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Recent Developments in Therapies and Strategies Against COVID-19
Published in Hanadi Talal Ahmedah, Muhammad Riaz, Sagheer Ahmed, Marius Alexandru Moga, The Covid-19 Pandemic, 2023
Misbah Hameed, M. Zia-Ul-Haq, Marius Moga
Lopinavir is a protease inhibitor and is prepared from structurally similar ritonavir antiretroviral agents. Aspartic protease is essential for the cleavage of proteins from precursor polypeptide strand of virus, which is needed for structural and functional proteins. The inhibition of protease results in immature and non-effective virions [20]. Lopinavir is a selective inhibitor of the HIV type 1 (HIV-1), which is required for mature infective virus production. The drug blocks infectivity by blocking the maturation of HIV-1. Lopinavir is a highly potent. These two drugs are available as formulation because when co-administered, ritonavir at low doses improves the pharmacokinetic profile and the activity of lopinavir against HIV-1 protease [21].
Order Ortervirales
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
The current combination of the order members was justified by the structure of their polymerase/reverse transcriptase proteins that are sharing a common origin. The polymerase proteins are similar in structure and include aspartic protease (retroviral aspartyl protease) and an integrase belonging to the DDE recombinase superfamily. They also share similar capsid and nucleocapsid proteins/domains (Krupovic and Koonin 2017). Moreover, belpaoviruses, metaviruses, pseudoviruses, and retroviruses have some other important features in common (Krupovic et al. 2018).
Plant Alkaloids and Their Derivatives Relevant to Alzheimer’s Disease
Published in Atanu Bhattacharjee, Akula Ramakrishna, Magisetty Obulesu, Phytomedicine and Alzheimer’s Disease, 2020
Atanu Bhattacharjee, Akula Ramakrishna
According to the ‘β-amyloid cascade’, deposition of the Aβ peptide triggers the neurotoxic cascade and promotes neuroinflammation, which ultimately results in neurodegeneration (Keyvan et al., 2006; Wang et al., 2009). Aβ is derived from sequential proteolytic cleavage of the amyloid precursor protein (APP) by β- and γ-secretases. Initial cleavage by β-secretase (β-site of APP cleaving enzyme, BACE), a membrane-anchored aspartic protease, generates a soluble N-terminal fragment and a membrane-associated C-terminal fragment (Peter et al., 2005; Lee et al., 2005; Urbain et al., 2004). The C-terminal fragment then undergoes proteolysis by γ-secretase to give the Aβ peptide. BACE has been shown to be a promising therapeutic target as it initiates the first step in Aβ production (Orhan et al., 2004; Gulachi et al., 2014). Abnormal processing of the APP is responsible for amyloid deposition. The two enzymes, β-secretase and γ-secretase, which catalyze the cleavage of the Aβ peptide, are important targets in the treatment of AD. Until recently, these approaches had not been explored, but recent studies have shown that the anti-amyloid strategy can be a powerful approach to halting the progression of AD. Berberine has gained attention in this direction as it can ameliorate Aβ pathology in AD (Durairajan et al., 2012). In-vitro studies have shown that nicotine can prevent the precipitation of the Aβ1–42 peptide as an amyloid-like deposit (Salomon et al., 1996).
Signal peptide peptidase: a potential therapeutic target for parasitic and viral infections
Published in Expert Opinion on Therapeutic Targets, 2022
Christopher Schwake, Michael Hyon, Athar H. Chishti
Current interest for utilizing known anti-viral compounds has increased significantly during the emergence of the pandemic strain of SARS-CoV-2 with devastating global implications in 2019–2022. Much initial attention was drawn to HIV aspartic protease inhibitors, specifically the combination of Lopinavir-Ritonavir. Unfortunately, this combination did not demonstrate efficacy in early clinical trials against COVID-19 [89]. Nonetheless, interest in using HIV protease inhibitors against COVID-19 is currently ongoing, and further studies will determine whether there is any therapeutic benefit of these inhibitors [90,91]. Future studies will determine whether direct inhibition of host SPP can prevent SARS-CoV-2 replication, and whether specific mammalian isoforms of SPP are required for infection.
Paeonol assists fluconazole and amphotericin B to inhibit virulence factors and pathogenicity of Candida albicans
Published in Biofouling, 2021
Min Pan, Qirui Wang, Ting Cheng, Daqiang Wu, Tianming Wang, Guiming Yan, Jing Shao
The assay for secreted aspartic protease (SAP) was performed as described previously with minor modifications (Srivastava et al. 2018). An aliquot of C. albicans (1×106 cells ml−1) was co-incubated for 3-5days at 37°C with the drugs alone or in combination at their synergistic concentrations in a medium containing 2% dextrose, 0.1% KH2PO4, 0.05% MgSO4, 2% agar, and 1% BSA. A fungal culture without the drug was used as the control. The effect of the drugs on SAP secretion was analyzed in terms of the PZ value calculated as: diameter of the colony/diameter of the precipitation circle + the diameter of the colony (Price et al. 1982). As used for phospholipase (PL) (Khan et al. 2014), the fungal inoculum and the drugs were co-cultured in a media comprising 1% peptone, 3% glucose, 0.055% CaCl2, 5.73% NaCl, and 10% sterile egg yolk. The remnant experimental conditions for PL evaluation were similar to those described for the SAP analyses.
Aloe vera and Honey Solution and Their Ethanolic Extraction Solution Could Act on Metastasis-Regulating Processes in Walker 256 Tumor Tissues In Vivo?
Published in Nutrition and Cancer, 2021
Rebeka Tomasin, Aislan Cristina Rheder Fagundes Pascoal, Marcos José Salvador, Maria Cristina Cintra Gomes-Marcondes
The aspartic protease cathepsin-D is traditionally located inside lysosomes, where it is involved in the acid digestion of proteins and peptides (8). During cancer progression, especially in solid tumors, cathepsin-D is commonly overexpressed and secreted by both cancer and stromal cells; it is believed to promote matrix remodeling, mitosis, angiogenesis, and metastasis (7, 8). Indeed, it has been extensively reported that high levels of cathepsin-D are linked to the occurrence of metastasis and more unsatisfactory outcome in cancer patients, and these effects are believed to be due to the proangiogenic role of cathepsin-D in solid tumors (9, 30). Moreover, several studies have shown that lower levels of cathepsin-D lead to less migration and invasion of several cancer cell lines in vitro, as well as a reduction in metastatic burden in animal models (31). Thus, the observed trend of a decrease in cathepsin-D activity in tumor samples from treated rats may be linked to reduced aggressiveness of these tumors; several independent clinical studies have shown that the cathepsin-D level of primary tumors is an independent prognostic parameter that is correlated with the incidence of metastasis and shorter survival times (9, 32–35).