By Masooma Hyder Baig
Black seeds (Nigella sativa) belonging to the family Ranunculaceae (Ahmad et al., 2021) have been part of various cultures for centuries in benefitting health and treating disease. From religious scripture to scientific research, black seeds have sparked interest in tackling blood pressure, type 2 diabetes, immunity, cancer, and respiratory wellness: a vast array of uses for something so small! This article aims to provide a brief understanding of N. Sativa and the scientific basis for its use in today’s world.
Ancient uses
Early uses of this seed have been documented in Egyptian, Middle Eastern, and Asian civilisations as a food spice and preservative (Dabeer et al., 2022). Its medicinal use is present in historical literature related to the Mesopotamians stating the plant is a cure for ‘ghost possession’ (Dabeer et al., 2022) when used in herbal preparation.
Religious literature also emphasises the importance of black seeds in healing disease. Referred to in the Bible as the curative ‘black cumin’ (Tariq, 2008) and in Islamic narrations (hadith) of the Prophet Muhammad (PBUH) as the remedy for all ailments except death (Al-Bukhari, 1976), it is evident that ancient use has slowly paved the way for this plant to be studied and understood further through the use of modern research techniques.
Bioactive compound
Thymoquinone
The main active compound in black seeds is a natural photochemical called thymoquinone (TQ). This compound is found in the volatile oil fraction of the seed (Edris, 2020). Thymoquinone is synthesised within these seeds from a precursor called γ-terpinene which undergoes a series of dehydrogenation, aromatisation, hydroxylation, and finally oxidation to form TQ (Poulose and Croteau, 1978). Studies have shown that TQ may exhibit anti-cancer properties through potentially neutralising free radical activity. This reduces the oxidative stress exerted on somatic cells that could lead to cancerous gene mutation, thus preventing cancer progression (Gali-Muhtasib et al., 2004). Additionally, thymoquinone may interfere with various intra-cellular signalling processes involving factors like NF-κB, MAPK, and PI3K/Akt that all play roles in cell growth, development, apoptosis (Woo et al., 2013) and the pro-inflammatory response.
Potential therapeutic effects and proposed mechanisms
Antihypertensive
Several studies carried out have demonstrated the role of N. sativa in reducing blood pressure and overall improving cardiovascular health (Pakkir Maideen, Balasubramanian and Ramanathan, 2020). Amongst these, multiple randomised, double-blinded clinical trials demonstrated that patients taking N. sativa experienced reductions in systolic blood pressure, low-density lipoprotein (LDL) cholesterol, and overall body weight (Qidwai et al., 2009), (Datau et al., 2010), (Dehkordi and Kamkhah, 2008).
To reduce blood pressure, total peripheral vascular resistance must be reduced through vasodilation and decreasing blood volume (cite.) N. sativa has demonstrated capabilities of doing both through calcium channel blocking and inhibition of angiotensin-converting enzyme (ACE) leading to vasodilation and through increasing diuretic activity thus reducing blood volume (Pakkir Maideen, Balasubramanian, and Ramanathan, 2020).
Antidiabetic
In addition to reducing LDL cholesterol, N. Sativa has proven to reduce high glucose levels in clinical trials observing its use in diabetic patients complementary to standard diabetic medications (Maideen, 2021). Proposed mechanisms of action of N sativa for this purpose include decreasing insulin resistance (Heshmati et al., 2015) and enhancing β-cell proliferation (cells that are responsible for secreting insulin) (Benhaddou-Andaloussi et al., 2008).
Anti-asthmatic
Black seeds acting as a potential bronchodilator have also been recorded (Naz, 2011), with studies suggesting its ability to reduce airway inflammation may be its main mechanism in alleviating asthmatic patient symptoms (Boskabady et al., 2007). Specifically, it has been suggested that thymoquinone and black seed essential oil may inhibit cyclooxygenase and 5-lipoxygenase pathways that metabolise the substrate arachidonic acid to produce pro-inflammatory effects (Houghton et al., 1995). N. sativa potentially inhibiting histamine (H1) receptors may also contribute to its anti-inflammatory properties (Boskabady and Sheiravi, 2002) related to the pathology of asthma.
Conclusion
Black seeds have vast potential to treat a plethora of conditions and have been used by civilisations for millennia. Now through the use of scientific research, we have come to understand the use of black seeds through its main active compound thymoquinone which provides promising treatment of cancer, hypertension, and diabetes. This plant can additionally provide aid to asthmatic patients. However, further research must be done to understand its therapeutic effects and its potential in treatment fully. With this, there is no doubt that this miraculous seed will provide many astounding benefits to come.
REFERENCES:
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Edited by Lamisa Chowdhury
Astra Stem 
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