Screening of medicinal plants unraveled the leishmanicidal credibility of Garcinia cowa; highlighting Norcowanin, a novel anti-leishmanial phytochemical through in-silico study

Computational and experimental approaches manifest the leishmanicidal potential of α-mangostin resourced from Garcinia cowa

Owing to the persistent number of parasitic deaths, Visceral leishmaniasis continues to haunt several economically weaker sections of India. The disease causes over 30,000 deaths and threatens millions annually on a global scale. The standard pentavalent antimonials, on the other hand, are associated with health adversities and disease relapse. The current study is focused on the search for the most potential natural bioactive phytocompound from the bark extract of the Northeastern Indian plant, Garcinia cowa, that shows potent anti-leishmanial properties. The High Resonance Liquid Chromatography followed by Mass Spectrometry (HR-LCMS) study followed by an in silico molecular docking using computational tools revealed that α-mangostin might potentially possess antiparasitic activity. To validate the anti-leishmanial efficacy of the compound, a cell viability assay was performed, which demonstrated the parasite-specific inhibitory activity of α-mangostin; with IC50 values ranging from 4.95 - 7.37 µM against the different forms of Leishmania donovani parasite. The flow cytometric analysis of the phytocompound treated parasites indicated an oxidative and nitrosative stress-mediated apoptotic cell death in the parasites, by the suggestive surge in nuclear fragmentation and mitochondrial dysfunction. Simultaneously, a cytokine profiling study suggested approximate two-to-three-fold upregulated levels of pro-inflammatory cytokines post-compound treatment, which is predicted to actively contribute to parasite-killing. α-mangostin was also found to reduce the chances of parasite survival by inhibiting arginase enzyme activity, which in favorable conditions facilitates its sustenance. This study thereby substantiates that α-mangostin significantly possesses anti-leishmanial potentiality that can be developed into a cure for this infectious disease.

A Comprehensive Review of the Phytochemical and Pharmacological Potential of an Evergreen Plant Garcinia cowa

Garcinia cowa of the Clusiaceae family, native to South-East Asia used in traditional medicine. It has antipyretic, antimicrobial, and many other biological activities. In this review, a thorough study of this plant's chemical constituents and pharmacological and therapeutic effects was conducted from the research articles from PubMed, Science Direct, Google Scholar, and Scopus from 1977 to 2022. Reported secondary metabolites are enriched with xanthones, phloroglucinols, depsidones, steroids, etc. α-mangostin, β-mangostin, cowaxanthone, rubraxanthone, cowanin, norcowanin, etc. represent the major xanthones. This article discusses the relationship between the different functional groups in xanthone compounds and their bioactivity against cancer, diabetes, bacteria, leishmania, malaria, and inflammation. This review is a comprehensive compendium of major bioactive molecules and its implication for human disease.

In-Silico Designing of a Multi-Epitope Vaccine against SARS-CoV2 and Studying the Interaction of the Vaccine with Alpha, Beta, Delta and Omicron Variants of Concern

BACKGROUND

The sudden appearance of the SARS-CoV2 virus has almost changed the future of vaccine development. There have been many different approaches to vaccination; among them, computational vaccinology in the form of multi-epitope vaccines with excellent immunological properties and minimal contamination or other adverse reactions has emerged as a promising strategy with a lot of room for further study in this area.

OBJECTIVE

Designing a multi-epitope vaccine from the spike protein of SARS-CoV2 based on immunoinformatics and in-silico techniques. Evaluating the binding affinity of the constructed vaccine against the major variants of concern (alpha, beta, delta, and omicron) using docking studies.

METHODS

The potential antigenic, immunogenic, and non-allergic T-cell epitopes were thoroughly explored using IEDB, NetCTL1.2, and NetMHCII pan 3.2 servers. The best suitable linker was identified using the ExPASy Protparam tool and VERIFY 3D. The 3D model of the vaccine was developed by RaptorX and the model was validated using ERRAT, Z-score, and Ramachandran Plot. Docking studies of the vaccine with TLR-2, 3, 4, and 7 and alpha, beta, delta, and omicron variants were performed using HADDOCK 2.4.

RESULTS

The vaccine construct showed good antigenic and immunogenic scores and was non-allergic as well. The model was capable of binding to all four selected Toll-like receptors. Docking scores with variants were also promising.

CONCLUSION

All the variants showed good binding ability with the vaccine construct. Interaction with the alpha variant was found to be the most intense, followed by delta, beta, and omicron.

A Novel Compound Plumercine from Plumeria alba Exhibits Promising Anti-Leukemic Efficacies against B Cell Acute Lymphoblastic Leukemia

The current study was focused to evaluate the antioxidant and the anti-cancerous properties of Plumeria alba. Plumeria alba was chosen due to its existing medicinal values. Antioxidant assays like Superoxide radical scavenging assay, Nitrous Oxide radical scavenging assay, were performed, on the methanolic and ethyl acetate extracts of the plant, that depicts the pro-oxidant nature of the extract. Further, they were tested to check cell viability on B cell Acute Lymphoblastic Leukemia (ALL) Cell line (NALM 6), human lung cancer cell line (A549), T cell Acute Lymphoblastic Leukemia cell line (MOLT4), and PBMC isolated from normal donors utilizing MTT assay. Robust anti-proliferative activity was observed in the case of NALM 6 followed by A549, MOLT4, whereas negligible activity was observed in the case of PBMC. Intrigued by this finding, in silico docking was performed using three bioactive compounds namely Plumericine, Isoplumericine, and 13-O-p-Coumaroylplumieride, unique to Plumeria sp. They were docked against five different cyclins and Cdk proteins responsible for ALL. The compounds have shown satisfactory results and their druggability and ADMET properties were checked further. Plumercine turned out to be the most competent compound and hence can be considered as a potential leukemic drug candidate in the future.