Characterization of Phytochemicals in Ulva intestinalis L. and Their Action Against SARS-CoV-2 Spike Glycoprotein Receptor-Binding Domain

Insight to phytochemical investigation and anti-hyperlipidemic effects of Eucalyptus camaldulensis leaf extract using in vitro, in vivo and in silico approach

Hyperlipidemia is a key risk factor mainly for hypertension and cardiac abnormalities. Previously eucalyptus plant (river red gum) had been used for its medicinal value for the treatment of many ailments. This study focused on phytochemical examination, investigation of an in vitro potential and in vivo effects in mice fed with high cholesterol diet, GC-MS analysis of extracts of Eucalyptus camaldulensis leaves and further confirmation of anti-hyperlipidemic potential of different constituents of plant extracts by using in silico technique. For in vitro study screening of different extracts of Eucalyptus camaldulensis leaves was performed by using pancreatic lipase enzyme inhibition assay. Ethanolic extract presented the highest potential among all the extracts by inhibiting pancreatic lipase having IC50-11.88 µg/mL. For in vivo study mice were fed with high cholesterol diet for induction of Hyperlipidemia. Water extract showed great anti-hyperlipidemic potential by reducing the level of cholesterol, triglycerides, low density lipoproteins and increasing high density lipoproteins level significantly (p < 0.05). Moreover, molecular docking and prime MM-GBSA study were applied for screening of compounds having anti-hyperlipidemic potential which showed that Alpha-cadinol was the lead compound for inhibition of pancreatic lipase enzyme having docking score (-6.604). The ADMET properties and toxicity profile of the top docked compounds were also detailed for ensuring their safety aspects. In this way in silico analysis substantiate the experimental findings by showing anti-hyperlipidemic potential in constituents of eucalyptus plant. Thus, there is a need of advanced research for isolation of active constituents having said anti-hyperlipidemic potential in the Eucalyptus camaldulensis plant.Communicated by Ramaswamy H. Sarma.

Lessons learnt from broad-spectrum coronavirus antiviral drug discovery

INTRODUCTION

Highly pathogenic coronaviruses (CoVs), such as severe acute respiratory syndrome CoV (SARS-CoV), Middle East respiratory syndrome CoV (MERS-CoV), and the most recent SARS-CoV-2 responsible for the COVID-19 pandemic, pose significant threats to human populations over the past two decades. These CoVs have caused a broad spectrum of clinical manifestations ranging from asymptomatic to severe distress syndromes (ARDS), resulting in high morbidity and mortality.

AREAS COVERED

The accelerated advancements in antiviral drug discovery, spurred by the COVID-19 pandemic, have shed new light on the imperative to develop treatments effective against a broad spectrum of CoVs. This perspective discusses strategies and lessons learnt in targeting viral non-structural proteins, structural proteins, drug repurposing, and combinational approaches for the development of antivirals against CoVs.

EXPERT OPINION

Drawing lessons from the pandemic, it becomes evident that the absence of efficient broad-spectrum antiviral drugs increases the vulnerability of public health systems to the potential onslaught by highly pathogenic CoVs. The rapid and sustained spread of novel CoVs can have devastating consequences without effective and specifically targeted treatments. Prioritizing the effective development of broad-spectrum antivirals is imperative for bolstering the resilience of public health systems and mitigating the potential impact of future highly pathogenic CoVs.

In vitro anticancer, antioxidant and antibacterial activities of crude extract prepared from Enteromorpha intestinalis habited in Jeddah, Saudi Arabia

The recent study purposes to evaluate the biological activities of Enteromorpha intestinalis gathered from Jeddah coastal area, Saudi Arabia, with respect to its phytochemical components. Our results indicated that the values ​​of moisture content, ash, total organic matter, total proteins, total lipids and total carbohydrates were 34.25 ± 5.6 %, 40.70 ± 2.3 %, 25.05 ± 1.73 %, 14.39 ± 0.8 %, 4.86 ± 6.9 % and 2.81 ± 1.4 %, respectively. The data also showed that the total phenols and flavonoids were 345.04 ± 1.50 and 320.67 ± 0.92 mg/g in the dried sample, respectively. Furthermore, four compounds were detected by HPLC at very low concentrations (quinic acid, ellagic acid, cinnamic acid, and phenanthrene) and flavonoids data confirmed the presence of apeginin, rudin, diosmin, and quercilin at high concentrations of 141.26, 11.42, 121.75, and 145.28. mg/g, respectively. The crude extract of Enteromorpha intestinalis exhibited cytotoxicity toward hepatocellular carcinoma cells (HepG-2 cell line) using an MTT assay with concentration range between 2 and 500 µg/mL for 48 h with IC50 = 40.02 ± 3.94 µg/mL. Evidently, the Enteromorpha intestinalis extract had Hepatoprotective activity with IC50 = 447.31 ± 14.59 μg/mL. The IC50 activity of a crude methanol extract of Enteromorpha intestinalis was compared with that of an antioxidant drug (Torolox). The value (98.82 ± 1.30 μg/mL) was recorded close to Torolox (62.4 ± 0.70 μg/mL). This extract also possessed moderate antibacterial activity with inhibition zones ranging between 10 mm against Pseudomonas aeruginosa to 16 mm against Escherichia coli. Green seaweed, along with other types of seaweed, has received significant attention in recent years. Despite their potential benefits, green seaweeds are underutilized in many parts of the world. Extensive studies on different green seaweed isolates and extracts are necessary.

Plant Molecular Pharming and Plant-Derived Compounds towards Generation of Vaccines and Therapeutics against Coronaviruses

The current century has witnessed infections of pandemic proportions caused by Coronaviruses (CoV) including severe acute respiratory syndrome-related CoV (SARS-CoV), Middle East respiratory syndrome-related CoV (MERS-CoV) and the recently identified SARS-CoV2. Significantly, the SARS-CoV2 outbreak, declared a pandemic in early 2020, has wreaked devastation and imposed intense pressure on medical establishments world-wide in a short time period by spreading at a rapid pace, resulting in high morbidity and mortality. Therefore, there is a compelling need to combat and contain the CoV infections. The current review addresses the unique features of the molecular virology of major Coronaviruses that may be tractable towards antiviral targeting and design of novel preventative and therapeutic intervention strategies. Plant-derived vaccines, in particular oral vaccines, afford safer, effectual and low-cost avenues to develop antivirals and fast response vaccines, requiring minimal infrastructure and trained personnel for vaccine administration in developing countries. This review article discusses recent developments in the generation of plant-based vaccines, therapeutic/drug molecules, monoclonal antibodies and phytochemicals to preclude and combat infections caused by SARS-CoV, MERS-CoV and SARS-CoV-2 viruses. Efficacious plant-derived antivirals could contribute significantly to combating emerging and re-emerging pathogenic CoV infections and help stem the tide of any future pandemics.

In Silico Screening of Bioactive Compounds of Representative Seaweeds to Inhibit SARS-CoV-2 ACE2-Bound Omicron B.1.1.529 Spike Protein Trimer

Omicron is an emerging SARS-CoV-2 variant, evolved from the Indian delta variant B.1.617.2, which is currently infecting worldwide. The spike glycoprotein, an important molecule in the pathogenesis and transmissions of SARS-CoV-2 variants, especially omicron B.1.1.529, shows 37 mutations distributed over the trimeric protein domains. Notably, fifteen of these mutations reside in the receptor-binding domain of the spike glycoprotein, which may alter transmissibility and infectivity. Additionally, the omicron spike evades neutralization more efficiently than the delta spike. Most of the therapeutic antibodies are ineffective against the omicron variant, and double immunization with BioNTech-Pfizer (BNT162b2) might not adequately protect against severe disease induced by omicron B.1.1.529. So far, no efficient antiviral drugs are available against omicron. The present study identified the promising inhibitors from seaweed’s bioactive compounds to inhibit the omicron variant B.1.1.529. We have also compared the seaweed’s compounds with the standard drugs ceftriaxone and cefuroxime, which were suggested as beneficial antiviral drugs in COVID-19 treatment. Our molecular docking analysis revealed that caffeic acid hexoside (−6.4 kcal/mol; RMSD = 2.382 Å) and phloretin (−6.3 kcal/mol; RMSD = 0.061 Å) from Sargassum wightii (S. wightii) showed the inhibitory effect against the crucial residues ASN417, SER496, TYR501, and HIS505, which are supported for the inviolable omicron and angiotensin-converting enzyme II (ACE2) receptor interaction. Cholestan-3-ol, 2-methylene-, (3beta, 5 alpha) (CMBA) (−6.0 kcal/mol; RMSD = 3.074 Å) from Corallina officinalis (C. officinalis) manifested the strong inhibitory effect against the omicron RBD mutated residues LEU452 and ALA484, was magnificently observed as the essential residues in Indian delta variant B.1.617.2 previously. The standard drugs (ceftriaxone and cefuroxime) showed no or less inhibitory effect against RBD of omicron B.1.1.529. The present study also emphasized the pharmacological properties of the considered chemical compounds. The results could be used to develop potent seaweed-based antiviral drugs and/or dietary supplements to treat omicron B.1.1529-infected patients.

Chemical Composition of the Red Sea Green Algae Ulva lactuca: Isolation and In Silico Studies of New Anti-COVID-19 Ceramides

Coronavirus disease 2019 (COVID-19) is the disease caused by the virus SARS-CoV-2 responsible for the ongoing pandemic which has claimed the lives of millions of people. This has prompted the scientific research community to act to find treatments against the SARS-CoV-2 virus that include safe antiviral medicinal compounds. The edible green algae U.&nbsp;lactuca. is known to exhibit diverse biological activities such as anti-influenza virus, anti-Japanese encephalitis virus, immunomodulatory, anticoagulant, antioxidant and antibacterial activities. Herein, four new ceramides in addition to two known ones were isolated from Ulva&nbsp;lactuca. The isolated ceramides, including Cer-1, Cer-2, Cer-3, Cer-4, Cer-5 and Cer-6 showed promising antiviral activity against SARS-CoV-2 when investigated using in silico approaches by preventing its attachment to human cells and/or inhibiting its viral replication. Cer-4 and Cer-5 were the most effective in inhibiting the human angiotensin converting enzyme (hACE)-spike protein complex which is essential for the virus to enter the human host. In addition to this, Cer-4 also showed an inhibition of the SARS-CoV-2 protease (M^pro) that is responsible for its viral replication and transcription. In this study, we also used liquid chromatography coupled to electrospray ionization high-resolution mass spectroscopy (LC-ESI-HRMS) to identify several metabolites of U.&nbsp;lactuca, including metabolites such as fatty acids, their glyceride derivatives, terpenoids, sterols and oxysterols from the organic extract. Some of these metabolites also possessed promising antiviral activity, as previously reported.