Mosquitocidal and Anti-Inflammatory Properties of The Essential Oils Obtained from Monoecious, Male, and Female Inflorescences of Hemp (Cannabis sativa L.) and Their Encapsulation in Nanoemulsions

Abstract

Among the various innovative products obtainable from hemp (Cannabis sativa L.) waste biomass originating from different industrial processes, the essential oil (EO) deserves special attention in order to understand its possible application in different fields, such as cosmetics, pharmaceuticals, and botanical insecticides. For the purpose, in the present work, we studied the chemical composition of EOs obtained from different hemp varieties, namely Felina 32 and Carmagnola Selezionata (CS) using monoecious, male, and female inflorescences, and we evaluated their mosquitocidal activities on larvae and pupae of two main malaria vectors, Anopheles gambiae and An. stephensi. Then, in order to evaluate the safe use of hemp EOs for operators, the potential pro- or anti-inflammatory effect of hemp EOs together with their toxicological profile were determined on dermal fibroblasts and keratinocytes. Given the promising results obtained by insecticidal and anti-inflammatory studies, a preliminary evaluation of EOs encapsulation into nanoemulsions (NEs) has been performed with the aim to develop a formulation able to improve their poor physicochemical stability. Felina 32 and CS inflorescences provided EOs with an interesting chemical profile, with monoterpene and sesquiterpene hydrocarbons as the major components. This study highlighted the potential application of male inflorescences, which are usually discharged during hemp product processing. These EOs could be exploited as potential sustainable and eco-friendly insecticides, given their capability to be toxic against mosquitoes and the possibility to use them to prepare stable and safe formulations. The LC50 values found in this study (<80 ppm) are lower, on average, than those of many plant EOs, with the advantage of using an industrial waste product. From MTT assay and gene and protein expression analysis, EOs showed no cytotoxicity at the appropriate doses and exerted an anti-inflammatory effect on the human cell lines tested. These findings encourage further applied research on hemp EOs in order support their industrial exploitation.

Metabolomic Profile and Antioxidant/Anti-Inflammatory Effects of Industrial Hemp Water Extract in Fibroblasts, Keratinocytes and Isolated Mouse Skin Specimens

“…As for HaCat cells, their viability seems affected by the exposure to the water extract when exposed to high concentrations (300 and 500 µg/mL) and longer experimental times (72 h) ( Figure 4 B). These findings are in line with recent literature in which the same cell line was treated with essential oil from female inflorescence [ 32 ]. Again, when cell proliferation is affected by H 2 O 2 administration, the exposure to hemp extract at concentration up to 100 µg/mL exerted a protective effect both at 24 and 48 h.…”

Essential Oils: Pharmaceutical Applications and Encapsulation Strategies into Lipid-Based Delivery Systems

“…The authors attributed this effect to the role of Lavandula angustifolia EO on the stimulation of TGF-β1, an important regulatory factor in reproduction fibroblasts which is involved in the formation of granular tissue as well as in the synthesis and accumulation of collagen fibers [ 167 ]. EOs-loaded nanoemulsions have also been studied for their potential anti-inflammatory activity by in vitro and in vivo (in zebrafish) assays [ 39 , 168 ]. In particular, Borges et al focused on the anti-inflammatory activity of nanoemulsions loaded with Rosmarinus officinalis L. EO, exploiting two parameters: the cellular antioxidant activity (CAA) and the nitric oxide (NO∙) production.…”

“…Therefore, authors concluded that the produced nanoemulsions was able to enhance the anti-inflammatory effect of EO, further reducing the production of NO∙. In particular, the potential pro- or anti-inflammatory effect of EO was investigated on human keratinocytes and fibroblasts, in order to evaluate their safe use for operators [ 168 ]. Herein, Rossi et al, as well as proving that EOs present a strong toxicity against larvae and pupae of the main malaria vectors An.…”

“…gambiae , in Asia and Africa, also demonstrated that the CBD-free hemp EOs did not induce an inflammatory condition. In particular, these compounds were able to revert the inflammation, reducing the release of the cytokine on skin cell lines, thus demonstrating that they could be safely used by operators [ 168 ].…”

Developing a Hazomalania voyronii Essential Oil Nanoemulsion for the Eco-Friendly Management of Tribolium confusum, Tribolium castaneum and Tenebrio molitor Larvae and Adults on Stored Wheat

“…Thanks to the reduced size of the droplets of the internal phase and the consequent increment of the surface area, NEs allow a better interaction of the encapsulated compounds into the target site [ 23 ] by overcoming the EO’s poor physicochemical stability and solubility issues [ 24 ]. This strategy can boost the applicability of EOs as natural insecticides [ 25 , 26 , 27 , 28 , 29 ].…”