Microwave-assisted extraction of Nigella sativa L. essential oil and evaluation of its antioxidant activity

Abstract

It has been previously reported that the essential oil of L. seeds and its major active component, thymoquinone (TQ), possess a broad variety of biological activities and therapeutic properties. In this work, microwave-assisted extraction (MAE) of the essential oil from L. seeds and its antioxidant activity were studied. Response surface methodology based on central composite design was used to evaluate the effects of extraction time, irradiation power and moisture content on extraction yield and TQ content. Optimal parameters obtained by CCD and RSM were extraction time 30 min, irradiation power 450 W, and moisture content 50%. The extraction yield and TQ content of the essential oil were 0.33 and 20% under the optimum conditions, respectively. In contrast, extraction yield and TQ amount of oil obtained by hydrodistillation (HD) were 0.23 and 3.71%, respectively. The main constituents of the essential oil extracted by MAE and HD were -cymene, TQ, α-thujene and longifolene, comprising more than 60% of total peak area. The antioxidant capacity of essential oils extracted by different methods were evaluated using 2,2-diphenyl-1-picrylhydrazyl and Ferric reducing antioxidant power assays, and compared with traditional antioxidants. The results showed that MAE method was a viable alternative to HD for the essential oil extraction from seeds due to the excellent extraction efficiency, higher thymoquinone content, and stronger antioxidant activity.

Antibacterial, Antifungal, Antimycotoxigenic, and Antioxidant Activities of Essential Oils: An Updated Review

“…According to Singh et al [ 188 ], the two major constituents of Nigella sativa L. (black cumin) are thmoquinone (37.6%) and p -cymene (31.4%). There are studies performed in the past, up until recent years, investigating the antioxidant characteristics of Nigella sativa L. (black cumin) [ 181 , 188 , 189 , 190 , 191 ], and in all these reports, the antioxidant activity of Nigella sativa L. (black cumin) EO has been mentioned. Ocimum basilicum L. (basil) is another plant EO that has been used in recent antioxidant studies [ 182 , 192 , 193 ].…”

Nigella Plants – Traditional Uses, Bioactive Phytoconstituents, Preclinical and Clinical Studies

“…Some studies suggest that N. sativa oil and extracts have antioxidant properties and can modulate oxidative stress, which could be beneficial for oxidative stress related diseases/disorders. In this sense, oils and solvent extracts from N. sativa seeds possessed antioxidant activity in vitro ( Toma et al, 2015 ; Mohammed et al, 2016 ; Abedi et al, 2017 ; Singhal et al, 2017 ), ex vivo ( Ghoreyshi et al, 2020 ), in vivo ( Mahmoudi et al, 2018 ; Rasoli et al, 2018 ) and in humans ( Nikkhah-Bodaghi et al, 2019 ). Moreover, in vivo regular intake of ethanolic extract of N. sativa seed (400 mg/kg) lowered the lipid peroxidation, and enhanced catalase activity in Wistar rats ( Rasoli et al, 2018 ).…”

Nutritional quality and phytochemical contents of cold pressed oil obtained from chia, milk thistle, nigella, and white and black poppy seeds

“…Due to its content of biologically active substances, it has anti-inflammatory, anticancer, antibacterial, antidiabetic and analgesic properties. Most of these properties are due to the presence of thymoquinone (2-methyl-5-isopropyl-1,4-benzoquinone) (Abedi et al, 2017). In addition, this oil also contains many valuable fatty acids, mainly linoleic, which further increase their nutritional value (Solati et al, 2014).…”