Science of Spices and Culinary Herbs - Latest Laboratory, Pre-clinical, and Clinical Studies

Saffron, as one of the most expensive spices in the world, is obtained from the stigma of Crocus sativus. Crocus sativus L. belongs to the Iridaceae family, and has been widely used as an herbal medicine, spice, food coloring, and a flavoring agent since ancient times. Saffron is one of the most famous plants cultivated in Iran, and this country now accounts for approximately 90% of the world production of saffron. Saffron has a long history in Islamic Traditional Medicine (ITM). It has been used for the treatment of several diseases such as urogenital, ocular, and respiratory disorders. Moreover, it has oxytocic, anti-depressant, aphrodisiac, cardioprotective, anticarcinogenic, and anti-inflammatory properties. There are several studies on pharmacological activities of saffron in vitro, in vivo, and clinical trials which not only confirm the application of saffron in traditional medicine, but also introduce some new medicinal aspects. In this chapter, we aim to present a comprehensive review on traditional and ethnomedicinal uses of saffron in different systems of traditional medicine, especially ITM. Then, we will discuss pharmacological activities reported for saffron in modern medicine as in vitro, in vivo, and clinical trial studies. Finally, we will compare the properties reported for saffron in traditional medicine with the activities in modern medicine to reveal the potential of this valuable herb for treatment of various diseases.

Saffron (Crocus sativus L. (C. sativus)), is a medicinal plant which is cultivated in some parts of the world including Iran. The main part of the plant used for medical purposes and as a food additive is its stigma. The most important constituents of the plant are safranal, crocin, and crocetin. In this chapter, traditional and experimental evidence regarding the effects of saffron and its constituents on respiratory disorders are reviewed.

To obtain related evidence, literature available in Google Scholar, PubMed and ScienceDirect databases were searched for articles published in English until the end of April 2018. In addition, traditional medical sources that discussed the effect of the plant on respiratory diseases, were also used.

In traditional medicine, saffron has been used not only for treatment of several diseases but also for improvement of respiratory function, treatment of asthma.

Experimental studies showed the relaxant effects of the plant and its constituents on tracheal smooth muscle and their possible underlying mechanisms. These results indicate the possible bronchodilatory potential of saffron and its constituents on obstructive pulmonary diseases. The effect of saffron and its constituents on lung inflammation, lung pathological changes and tracheal responsiveness to methacholine and ovalbumin as well as its influence on Th1/Th2 cytokines in animal models of asthma, were also demonstrated. These results indicated the preventive effects of this plant and its constituents on respiratory diseases. In addition, antitussive effect of saffron and its constituents was also shown.

Both traditional and experimental evidence indicate the possible therapeutic effect of saffron and its constituents on respiratory disorders. However, more clinical investigations are needed before introduction of this plant and its constituents as treatments of respiratory disorders.

The rhizome of turmeric (Curcuma longa) is an important spice crop extensively cultivated and consumed in tropical countries such as India. This spice is understood to exert multiple beneficial effects on health. Turmeric imparts characteristic flavour, aroma and yellow colour to foods. The chemical constituent curcumin from the rhizome of turmeric is responsible for the yellow colour and is also considered to be the bioactive component of this spice. Turmeric is endowed with many curative virtues according to the indigenous Ayurvedic system of medicine of India. It is considered as an analgesic, antibacterial, antiseptic, antispasmodic, appetizer, carminative, diuretic, cardiovascular protectant, and antitumour. The medicinal properties of turmeric known for centuries include: wound healing, antiinflammatory, and usefulness in liver diseases such as jaundice. In the past couple of decades, many health beneficial physiological effects of turmeric or its constituent ─ curcumin have been documented in experimental and/or clinical studies which suggest that consumption of this spice offers benefits beyond sensory attributes. Turmeric and curcumin have been shown to exert preventive and ameliorative influence on diabetes, cardiovascular disease, inflammatory disorders, and cancer. The antioxidant property of turmeric/ curcumin explains its diverse pharmacological potential. Curcumin effectively reduces lipid peroxidation through its antioxidant influence. Turmeric is traditionally employed as an anti-inflammatory drug. Experimental research indicates that curcumin suppresses both tumour initiation and promotion. The anticarcinogenic effect of curcumin is mediated through inhibition of the transcription factor NFkB and proinflammatory pathways. Curcumin induces apoptosis, and suppresses tumour proliferation and angiogenesis. The anticancer potential of curcumin is also evidenced in clinical studies.

Turmeric is not only used as a spice and a colouring agent, but it is also used as an ethnomedicine in the Ayurveda since time immemorial. Turmeric (Curcuma longa) contains curcuminoids, and various sesquiterpenes which contributes towards a wide array of biological activities, e.g. anti-inflammatory, wound healing, anticancer, and antibacterial activities. Curcuminoids and sesquiterpenes are the main constituents of turmeric, for which a plethora of molecular targets, and pharmacological activities have been reported. The most studied activity of the curcuminoids present in turmeric in the recent year is the anticarcinogenic activity. Experiments have shown that curcuminoids modify the gene expression of cancer related markers. Curcumin has the potential to regulate genes related to cell division, cell cycle regulation, and apoptosis. The anticarcinogenic activity of turmeric has been studied in case of lung, breast, prostate, ovarian, colorectal cancers, leukemia, and multiple myelomas. Turmeric significantly inhibits benzopyrene induced forestomach papillomas. Dietary turmeric, along with catechin, is a chemoprotective agent. Besides anticarcinogenic effect, the antibacterial activity of turmeric against various bacteria, such as Streptococcus aureus, Trichophyton gypseum, Salmonella paratyphi, and Mycobacterium tuberculosis has also been explored. Curcuma longa rhizome extracts and oils were found to have antibacterial role against pathogenic strains of Gram +ve (Streptococcus aureus, Staphylococcus epidermidis) and Gram -ve (Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium) bacteria. The active ingredients of turmeric can be used as lead compounds to design potential drugs for the treatment of different types of bacterial diseases and cancers.

Curcumin is the main component in turmeric. It has been used as a food and as a medicinal agent in the Indo-Asian region from time immemorial. Curcumin has been reported to have anti-cancer, anti-inflammatory, anti-microbial, anti-oxidant, and anti-viral bioactivities. It has been widely researched and clinical studies have been conducted to establish the potency of curcumin as a useful therapeutic and nutraceutical. One of the main drawbacks in assessing its biological activity is the insolubility of curcumin which results in its poor bioavailability. Many attempts have been made to improve the bioavailability of curcumin to increase its potency. Encapsulation is a technique that allows increased solubility of lipophilic substances like curcumin. Encapsulation produces microparticles and nanoparticles, of which improved potency of encapsulants has been observed to a greater extent at the nano level. Several encapsulants have been used for this purpose, and are described herein. Among the many methods used to enhance the bioactivity of curcumin are incorporation in o/w nanoemulsions and liposomes. Formation of cocrystals, and other biological and chemical methods, including modification and conjugation for improving bioactivity, are also reviewed.

Curcumin, the main active component of turmeric (Curcuma longa), is widely used as a flavoring and coloring agent in food, and also exhibits multiple pharmacological activities. It has been traditionally used in Asian countries as a medical herb for several pathologies due to its anti-inflammatory, antioxidant, antimicrobial, antimutagenic, and anticancer properties. Further, curcumin may potentially complement the conventional treatment of insulin resistant conditions, including obesity, pre-diabetes, metabolic syndrome, and type II diabetes. Recently, its potential utility in Auto-Immune Deficiency Syndrome (AIDS) had been demonstrated.

However, curcumin has poor systemic bioavailability which makes its pharmacology intriguing and also hinders its clinical application. It also suffers from biotransformation during the absorption from the bowel and reductive metabolites are the predominant metabolites in the human intestinal microflora system and appear to be easily conjugated especially by glucuronidation to form tetrahydrocurcumin and hexahydrocurcumin derivatives.

In the recent years, an exponentially increasing number of studies have proved that the alterations in the gut microbiota are linked with many metabolic diseases, and the intestinal microbiota is proposed to be a novel potential therapeutic target for these microbiota-associated diseases. Owing to the high concentration of curcumin in the gastrointestinal tract after oral administration, a number of researches have been conducted to evaluate its regulative effects on the gut microbiota.

Thus, the current chapter will be designed to review the two-way relationship between curcumin and gut microbiota from two perspectives: i) impact of curcumin on gut microbiota ii) curcumin biotransformation by GI microbiota. This chapter highlights some important mechanisms of action of curcumin and opens the door for future researches plan in order to use this natural compound in the treatment and prevention of many human diseases.

Thus, the current chapter will be designed to review the regulative effects of oral administration of curcumin on the gut microbiota in order to provide deeper insights into the pharmacology of curcumin.

Inflammation, a common part of several pathological conditions, is involved in the development of a growing number of human diseases. Numerous investigations have been conducted in the past several years which have resulted in the introduction of anti-inflammatory drugs such as corticosteroids, and non-steroidal anti-inflammatory drugs (NSAIDs) as the old anti-inflammatory agents, as well as newly developed drugs like monoclonal antibodies, which specifically target different mediators of inflammatory pathways. Yet, the clinical results obtained by these agents are not conclusive enough, motivating researchers to seek for better options with higher efficacy, and lower adverse effects. Turmeric (Curcuma longa L.) and its major ingredients, curcuminoids, are the well-known natural products used for the management of several inflammatory conditions including inflammatory bowel diseases, irritable bowel syndrome, osteoarthritis, rheumatoid arthritis, renal diseases, oral lichen planus, gingivitis and periodontitis, radiation-induced oral mucositis and dermatitis, psoriasis, and respiratory problems. Main inflammatory markers in chronic inflammation include C-reactive protein, tumor necrosis factor-α, and different interleukins which are assessed in the clinical trials. Turmeric and curcumin have demonstrated significant effect in some clinical trials; however, small sample size and short follow-up periods makes future clinical studies necessary for further clarification about the effective dosage of these agents. In this chapter, current clinical studies assessing the effect of turmeric and/ or curcumin in different inflammatory diseases are reviewed, and commented.

Turmeric or Curcuma longa a golden plant in Indian landmass has been used to give color and taste to food preparations since prehistoric times. Modern science has provided the scientific basis for the use of the plant against many different diseases. Many chemical constituents have been isolated from the spice, like sterols, alkaloids, polyphenols, diterpenes, triterpenoids, and sesquiterpenes. Curcumin (2-5% of turmeric), is possibly the most-studied constituent. Curcumin mimicked some of the activities of turmeric while some are curcumin-independent. A spice initially familiar in the kitchen is also showing activities in the clinic. This review was compiled to provide recent consolidated information covering different aspects of the plant, physiochemical, pharmacological, and its potential in the clinic to provide a basis of future studies and to promote sustainable uses of C. longa. This chapter has pre-clinical / animal studies conducted on turmeric and curcumin and their formulations.