Tulsi (Ocimum sanctum L.), also known as holy basil or sacred basil, belongs to the plant genus Ocimum in the Lamiaceae/Labiatae family and is closely related to sweet basil (Ocimum basilicum), a commonly used herb in Europe and North America. Tulsi has also been described as Ocimum tenuiflorum (basil with small flowers) or Ocimum gratissimum (very grateful basil). Species of Ocimum as well as their commercial cultivars vary in growth habit, color and aromatic composition and are commonly named on the basis of such characteristics e.g., Sweet, Greek, Purple and Scented basil. Some varieties of Tulsi are highly aromatic and may contain flavours of spices such as mint and clove along with other unique scents. Three distinct forms of Tulsi are commonly distributed throughout the Indian subcontinent: 1) Sri or Rama Tulsi with green leaves; 2) Krishna Tulsi with dark green to purple leaves; and 3) Van Tulsi with green leaves, all of which grow in the wild, with Rama and Krishna being the most commonly grown forms in homes and widely used in Ayurvedic preparations.
Tulsi is renowned as one of the holiest and most cherished plants of India for its religious and spiritual sanctity. The name Tulsi is a Sanskrit word for “the incomparable or matchless one”. Tulsi is also known as the ‘Queen of Herbs’ and ‘Mother Medicine of Nature’ and has a peerless importance in Indian culture, traditions and health care. Tulsi plants, often placed in special Tulsi pots, symbolize the purity and sacredness of a Hindu home. In large dwellings many Tulsi plants are grown in the garden as a miniature holy forest. Tulsi is considered a symbol of utmost purity and is believed to ward off the evil. The significance of this plant can be seen in many of the rituals practiced in India for centuries. Thus, it is not surprising that Tulsi has been a permanent fixture in Hindu homes, temples, and sacred shrines. The widespread tradition of worshiping Tulsi has its origin in numerous mythological tales described in ancient Indian literature.
Apart from its religious significance, Tulsi has a long history of medicinal use and is mentioned in ancient Ayurvedic texts such as Charak Samhita. Ayurveda, the science of life, is a system of traditional medicine native to India that is also practiced in other parts of the world as a form of alternative medicine. In Ayurvedic tradition, the emphasis is on disease prevention and maintenance of health through healthy food, lifestyle, yoga and meditation, exercise, and herbal nutrition for cleansing of toxins and rejuvenation of health. Among Ayurvedic practitioners, Tulsi is considered a premier adaptogen capable of sustaining a balance of physiological and psychological functions of the body and the mind through enhanced endurance against the physical, emotional and environmental stresses. Ayurvedic practitioners recommend Tulsi as tea, powders and food additives to treat a range of disorders including nausea, vomiting, cramping, chronic fever, malaria, viral infections, bronchitis, bronchial asthma, diarrhoea, dysentery, skin diseases, arthritis, eye diseases, ulcer and oral infections. Tulsi extract of fresh leaves and stems have high antioxidant activity which has been implicated in enhanced digestion and absorption of food nutrients, purification of blood, as well as, reduced blood glucose, cholesterol, and urinary uric acid. The leaves may serve as a nerve tonic due to the presence of neurotransmitters, improve cognitive functions and alleviate pain. Essential oil extracted from Tulsi is also used in herbal cosmetics and improvement of shelf life of food products. Tulsi is traditionally consumed as cold and hot tea made with fresh or dried leaves, fresh leaves, leaf juice and alcohol tinctures. Formulations are also prepared from Tulsi seeds and other parts of the plant extracted in various oils and ghee (clarified butter).
Given the above, it is not surprising that medicinal benefits of Tulsi have been summed up as “one complete pharmacy” for preventing disease, promoting health and prolonging life. Recently, scientific evidence has started to emerge in mainstream medical journals which indicates that regular use of Tulsi reduces stress and inflammation, boosts immune system, protects against radiation damage and lessens age factors in addition to its antibiotic, antiviral and antifungal properties. The chemical composition of Tulsi is highly complex, containing many nutrients, essential oils and other biologically active terpenoids and phenolic derivatives such as hydroxycinnamic acid derivatives, benzoic acid derivatives, flavonoids and their glycosides, and eugenol and eugenol glycosides (Gupta et al., 2007). Many of these chemicals have been described as anti-inflammatory, anti-tumorigenesis, anti-convulsant, anthelmintic, anti-bacterial, anti-giardial, anti-stress, anti-ulcer, anti-diabetic, anti-hypercholesterolaemic, antitussive, hepato-protective, immuno-modulatory, chemo-protective, nootropic and wound healing (Prakash & Gupta 2005; Sing, Birendra & Suvagiya 2011).
Given the quality of a medicinal plant can be affected by a multitude of factors including the medicinal plant’s genetic make-up, the environment it is grown in, or the way in which it is harvested and processed, it is safe to say that no two medicinal plants from the same species are chemically identical. This notion is problematic as regulatory agencies in North America, Europe and many other countries have adopted more restrictive regulations on herbal medicines. For instance, the manufacturers and producers are required to provide evidence of the safety, quality and efficacy of all NHPs. Thus, the use of controlled environment systems offers a unique resolution for meeting market demands with regards to medicinal plant production, while also ensuring plants are produced in a sustainable way.
Plant tissue culture is a techniques used to grow plants under sterile and controlled environment conditions in order to gain greater control over plant growth and development. Once plants have reached a specific age they are then transferred to greenhouses or growth chambers. This method offers a technique by which large numbers of genetically and physiologically similar plants can be produced in a short time frame and small amount of space. It is also geographically and seasonally independent allowing year-round production in all climates and also reduces the pressure on increasingly valuable agricultural land. Most importantly, genetic and physiological uniformity also ensures that plants exhibit a consistent chemical profile which in turn provides greater assurances to consumers that the medicinal plants they are consuming possess biologically active chemicals that are necessary to facilitate their therapeutic effect.
Controlled cultivation of medicinal plants is very likely to change the way plant-based medicines will be harvested and processed in the near future (Saxena 2001; Zheng, Dixon & Saxena 2006). Tulsi is one of the best models to introduce traditional Ayurvedic spiritual and medicinal plants to Agriculture using modern production technologies due to its proven safety, popularity and health benefits. For example, controlled environment production systems would avoid many of the problems associated with field production of Tulsi such as contamination with heavy metals, soil and soil-borne organisms, diseases, herbicides and pesticides, as well as weeds and other plant materials. Also, Tulsi is a temperature-sensitive plant and thus hard to grow in temperate field conditions throughout the year, making this approach ideal for introducing Ayurvedic medicinal plants to North American and European markets. Despite the advantages described above, this model is relatively new to plant based medicines, still the technology is likely to play a significant role in the production of high quality, chemically-consistent plant materials, which in turn can help mitigate consumer concerns towards medicinal plant efficacy, while also reducing supply chain reliance upon wild harvested plants that are currently endangered or threatened.
ABOUT THE AUTHOR
Mukund Shukla obtained a PhD in Plant Breeding and Genetics from the Gujarat Agricultural University (India), studying plant morphogenesis and micropropagation of medicinal plant species. Since joining the Gosling Research Institute for Plant Preservation (GRIPP) in 2010, his research has focused on the development of integrated plant production system for conservation of endangered and economical important plant species.