Chemical composition and phytotoxicity of essential oils of Croton doctoris S. Moore (Euphorbiaceae)

Abstract

Essential oils from the stems and leaves of Croton doctoris were analyzed by gas chromatography and mass spectrometry, resulting in 22 identified compounds. The effects of these essential oils on the germination, root and shoot growth, total chlorophyll content, potential root respiration, peroxidase activity, catalase, superoxide dismutase, and mitotic index in lettuce and onion were determined. Antioxidant, antimicrobial, and cytotoxic activity were also investigated. The results revealed that the stem oil consisted of 15 compounds, of which caryophyllene oxide (24.5%) and E-caryophyllene (13.3%) were the major constituents. The leaf oil contained E-caryophyllene (39.6%) and α-humulene (13.2%) as major compounds. The oils inhibited the germination and growth of lettuce and onion seedlings and reduced chlorophyll content, root respiration, and cell division. They also caused oxidative stress, indicated by the increased activity of the evaluated antioxidant enzymes. These abnormal physiological processes contributed to the inhibition of plant growth. The most pronounced phytotoxic effects were observed in the stem oil. The cytotoxicity tests indicated that leaf oil was more active than stem oil, resulting from the presence of biologically active sesquiterpenes that inhibit the growth of cancer cells.

Phytochemical Profile and Herbicidal (Phytotoxic), Antioxidants Potential of Essential Oils from Calycolpus goetheanus (Myrtaceae) Specimens, and in Silico Study

“…In both cases analyzed, we can see that, for this variable studied, receptor plant S. obtusifolia was the most affected by the EOs. The results of this study, when compared to the literature, do not follow the same pattern of response; for example, in previous studies, the most affected receptor species was M. pudica [ 59 , 60 ]; however, these response patterns depend on factors other than the receptor species, such as the chemical profile of the essential oil [ 60 , 61 , 62 , 63 ].…”

“…According to Shao et al, [ 65 ], the 1,8-cineole compound obtained lower results for the inhibition of the root growth of Amaranthus retroflexus and Poa annua , when compared to the other two major constituents of the Seriphidium terrae-albae essential oil (α-thujone and β-thujone). Other authors also demonstrate the phytotoxic potential of 1,8-cineole on different species of receptor plants [ 66 , 67 , 68 ]; in addition, compounds such as δ-cadinene and ( E )-Caryophyllene have also shown phytotoxic potential on several plant species; in addition, other compounds such as δ-cadinene and ( E )-Caryophyllene have also shown phytotoxic potential on several plant species such as Mimosa pudica , Senna obtusifolia , Sinapis arvensis , Trifolium campestre , and Phalaris canariensis weeds [ 58 , 69 ], results similar to those of other authors [ 63 , 70 ]. Jaradat [ 71 ] points out that the Teucrium polium L. essential oil has α-cadinol as the component with the highest content (46.80%).…”

Cytotoxicity of extracts and compounds isolated from Croton echioides in animal tumor cell (HTC)

“…In the study by Monteiro (2012), with extracts obtained from C. campestris, it was identified that the crude ethyl acetate extract had the best profile of antitumor activity in vitro due to the decrease in cell viability, increase in cell population in sub-G1 and necrotic cell death. The essential oils of C. doctoris leaf also showed cytotoxic effect for melanoma cells (UACC62) and ovarian cancer (OVCAR), which according to the authors must be the presence of biologically active sesquiterpenes that acted by inhibiting the growth of cancer cells (Cândido et al, 2021). These results also may be due to the antioxidant activity of the Croton extract, as identified by Morais et al (2006), with C. zenhtneri, C. nepetaefolius and C. argyrophylloides and the EAF fraction of the present study, as demonstrated by Novello et al (2016).…”

Chemical Evaluation, Phytotoxic Potential, and In Silico Study of Essential Oils from Leaves of Guatteria schomburgkiana Mart. and Xylopia frutescens Aubl. (Annonaceae) from the Brazilian Amazon

“…According to the authors, the volatile concentrate influenced both the seed germination and seedling growth of lettuce. Cândido et al [ 97 ] indicated that the EO of the stem of Croton doctoris contained caryophyllene oxide (24.50%) as the major component. The authors emphasized that this EO exhibited herbicidal activity on seed germination and on lettuce radicle and hypocotyl growth.…”