Black Cumin (Nigella Sativa)

Abstract

Nigella sativa has been used as traditional medicine for centuries. The crude oil and thymoquinone (TQ) extracted from its seeds and oil are effective against many diseases like cancer, cardiovascular complications, diabetes, asthma, kidney disease etc. It is effective against cancer in blood system, lung, kidney, liver, prostate, breast, cervix, skin with much safety. The molecular mechanisms behind its anticancer role is still not clearly understood, however, some studies showed that TQ has antioxidant role and improves body’s defense system, induces apoptosis and controls Akt pathway. Although the anti-cancer activity of N. sativa components was recognized thousands of years ago but proper scientific research with this important traditional medicine is a history of last 2∼3 decades. There are not so many research works done with this important traditional medicine and very few reports exist in the scientific database. In this article, we have summarized the actions of TQ and crude oil of N. sativa against different cancers with their molecular mechanisms.

Keywords: Traditional medicine, Nigella sativa, Thymoquinone, Antioxidant, Anti-cancer mechanism

Introduction

Cancer is one of the major threats of modern life, which is considered as the second cause of death after myocardial infarction (Grundy, 1991). Millions of people die every year in different types of cancer despite tremendous efforts to find methods of control and cure. In the last century, great advances were made in modern medical science to control disease. But many diseases like cancers are not yet curable fully. To find out new and authentic therapies, scientists are working with traditional or folk medicines in parallel of modern medicine. Nigella sativa has been used for medicinal purposes for centuries. It originated from Southeastern Asia and also used in ancient Egypt, Greece, Middle East and Africa. In Islam, it is regarded as one of the greatest forms of healing medicine available (Nigella-sativa-research.com, 2010; Wikipedia, 2010). It is a flowering plant, of which seed is used as a spice. The seed is called black cumin in English, while in old Latin it was called ‘Panacea’ meaning ‘cure all’; in Arabic it is termed as ‘Habbah Sawda’ or ‘Habbat el Baraka’ translated as ‘Seeds of blessing’. It is also known as ‘Kalo jeera’ (in Bangladesh), ‘Kalonji’ (in India) and ‘Hak Jung Chou’ in (China) (Aggarwal et al., 2008). Both seeds and oil extracted from this plant are used in medicinal purposes.

The active ingredients of N. sativa have beneficial effects against many diseases, including:

  • anti-cancer
  • reduces risk of atherosclerosis
  • therapeutic and protective effects in diabetes
  • effective agains hypertension
  • potent anti-histaminic effect on airways for asthmatic patients
  • complement to schistosomiasis specific treatment
  • protects kidney tissue against oxygen free radicals
  • prevents renal dysfunction
  • prevents morphological abnormalities

Role of N. sativa as an anticancer agent

Many active ingredients have been found in the seeds of N. sativa. The seeds contain both fixed and essential oils, proteins, alkaloids and saponin (Ali and Blunden, 2003). Ghosheh et al. (1999) described the quantification of four pharmacologically important components: thymoquinone (TQ), dithymoquinone (DTQ), thymohydroquinone (THQ), and thymol (THY), in the oil of N. sativa seed by HPLC. Much of the biological activities of the seeds have been shown to be due to thymoquinone, the major component of the essential oil, which is also present in the fixed oil (Ali and Blunden, 2003). TQ is considered as potent anti-oxidant (Badary et al., 2003), anti-carcinogenic and anti-mutagenic agent (Bourgou et al., 2008; Khader et al., 2010) (structure of thymoquinone is shown in Figure 1a). Moreover, TQ is a relatively safe compound, particularly when given orally to experimental animals (Al-Ali et al., 2008). Alpha (α)-hederin, a pentacyclic triterpene saponin (structure: Figure 1b) isolated from the seeds of N. sativa, was also reported to have potent in vivo antitumor activity (Swamy and Huat, 2003).

Figure 1

Chemical structure of anti-tumor agents isolated from N. sativa

N. sativa seeds or oils or its active ingredients like TQ are effective against different cancers:

  • blood cancer
  • breast cancer
  • colon cancer
  • pancreatic cancer
  • hepatic cancer
  • lung cancer
  • skin cancer
  • fibrosarcoma
  • renal cancer
  • prostate cancer
  • cervical cancer

Supporting Data

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