Anti-Cancer Agents in Medicinal Chemistry (Formerly Current Medicinal Chemistry - Anti-Cancer Agents) - Volume 22, Issue 20, 2022

Ocimum sanctum is a sacred herb of India and is commonly known as ‘Tulsi’ or ‘Holy Basil’ in regional languages of the country. Various parts of O. sanctum are recognised to have remarkable therapeutic efficacy, and are therefore used in Indian traditional medicine system, Ayurveda. Scientific studies have shown that O. sanctum has a range of pharmacological activities. The presence of a substantial amount of polyphenols in O. sanctum could be the reason for its excellent bioactivity. Polyphenols are used to prevent or treat oncologic diseases due to their anti-cancer effects, which are related to activation of apoptotic signaling, cell cycle arrest, binding ability with membrane receptors, and potential effects on immunomodulation and epigenetic mechanisms. The poor bioavailability of polyphenols restricts their clinical use. The application of nanonization has been implemented to improve their bioavailability, penetrability, and prolong their anticancer action. The present review analyses the recent preclinical studies related to the chemo-preventive and therapeutic potential of polyphenols present in O. sanctum. Moreover, the current article also examines in-depth the biochemical and molecular mechanisms involved in the antineoplastic actions of the considered polyphenols.

Flavonoids, a class of polyphenolic secondary metabolites, are present in fruits, vegetables, beverages such as wine and tea abundantly. Flavonoids exhibit a diverse array of pharmacological activities, including anticancer activity, and are toxic to cancer cells but not harmful to healthy cells. Besides, humans and animals cannot synthesize flavonoids, which leads to a dramatic increase in the consumption of plant flavonoids. Flavonoids consist of a 15- carbon skeleton in C6-C3-C6 rings with divergent substitution patterns to form a series of compounds. Due to their multi-faceted mechanism of action by modulating various signaling pathways associated with apoptosis, cellular proliferation, inflammation, differentiation, metastasis, angiogenesis, they interrupt the initiation, promotion, and progression of cancer. The present review highlights the Structural Activity Relationship (SAR) of flavonoids and recent insights on the progress of natural flavonoids and their synthetic analogs as prospective drug candidates against cancer, along with molecular mechanisms of action.

Tyrosine kinases are known to play a role in tumour growth and proliferation, and they have become common drug targets. Tyrosine kinase inhibitors (TKIs) prohibit associated kinases from phosphorylating tyrosine residues in their substrates, preventing downstream signaling pathways from being activated. Multiple robust and well-tolerated TKIs targeting single or multiple targets, including EGFR, ALK, ROS1, HER2, NTRK, VEGFR, RET, MET, MEK, FGFR, PDGFR, and KIT, have been developed over the last two decades, contributing to our understanding of precision cancer medicine based on a patient's genetic alteration profile. The epidermal growth factor receptor (EGFR) family consists of four transmembrane tyrosine kinases (EGFR1/ErbB1, Her2/ErbB2, Her3/ErbB3, and Her4/ErbB4) and thirteen polypeptide ligands produced by them. Multiple solid tumours, including breast, pancreatic, head and neck, kidney, vaginal, renal, colon, and non-small cell lung cancer, overexpress EGFRs. Overexpression of these genes stimulates downstream signaling channels, causing cell proliferation, differentiation, cell cycle progression, angiogenesis, cell motility, and apoptosis inhibition. EGFRs' high expression and/or adaptive activation coincide with the pathogenesis and development of many tumours, making them appealing candidates for both diagnosis and therapy. Several strategies for targeting these receptors and/or the EGFR-mediated effects in cancer cells have been established. The majority of methods include the development of anti-EGFR antibodies and/or small-molecule EGFR inhibitors. This review presents the recent advances in EGFR TKIs and their role in the treatment of cancer.

Cancer has a significant social consequence all around the globe. In 2020, approximately 19.3 million new cases of cancer were diagnosed worldwide, with about 10 million cancer deaths. In the next two decades, suspected cases are anticipated to increase by roughly 47%. The rising number of cancer patients, as well as the inadequacy of traditional chemotherapeutic agents, radiation, and invasive surgical procedures, all rely on massive cell death with hardly any selectivity, causing severe toxicities. In comparison to synthetic medications, there has subsequently been a surge in international interest in non-synthetic and alternative remedies, owing to improved adaptability and reduced side effects of drug responses. Several people with cancer prefer alternative and complementary therapy treatments, and natural remedies play a crucial role in cancer chemoprevention as they are thought to be harmless, offer fewer negative effects, and become less sufficient to evoke addiction by the wider population. Chemopreventive, antimetastatic, cytotoxic, and anti-angiogenic actions are among the promising clinical advantages, which have been established in vitro research and certain clinical trials; nevertheless, additional clinical trials are needed. This review examines several phytochemicals that may have anti-cancer and chemopreventive properties.

Cancer involves the uncontrolled division of cells resulting in abnormal cell growth due to various gene mutations and is considered the second major cause of death. Due to drug resistance to current anticancer drugs, cancer incidence is rising, and seeking effective treatment is a major concern. Natural products are prospective to yield unique molecules, as nature is a leading source of various drug molecules due to plenty of pharmacologically active molecules. Thymoquinone, a bioactive constituent obtained from Nigella sativa L., has drawn considerable attention among researchers in recent years due to its anticancer potential involving various molecular targets, including initiation of apoptosis initiation, arrest of cell cycle and generation of ROS, besides targeting multiple kinases such as tyrosine kinase, MAPK, and Janus kinase. The current review summarizes the thymoquinone chemistry, sources and anticancer potential involving various molecular targets.

Aims: The present study aimed to isolate and characterize chemical compounds from Anthocephalus cadamba Miq. bark and evaluate their anticancer activity by in silico, molecular docking, and in vitro studies. Background: Anthocephalus cadamba is a traditionally used Indian medicinal plant. The anticancer and phytochemical properties of this plant remain unexplored except for a few studies. Objectives: The objective of the study was to evaluate the antiproliferative activity of extract and fractions against breast cancer and prostate cancer cell lines and isolate and characterize active compounds from bio-active guided fractions. Moreover, the anticancer activity of isolated compounds against breast and prostate cancer cell lines was also evaluated, in addition to in silico and molecular docking interactions of isolated compounds with VEGFR2 and PDGFRα target proteins. Methods: The compounds were isolated and purified with the help of repeated column chromatography, and spectral techniques, such as 1D, 2D NMR, and GC-MS/MS, were used to identify and elucidate the structure of the compounds. Moreover, prediction of activity spectra for substances, physiochemical properties, bioactivity radar prediction, bioactivity score, natural-product likeness, ADME, and toxicity parameters of isolated compounds (AC-1 to AC-4) was performed through various in-silico databases and servers. To evaluate the docking interaction profile and binding energies of compounds, three docking tools were utilized, such as AutoDock, AutoDock Vina, and iGEMDOCK, against two targets VEGFR2 and PDGFRα. MD simulation was performed through ligand and receptor molecular dynamic server (LARMD). Results: It was found that the A. cadamba bark chloroform fraction demonstrated a significant inhibitory effect against MDA-MB-231, MCF-7, and PC-3 cells in a dose-time-dependent manner. The bioassay-guided isolation afforded four molecules AC-1 to AC-4 from chloroform fraction. Moreover, the GC-MS/MS profiling identified fourteen new molecules which were not reported earlier from A. cadamba. The in-silico study showed that the isolated compounds (AC-1 to AC-4) followed Lipinski’s rule and had good oral bioavailability. While compound AC-4 had positive bioactivity scores except for kinase inhibitor activity. The ADMET profiling revealed that AC-4 was non-toxic and easily absorbed in the human intestine, and transportable in the blood-brain barrier compared to AC-1, AC-2, AC-3, and standard drug doxorubicin. Molecular docking and MD simulation assessment also signified AC-4 anticancer activity with dual inhibitory action against the target proteins VEGFR2 and PDGFRα amongst the studied compounds. The in vitro cell viability assay of isolated compounds demonstrated that AC-1 showed IC50 (μg/mL) value of 34.96 ±3.91, 47.76±3.80 69.1±4.96, AC-2; 68.26±4.22, 54.03±5.14, >100, AC-3; 35.34±4.14, 51.5±51.5, 70.8±5.25 and AC-4; 44.2±3.57, 24.2±2.67, 51.2±2.54 for MDA-MB-231, MCF-7, and PC-3 cancer cell lines, respectively and compared with standard drug doxorubicin. Moreover, fluorescence microscopy confirmed the apoptogenic property of compounds. We also found that AC-4 exhibited significant intracellular ROS production in breast cancer cells, thereby inducing apoptosis and eventually cell death. Conclusion: In conclusion, A. cadamba afforded four pure molecules AC-1 to AC-4 with the identification of fourteen new compounds. The entire in-silico studies concluded that the AC-4 compound had better oral bioavailability, bioactivity score, and ADMET profile among studied molecules. Molecular docking analysis and MD simulation also supported AC-4 dual inhibitory action against both VEGFR2 and PDGFRα receptors. Moreover, the isolated molecules AC-1, AC-2, AC-3, and AC-4 were found to be active against MDA-MB-231, MCF-7, and PC-3 cancer cells. The molecule AC-4 was found to induce ROS-mediated apoptosis in breast cancer cells. It was found that the anticancer inhibitory potentiality of AC-4 is directed to its molecular stereochemistry which specifically binds to the target proteins of breast cancer cells with no toxicological effect. Therefore, AC-4 is suggested to be an effective aspirant for novel drug design and discovery.

Over the past 55 years of research, various experimental methods have been developed for the total synthesis of the anticancer camptothecin, a potent antitumor antibiotic, and its numerous active derivatives. The discoveries made in synthetic pathways of the camptothecin heterocyclic core have contributed significantly to the theory and strategy of directed organic synthesis aimed at finding effective anticancer drugs. The synthetic, medicinal chemistry of camptothecin, the development of structures of anticancer camptothecin analogues, and the mechanism of their activity in inhibiting the growth of different types of cancers, such as lung, ovarian, breast, pancreas, and stomach cancers are analyzed. Various structural modifications in the A, B, C, D, and E-rings of the camptothecin molecule have been thoroughly studied to improve bioavailability and diminish toxicity. Modern synthetic approaches to the camptothecin analogues and several semi-synthetic methods are reviewed.

Background: Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. Rhizoma paridis saponins (RPS), the main bioactive ingredients of Paris polyphylla Smith var. yunnanensis (PPY), have been proved to have remarkable effects on NSCLC cell lines. However, the multi-component synergistic effects and mechanisms of RPS on NSCLC have not been elucidated. Objective: To decipher the multi-RPS synergistic effects and mechanisms against NSCLC based on network pharmacology combined with segmented solid-phase extraction (SPE) and bioactivity screening method. Methods: Firstly, segmented SPE and cytotoxicity assays were performed to screen the RPS-enrichment fraction of PPY, and the steroidal saponins in it were identified by LC-MS/MS. Then, a network pharmacology analysis was performed to predict the potential therapeutic targets of RPS on NSCLC. Finally, viable cell counting tests and RT-qPCR were utilized to verify the synergistic effects and mechanisms of RPS. Results: 48 potentially active compounds were identified from the 30% MeOH/EtOAc fraction of PPY (30% M/E PPY). The results of the network pharmacology analysis indicated that RPS exerted joint effects by regulating six key targets in the PI3K-AKT signaling pathway. In vitro experiments showed that due to the synergistic effects, 30% M/E PPY at 13.90 μg/mL could exert a stronger inhibitory activity on A549 cells by reducing the overexpression of six hub genes compared with the parallel control groups. Conclusion: This research elaborates on the multi-RPS synergy mechanisms against NSCLC and provides a way to develop new combination medicines for NSCLC.