Cancer is one of the most complex and systemic diseases affecting the health of mankind, causing major deaths with a significant increase. This pathology is caused by several risk factors, of which genetic disturbances constitute the major elements, which not only initiate tumor transformation but also epigenetic disturbances which are linked to it and which can induce transcriptional instability. Indeed, the involvement of epigenetic disturbances in cancer has been the subject of correlations today, in addition to the use of drugs that operate specifically on different epigenetic pathways. Natural molecules, especially those isolated from medicinal plants, have shown anticancer effects linked to mechanisms of action. The objective of this review is to explore the anticancer effects of alkaloids, terpenoids, quinones, and isothiocyanates.

Trichostatin A (TSA), a natural derivative of dienohydroxamic acid derived from a fungal metabolite, exhibits various biological activities. It exerts antidiabetic activity and reverses high glucose levels caused by the downregulation of brain-derived neurotrophic factor (BDNF) expression in Schwann cells, anti-inflammatory activity by suppressing the expression of various cytokines, and significant antioxidant activity by suppressing oxidative stress through multiple mechanisms. Most importantly, TSA exhibits potent inhibitory activity against different types of cancer through different pathways. The anticancer activity of TSA appeared in many in vitro and in vivo investigations that involved various cell lines and animal models. Indeed, TSA exhibits anticancer properties alone or in combination with other drugs used in chemotherapy. It induces sensitivity of some human cancers toward chemotherapeutical drugs. TSA also exhibits its action on epigenetic modulators involved in cell transformation, and therefore it is considered an epidrug candidate for cancer therapy. Accordingly, this work presents a comprehensive review of the most recent developments in utilizing this natural compound for the prevention, management, and treatment of various diseases, including cancer, along with the multiple mechanisms of action. In addition, this review summarizes the most recent and relevant literature that deals with the use of TSA as a therapeutic agent against various diseases, emphasizing its anticancer potential and the anticancer molecular mechanisms. Moreover, TSA has not been involved in toxicological effects on normal cells. Furthermore, this work highlights the potential utilization of TSA as a complementary or alternative medicine for preventing and treating cancer, alone or in combination with other anticancer drugs.

The majority of the Origanum species are important medicinal plants as well as culinary herbs and have thus a great economic value. Some taxonomic issues are still pending within the genus and the cytogenetic studies about this genus are still very scarce. Therefore, studies concerning chromosome number and genome size can provide complementary data that may be useful to characterize the genus Origanum. These two approaches have been used to characterize five Moroccan taxa of the genus Origanum occurring in the wild in addition to the exotic species O. onites. All investigated taxa are diploid with chromosome number of 2n = 30. This is the first time the chromosome numbers have been counted in O. grosii, O. compactum and O. × font-queri as well as in O. vulgare subsp. virens from Morocco. The genome sizes are considered as small, and the mean values ranged from 1.43 pg/2C in O. vulgare subsp. virens to 1.53 pg/2C in O. compactum. Besides, no significant intraspecific variability in genome size was observed among populations of O. elongatum as well as of O. grosii.

Phytochemicals in the ethanol extract of Artemisia herba-alba were examined and evaluated for the antioxidant and cytotoxicity potential. The extraction was performed using an accelerated solvent extraction (ASE300), analyzed by GC-MS and the total phenolics was estimated by Folin–Ciocalteau method. The antioxidant activity of the extract was evaluated using three methods and its cytotoxicity was evaluated in-vitro on NCI-N417 tumor cell line using MTT test and flow cytometry. Twenty-one compounds were identified in the A. herba-alba extract, which was rich in phenolic compounds (248.56 ± 11.05 μg GAE mg⁻¹ extract) and had antioxidant activity characterized by a high DPPH-radical-scavenging activity (IC50 = 69.01 ± 0.03 μg mL⁻¹), inhibitory effect of β-carotene oxidation (95.75%±0.013), and reducing power (DO700nm = 0.751 ± 0.001). Ethanol extract from A. herba-alba demonstrated cytotoxic and antiproliferative activity.

DNA methylation is an epigenetic mark involving the addition of a methyl group to DNA, particularly at cytosine residues. This methylation plays an important role in regulating gene expression through direct gene repression or through the control of other epigenetic modifications such as histone modification or chromatin remodeling. DNA methylation is catalyzed by de novo and maintenance DNMT methyltransferase type enzymes and requires the transfer of a methyl group to cytosine to transform it into 5-methyl-cytosine. Currently, several investigations have highlighted the involvement of aberrant DNA methylation with certain tumors. Indeed, the methylation of antioncogenes and/or the demethylation of oncogenes are the major alterations that are strongly linked to human cancers. DNMTs play a central role in the epigenetic regulation of the human genome, both in normal and pathological processes. Recent discoveries on the differentiated roles of DNMTs in DNA methylation, and their implication in various cancers, open the way to new therapeutic approaches targeting these enzymes to treat epigenetic diseases. It is essential to continue exploring the roles of DNMTs to better understand their implication in tumorigenesis mechanisms and to develop more effective treatment strategies.