Cytotoxicity of Lissoclibadins and Lissoclinotoxins, Isolated from a Tropical Ascidian Lissoclinum cf. badium, against Human Solid-Tumor-Derived Cell Lines

Marine biome-derived secondary metabolites, a class of promising antineoplastic agents: A systematic review on their classification, mechanism of action and future perspectives

Cancer is one of the most deadly diseases on the planet. Over the past decades, numerous antineoplastic compounds have been discovered from natural resources such as medicinal plants and marine species as part of multiple drug discovery initiatives. Notably, several marine flora (e.g. Ascophyllum nodosum, Sargassum thunbergii) have been identified as a rich source for novel cytotoxic compounds of different chemical forms. Despite the availability of enormous chemically enhanced new resources, the anticancer potential of marine flora and fauna has received little attention. Interestingly, numerous marine-derived secondary metabolites (e.g., Cytarabine, Trabectedin) have exhibited anticancer effects in preclinical cancer models. Most of the anticancer drugs obtained from marine sources stimulated apoptotic signal transduction pathways in cancer cells, such as the intrinsic and extrinsic pathways. This review highlights the sources of different cytotoxic secondary metabolites obtained from marine bacteria, algae, fungi, invertebrates, and vertebrates. Furthermore, this review provides a comprehensive overview of the utilisation of numerous marine-derived cytotoxic compounds as anticancer drugs, as well as their modes of action (e.g., molecular target). Finally, it also discusses the future prospects of marine-derived drug developments and their constraints.

Antitumor Potential of Immunomodulatory Natural Products

Cancer is one of the leading causes of death globally. Anticancer drugs aim to block tumor growth by killing cancerous cells in order to prevent tumor progression and metastasis. Efficient anticancer drugs should also minimize general toxicity towards organs and healthy cells. Tumor growth can also be successfully restrained by targeting and modulating immune response. Cancer immunotherapy is assuming a growing relevance in the fight against cancer and has recently aroused much interest for its wider safety and the capability to complement conventional chemotherapeutic approaches. Natural products are a traditional source of molecules with relevant potential in the pharmacological field. The huge structural diversity of metabolites with low molecular weight (small molecules) from terrestrial and marine organisms has provided lead compounds for the discovery of many modern anticancer drugs. Many natural products combine chemo-protective and immunomodulant activity, thus offering the potential to be used alone or in association with conventional cancer therapy. In this review, we report the natural products known to possess antitumor properties by interaction with immune system, as well as discuss the possible immunomodulatory mechanisms of these molecules.

Exploration of marine natural resources in Indonesia and development of efficient strategies for the production of microbial halogenated metabolites

Nature is a prolific source of organic products with diverse scaffolds and biological activities. The process of natural product discovery has gradually become more challenging, and advances in novel strategic approaches are essential to evolve natural product chemistry. Our focus has been on surveying untouched marine resources and fermentation to enhance microbial productive performance. The first topic is the screening of marine natural products isolated from Indonesian marine organisms for new types of bioactive compounds, such as antineoplastics, antimycobacterium substances, and inhibitors of protein tyrosine phosphatase 1B, sterol O-acyl-transferase, and bone morphogenetic protein-induced osteoblastic differentiation. The unique biological properties of marine organohalides are discussed herein and attempts to efficiently produce fungal halogenated metabolites are documented. This review presents an overview of our recent work accomplishments based on the MONOTORI study.

Purified compounds from marine organism sea pen induce apoptosis in human breast cancer cell MDA-MB-231 and cervical cancer cell Hela

Marine organisms are an important source of chemical compounds which are appropriate for use as therapeutic agents. Among them, Sea pens produce valuable chemical compounds being used as anti-cancer drugs. The aim of this study was to investigate anti-cancer property of extracted and purified compounds from marine organism Sea pen and evaluate their effects on inducing of apoptosis. The extracts were prepared from dried colony of Virgularia gustaviana. The compounds (3β)-Cholest,5en,3ol (cholesterol) (15 mg), Hexadecanoic acid (2.5 mg) and 2-Hexadecanol (10.7 mg) were identified by GC-MS and NMR. The cytotoxic effects of the compounds were evaluated on Hela and MDA-Mb-231 human cancer cell lines with MTT assay. Immunocytochemistry and Western Blot analyses were used to evaluate the expression of apoptosis related markers Caspase 3, Caspase 8, Bax and BCL2 in cancer cells after treating with three compounds. The purified compounds reduced viability of human breast cancer cell line MDA-MB-231 and human cervical cancer cell line Hela concentration-dependently. 2-Hexadecanol reduced significantly the viability of both cancer cell lines in comparison to the other purified compounds. Treatment of cancer cells with the three purified compounds increased the expression of caspase-3, caspase-8 and Bax proteins and decreased the relative Bcl-2/Bax ratio, demonstrating induction of apoptosis as possible mechanism of action. According to the results, three purified compounds inhibit the growth of cancer cells by inducing of apoptosis pathway; an effect which needs to be further investigated in the future studies.

Marine Natural Products from Indonesian Waters

Natural products are primal and have been a driver in the evolution of organic chemistry and ultimately in science. The chemical structures obtained from marine organisms are diverse, reflecting biodiversity of genes, species and ecosystems. Biodiversity is an extraordinary feature of life and provides benefits to humanity while promoting the importance of environment conservation. This review covers the literature on marine natural products (MNPs) discovered in Indonesian waters published from January 1970 to December 2017, and includes 732 original MNPs, 4 structures isolated for the first time but known to be synthetic entities, 34 structural revisions, 9 artifacts, and 4 proposed MNPs. Indonesian MNPs were found in 270 papers from 94 species, 106 genera, 64 families, 32 orders, 14 classes, 10 phyla, and 5 kingdoms. The emphasis is placed on the structures of organic molecules (original and revised), relevant biological activities, structure elucidation, chemical ecology aspects, biosynthesis, and bioorganic studies. Through the synthesis of past and future data, huge and partly undescribed biodiversity of marine tropical invertebrates and their importance for crucial societal benefits should greatly be appreciated.

Natural Products with Heteroatom-Rich Ring Systems

This review focuses on all known natural products that contain a "heteroatom-rich" ring system, specifically a five-, six- or seven-membered ring that contains three or more heteroatoms. The isolation and biological activity of these natural products is discussed, along with the biosynthetic processes that Nature employs to assemble these rare heterocyclic frameworks.

Lissoclibadin 1, a Polysulfur Aromatic Alkaloid from the Indonesian Ascidian Lissoclinum cf. badium, Induces Caspase-Dependent Apoptosis in Human Colon Cancer Cells and Suppresses Tumor Growth in Nude Mice

Lissoclibadins, polysulfur aromatic alkaloids, were isolated from the Indonesian ascidian Lissoclinum cf. badium. Lissoclibadins 1 (1), 3 (2), 4 (3), 7 (4), 8 (5), and 14 (6) inhibited the growth of four human solid cancer cell lines: HCT-15 (colon adenocarcinoma), HeLa-S3 (cervix adenocarcinoma), MCF-7 (breast adenocarcinoma), and NCI-H28 (mesothelioma). Lissoclibadin 1 (1) exerted the most potent cytotoxic effects in vitro and mainly promoted apoptosis through an intrinsic pathway with the activation of a caspase-dependent pathway in HCT-15 cells. In vivo studies demonstrated that 1 suppressed tumor growth in nude mice carrying HCT-15 cells without significant secondary adverse effects. In conclusion, the results obtained in the present study demonstrate that 1 has potential as a chemotherapeutic candidate for preclinical investigations.

Natural Products Diversity of Marine Ascidians (Tunicates; Ascidiacea) and Successful Drugs in Clinical Development

This present study reviewed the chemical diversity of marine ascidians and their pharmacological applications, challenges and recent developments in marine drug discovery reported during 1994-2014, highlighting the structural activity of compounds produced by these specimens. Till date only 5% of living ascidian species were studied from <3000 species, this study represented from family didemnidae (32%), polyclinidae (22%), styelidae and polycitoridae (11-12%) exhibiting the highest number of promising MNPs. Close to 580 compound structures are here discussed in terms of their occurrence, structural type and reported biological activity. Anti-cancer drugs are the main area of interest in the screening of MNPs from ascidians (64%), followed by anti-malarial (6%) and remaining others. FDA approved ascidian compounds mechanism of action along with other compounds status of clinical trials (phase 1 to phase 3) are discussed here in. This review highlights recent developments in the area of natural products chemistry and biotechnological approaches are emphasized.

A new synthetic varacin analogue, 8-(trifluoromethyl)-1,2,3,4,5-benzopentathiepin-6-amine hydrochloride (TC-2153), decreased hereditary catalepsy and increased the BDNF gene expression in the hippocampus in mice

RATIONALE

The creation of effective psychotropic drugs is the key problem of psychopharmacology. Natural compounds and their synthetic analogues attract particular attention.

OBJECTIVES

The effect of a new synthetic analogue of varacin, 8-(trifluoromethyl)-1,2,3,4,5-benzopentathiepin-6-amine hydrochloride (TC-2153), on the behavior and the expression of the genes coding BDNF (Brain-Derived Neurotrophic Factor, Bdnf) and CREB (cAMP response element-binding protein, Creb) implicated in the mechanism of psychotropic drug action as well as gp130 (Il6st) implicated in the mechanism of hereditary catalepsy in the brain of mice of ASC (Antidepressant Sensitive Catalepsy) strain was studied.

RESULTS

Acute per os administration of 20 or 40 mg/kg, but not 10 mg/kg of TC-2153 significantly decreased catalepsy. At the same time, in the open field test, 10 or 20 mg/kg of TC-2153 did not influence the locomotor activity, grooming or time spent in the center, while the highest dose of the drug (40 mg/kg) significantly reduced time in the center without any effect on locomotion and grooming. Chronic TC-2153 treatment (10 mg/kg for 12-16 days) did not influence the behavior in the open field but significantly attenuated catalepsy, increased Bdnf mRNA and decreased Il6st mRNA levels in the hippocampus.

CONCLUSIONS

The results suggest: 1) TC-2153 as a new drug with potential psychotropic and anticataleptic activities and 2) the involvement of BDNF and gp130 in the molecular mechanism of TC-2153 action.

Diving for drugs: tunicate anticancer compounds

The marine biosphere boasts tremendous biodiversity replete with structurally unique, active and selective secondary metabolites. Bioprospecting for antitumor compounds has been rewarding, and tunicates have been especially successful in yielding prospective cancer therapies. These compounds are now subjected to clinical trials in Europe and the USA. With the ongoing search for potent and specific anticancer drugs, in this article we discuss the unique perspectives, compounds and opportunities afforded by this rich source of potential pharmaceuticals. We discuss marine-derived antitumor drugs, their structures, and their various types and levels of antitumor activities in bench and bedside efforts.

Marine natural products

This review covers the literature published in 2007 for marine natural products, with 948 citations(627 for the period January to December 2007) referring to compounds isolated from marine microorganisms and phytoplankton, green algae, brown algae, red algae, sponges, cnidarians,bryozoans, molluscs, tunicates, echinoderms and true mangrove plants. The emphasis is on new compounds (961 for 2007), together with the relevant biological activities, source organisms and country of origin. Biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.1 Introduction, 2 Reviews, 3 Marine microorganisms and phytoplankton, 4 Green algae, 5 Brown algae, 6 Red algae, 7 Sponges, 8 Cnidarians, 9 Bryozoans, 10 Molluscs, 11 Tunicates (ascidians),12 Echinoderms, 13 Miscellaneous, 14 Conclusion, 15 References.