Category: Phytochemicals

Potential protective effect of Trans-10-hydroxy-2-decenoic acid on the inflammation induced by Lipoteichoic acid

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Royal jelly (RJ) is known as a functional food for its diverse health-beneficial properties and complicated chemical compositions. Trans-10-hydroxy-2-decenoic acid (10-HDA) is the exclusive lipid component in RJ. In the present study, the in vitro anti-inflammatory effect of 10-HDA in LTA (Lipoteichoic acid from Staphylococcus aureus) induced RAW 264.7 macrophages are evaluated. The results showed that 10-HDA had potent, dose-dependent inhibitory effects on the release of major inflammatory mediators and NO. Several key inflammatory genes, including IL-1β, IL-6, MCP-1 and COX-2 have also been suppressed by 10-HDA. Furthermore, the effects of 10-HDA on LTA-induced pulmonary damage were also examined in mice. It was found that the administration of 10-HDA (100 mg/kg) can provide protective effects by attenuating lung histopathological changes and modulating the secretion of LTA-stimulated inflammatory cytokines in mice, such as IL-10, MCP-1 and TNF-α. Conclusively, the results reveal the potent anti-inflammatory properties of 10-HDA and provide biological information for the future application.(Journal of Functional Foods. Volume 45, June 2018, Pages 491-498.)

Perspectives on Biologically Active Camptothecin Derivatives

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Camptothecins (CPTs) are cytotoxic natural alkaloids that specifically target DNA topoisomerase I. Research on CPTs has undergone a significant evolution from the initial discovery of CPT in the late 1960s through the study of synthetic small molecule derivatives to investigation of macromolecular constructs and formulations. Over the past years, intensive medicinal chemistry efforts have generated numerous CPT derivatives. Three derivatives, topotecan, irinotecan, and belotecan, are currently prescribed as anticancer drugs, and several related compounds are now in clinical trials. Interest in other biological effects, besides anticancer activity, of CPTs is also growing exponentially, as indicated by the large number of publications on the subject during the last decades. Therefore, the main focus of the present review is to provide an ample but condensed overview on various biological activities of CPT derivatives, in addition to continued up-to-date coverage of anticancer effects.

Camptothecin (CPT) is a pentacyclic alkaloid isolated by Wall et al. in the early 1960s from the Chinese tree Camptotheca acuminata. This compound attracted immediate interest as a potential cancer chemotherapeutic agent due to its impressive activity against leukemias and various solid tumors in experimental systems. Due to CPT’s negligible water solubility, clinical trials were initiated using the water-soluble sodium salt of CPT in the early 1970s. The trials were suspended in the 1970s due to lower efficacy of 2, accompanied by unpredictable and severe levels of toxicity, including hemorrhagic cystitis and myelotoxicity. Interest in CPT then subsided for over a decade. Revived attention resulted from the breakthrough discovery of DNA topoisomerase I (Topo I) as a therapeutic target for CPT. This discovery put CPT back on the frontlines of anticancer drug development in the late 1980s. Accordingly, CPT’s total synthesis, mechanism of action, structure–activity relationship (SAR), analog synthesis as well as pharmacology, formulation, drug delivery, preclinical studies and clinical trials have been studied extensively. Recent interesting research approaches include using prodrug concepts and drug delivery systems for CPT.
As the result of these renewed research efforts, three CPT analogues, topotecan (TPT), irinotecan (CPT-11), and belotecan (CKD-602), received governmental approval for the clinical treatment of ovarian, small-cell lung, and refractory colorectal cancers. Three additional water-soluble analogues, exatecan (DX-8951f) lurtotecan (GG-211), and sinotecan, are currently under clinical evaluation. (Med Res Rev. 2015 Jul; 35(4): 753–789.)

Natural product-derived phytochemicals as potential agents against coronaviruses: A review

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Coronaviruses are responsible for a growing economic, social and mortality burden, as the causative agent of diseases such as severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), avian infectious bronchitis virus (IBV) and COVID-19. However, there is a lack of effective antiviral agents for many coronavirus strains. Naturally existing compounds provide a wealth of chemical diversity, including antiviral activity, and thus may have utility as therapeutic agents against coronaviral infections. The PubMed database was searched for papers including the keywords coronavirus, SARS or MERS, as well as traditional medicine, herbal, remedy or plants, with 55 primary research articles identified. The overwhelming majority of publications focussed on polar compounds. Compounds that show promise for the inhibition of coronavirus in humans include scutellarein, silvestrol, tryptanthrin, saikosaponin B2, quercetin, myricetin, caffeic acid, psoralidin, isobavachalcone, and lectins such as griffithsin. Other compounds such as lycorine may be suitable if a therapeutic level of antiviral activity can be achieved without exceeding toxic plasma concentrations. It was noted that the most promising small molecules identified as coronavirus inhibitors contained a conjugated fused ring structure with the majority being classified as being polyphenols.

Coronaviruses (CoVs) belong to the family Coronaviridae, subfamily Coronavirinae and are large (genome size 26−32 kb; Wu et al., 2020a), enveloped, positive-sense single-stranded ribonucleic acid (RNA) viruses that can infect both animals and humans. Based on their genotypic and serological characteristics, the viruses are subdivided into four genera: Alpha-, Beta-, Gamma-, and Deltacoronavirus (Chu et al., 2020; Lu et al., 2015). At present, all identified CoVs that are capable of infecting humans belong to the first two genera. These include the alphacoronaviruses (αCoVs) HCoV-NL63 (Human CoV-NL63) and HCoV-229E and the betacoronaviruses (βCoVs) HCoV-OC43 (Human CoV-OC43), HKU1 (Human CoV), SARS-CoV (Severe Acute Respiratory Syndrome CoV), and MERS-CoV (Middle Eastern Respiratory Syndrome CoV) (Lu et al., 2015). In the past two decades there have been three epidemics caused by the betaCoVs, namely SARS in 2002−03, MERS in 2012 and COVID-19, first identified in 2019. (Virus Res. 2020 Jul 15;284:197989. )