HPLC Quantification of Thymoquinone Extracted from Nigella sativa L. (Ranunculaceae) Seeds and Antibacterial Activity of Its Extracts against Bacillus Species

Abstract

The medicinal importance of Nigella sativa seeds for treating various ailments is portrayed by its traditional uses. Owing to its immense pharmacological importance, the thymoquinone phytoconstituent of N. sativa can prove beneficial for the South Asian countries including Pakistan, where this seed is commonly produced and healthcare facilities are limited. In this study, the antibacterial activity of various extracts of N. sativa seeds, extracted thymoquinone, and oil samples have been investigated against Bacillus subtilis and Bacillus licheniformis using well and disc diffusion assay. The inhibition zones ranged between 7 and 44 mm against both the bacterial strains by well diffusion assay, while disc diffusion assay provided inhibition zones in the range of 7–23 mm. Commercial and local Kalonji oil samples were included in the study. Oil samples dissolved in methanol showed increased inhibition of bacteria. However, the extracted thymoquinone showed highest antibacterial activity. Medicine formulated using thymoquinone will prove to be an herbal alternate against the resistant microbiota associated with bacterial infections. Antibacterial activity against some Bacillus species will help signify the effect on normal gut flora when oral therapy is followed. Trying different extraction protocols can help increase extraction efficiency. Study on extraction of thymoquinone in local produce of black seed can be fruitful for conducting the stability studies and can help to gain maximum benefits from the bioactives. The crude extracts from 10 g of these seeds were subjected to preliminary phytochemical investigation. Results showed that although methanol extract had the presence of maximum phytochemicals, hexane extract was the most potent in terms of antibacterial activity. Thymoquinone, a therapeutically important bioactive in N. sativa seed, was extracted employing both solvents. TLC assay and UV spectroscopy were used for its qualitative assessment, while HPLC-UV quantification showed that 250 mg/mL of methanol extract had 368.3 μg/mL thymoquinone, while its successive extraction yielded 32.94 μg/mL thymoquinone.

Repeated 28-Day Oral Toxicological Study and Gastroprotective Effects of Nigella sativa L. Oil (Shuhada) against Ethanol-Induced Gastric Mucosal Injury in Rats

“…The major bioactive compound in BSO behind its anti-inflammatory activity is TQ. In the present study, the TQ content in BSO was 7.3 mg/mL, which is higher than those reported by previous studies [ 21 , 22 ]. TQ reduced the levels of pro-inflammatory cytokines in lipopolysaccharide-stimulated murine macrophage-like RAW264.7 cells in earlier investigations [ 23 , 24 ].…”

Development and Optimization of Methylcellulose-Based Nanoemulgel Loaded with Nigella sativa Oil for Oral Health Management: Quadratic Model Approach

“…The authenticity of NSO with respect to its active constituents was assessed using a GC–MS technique and data were compiled for the percentage availability of its constituents, mainly TQ [ 18 ]. The purchased NSO was diluted 100 times using methanol and 2 µL of the diluted solution was injected directly to the GC–MS instrument using autosampler.…”

Response of Yield and Chemical Composition of Black Cumin to Different Fertilizer in Sulaimani Region

“…The identities of peaks of Thymoquinone and Thymohydroquinone were determined by comparing the chromatogram of each sample solution with that of standards. The amount of Thymoquinone and Thymohydroquinone present in the sample was calculated by using the following formulas (14,22).…”