Antimicrobial peptide magainin 2 forms pores in lipid bilayers, a property that is considered the main cause of its bactericidal activity. Recent data suggest that tension or stretching of the inner monolayer plays an important role in magainin 2-induced pore formation in lipid bilayers. Here, to elucidate the mechanism of magainin 2-induced pore formation, we investigated the effect on pore formation of asymmetric lipid distribution in two monolayers. First, we developed a method to prepare giant unilamellar vesicles (GUVs) composed of dioleoylphosphatidylglycerol (DOPG), dioleoylphosphatidylcholine (DOPC), and lyso-PC (LPC) in the inner monolayer and of DOPG/DOPC in the outer monolayer. We consider that in these GUVs, the lipid packing in the inner monolayer was larger than that in the outer monolayer. Next, we investigated the interaction of magainin 2 with these GUVs with an asymmetric distribution of LPC using the single GUV method, and found that the rate constant of magainin 2-induced pore formation, k, decreased with increasing LPC concentration in the inner monolayer. We constructed a quantitative model of magainin 2-induced pore formation, whereby the binding of magainin 2 to the outer monolayer of a GUV induces stretching of the inner monolayer, causing pore formation. A theoretical equation defining k as a function of magainin 2 surface concentration, X, reasonably explains the experimental relationship between k and X. This model quantitatively explains the effect on k of the LPC concentration in the inner monolayer. On the basis of these results, we discuss the mechanism of the initial stage of magainin 2-induced pore formation.

1. The effects of edible oyster mushroom Pleurotus ostreatus on plasma and liver lipid profiles and on the plasma total anti-oxidant status were estimated in hyper- and normocholesterolaemic Long Evans rats. 2. The feeding of 5% powder of the fruiting bodies of P. ostreatus mushrooms to hypercholesterolaemic rats reduced their plasma total cholesterol by approximately 28%, low-density lipoprotein-cholesterol by approximately 55%, triglyceride by approximately 34%, non-esterified fatty acid by approximately 30% and total liver cholesterol levels by > 34%, with a concurrent increase in plasma high-density lipoprotein-cholesterol concentration of > 21%. However, these effects were not observed in mushroom-fed normocholesterolaemic rats. 3. Mushroom feeding significantly increased plasma fatty acid unsaturation in both normo- and hypercholesterolaemic rats. 4. Plasma total anti-oxidant status, as estimated by the oxidation of 2,2'-azino-bis-[3-ethylbenz-thiazoline-6-sulphonic-acid], was significantly decreased in mushroom-fed hypercholesterolaemic rats, concomitant with a decrease in plasma total cholesterol. 5. The present study suggests that 5% P. ostreatus supplementation provides health benefits, at least partially, by acting on the atherogenic lipid profile in the hypercholesterolaemic condition.

The stretching of plasma membranes of cells and lipid bilayers of vesicles affects the physical properties of the membrane as well as the functions of proteins/peptides in the membranes. Here, we examined the effect of membrane tension on the rate constant of the transbilayer movement (k) of fluorescent probe-labeled lipids using a new method. Specifically, we recently reported [Hasan et al., Langmuir 34, 3349 (2018)] the development of a technique that employs giant unilamellar vesicles (GUVs) with asymmetric lipid compositions in two monolayers. In the present work, we found that the k greatly increased with tension without leakage of water-soluble fluorescent probes from the GUV lumen (i.e., without the formation of pores in the GUV membrane). We discussed the plausible mechanisms for the effect of tension on the transbilayer movement of lipids. As one of the mechanisms, we hypothesized that the transbilayer movement of lipids occurs through the lateral diffusion of lipids in the walls of hydrophilic pre-pores.

Background and Aims Vaccines are the first line of defense against coronavirus disease 2019 (Covid‐19). However, the antiviral drugs provide a new tool to fight the Covid‐19 pandemic. Here we aimed for a comparative evaluation of authorized drugs for treating Covid‐19 patients. Methods We searched in PubMed and Google Scholar using keywords and terms such as Covid, SARS‐CoV‐2, Coronavirus disease 2019, therapeutic management, hospitalized Covid‐19 patients, Covid‐19 treatment. We also gathered information from reputed newspapers, web portals, and websites. We thoroughly observed, screened, and included the studies relevant to our inclusion criteria. We included only the United States Food and Drug Administration (FDA) authorized drugs for this review. Results We found that molnupiravir and paxlovid are available for oral use, and remdesivir is for only hospitalized patients. Paxlovid is a combination of nirmatrelvir and ritonavir, nirmatrelvir is a protease inhibitor (ritonavir increases the concentration of nirmatrelvir), and the other two (remdesivir and molnupiravir) are nucleoside analog prodrugs. Remdesivir and molnupiravir doses do not need to adjust in renal and hepatic impairment. However, the paxlovid dose adjustment is required for mild to moderate renal or hepatic impaired patients. Also, the drug is not allowed for Covid‐19 patients with severe renal or hepatic impairment. Preliminary studies showed oral antiviral drugs significantly reduce hospitalization or death among mild to severe patients. Moreover, the US FDA has approved four monoclonal antibodies for Covid‐19 treatment. Studies suggest that these drugs would reduce the risk of hospitalization or severity of symptoms. World Health Organization strongly recommended the use of corticosteroids along with other antiviral drugs for severe or critically hospitalized patients. Conclusion All authorized drugs are effective in inhibiting viral replication for most SARS‐CoV‐2 variants. Therefore, along with vaccines, these drugs might potentially aid in fighting the Covid‐19 pandemic.

Objectives Vaccination rollout against COVID-19 has started in developed countries in early December 2020. Mass immunization for poor or low-income countries is quite challenging before 2023. Being a lower–middle-income country, Bangladesh has begun a nationwide COVID-19 vaccination drive in early February 2021. Here, we aimed to assess the opinions, experiences, and adverse events of the COVID-19 vaccination in Bangladesh. Methods We conducted this online cross-sectional study from 10 February 2021, to 10 March 2021, in Bangladesh. A self-reported semi-structured survey questionnaire was used using Google forms. We recorded demographics, disease history, medication records, opinions and experiences of vaccination, and associated adverse events symptoms. Results We observed leading comorbid diseases were hypertension (25.9%), diabetes (21.1%), heart diseases (9.3%), and asthma (8.7%). The most frequently reported adverse events were injection site pain (34.3%), fever (32.6%), headache (20.2%), fatigue (16.6%), and cold feeling (15.4%). The chances of having adverse events were significantly higher in males than females ( p = 0.039). However, 36.4% of respondents reported no adverse events. Adverse events usually appeared after 12 h and went way within 48 h of vaccination. Besides, 85.5% were happy with the overall vaccination management, while 88.0% of the respondents recommended the COVID-19 vaccine for others for early immunization. Conclusion According to the present findings, reported adverse events after the doses of Covishield in Bangladesh were non-serious and temporary. In Bangladesh, the early vaccination against COVID-19 was possible due to its prudent vaccine deal, previous mass vaccination experience, and vaccine diplomacy.