Carlina oxide from Carlina acaulis root essential oil acts as a potent mosquito larvicide

Abstract

Background: One of the most important causative agents of visceral leishmaniasis (VL) is Leishmania infantum, which is mainly spread by Phlebotomus and Lutzomyia sandflies in the Old and New World, respectively. Novel and effective drugs to manage this neglected vector-borne disease are urgently required. In this study, we evaluated the toxicity of carvacrol, thymol and linalool, three common essential oil constituents, on amastigotes and promastigotes of L. infantum. Methods: in vitro experiments were performed by 24 h MTT assay. Carvacrol, thymol and linalool at concentrations ranging from 1.3 to 10 µg/mL were tested on promastigotes of L. infantum. For in vivo test, two groups of hamsters (Mesocricetus auratus) received 100 mg/kg of body weight/day of carvacrol and thymol as intraperitoneal injection on day 7 post-infection, followed by a 48 h later injection. The third group was treated with the glucantime as standard drug (500 mg/kg) and the last group (control) just received normal saline. On the 16th day, the number of parasites and histopathological changes in liver and spleen were investigated. Results: 24 h MTT assay showed promising antileishmanial activity of thymol and carvacrol, with IC 50 values of 7.2 (48 µM) and 9.8 µg/mL (65 µM), respectively. Linalool at all concentrations did not affect L. infantum promastigote viability. In vivo toxicity data of carvacrol and thymol showed that the former at 100 mg/kg was the safest and most effective treatment with little side effects on the liver. Conclusions: Overall, thymol and carvacrol are highly promising candidates for the development of effective and safe drugs in the fight against VL.

Developing a Highly Stable Carlina acaulis Essential Oil Nanoemulsion for Managing Lobesia botrana

“…Through gas chromatography–mass spectrometry (GC–MS) analysis, the EO extracted from the roots of C . acaulis was characterised and the data obtained were in accordance with the work of Benelli et al [ 56 ]. Seven compounds were identified, among which carlina oxide was the predominant EO component, comprising 94.6% of the relative content.…”

“…Herein, we decided to deepen our knowledge about EO and EO-based NE effectiveness against this harmful insect pest. For this purpose, we selected the EO obtained from the root of Carlina acaulis L. (Asteraceae), which has revealed to be promising as an active ingredient of botanical insecticides, highly effective against vectors and stored product insects [ 55 , 56 ].…”

“…In this scenario, reminding the importance of botanical EOs for the development of new sustainable pesticides, considering the promising insecticidal activities showed by the C . acaulis EO [ 56 , 71 ], and the limitations linked with its lipophilicity and volatility as well, herein a highly stable C . acaulis -based NE was developed.…”

The Impact of Different Cultivation Systems on the Content of Selected Secondary Metabolites and Antioxidant Activity of Carlina acaulis Plant Material

“…The large difference in the CO content between the soil-grown plants and hydroponic plants may be related to both different growth conditions and the age of the plant [31,32]. Taking into consideration the latest research on insecticidal activity of CO, which showed that CO is a very effective insecticide [14], it should be assumed that this compound can be used for plant protection in the future. CO is found in only a few plant species and soil cultivation of C. acaulis can be a promising way to obtain it.…”

“…Both roots and aboveground parts of the plant are used as diaphoretic, diuretic, anthelmintic, and antibacterial drugs in ethnomedicine in Italy [2,3], Montenegro, Bosnia and Herzegovina, Serbia [4], and Macedonia [5]. The biological activity of extracts from Carlina plants is associated with the presence of such compounds as pentacyclic triterpenes: oleanolic (OA) and ursolic acids (UA) [6], chlorogenic acid (ChA), and 3,5-di-caffeoylquinic acid (3,5CQA) [7,8]; flavonoids: vitexin, orientin, homoorientin and schaftoside [9,10]; and carlina oxide (CO) [10][11][12][13][14].…”