Anticancer Properties of Essential Oils: An Overview

BACKGROUND

Essential oils are complex mixtures of low molecular weight compounds extracted from plants. Their main constituents are terpenes and phenylpropanoids, which are responsible for their biological and pharmaceutical properties, such as insecticidal, parasiticidal, antimicrobial, antioxidant, anti-inflammatory, analgesic, antinociceptive, anticarcinogenic, and antitumor properties. Cancer is a complex genetic disease considered as a serious public health problem worldwide, accounting for more than 8 million deaths annually.

OBJECTIVE

The activities of prevention and treatment of different types of cancer and the medicinal potential of essential oils are addressed in this review.

CONCLUSION

Several studies have demonstrated anti-carcinogenic and antitumor activity for many essential oils obtained from various plant species. They may be used as a substitution to or in addition to conventional anti-cancer therapy. Although many studies report possible mechanisms of action for essential oils compounds, more studies are necessary in order to apply them safely and appropriately in cancer therapy.

Inhibition by essential oils of Mentha viridis and Mentha pulegium (Lamiaceae) in proteolysis, fibrinogenolysis and coagulation caused by venomous snakes

Snake venom are widely used as laboratory tools for studies of physiological, pharmacological and toxicological mechanisms. Venoms used here are rich sources of several classes of proteases that act on factors of the coagulation cascade, fibrinogenolysis and fibrinolysis, altering the hemostatic processes, and phospholipases A2 which are involved mainly in inflammatory and clotting processes since they act hydrolyzing membrane phospholipids and may result in the release of arachidonic acid whose structure is a precursor of eicosanoids by cyclooxygenase and lipoxygenase pathways. Natural products such as essential oils are made up of active ingredients with wide application in the food, pharmaceutical and cosmetic industries. Thus, in this study evaluate the essential oils from Mentha viridis and Mentha pulegium on coagulation, fibrinogenolysis and degradation of azocasein, induced by Bothrops sp and Lachesis muta muta venoms. These oils were achieved by hydrodistillation and presented, respectively, as the main constituents linalool (40.70%), carvone (13.52%) and α-terpinene (8.56%); pulegone (50.01%), menthol (31.90%) and menthone (16.56%). The essential oils were previously incubated with Bothrops alternatus venom, for two different times, plasma was added and timing. The M. pulegium and M. viridis oils in the volume of 0.30 μL (10 min of incubation) presented greater anticlotting potential. Meanwhile, 0.15 μL the M. pulegium oil presented proclotting activity. In 20 min of incubation, both oils presented anticlotting activity with 0.15 and 0.30 μL. At azocaseinolytic assay the oil from M. pulegium reduced the activity for all evaluated venoms. The highest inhibitions were 34.33% and 39.99% for 0.6 and 1.2 μL of oil, respectively; on activity induced by B. jararacussu, M. viridis with 0.6 and 1.2 μL reduced the activity in 40.93% and 57.72%, respectively. On B. moojeni, the same volumes were responsible for inhibitions of 74.67% and 47.4%, respectively. The fibrinogenolysis induced by B. moojeni venom was totally inhibited by both oils in the evaluated proportions. The results show the presence in oils of protease inhibitors, considering metalloproteases (mainly with thrombin-like and hemorrhagic activity) and serineproteases (actuating on clotting factors), as well as phospholipase A2­ inhibitors (involved in inflammation and clotting processes) of wide application in medical and biotechnology areas.  

A rapid method to increase the number of F₁ plants in pea (Pisum sativum) breeding programs

In breeding programs, a large number of F₂ individuals are required to perform the selection process properly, but often few such plants are available. In order to obtain more F₂ seeds, it is necessary to multiply the F₁ plants. We developed a rapid, efficient and reproducible protocol for in vitro shoot regeneration and rooting of seeds using 6-benzylaminopurine. To optimize shoot regeneration, basic medium contained Murashige and Skoog (MS) salts with or without B5 Gamborg vitamins and different concentrations of 6-benzylaminopurine (25, 50 and 75 μM) using five genotypes. We found that modified MS (B5 vitamins + 25 μM 6-benzylaminopurine) is suitable for in vitro shoot regeneration of pea. Thirty-eight hybrid combinations were transferred onto selected medium to produce shoots that were used for root induction on MS medium supplemented with α-naphthalene-acetic acid. Elongated shoots were developed from all hybrid genotypes. This procedure can be used in pea breeding programs and will allow working with a large number of plants even when the F₁ plants produce few seeds.

Diversity of pea (Pisum sativum) accessions based on morphological data for sustainable field pea breeding in Argentina

We characterized 13 accessions of dry peas of different origins from various growing regions in Argentina, based on three replications of 20 plants cultivated in 2009 and 2010 in a greenhouse, with the objective of selecting those with favorable characteristics for use in breeding programs. Significant differences were found for length and width of stipule and pod, length of the internodes and leaflets, plant height, total number of nodes, number of nodes at the first pod, number of days to flowering and to harvest, number of pods and seeds per pod, 100-seed weight and grain diameter, demonstrating a high degree of genetic variability. Phenotypic correlation analysis demonstrated that large pods produced more seeds per pod, but the seed weight decreased. Plants with smaller number of nodes in the first pod were more productive. Estimates of genotypic correlation coefficients indicated a strong inherent association among the different traits. Clustering methods grouped the accessions into five clusters. Cluster 5 included two accessions and showed the highest values for length and width of stipules (4.9 and 4.5 cm, respectively), length of leaflets (7.43 cm) and days to flowering (122.6), while cluster 3, with one accession, and cluster 4, with two accessions, showed the highest values for number of seeds per pod (3.78 and 4.39), number of pods per plant (5.33 and 5.70), length of pods (5.54 and 5.72 cm), and width of pods (1.21 and 1.20 cm, respectively). We conclude that accessions in clusters 3 and 4 would be useful for crosses with other cultivars in pea breeding programs.