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Industrial hemp (Cannabis sativa L.), due to its bioactive compounds (terpenes and cannabinoids), has gained increasing interest in different fields, including for medical purposes. The evaluation of the safety profile of hemp essential oil (EO) and its encapsulated form (nanoemulsion, NE) is a relevant aspect for potential therapeutic applications. This study aimed to evaluate the toxicological effect of hemp EOs and NEs from cultivars Carmagnola CS and Uso 31 on three cell lines selected as models for topical and inhalant administration, by evaluating the cytotoxicity and the cytokine expression profiles. Results show that EOs and their NEs have comparable cytotoxicity, if considering the quantity of EO present in the NE. Moreover, cells treated with EOs and NEs showed, in most of the cases, lower levels of proinflammatory cytokines compared to Etoposide used as a positive control, and the basal level of inflammatory cytokines was not altered, suggesting a safety profile of hemp EOs and their NEs to support their use for medical applications. [ABSTRACT FROM AUTHOR]

BACKGROUND: Solvent‐free microwave‐assisted extraction (MAE) is a green extraction method capable of boosting the yield and quality profile of hemp essential oil when compared with other conventional extraction techniques. During this process, two by‐products are produced, namely the aqueous residue containing bioactive phenolics and the residual deterpenated biomass, which can be used for further extraction and purification of phytocannabinoids. To date, the hemp industry has not utilized these products, although they can be valuable for the food, cosmetic, nutraceutical and pharmaceutical market. RESULTS: This study assessed and optimized the variables affecting MAE efficiency, namely microwave irradiation power, extraction time and added water, which were studied using a central composite design approach, and results were used to optimize the extraction process for recovering three valuable fractions: essential oil, polyphenols and phytocannabinoids. The products obtained using the optimized conditions were characterized in terms of yield, chemical profile and antioxidant potential. Moreover, the by‐products obtained during the optimized run were further analyzed in terms of their biological activity using both enzymatic and non‐enzymatic assays. The aqueous residue demonstrated a powerful α‐glucosidase inhibition, a good activity in terms of superoxide radical scavenging activity, a modest efficacy in terms of inhibition of advanced glycation end products formation and no activity in terms of lipase inhibition. The residual deterpenated biomass did not possess significant biological activity. CONCLUSION: This work demonstrated valorization of industrial hemp essential oil and its by‐products, obtained by a sustainable and eco‐friendly extraction method, through an almost waste‐free approach. Cannabinoids as well as other valuable bioactive compounds such as glycosidic flavones may be recovered from the residues of the essential oil extraction, representing interesting substances in the pharmaceutical, cosmetic and nutraceutical fields. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

• Hemp essential oil was obtained by microwave-assisted extraction. • The operative conditions were optimized using a central composite design. • CBD-enriched essential oil can be obtained by MAE optimization. • Hydrodistillation was carried out for comparative purposes. • The enantiomeric ratio of chiral terpenes was determined. The increase of cultivation of industrial hemp (Cannabis sativa L.) all over the world offers new opportunities for the industry to manufacture innovative products from this multipurpose crop. In this regard, the hemp essential oil represents a niche product with potential interest for the pharmaceutical, nutraceutical, cosmeceutical and agrochemical companies. On this basis, in the present work we used the microwave-assisted extraction (MAE) to get an essential oil enriched in bioactive compounds, especially cannabidiol (CBD), from the dry inflorescences of the Italian variety CS (Carmagnola Selezionata). For this purpose, the operative conditions to increase the essential oil yield and CBD concentration in terms of microwave irradiation power (W/g), extraction time (min) and water added to the plant matrix after moistening (%), were optimized using a central composite design (CCD) approach using a Milestone ETHOS X device. The conventional hydrodistillation (HD) performed for 240 min was used for comparative purposes. The qualitative compositions of essential oils obtained by MAE and HD were analysed by GC-MS, whereas the quantitative detection of CBD and main terpenoids (α-pinene, β-pinene, myrcene, limonene, terpinolene, (E)-caryophyllene, α-humulene and caryophyllene oxide) was achieved by GC-FID. Furthermore, the enantiomeric distribution of the chiral constituents (α-pinene, β-pinene, limonene, (E)-caryophyllene and caryophyllene oxide) was determined using chiral chromatography. Results showed that the MAE treatment, using high irradiation power and relatively long extraction times, increased significantly the content of CBD in the essential oil while maintaining high oil yield values when compared with conventional HD. The enantiomeric excess of three chiral monoterpenes (α-pinene, β-pinene and limonene) was determined, with the (+)-enantiomers being predominant, whereas (E)-caryophyllene and caryophyllene oxide were enantiomerically pure. In conclusion, the MAE was successfully applied to hemp dry inflorescences in order to obtain a CBD-rich essential oil which may be exploited in several industrial applications. [ABSTRACT FROM AUTHOR]