Anticancer activity of monoterpenes: a systematic review.

Secondary metabolites have been recognized for centuries as medicinal agents, in particular monoterpenes which have been the target of research in the discovery of antineoplastic drugs, as they have potential antitumor effect and low toxicity and are used as additives in foods and cosmetics. Another advantage of monoterpenes is structural diversity, which gives greater plasticity when interacting with cells. The purpose of this review was to summarize and critically discuss the anticancer potential of monoterpenes and their respective mechanisms of action. A systematic review of articles in the MEDLINE/PubMed, Web of Science, Scopus and Science Direct electronic databases was independently conducted by three reviewers using the combination of the following keywords: monoterpenes AND anticancer AND in vitro. Restriction in selecting articles followed pre-established inclusion and exclusion criteria by the reviewers, and also a time limitation with works published between 2015 and 2019 being selected. In total, 39 works were deemed eligible for inclusion in the final review. Monoterpenes have cytotoxic activity in a wide variety of tumor cell lines, and mainly appear to exert this effect by inducing apoptosis caused by oxidative stress. In addition, improved use of monoterpenes when used in drug delivery systems and the synergistic effect with conventional chemotherapeutic drugs are reported. These findings validate this class of compounds as a promising source of chemotherapeutic drugs yet to be explored.

Exposure to Anacardiaceae volatile oils and their constituents induces lipid peroxidation within food-borne bacteria cells.

The chemical composition of the volatile oils from five Anacardiaceae species and their activities against Gram positive and negative bacteria were assessed. The peroxidative damage within bacterial cell membranes was determined through the breakdown product malondialdehyde (MDA). The major constituents in Anacardium humile leaves oil were (E)-caryophyllene (31.0%) and α-pinene (22.0%), and in Anacardium occidentale oil they were (E)-caryophyllene (15.4%) and germacrene-D (11.5%). Volatile oil from Astronium fraxinifolium leaves were dominated by (E)-ß-ocimene (44.1%) and α-terpinolene (15.2%), whilst the oil from Myracrodruon urundeuva contained an abundance of δ-3-carene (78.8%). However, Schinus terebinthifolius leaves oil collected in March and July presented different chemical compositions. The oils from all species, except the one from A. occidentale, exhibited varying levels of antibacterial activity against Staphylococcus aureus, Bacillus cereus and Escherichia coli. Oil extracted in July from S. terebinthifolius was more active against all bacterial strains than the corresponding oil extracted in March. The high antibacterial activity of the M. urundeuva oil could be ascribed to its high δ-3-carene content. The amounts of MDA generated within bacterial cells indicate that the volatile oils induce lipid peroxidation. The results suggest that one putative mechanism of antibacterial action of these volatile oils is pro-oxidant damage within bacterial cell membrane explaining in part their preservative properties.

Chemical constituents from Piptadenia rigida Benth., Fabaceae, "angico"

The phytochemical investigation of the roots of Piptadenia rigida Benth., Fabaceae, known as "angico", afforded sitosterol, lupeol, betuline, the chalcone isoliquiritigenin, the flavonoids, 7,4'-dihydroxyflavone, 7,3',4'-trihydroxyflavone, 7,8,3',4'-tetrahydroxyflavanone, 4-hydroxy-3,5-dimethoxybenzaldehyde and methyl-3,4-dihydroxy-benzoate. Both flavones were also isolated from the branches of this plant. Five derivatives of the aldehyde were obtained by diazomethane treatment. The structures of compounds were identified by IR, NMR and mass spectral data analysis of natural compounds and some derivatives, and by comparison with literature data.