Alteration in Thymoquinone Content of Nigella sativa Seeds After Processing by a Traditional Method and Stability Assessment of Raw and Processed Seeds

Document Type: Original paper


1 Traditional Medicine and Materia Medica Research Center and Department of Traditional Pharmacy, School of Traditional Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

2 Department of Traditional Medicine, School of Traditional Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

3 Traditional Medicine and Materia Medica Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.


Background and objectives: Nigella sativa L. is one of the most important species in Iranian traditional medicine (ITM). According to ITM, the plant seeds can cause bronchospasm in patients with hot temperament; therefore it is recommended to process the seeds with grape vinegar before usage. This process may influence some components of the seeds; thus, in the present investigation, the effect of processing on thymoquinone, which is one of the most important active ingredients of the seeds, has been studied. Moreover, the stability of Nigella capsules containing raw and processed seeds and Nigella-honey mixture, “Maajoon”, were assessed. Methods: Nigella sativa seeds were processed by two methods: vinegar was added to the whole intact seeds, then the seeds were dried and crushed; the second method consisted of first crushing the seeds and then performing the vinegar adding and drying steps. The essential oil of the powders was obtained by using hydrodistillation method and thymoquinone content of the oils was measured by gas chromatography. In order to estimate the stability of the Nigella capsules and “Maajoon”, thymoquinone content of the products was measured after one, two and three months at room temperature. Results: The results showed that thymoquinone was absent in the processed seeds which were powdered before processing; but thymoquinone percentage had decreased in processed seeds which were powdered after processing (maximum content: 64.1%). The reduction of thymoquinone after three months was 40.1 and 78.5% in raw and processed capsules, respectively. No thymoqinone was found in the “Maajoon”. Conclusion: Since many effects of Nigella is due to thymoquinone, it seems that grinding before processing and making “Maajoon” are not suitable methods for Nigella preparation. Powdering after processing had decreased thymoquinone content which might result in decrease in bronchospasm as the side effect of thymoquinone; therefore, this method of processing seems to be suitable.  Due to low stability of Nigella powder, powdering just before usage is recommended when necessary.


[1] Aghili Khorasani M. Makhzan ol Advieh Shams Ardakani MR, Rahimi R, Farjadmand F, Eds. Tehran: Sabz-arang and Tehran University of Medical Sciences, 2009.

[2] Tonekaboni M. Rahimi R, Shams Ardakani MR, Farjadmand F, Eds. Tohfat-al-mumenin. Tehran: TMRC, 2007.

[3] Chakravarty N. Inhibition of histamine release from mast cells by nigellone. Ann Allergy. 1993; 70(30): 237-242.

[4] Al-Ghamdi MS. The anti-inflammatory, analgesic and antipyretic activity of Nigella sativa. J Ethnopharmacol. 2001; 76(1): 45-48.

[5] Abdel-Fattah AM, Matsumoto K, Watanabe H. Antinociceptive effects of Nigella sativa oil and its major component, thymoquinone in mice. Eur J Pharmacol. 2000; 400(1): 89-97.

[6] Burits M, Bucar F. Antioxidant activity of Nigella sativa essential oil. Phytother Res. 2000; 14(5): 323-328.

[7] Gali-Muhtasib H, El-Najjar N, Schneider-Stock R. The medicinal potential of black seed (Nigella sativa) and its components. M.T.H. Khan and A. Ather (Eds.). In: lead molecules from natural products. Amsterdam: Elsevier, 2006.

[8] Gourchian A, Hajimehdipoor H, Ara L, Choopani R, Kamalinejad M, Salimzadeh A, Ghachkar L, Malekfar M. Essential oil and fixed oil content of Nigella sativa after a traditional medicine processing-a comparative study. Biol Forum-An Int J. 2016; 8(2): 120-125.

[9] Amin Gh. Popular medicinal plants of Iran. Tehran: Tehran University of Medical Sciences, 2005.

[10] Al-Jassir MS. Chemical composition and microflora of black cumin (Nigella sativa L.) seeds growing in Saudi Arabia. Food Chem. 1992; 45(4): 239-242.

[11]  Atta-Ur-Rahman. Nigellidine-a new indazole alkaloid from the seed of Nigella sativa. Tetrahedron Lett. 1995; 36(12): 1993-1994.

[12] Nickavar B, Mojab F, Javidnia K, Roodgar Amoli MA. Chemical composition of the fixed and volatile oils of Nigella sativa L. from Iran. Z Natrforsch C. 2003; 58(9-10): 629-631.

[13] El Tahrir KE, Ashour MM, al-Harbi MM. The respiratory effects of the volatile oil of the black seed (Nigella sativa) in guinea-pigs: elucidation of the mechanism(s) of action. Gen Pharmacol. 1993; 24(5): 1115-1122.

[14] El Tahrir KEH, Ageel AM. Effect of the volatile oil of Nigella sativa on the arterial blood pressure and heart rate of the guinea-pig. Saudi Pharm J. 1994; 2(4): 163-168.

[15] EL Tahrir Kamal EH, Al-Ajmi MF, Al-Bekairi AM. Some cardiovascular effects of the dethymoquinonated Nigella sativa volatile oil and its major components α-pinene and ρ-cymene in rats. Saudi Pharm J. 2003; 11(3): 104-110.

[16] El-Dakhakhny M. Studies on the Egyptian Nigella sativa some pharmacological properties of the seeds active principle in comparison to its dihydro compound and its polymer. Arzneim Forsch (Drug Res). 1965; 15(10): 1227-1229.

[17]  Daba MH, Abdel-Rahman MS. Hepatoprotective activity of thymoquinone in isolated rat hepatocytes. Toxicol Lett. 1998; 95(1): 23-29.

[18] Al-Gharably NM, Badry OA, Nagi MN. Protective effect of thymoquinone against carbon tetrachloride-induced hepatotoxicity in mice. Res Comm Pharmacol Toxicol. 1997; 2(1): 41-50.

[19] Nagi MN, Alam, Badary OA, Al-Shabanah OA, Al-Sawaf HA, Al-Behairy AM. Thymoquinone protects against CCl4-hepatotoxicity in mice via an antioxidant mechanism. Biochem Mol Bio Int. 1999; 47(1); 153-159.