacteria.

The chemical composition of root exudates and root extracts from Chrysopogon zizanioides (L.) Roberty cv KS-1 was determined in the presence of lead [Pb(II)]. Hitherto, no information is available in the literature concerning the phytochemical components of root exudates of C. zizanioides. Significantly higher concentrations of total carbohydrates (26.75 and 42.62% in root exudates and root extract, respectively), reducing sugars (21.46 and 56.11% in root exudates and root extract, respectively), total proteins (9.22 and 23.70% in root exudates and root extract, respectively), total phenolic acids (14.69 and 8.33% in root exudates and root extract, respectively), total flavonoids (14.30 and 12.28% in root exudates and root extract, respectively), and total alkaloids (12.48 and 7.96% in root exudates and root extract, respectively) were observed in samples from plants growing under Pb(II) stress in comparison to the respective controls. GC-MS profiling showed the presence of a diverse group of compounds in root exudates and extracts, including terpenes, alkaloids, flavonoids, carotenoids, plant hormones, carboxylic/organic acids, and fatty acids. Among the detected compounds, many have an important role in plant development, regulating rhizosphere microbiota and allelopathy. Furthermore, the results indicated that C. zizanioides exudates possess a chemotactic response for rhizospheric bacterial strains Bacillus licheniformis, Bacillus subtilis, and Acinetobacter junii Pb1.

Valorization of Wild-Type Cannabis indica by Supercritical CO2 Extraction and Insights into the Utilization of Raffinate Biomass

Supercritical CO2 extraction (SCCO2) extraction of cannabis oil from Indian cannabis (Cannabis indica) leaves was optimized through a central composite design using CO2 pressure (150-250 bar), temperature (30-50 °C) and time (1-2 h). From the regression model, the optimal CO2 pressure, extraction temperature and time were 250 bar, 43 °C and 1.7 h, respectively resulting in the experimental yield of 4.9 wt% of cannabis oil via SCCO2 extraction. The extract contained cannabidiol, tetrahydrocannabivarin, Δ9-tetrahydrocannabinol and Δ8-tetrahydrocannabinol as well as two terpenoids such as cis-caryophyllene and α-humulene. Besides SCCO2 extraction of cannabis oil, the raffinate biomass was utilized to extract polyphenols using water as the extraction medium. Cannabis oil and water extractive were investigated for their half-maximal inhibitory concentration (IC50) values, which were found to be 1.3 and 0.6 mg/mL, respectively. This is comparable to the commercially available antioxidant such as butylated hydroxytoluene with an IC50 value of 0.5 mg/mL. This work on SCCO2 extraction of cannabinoids and other valuable bioactive compounds provides an environmentally sustainable technique to valorize cannabis leaves.

Antiviral activity of sulfated polysaccharides from marine algae and its application in combating COVID-19: Mini review.

Marine-derived sulfated polysaccharides possess various antiviral activities against a broad range of enveloped and non-enveloped viruses. It has become the potential source of antiviral drugs for pharmaceutical development. In this review, we will discuss the different types of sulfated polysaccharides and their structural classification. Some of the major sulfated polysaccharides with potent antiviral activity, including carrageenan, agar, ulvan, fucoidan, and alginates, are considered in this review. The mechanism of these sulfated polysaccharides in inhibiting the different stages of the viral infection process inside the host cell is also demonstrated. It involves blocking the initial entry of the virus or inhibiting its transcription and translation by modulating the immune response of the host cell. In addition, we explore the potential of sulfated polysaccharides as antiviral agents in preventing recent Corona Virus Disease-2019 (COVID-19).

Antibody Combinations Targeting the Essential Antigens CyRPA, RH5, and MSP-119 Potently Neutralize Plasmodium falciparum Clinical Isolates From India and Africa.

BACKGROUND: Targeting multiple key antigens that mediate distinct Plasmodium falciparum erythrocyte invasion pathways is an attractive approach for the development of blood-stage malaria vaccines. However, the challenge is to identify antigen cocktails that elicit potent strain-transcending parasite-neutralizing antibodies efficacious at low immunoglobulin G concentrations feasible to achieve through vaccination. Previous reports have screened inhibitory antibodies primarily against well adapted laboratory parasite clones. However, validation of the parasite-neutralizing efficacy against clinical isolates with minimal in vitro cultivation is equally significant to better ascertain their prospective in vivo potency. METHODS: We evaluated the parasite-neutralizing activity of different antibodies individually and in combinations against laboratory adapted clones and clinical isolates. Clinical isolates were collected from Central India and Mozambique, Africa, and characterized for their invasion properties and genetic diversity of invasion ligands. RESULTS: In our portfolio, we evaluated 25 triple antibody combinations and identified the MSP-Fu+CyRPA+RH5 antibody combination to elicit maximal parasite neutralization against P. falciparum clinical isolates with variable properties that underwent minimal in vitro cultivation. CONCLUSIONS: The MSP-Fu+CyRPA+RH5 combination exhibited highly robust parasite neutralization against P. falciparum clones and clinical isolates, thus substantiating them as promising candidate antigens and establishing a proof of principle for the development of a combinatorial P. falciparum blood-stage malaria vaccine.

Evaluation of the cytotoxicity and interaction of lead with lead resistant bacterium Acinetobacter junii Pb1.

This study explores the potential of lead resistant bacterium Acinetobacter junii Pb1 for adsorption/accumulation of lead using various techniques. In the present work, growth of A. junii Pb1 was investigated in the presence of a range of Pb(II) concentrations (0, 100, 250, 500, and 1000 mg l-1). Lead was found to have no toxic effect on the growth of A. junii Pb1 at 100 and 250 mg l-1 concentrations. However, further increase in Pb(II) concentration (500 mg l-1) showed increase in lag phase, though growth remained unaffected and significant growth inhibition was observed when concentration was increased to 1000 mg l-1. Same was confirmed by the observations of flow cytometry. Further, the effect of Pb(II) on A. junii Pb1 was evaluated by using fluorescence microscopy, spectrofluorimetry, and flow cytometry. The spectrofluorimetry and fluorescence microscopy results revealed the accumulation of Pb(II) inside the bacterial cells as evident by green fluorescence due to lead binding fluorescent probe, Leadmium Green AM dye. Flow cytometry observations indicate an increase in cell size and granularity of exposure to lead. Thus, present work provides a new understanding of Pb(II) tolerance in A. junii Pb1 and its potential use in remediation of lead from contaminated soil.

Improved methane yield from wastewater grown algal biomass.

Methane production from the algal biomass cultivated in a laboratory scale continuous photobioreactor (PBR) using sewage was evaluated in the present work. During the preliminary experiments, algal biomass reached up to 1.69 ± 0.35 g L-1 in 12 days' growth period. Besides, 65 to 100% removal in concentrations of total dissolved phosphorus (TDP), nitrate nitrogen (NO3-N), total ammoniacal nitrogen (TAN) and soluble chemical oxygen demand (sCOD) was also recorded. The sCOD removal in the reactor was 100%, whereas removal of TDP, NO3-N and TAN were up to 75, 40 and 92%, respectively. Upon anaerobic digestion, the fresh algal biomass showed methane yield of 180 mL g-1 VSfed. Further, algal biomass was stored under natural conditions in open containers (aerobic conditions) in darkness at room temperature (27-30 °C) for 72 h. Interestingly, >48% COD solubilization from algal biomass was observed during storage. Pretreatment through natural storage was further confirmed with qualitative observations including scanning electron and fluorescence microscopic analysis. Moreover, higher methane yield (284.38 mL g-1 VSfed) was observed from the samples stored for 60 h. Thus, natural storage for a designated period may be recommended as a prerequisite stage in the process of methane production from wastewater-grown algal biomass.

A critical review on speciation, mobilization and toxicity of lead in soil-microbe-plant system and bioremediation strategies.

Lead accumulation in soils is of serious concern in agricultural production due to the harmful effects on soil microflora, crop growth and food safety. In soil, speciation of lead greatly affects its bioavailability and thus its toxicity on plants and microbes. Many plants and bacteria have evolved to develop detoxification mechanisms to counter the toxic effect of lead. Factors influencing the lead speciation include soil pH, organic matter, presence of various amendments, clay minerals and presence of organic colloids and iron oxides. Unlike, other metals little is known about the speciation and mobility of lead in soil. This review focuses on the speciation of lead in soil, its mobility, toxicity, uptake and detoxification mechanisms in plants and bacteria and bioremediation strategies for remediation of lead contaminated repositories.

Identification and localization of a Novel Invasin of Plasmodium falciparum.

Plasmodium falciparum is the causative organism for the most severe form of malaria among humans. The clinical symptoms are accredited to the asexual stage of parasite life cycle, involving merozoite invasion of erythrocyte, development and re-invasion into the new erythrocyte. Interaction of parasite proteins present on the surface or secreted from apical organelles with the host receptors is indispensable for the invasion process. Identification and elucidation of precise localization and function of these proteins will not only enhance our understanding of this process but will also aid in the progress of development of treatment strategies against malaria. Here we report the identification and localization of a novel protein, PfAEP (P. falciparum Apical Exonemal Protein) (PF3D7_1137200/ PF11_0383) which is conserved across Plasmodium species. Transcription and translation analysis have confirmed its expression in the schizont stage of P. falciparum. Super-resolution microscopy in schizonts and merozoites revealed its localization in the exonemes of P. falciparum.

Identification and characterization of a novel Plasmodium falciparum adhesin involved in erythrocyte invasion.

Malaria remains a major health problem worldwide. All clinical symptoms of malaria are attributed to the asexual blood stages of the parasite life cycle. Proteins resident in apical organelles and present on the surface of P. falciparum merozoites are considered promising candidates for the development of blood stage malaria vaccines. In the present study, we have identified and characterized a microneme associated antigen, PfMA [PlasmoDB Gene ID: PF3D7_0316000, PFC0700c]. The gene was selected by applying a set of screening criteria such as transcriptional upregulation at late schizogony, inter-species conservation and the presence of signal sequence or transmembrane domains. The gene sequence of PfMA was found to be conserved amongst various Plasmodium species. We experimentally demonstrated that the transcript for PfMA was expressed only in the late blood stages of parasite consistent with a putative role in erythrocyte invasion. PfMA was localized by immunofluorescence and immuno-electron microscopy to be in the micronemes, an apical organelle of merozoites. The functional role of the PfMA protein in erythrocyte invasion was identified as a parasite adhesin involved in direct attachment with the target erythrocyte. PfMA was demonstrated to bind erythrocytes in a sialic acid independent, chymotrypsin and trypsin resistant manner and its antibodies inhibited P. falciparum erythrocyte invasion. Invasion of erythrocytes is a complex multistep process that involves a number of redundant ligand-receptor interactions many of which still remain unknown and even uncharacterized. Our work has identified and characterized a novel P. falciparum adhesin involved in erythrocyte invasion.

Effect of allopurinol on blood pressure: a systematic review and meta-analysis.

Allopurinol is a potent xanthine oxidase inhibitor that is used in hyperuricemic patients to prevent gout. It has also been shown to decrease cardiovascular complications in a myriad of cardiovascular conditions. However, studies have reported conflicting evidence on its effects on blood pressure (BP). A systematic review was conducted using Medline, PubMed, Embase, and the Cochrane Library for all the longitudinal studies that assessed the efficacy of allopurinol on systolic and diastolic BP. A total of 10 clinical studies with 738 participants were included in the analysis. Compared with the control group, systolic BP decreased by 3.3 mm Hg (95% confidence interval [CI], 1.4-5.3 mm Hg; P=.001) and diastolic BP decreased by 1.3 mm Hg (95% CI, 0.1-2.5 mm Hg; P=.03) in patients treated with allopurinol. When analysis was restricted to the higher-quality randomized controlled trials, similar changes in systolic and diastolic BPs were found: 3.3 mm Hg (95% CI, 0.8-5.8 mm Hg; P<.001) and 1.4 mm Hg (95% CI, 0.1-2.7 mm Hg; P=.04), respectively. Allopurinol is associated with a small but significant reduction in BP. This effect can be potentially exploited to aid in controlling BP in hypertensive patients with hyperuricemia.

Identification of novel rhoptry neck protein of Plasmodium falciparum.

The clinical symptoms of malaria are attributed to the blood stage life cycle of parasite in which merozoite invades erythrocyte, undergoes multiplication and exit to re-invade into new erythrocyte to continue its life cycle. The interaction of repertoire of parasite proteins with host cell receptors is essential for invasion process. Identification, characterization and localization of the proteins involved in invasion will enrich our understanding of this complex process. In the present study we have identified a novel Apical Rhoptry Neck Protein in Plasmodium falciparum, which harbours a predicted signal and transmembrane domain and is conserved across the species. The transcription and translation analysis confirmed its expression in schizont stage of asexual cycle of P. falciparum. Immunoflouresence microscopy in schizonts and merozoites revealed its localization in the neck of rhoptries of P. falciparum. Furthermore, PfARNP has been found at the tight junction during invasion of P. falciparum merozoite to erythrocyte.

Takotsubo-like cardiomyopathy in pheochromocytoma.

BACKGROUND: Takotsubo Cardiomyopathy (TTC) is commonly triggered by acute illness, physical or emotional stress and has been associated with elevated catecholamine levels. TTC has also been associated with pheochromocytoma (TTC-pheo). METHODS: We performed a computer assisted search of the electronic databases Medline, Scopus and Google Scholar from 1965 to January 2011. All case reports with reported TTC-pheo were selected and compared to a recent review by Gianni et al. which examined primary TTC (TTC-primary). STATISTICS: Data analysis was performed using SPSS version 18. Chi-square test of Fisher's exact test was used as appropriate to compare categorical data. RESULTS: 38 cases of TTC-pheo were retrieved from literature and compared to 254 cases of TTC-p. Chest pain was the most common presentation in both groups. The TTC-pheo patients were on average 18 years younger than patients with TTC-p (p<0.01). Only a minority of TTC-pheo patients presented with classical features of pheochromocytoma including hypertension (52.6%), headache (28.9%), palpitations (31.6 %), and diaphoresis (26.3%). In TTC-pheo complications rates were higher compared to TTC-p, including cardiogenic shock (34.2% vs. 4.2%, p<0.01) and heart failure (46.7% vs. 17.7%, p<0.01). Antecedent stressors were less common in TTC-pheo. About one-third of TTC-pheo patients presented with the inverted pattern, which compared to the apical pattern, was associated with higher complication rates, including, cardiogenic shock, heart failure, acute renal failure and arrhythmias. CONCLUSIONS: Although rare, pheochromocytoma should be considered in the differential diagnosis of TTC especially in younger patients presenting without antecedent stressors and a high complication rate. The similarities in the clinical features and outcomes in patients with TTC-p and TTC-pheo point to a similar underlying cardiac pathophysiologic process at the time of the acute presentation.

Effects of mobile phone use on specific intensive care unit devices.

BACKGROUND AND AIMS: To observe the effects of mobile phone use in the vicinity of medical devices used in a critical care setting. SUBJECTS AND METHODS: Electromagnetic interference (EMI) was tested by using two types of mobile phones - GSM and CDMA. Mobile phones were placed at a distance of one foot from three medical devices - syringe pump, mechanical ventilator, and the bedside monitor - in switch off, standby, and talking modes of the phone. Medical devices were observed for any interference caused by the electromagnetic radiations (EMR) from the mobile phones. RESULTS: Out of the three medical devices that were tested, EMI occurred while using the mobile phone in the vicinity of the syringe pump, in the 'talk mode.' The mean variation observed in the calculated and delivered volume of the syringe pump was 2.66 ml. Mechanical ventilator did not show any specific adverse effects with mobile phone use in the one-foot vicinity. No other adverse effects or unexplained malfunctions or shutdown of the syringe pump, mechanical ventilator, or the bedside monitor was noted during the study period of 36 hours. CONCLUSION: EMI from mobile phones have an adverse effect on the medical devices used in critical care setup. They should be used at least one foot away from the diameter of the syringe pump.