Carlina acaulis essential oil nanoemulsion as a new grain protectant against different developmental stages of three stored-product beetles

Polyphenolic Composition of Carlina acaulis L. Extract and Cytotoxic Potential against Colorectal Adenocarcinoma and Cervical Cancer Cells

Carlina acaulis is highly valued in the traditional medicine of many European countries for its diuretic, cholagogue, anthelmintic, laxative, and emetic properties. Moreover, practitioners of natural medicine indicate that it has anti-cancer potential. However, its phytochemistry is still little known. In the present study, the polyphenolic composition of the plant was investigated using ultra-high-performance liquid chromatography coupled with a high-resolution/quadrupole time-of-flight mass spectrometer (UHPLC-HR/QTOF/MS-PDA). The fractionation of the extract was carried out using liquid-liquid extraction and preparative chromatography techniques. Cytotoxicity was assessed based on neutral red and MTT assays. The obtained data showed that the species is rich in chlorogenic acids and C-glycosides of luteolin and apigenin. The total amount of chlorogenic acids was 12.6 mg/g. Among flavonoids, kaempferol dihexosidipentose and schaftoside were the most abundant, reaching approximately 3 mg/g, followed by isoorientin, vitexin-2-O-rhamnoside, and vicenin II, each with a content of approximately 2 mg/g. Furthermore, the cytotoxic potential of the plant against human colorectal adenocarcinoma (HT29) and human cervical cancer (HeLa) cells was investigated using the normal epithelial colon cell line (CCD 841CoTr) as a reference. It has been demonstrated that the ethyl acetate fraction was the most abundant in polyphenolic compounds and had the most promising anticancer activity. Further fractionation allowed for the obtaining of some subfractions that differed in phytochemical composition. The subfractions containing polyphenolic acids and flavonoids were characterized by low cytotoxicity against cancer and normal cell lines. Meanwhile, the subfraction with fatty acids was active and decreased the viability of HeLa and HT29 with minimal negative effects on CCD 841CoTr. The effect was probably linked to traumatic acid, which was present in the fraction at a concentration of 147 mg/g of dried weight. The research demonstrated the significant potential of C. acaulis as a plant with promising attributes, thus justifying further exploration of its biological activity.

Exploration of Synergistic Pesticidal Activities, Control Effects and Toxicology Study of a Monoterpene Essential Oil with Two Natural Alkaloids

With the increasing development of pest resistances, it is not easy to achieve satisfactory control effects by using only one agrochemical. Additionally, although the alkaloid matrine (MT) isolated from Sophora flavescens is now utilized as a botanical pesticide in China, in fact, its pesticidal activities are much lower in magnitude than those of commercially agrochemicals. To improve its pesticidal activities, here, the joint pesticidal effects of MT with another alkaloid oxymatrine (OMT) (isolated from S. flavescens) and the monoterpene essential oil 1,8-cineole (CN) (isolated from the eucalyptus leaves) were investigated in the laboratory and greenhouse conditions. Moreover, their toxicological properties were also studied. Against Plutella xylostella, when the mass ratio of MT and OMT was 8/2, good larvicidal activity was obtained; against Tetranychus urticae, when the mass ratio of MT and OMT was 3/7, good acaricidal activity was obtained. Especially when MT and OMT were combined with CN, the significant synergistic effects were observed: against P. xylostella, the co-toxicity coefficient (CTC) of MT/OMT (8/2)/CN was 213; against T. urticae, the CTC of MT/OMT (3/7)/CN was 252. Moreover, the activity changes over time of two detoxification enzymes, carboxylesterase (CarE) and glutathione S-transferase (GST) of P. xylostella treated with MT/OMT (8/2)/CN, were observed. In addition, by scanning electron microscope (SEM), the toxicological study suggested that the acaricidal activity of MT/OMT (3/7)/CN may be related to the damage of the cuticle layer crest of T. urticae.

The Type of Grain Counts: Effectiveness of Three Essential Oil-Based Nanoemulsions against Sitophilus oryzae

Essential oil (EO)-based nanoemulsions (NEs) are promising grain protectants in the management of stored-product pests. However, the potential impact of the stored-grain species on the green insecticide effectiveness has been poorly studied. In this study, two concentrations of EO-based NEs from Carlina acaulis L., Mentha longifolia (L.) Huds., and Hazomalania voyronii (Jum.) Capuron were evaluated as insecticides against the major stored-product pest Sitophilus oryzae (L.) on barley, oats, and maize kernels. The C. acaulis EO-based NE applied at 1000 ppm on barley achieved the highest mortality, killing 94.4% of S. oryzae adults after a 7-day exposure, followed by 1000 ppm of H. voyronii EO-based NE (83.3%). The lowest mortality (1.1%) was recorded with 500 ppm of M. longifolia EO-based NE on maize after the same interval. All tested NEs exhibited elevated efficacy when applied on barley, while mortalities were lower on oats and maize. Furthermore, C. acaulis EO-based NE was the most effective when applied on all commodities, followed by H. voyronii and M. longifolia EO-based NEs. Overall, our results highlighted the significant impact of the stored cereal on the insecticidal effectiveness of EO-based NE used for stored-product pest control. Sitophilus oryzae adults on barley can be adequately controlled through the application of C. acaulis and H. voyronii EO-based NEs.