Nigella sativa– the saga and the science
Figure 1. Clockwise above are photos of the leaves [A], flowers [B] and seeds [C] of Nigella sativa, the most widely cultivated of the 20 Nigella species. The seeds [C] of N. sativa are prized for both their spicy flavor and purported medicinal properties. N. sativa is an annual herbaceous plant belonging to the Ranunculaceae (Buttercup) family that grows about 10 - 28 inches tall, with finely divided, linear leaves and delicate, white or pale blue flowers containing 5-10 petals. The fruit of N. sativa is composed of 3-7 united follicles that contain large quantities of the dark, oily seeds. Photo from: ICS UNIDO http://maps.ics.trieste.it/Home/Plant/633
Ironically, Nigella sativa, one of the newest plants to be receiving intense interest in the scientific and dietary supplement fields, is also one of the oldest medicinal plants known. The seeds of this plant were used for centuries as a spicy flavoring for breads, wine and honey as well as a remedy for a broad range of illnesses in the Middle East, south Asia, and the Far East. From Turkish archeological sites and Egyptian tombs, it has been estimated that the seeds of the N. sativa plant have been consumed for over 4,000 years as both a food and medicine. Biblical and Islamic references provide further evidence of the medical applications of N. sativa. Over a span of 1500 years, Greek and Persian medical texts describe N. sativa’s curative properties for liver and digestive disorders as well as its stimulatory effects. The traditional uses of N. sativa are so numerous that, according to ancient Arabic and Roman tradition, it is a remedy for all aliments or in Latin panacea after Panakeia the Greek goddess of Universal remedy. This historical characterization of N. sativa as a cure-all has, however, created a sense of confusion over the real medical possibilities of this plant. Fortunately, over the last decade, the scientific community has begun an expanding evaluation of the pharmaceutical properties of the N. sativa seed and its chemical constituents.
Figure 2. Time-line illustrating 4,000 years of Nigella sativa use in medicinal formulations. From the first documented N. sativa formulations made with honey in the Middle Hittite Kingdom to the explosion of published, scientific research over the last decade, Brookton Labs offers the first and only standardized, commercial products.
While there were few scientific publications on the pharmacological attributes of N. sativa seeds before 1970, the research literature has exploded in the last decade with the number of medical and biological publications now doubling approximately every five years. India, Egypt and the United States have the largest number of institutions in which research on N. sativa is being conducted. Based solely on the number of publications, antioxidant and anticancer activities represent the most studied biological effects of N. sativa and its phytochemical components. Articles describing the antimicrobial and anti-inflammatory actions of various extracts of N. sativa seeds represent a second tier of publications by frequency. Also in this second tier are laboratory and clinical studies describing positive effects on hyperglycemia and obesity in cellular and animal models of metabolic syndrome as well as reports on the natural variability of the composition of N. sativa seeds and extracts.
Figure 3. Scientific publications regarding the pharmacological effects of Nigella sativa or thymoquinone by year over the last decade.
Moreover, the weight of published, scientific evidence supports the antimicrobial, antioxidative, analgesic, anti-inflammatory, hypoglycemic, hypotensive, anti-arthritic and anti-cancer properties of N. sativa seed oil. With such seemingly great potential for medical use, the search for the source of the biological activity of N. sativa has also seen a dramatic increase. In addition to the characterization of the protein, fat, carbohydrate and fiber content of black cumin seeds, researchers have identified compounds from a variety of chemical classes including quinones, monoterpenoid phenols, alkaloids and saponins with an impressive arrange of biological activity. Of the eight to ten compounds isolated from N. sativa, which have been independently studied with respect to their pharmacological activity, one compound thymoquinone has become the focus of N. sativa research.
Since 2005, the greatest increases in publications involving N. sativa phytochemicals, especially thymoquinone, have been in the fields of cancer, inflammation and metabolic syndrome/diabetes. In general, published results supports the inference that thymoquinone is the most important compound in N. sativa oil with respect to efficacy against these diseases. These studies also demonstrate, however, a significant effect of the essential oil matrix itself. That is, the pharmacological effects observed can be greater than pure thymoquinone and can also be a function of the extraction process (e.g. the solvents and temperatures used for obtaining the thymoquinone-containing essential oil from the ground seeds). Further, studies on regional variation of N. sativa components have confirmed that seasonal, and regional differences dramatically impact the phytochemical composition of N. sativa essential oil. For example, the essential oil fraction of N. sativa, considered the most pharmacologically active portion, can range from 0.5 to 1.5% of the seed. The thymoquinone content of the essential oil isolates can vary from 0 to 57%.
Obviously, such variability is inconsistent with the commercialization of N. sativa products expected to perform in a specific manner when applied or consumed. Bionexus has been researching the pharmacological activity of thymoquinone as well as commercial N. sativa ground seeds and oil for seven years. Using fat, muscle, intestinal and prostate cells in laboratory studies, we identified several novel activities of thymoquinone indicating its potential usefulness in skin disorders, metabolic syndrome/type 2 diabetes, exercise, obesity and prostate hyperplasia. When we tested both wholesale and retail commercial products, however, we were unable to duplicate the effectiveness seen with thymoquinone. In fact, in some of our studies the commercial Nigella products were harmful and produced results opposite those of pure thymoquinone. As a result, five years ago Bionexus began developing a sourcing, extraction and formulation technology using both analytical and cell culture results to standardize each formulation for its intended use.
Bionexus’ GellX™ patent-pending, nontoxic, supercritical fluid extraction and recombination technology represents the cumulative efforts of our work. The supercritical fluid extraction process produces up to five novel extracts of Nigella sativa seeds simultaneously. These extracts are then combined in varying amounts based on thymoquinone content and biological assays. This proprietary combination process optimizes the final formulation for use in specific topical or systemic indications; and results in commercial products with greater consistency and potential efficacy than has ever been achieved with N. sativa extracts or whole seeds. No other N. sativa product is produced in this manner, or standardized with respect to thymoquinone content.