Evaluation Efficacy and Persistence of Some Volatile Plant Oils on Immature Stages of Galleria mellonella (L.)

The Experiment was carried out to measure the effect of four natural plant oils (namely: Cinnamonium zeylanicum L., Syzygium aromatic L., Citrus aurantium amara, and Lavandula spica) on controlling the greater wax moth and their ability to persist. The methodology included collecting and rearing the greater wax moth under laboratory conditions to be able to isolate the target tested stages. The immature stages (eggs and larvae) of the experiment moth were exposed to fumes of tested oils (50 µl/500 ml) to calculate hatchability and mortality percentage. The results were clear that fumes of C. zeylanicum and S. aromatic were caused 100% unhatching eggs after zero time as the same recorded by comparable compound (paradix) and able to persist their effect at the closed and limited zone for 60 days. On another side, C. zeylanicum and S. aromat were affected on last larval instars and emerged adults. The accumulative effect was appeared in the case of treatment by C. zeylanicum which was caused sterility to emerged adults and reduced eggs deposition to zero. The data indicated that some natural product compounds could be used as an alternative way of control insect pests.

Discovering the Potent Inhibitors Against Babesia bovis in vitro and Babesia microti in vivo by Repurposing the Natural Product Compounds

In the present study, we screened 502 natural product compounds against the in vitro growth of Babesia (B.) bovis. Then, the novel and potent identified compounds were further evaluated for their in vitro efficacies using viability and cytotoxicity assays. The in vivo inhibitory effects of the selected compounds were evaluated using B. microti “rodent strain” in mice model. Three potent compounds, namely, Rottlerin (RL), Narasin (NR), Lasalocid acid (LA), exhibited the lowest IC50 (half-maximal inhibitory concentration) as follows: 5.45 ± 1.20 μM for RL, 1.86 ± 0.66 μM for NR, and 3.56 ± 1.41 μM for LA. The viability result revealed the ability of RL and LA to prevent the regrowth of treated parasite at 4 × IC50 and 2 × IC50, respectively, while 4 × IC50 of NR was sufficient to stop the regrowth of parasite. The hematology parameters of B. microti in vivo were different in the NR-treated groups as compared to the infected/untreated group. Interestingly, intraperitoneal administration of NR exhibiting inhibition in the growth of B. microti in mice was similar to that observed after administration of the commonly used antibabesial drug, diminazene aceturate (DA) (76.57% for DA, 74.73% for NR). Our findings indicate the richness of natural product compounds by novel potent antibabesial candidates, and the identified potent compounds, especially NR, might be used for the treatment of animal babesiosis.

All-Trans Retinoic Acid Exhibits Antiviral Effect against SARS-CoV-2 by Inhibiting 3CLpro Activity

The pandemic of COVID-19 caused by SARS-CoV-2 continues to spread despite the global efforts taken to control it. The 3C-like protease (3CLpro), the major protease of SARS-CoV-2, is one of the most interesting targets for antiviral drug development because it is highly conserved among SARS-CoVs and plays an important role in viral replication. Herein, we developed high throughput screening for SARS-CoV-2 3CLpro inhibitor based on AlphaScreen. We screened 91 natural product compounds and found that all-trans retinoic acid (ATRA), an FDA-approved drug, inhibited 3CLpro activity. The 3CLpro inhibitory effect of ATRA was confirmed in vitro by both immunoblotting and AlphaScreen with a 50% inhibition concentration (IC50) of 24.7 ± 1.65 µM. ATRA inhibited the replication of SARS-CoV-2 in VeroE6/TMPRSS2 and Calu-3 cells, with IC50 = 2.69 ± 0.09 µM in the former and 0.82 ± 0.01 µM in the latter. Further, we showed the anti-SARS-CoV-2 effect of ATRA on the currently circulating variants of concern (VOC); alpha, beta, gamma, and delta. These results suggest that ATRA may be considered as a potential therapeutic agent against SARS-CoV-2.

Ensemble-based virtual screening of Mycobacterium tuberculosis ClpC1 inhibitors

Tuberculosis (TB) is an airborne transmissible disease caused by Mycobacterium tuberculosis (Mtb), responsible for 1.3 million deaths per year. Due to increased cases of drug resistance to Mtb, a new treatment regime for TB needs to be discovered. ClpC1 plays a crucial role in the protein homeostasis of Mtb thus, presents as a promising target in controlling TB infection. The present study aimed to identify potential inhibitors for the ClpC1 N-terminal domain (ClpC1-NTD) by applying the relaxed complex scheme in virtual screening that accounts for the target and ligand flexibility. A filtered library of natural product compounds was virtually screened against each of the selected ClpC1-NTD dominant conformations from the ensemble generated using molecular dynamics simulation. The promising compounds with the strong binding affinity to ClpC1 protein were then further analysed for their molecular interactions. The stability of the most potent compound was examined through a complex MD simulation while the pharmacokinetics properties were gathered using SwissADME and pkCSM. The results showed that ligand NP132 formed a strong and stable complex with good pharmacokinetics and toxicological profile.

Screening and Purification of Natural Products from Actinomycetes that Induce a “Rounded” Morphological Phenotype in Fission Yeast

This study was designed to identify and investigate bioactive natural product compounds that alter the cellular shape of the fission yeast Schizosaccharomyces pombe and induce a “rounded” or “small” cellular morphological phenotype. Bioassays using a range of antifungal agents against a multidrug-sensitive fission yeast strain, SAK950 showed that many induced a “rounded” phenotype. We then investigated whether 46 of the actinomycete strains identified in our previous study as inducing a similar phenotype produced antifungal agents of similar classes. We show that five of the strains produced streptothricin and that 26 strains produced polyenes, including fungichromin, filipin and candicidin, the last of which was produced by 24 strains. A taxonomic study of the strains indicated that the majority of the candicidin only producers were Streptomyces hydrogenans and S. albidoflavus whilst those that additionally produced streptothricin were related to S. enissocaesilis. A follow-up study to investigate the natural products made by related strains indicated that they followed a similar pattern. The identification of several compounds from the actinomycete strains similar to the antifungal agents initially tested confirm the validity of an approach using the S. pombe morphological phenotype and actinomycete taxonomy as a predictive tool for natural product identification. Graphic Abstract

Phenolic Constituents from the Stems of Morus nigra and their α-Glucosidase Inhibitory Activities

AbstractsA new sanggenon-type flavanone, nigragenon F (1), together with 11 known compounds, trans-resveratrol (2), (E)-4-isopentenyl-3,5,2′,4′-tetrahydroxystilbene (3), notabilisin E (4), notabilisin A (5), morusin (6), petalopurpurenol (7), 8-geranyl-5,7-dihydroxycoumarin (8), 2,4-dihydroxybenzaldehyde (9), 4-ethoxy-2,6-dihydroxybenzoic acid (10), 3-hydroxy-4-methoxybenzaldehyde (11), and 4-hydroxybenzaldehyde (12), were isolated from the stems of Morus nigra. Compound 10 was a new natural product, compounds 3, 4, 7, and 8 were reported from the Morus genus for the first time. All of the isolated compounds were evaluated for their α-glucosidase inhibition activity. Among them, six compounds showed obvious inhibitory effects against α-glucosidase with IC50 values ranging from 1.24 to 19.00 µmol/L.

Natural Product Compounds for Breast Cancer Treatment

Breast cancer is the primary cause of cancer death in women. Although current therapies have shown some promise against breast cancer, there is still no effective cure for the majority of patients in the advanced stages of breast cancer. Treatment with present synthetic drugs may lead to a number of adverse effects. Consequently, research into natural product compounds may provide an alternative pathway to determining effective against breast cancer. This chapter reviews molecular targets of breast cancer treatment as well as bioactive compounds sourced from bibliographic information such as Medline, Google Scholar, PubMed databases. The authors hope that this book chapter contributes significantly to previous and ongoing research and encourages further investigation into the potential of natural product compounds in breast cancer.

Natural products may interfere with SARS-CoV-2 attachment to the host cell

Objectives: SARS-CoV-2 has been emerged in December 2019 in China, causing deadly (5% mortality) pandemic pneumonia, termed COVID-19. More than one host-cell receptor is reported to be recognized by the viral spike protein, among them is the cell-surface Heat Shock Protein A5 (HSPA5), also termed GRP78 or BiP. Upon viral infection, HSPA5 is upregulated, then translocating to the cell membrane where it is subjected to be recognized by the SARS-CoV-2 spike. In this study, some natural product compounds are tested against the HSPA5 substrate-binding domain β (SBDβ), which reported to be the recognition site for the SARS-CoV-2 spike. Methods: Molecular docking and molecular dynamics simulations are used to test some natural compounds binding to HSPA5 SBDβ. Results: The results show high to a moderate binding affinity for the phytoestrogens (Diadiazin, Genistein, Formontein, and Biochanin A), chlorogenic acid, linolenic acid, palmitic acid, caffeic acid, caffeic acid phenethyl ester, hydroxytyrosol, cis-p-Coumaric acid, cinnamaldehyde, and thymoquinone to the HSPA5 SBDβ. Based on its binding affinities, the natural compounds, and some hormones, may interfere with SARS-CoV-2 attachment to the stressed cells. Conclusion: These compounds can be successful as anti-COVID-19 agents for people with a high risk of cell stress like elders, cancer patients, and front-line medical staff.

Natural Product Compounds in Alpinia officinarum and Ginger are Potent SARS-CoV-2 Papain-like Protease Inhibitors

SARS-CoV-2 or COVID-19 has caused more than 10,00,000 infections and ~55,000 deaths worldwide spanning over 203 countries, and the numbers are exponentially increasing. Due to urgent need of treating the SARS infection, many approved, pre-clinical, anti-viral, anti-malarial and anti-SARS drugs are being administered to patients. SARS-CoV-2 papain-like protease (PLpro) has a protease domain which cleaves the viral polyproteins a/b, necessary for its survival and replication, and is one of the drug target against SARS-CoV-2. 3D structures of SARS-CoV-2 PLpro were built by homology modelling. Two models having partially open and closed conformations were used in our study. Virtual screening of natural product compounds was performed. We prepared an in house library of compounds found in rhizomes, Alpinia officinarum, ginger and curcuma, and docked them into the solvent accessible S3-S4 pocket of PLpro. Eight compounds from Alpinia officinarum and ginger bind with high in silico affinity to closed PLpro conformer, and hence are potential SARS-CoV-2 PLpro inhibitors. Our study reveal new lead compounds targeting SARS-CoV-2. Further structure based modifications or extract formulations of these compounds can lead to highly potent inhibitors to treat SARS-CoV-2 infections.<br>