In this work, facile fabrication of lignin nanoparticles (LNP)-based three-dimensional reduced graphene oxide hydrogel (rGO@LNP) has been demonstrated as a novel strategy for environmental applications. Herein, LNP were facilely synthesized from walnut shell waste through a direct chemical route. These LNP were incorporated into the continuous porous network of rGO network to fabricate rGO@LNP hydrogel. Characterization studies were carried out using various analytical techniques viz. scanning electron microscopy, Fourier transform IR spectroscopy, X-ray diffraction and thermogravimetric analysis. The efficiency of rGO@LNP hydrogel as adsorptive platform was evaluated by employing methylene blue and Pb2+ as model pollutants, whilst the effect of various experimental parameters was ascertained for optimal performance. Furthermore, Agar well diffusion method was used to check the antibacterial activities of the hydrogel using two bacterial pathogenic strains, i.e. Klebsiella pneumoniae (gram negative) and Enterococcus faecalis (gram positive). Results showed that after the inclusion of LNP into rGO hydrogel, there was a marked improvement in pollutant's uptake ability and compared to bare LNP and rGO, the composite hydrogel showed enhanced bactericidal effect. Overall, this approach is outstanding because of the synergy of functional properties of nano-lignin and rGO due to multi-interaction sites in the resulting hydrogel. The results presented herein support the application of rGO@LNP as innovative water filter material for scavenging broad spectrum pollutants and bactericidal properties.
Tocotrienols have been reported to exert anticancer, anti-inflammatory, antioxidant, cardio-protective and boneprotective effects through modulation of NFκB signalling pathway. The objective of this systematic review is to evaluate available literature showing the effect of tocotrienols on NFκB signalling pathway and identify the potential mechanisms involved. A comprehensive search was conducted using PubMed and SCOPUS databases using the keywords "tocotrienol" and "NFκB" or "nuclear factor kappa b". Main inclusion criteria were English language original articles showing the effect of tocotrienol on NFκB signalling pathway. Fifty-nine articles were selected from the total of 117 articles initially retrieved from the literature search. Modulation of regulatory proteins and genes such as inhibition of farnesyl prenyl transferase were found to be the mechanisms underlying the tocotrienol-induced suppression of NFκB activation.
Large amounts of agricultural waste, especially marine product waste, are produced annually. These wastes can be used to produce compounds with high-added value. Chitosan is one such valuable product that can be obtained from crustacean wastes. Various biological activities of chitosan and its derivatives, especially antimicrobial, antioxidant, and anticancer properties, have been confirmed by many studies. The unique characteristics of chitosan, especially chitosan nanocarriers, have led to the expansion of using chitosan in various sectors, especially in biomedical sciences and food industries. On the other hand, essential oils, known as volatile and aromatic compounds of plants, have attracted the attention of researchers in recent years. Like chitosan, essential oils have various biological activities, including antimicrobial, antioxidant, and anticancer. In recent years, one of the ways to improve the biological properties of chitosan is to use essential oils encapsulated in chitosan nanocarriers. Among the various biological activities of chitosan nanocarriers containing essential oils, most studies conducted in recent years have been in the field of antimicrobial activity. It was documented that the antimicrobial activity was increased by reducing the size of chitosan particles in the nanoscale. In addition, the antimicrobial activity was intensified when essential oils were in the structure of chitosan nanoparticles. Essential oils can increase the antimicrobial activity of chitosan nanoparticles with synergistic effects. Using essential oils in the structure of chitosan nanocarriers can also improve the other biological properties (antioxidant and anticancer activities) of chitosan and increase the application fields of chitosan. Of course, using essential oils in chitosan nanocarriers for commercial use requires more studies, including stability during storage and effectiveness in real environments. This review aims to overview recent studies on the biological effects of essential oils encapsulated in chitosan nanocarriers, with notes on their biological mechanisms.
Inorganic and synthetic flocculants are widely investigated for removing harmful microalgae, such as Microcystis aeruginosa. However, their toxicity and non-biodegradability are shortcomings. Bioflocculants based on extracellular polysaccharides have attracted much attention as alternative flocculants. However, its high production cost is a limiting factor for applying bioflocculants. Here, we investigate the potential of the dead cells of a marine filamentous bacterium, Aureispira sp. CCB-QB1, as a novel flocculant on M. aeruginosa cells. The removal efficiency of M. aeruginosa cells by the dead cells was measured by mixing and shaking both components in a buffer with 5 mM CaCl2 in different incubation times and concentrations of the dead cells. After that, the minimum effective concentration of CaCl2 was determined. The combination effect of FeCl3 and the dead cells on the removal efficiency was tested. The structure of cell aggregates consisted of the dead cells and M. aeruginosa cells were also observed using a scanning electron microscope. The maximum removal efficiency (75.39%) was reached within 3 min in the presence of CaCl2 when 5 mg/ml of the dead cells (wet cells) were added. The optimal concentration of CaCl2 was 5 mM. The combination of the dead cells and a low concentration of FeCl3 (10 mg/L) with 5 mM of CaCl2 significantly improved the removal efficiency by about 1.2 times (P
The worldwide spreading of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has posed a serious threat to health, economic, environmental, and social aspects of human lives. Currently, there are no approved treatments that can effectively block the virus although several existing antimalarial and antiviral agents have been repurposed and allowed use during the pandemic under the emergency use authorization (EUA) status. This review gives an updated overview of the antiviral effects of phytochemicals including alkaloids, flavonoids, and terpenoids against the COVID-19 virus and their mechanisms of action. Search for natural lead molecules against SARS-CoV-2 has been focusing on virtual screening and in vitro studies on phytochemicals that have shown great promise against other coronaviruses such as SARS-CoV. Until now, there is limited data on in vivo investigations to examine the antiviral activity of plants in SARS-CoV-2-infected animal models and the studies were performed using crude extracts. Further experimental and preclinical investigations on the in vivo effects of phytochemicals have to be performed to provide sufficient efficacy and safety data before clinical studies can be performed to develop them into COVID-19 drugs. Phytochemicals are potential sources of new chemical leads for the development of safe and potent anti-SARS-CoV-2 agents.
Introduction Listeriosis, a foodborne infection caused by Listeria monocytogenes, could lead to febrile listerial gastroenteritis and a more invasive form which is often associated with a high mortality and hospitalisation rate. Gentamicin, used as an adjunct therapy with ampicillin, remains the treatment of choice for this life-threatening and invasive infection.Gap statement Nevertheless, there is little data on gentamicin resistance determinants in L. monocytogenes.Aim In this study, we selected and characterised B2b, a gentamicin-resistant mutant derived from L. monocytogenes ATCC 19115 to determine the target(s) of resistance in L. monocytogenes after exposure to gentamicin.Methodology Whole-genome sequencing was carried out to identify the mutation site(s) and possible mechanism(s) of resistance. The mutant was characterised using antimicrobial susceptibility testing and PCR. For biological verifications, complementation and allelic exchange mutagenesis were carried out.Results We found that the gentamicin resistance in B2b was caused by a 10 bp deletion in atpG2 which encodes a gamma subunit of the ATP synthase in L. monocytogenes. Using atpG2 PCR, various other mutations were identified in other gentamicin resistant mutants derived from ATCC 19115. In addition, the mutation from B2b, when introduced into L. ivanovii, also caused gentamicin resistance in this Listeria species.Conclusion Hence, atpG2 mutations appear to be important determinants of gentamicin resistance not only in L. monocytogenes but possibly also in other Listeria species.
Plant bioresources are relied upon as natural, inexpensive, and sustainable remedies for the management of several chronic diseases worldwide. Plants have historically been consumed for medicinal purposes based on traditional belief, but this trend is currently changing. The growing interest in the medicinal properties of plant bioresources stems from concerns of side effects and other adverse effects caused by synthetic drugs. This interest has yielded a better understanding of the roles of plant bioactive compounds in health promotion and disease prevention, including the underlying mechanisms involved in such functional effects. The desire to maximize the potential of phytochemicals has led to the development of "rich fractions," in which extracts contain bioactive compounds in addition to elevated levels of the primary compound. Although a rich fraction effectively increases the bioactivity of the extract, the standardization and quality assurance process can be challenging. However, the supercritical fluid extraction (SFE) system is a promising green technology in this regard. Future clinical and pharmacological studies are needed to fully elucidate the implications of these preparations in the management of human diseases, thereby fostering a move toward evidence-based medicine.
Natural polysaccharides are renewable with a high degree of biocompatibility, biodegradability, and ability to mimic the natural extracellular matrix (ECM) microenvironment. Comprehensive investigations of polysaccharides are essential for our fundamental understanding of exploiting its potential as bio-composite, nano-conjugate and in pharmaceutical sectors. Polysaccharides are considered to be superior to other polymers, for its ease in tailoring, bio-compatibility, bio-activity, homogeneity and bio-adhesive properties. The main focus of this review is to spotlight the new advancements and challenges concerned with surface modification, binding domains, biological interaction with the conjugate including stability, polydispersity, and biodegradability. In this review, we have limited our survey to three essential polysaccharides including cellulose, starch, and glycogen that are sourced from plants, microbes, and animals respectively are reviewed. We also present the polysaccharides which have been extensively modified with the various types of conjugates for combating last-ditch pharmaceutical challenges.
Honey is a natural substance with many medicinal properties, including antibacterial, hepatoprotective, hypoglycemic, antioxidant and antihypertensive effects. It reduces hyperglycemia in diabetic rats and humans. However, the mechanism(s) of its hypoglycemic effect remain(s) unknown. Honey comprises many constituents, making it difficult to ascertain which component(s) contribute(s) to its hypoglycemic effect. Nevertheless, available evidence indicates that honey consists of predominantly fructose and glucose. The objective of this review is to summarize findings which indicate that fructose exerts a hypoglycemic effect. The data show that glucose and fructose exert a synergistic effect in the gastrointestinal tract and pancreas. This synergistic effect might enhance intestinal fructose absorption and/or stimulate insulin secretion. The results indicate that fructose enhances hepatic glucose uptake and glycogen synthesis and storage via activation of hepatic glucokinase and glycogen synthase, respectively. The data also demonstrate the beneficial effects of fructose on glycemic control, glucose- and appetite-regulating hormones, body weight, food intake, oxidation of carbohydrate and energy expenditure. In view of the similarities of these effects of fructose with those of honey, the evidence may support the role of fructose in honey in mediating the hypoglycemic effect of honey.
Haruan, Channa striatus, is a snakehead fish consumed in many parts of the southeast Asian region. It is believed to promote wound healing, as well as reduce post-operative pain. In an attempt to establish the scientific basis for the alleged pain-relieving benefits of this fish, we studied the antinociceptive effects of whole fillet and mucus extracts from haruan in the mouse using the abdominal constriction and tail flick tests. In the abdominal constriction test, the 30 min fillet extract exhibited concentration-dependent inhibition of the writhing response in the 10-50% concentration range, with 20% as the IC50 value. This activity was not dependent on the duration of extraction, with no significant differences among the extracts obtained at durations of 10, 20, 30, 60, 90 and 120 min (range between 45-54% inhibition at 20% concentration). The mucus extract also showed concentration-dependent inhibition of the abdominal constriction response-at the highest concentration used the average inhibition was 68.9%, while IC50 value was 25%. Neither the fillet extract (30 min, 20%) nor the mucus extract (25%) had any demonstrable effect on the tail flick latency on their own, but significantly enhanced the antinociceptive activity of morphine in this assay. Similarly, low concentrations of the mucus and fillet extract enhanced the effects of morphine in the abdominal constriction test. Collectively, these results suggest a scientific basis for the folklore practice of eating haruan fish in the post-operative period for pain relief: Haruan extracts have antinociceptive activity and enhance the activity of other antinociceptive agents.
We read with interest the narrative review authored by Kiser et al. (2021), which discussed extensively the antioxidant effect and anti-inflammatory effect of sulforaphane, a dietary supplement found in high amounts in cruciferous vegetables that ais orally accessible and well-tolerated. Notably, in their review, the authors also discussed the potential use of sulforaphane in patients with coronavirus disease 2019 (COVID-19). Sulforaphane mediates the inhibitory effect on NLRP3 inflammasome activation and we believe that this could be the main mechanism where sulforaphane is useful for patients with COVID-19.
To formulate a dental bleaching agent with strawberry extract that has potent bleaching properties and antimicrobial efficacy. Enamel specimens (3 × 3 × 2 mm3) were prepared. Quaternary Ammonium Silane (CaC2 enriched) was homogenized with fresh strawberries: Group 1: supernatant strawberry (10 g) extract
This review identifies terpenes isolated from the medicinal Angiosperms of Asia and the Pacific with antibacterial and/or antifungal activities and analyses their distribution, molecular mass, solubility, and modes of action. All data in this review were compiled from Google Scholar, PubMed, Science Direct, Web of Science, ChemSpider, PubChem, and library searches from 1968 to 2022. About 300 antibacterial and/or antifungal terpenes were identified during this period. Terpenes with a MIC ≤ 2 µg/mL are mostly amphiphilic and active against Gram-positive bacteria, with a molecular mass ranging from about 150 to 550 g/mol, and a polar surface area around 20 Å². Carvacrol, celastrol, cuminol, dysoxyhainic acid I, ent-1β,14β-diacetoxy-7α-hydroxykaur-16-en-15-one, ergosterol-5,8-endoperoxide, geranylgeraniol, gossypol, 16α-hydroxy-cleroda-3,13 (14)Z-diene-15,16-olide, 7-hydroxycadalene, 17-hydroxyjolkinolide B, (20R)-3β-hydroxy-24,25,26,27-tetranor-5α cycloartan-23,21-olide, mansonone F, (+)-6,6'-methoxygossypol, polygodial, pristimerin, terpinen-4-ol, and α-terpineol are chemical frameworks that could be candidates for the further development of lead antibacterial or antifungal drugs.
Oil-in-water (o/w) emulsion is utilized as an insecticide delivery system for mosquito control. However, evaporation inhibition adjuvant is needed to prevent fog drift, inhibit release of insecticidal actives and prolong suspension time. In the current study, we evaluated the effect of different short-chain alcohols, namely, propylene glycol, 1,3-propanediol, glycerol and crude glycerol, as adjuvants on the physicochemical properties of d-phenothrin o/w emulsion system. The bioactivity of optimized formulations containing 20 wt% glycerol (D1), 20 wt% propylene glycol (D2) and without added alcohol (negative control) were tested against larvae, pupae and adult Aedes aegypti (Ae. aegypti). It was found that propylene glycol produced smaller droplets at lower concentrations but poor long-term stability at higher concentrations, whereas glycerol had an appreciable effect on initial droplet size and stability with increasing concentration. According to the dose-response bioassays and room size chamber testing, the highest larvicidal, pupicidal and adulticidal activities were observed with D2, followed by D1 and negative control. Overall, the above study demonstrated improved emulsion stabilities and potency against Ae. aegypti larvae, pupae and adults using glycerol as adjuvant for effective mosquito control.
BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is a monogenic kidney disorder that impairs renal functions progressively leading to kidney failure. The disease affects between 1:400 and 1:1000 ratio of the people worldwide. It is caused by the mutated PKD1 and PKD2 genes which encode for the defective polycystins. Polycystins mimic the receptor protein or protein channel and mediate aberrant cell signaling that causes cystic development in the renal parenchyma. The cystic development is driven by the increased cyclic AMP stimulating fluid secretion and infinite cell growth. In recent years, natural product-derived small molecules or drugs targeting specific signaling pathways have caught attention in the drug discovery discipline. The advantages of natural products over synthetic drugs enthusiast researchers to utilize the medicinal benefits in various diseases including ADPKD.
CONCLUSION: Overall, this review discusses some of the previously studied and reported natural products and their mechanisms of action which may potentially be redirected into ADPKD.
Acinetobacter baumannii (A. baumannii) is one of the members of ESKAPE bacteria which is considered multidrug resistant globally. The objective of this study is to determine the protein docking of different antibiotic resistance gene (ARGs) in A. baumannii. In silico analysis of antibiotic resistance genes against carbapenem are the blaOXA-51, blaOXA-23, blaOXA-58, blaOXA-24, blaOXA-143, NMD-1 and IMP-1 in A. baumannii. The doripenem, imipenem and meropenem were docked to blaOXA-51 and blaOXA-23 using PyRx. The top docking energy was -5.5 kcal/mol by imipenem and doripenem and meropenem showed a binding score of -5. 2 kcal/mol each and blaOXA-23 energy was -4.3 kcal/mol by imipenem and meropenem showed a binding score of -2.3 kcal/mol, while doripenem showed the binding score of -3.4 kcal/mol. Similarly, doripenem imipenem and meropenem were docked to blaOXA-58, IMP-1, Rec A and blaOXA-143, with docking energy was -8.8 kcal/mol by doripenem and meropenem each while imipenem showed a binding score of -4.2 kcal/mol and with IMP-1 demonstrated their binding energies. was -5.7 kcal/mol by meropenem and doripenem showed a binding score of -5.3 kcal/mol, while imipenem showed a binding score of -4.5 kcal/mol. And docking energy was -4.9 kcal/mol by imipenem and meropenem showed binding energy of -3.6 kcal/mol each while doripenem showed a binding score of -3.9 kcal/mol in RecA and with blaOXA-143 docking energy was -3.0 kcal/mol by imipenem and meropenem showed a binding score of -1.9 kcal/mol, while doripenem showed the binding score of -2.5 kcal/mol respectively. Doripenem, imipenem, and meropenem docking findings with blaOXA-24 confirmed their binding energies. Doripenem had the highest docking energy of -5.5 kcal/mol, meropenem had a binding score of -4.0 kcal/mol, and imipenem had a binding score of -3.9 kcal/mol. PyRx was used to dock the doripenem, imipenem, and meropenem to NMD-1. Docking energies for doripenem were all - 4.0 kcal/mol, whereas meropenem had docking energy of -3.3 kcal/mol and imipenem was -1.50 kcal/mol. To the best of our knowledge the underlying mechanism of phenotypic with genotypic resistance molecular docking regarding carbapenem resistance A. baumannii is unclear. Our molecular docking finds the possible protein targeting mechanism for carbapenem-resistant A.baumannii.