The Indian phytochemical industry is not a distinct industry sector and it is more or less attached with herbal or ayurvedic or nutraceutical drug sector. More precisely, phytochemicals are part of standardised herbal extracts.

Education to phytochemistry
In pharmacy courses, study of phytochemistry is more or less associated with pharmacognosy. Chemistry of natural products is specialty course related to phytochemicals or secondary metabolites. In ayurvedic courses, preliminary information of phytochemistry is part and parcel of Drvayaguna.

Standardised herbal extracts
Standardised herbal extracts contain a guaranteed and quantified amount of certain constituents. Although the most obvious aspect of standardisation is the guaranteed content of one or more active constituents or marker compounds, standardisation involves much more than guaranteed levels of constituents. Chemical analysis using appropriate techniques such as high performance liquid chromatography, gas liquid chromatography, and thin layer chromatography, is a key aspect of standardisation.

Other important aspects include the growing and harvesting of the plants, post harvest treatment (drying, storage), extraction method, extraction solvent, particle size and concentration process, the use of an excipient to achieve the desired level of active constituents or marker compounds, and efforts to ensure the stability of the extract.

Why herbal standardised extracts?
Because herbal extracts are made directly from crude plant material, they can show very substantial variation in composition, quality, and therapeutic effects. The variation and diversity of life is enormous, even within a species. In other words, two medicinal plants of the same species may look similar, yet be substantially different in the levels of active constituents they contain.

Herbal medicines made from plants that differ markedly in their chemical constituents cannot produce the same therapeutic effects. Because the practitioner or consumer will be unable to assess the difference, they cannot compensate for it. The consequence will be inconsistent clinical results.

Following are standardised herbal extracts derived from ayurvedic medicinal plants: Adhatoda vasica (Vasicine 0.5%); Allium sativum (Allicin 0.6%); Andrographis paniculata (Andrographolide 10%); Asparagus racemosus (Saponin 30%); Azadirachita indica (Azadiractin 2%); Bacopa monneri (Bacoside 20%); Boswellia seratta (Boswellic acid 40% and 70%); Centella asiatica (Asiaticoside 3%); Commiphora mukal (Guggulsterones 5%); Curcuma longa (Curcumin 95%); Embelia ribes (Embelin 8%); Garcinia cambogia (Hydroxy cirtic acid (50%); Glycyrrihiza glabra (Glycyrrhizin 20%); Gymnema sylvestre (Gymnemic acid 75%); Momordica charantia (Bitters 3%); Ocimum sanactum (Ursolic acid 8%); Phyllanthus niruri (Bitters 2%); Picrorrhiza kurroa (Kutkosides 10%); Pueraria tuberosa (Disogenin 7%); Saraca indica (Tannins 8%); Terminalia arjuna (Tannins 8%); Terminalia belerica (Tannins (40%); Terminelia chebula (Tannins 60%); Tribulus terrestris (Saponin 20% and 40%); Trigonella foenum graecum (Saponin 10%); Valeriania officinalis (Valerenic acid 0.8%); Withania somnifera (Withanolides 1.5%); and Zingiber officinale (Gingerols 5%).

Current scenario of herbal industry
The recent upsurge in use of ayurvedic medicines has led to a sudden increase in ayurvedic manufacturing industry. In India, there are about 14 well-recognized and 86 medium scale manufacturers of ayurvedic drugs. Other than this about 8,000 licensed small manufacturers in India are on record. In addition, thousands of Vaidyas (ayurvedic physicians) also have their own miniature manufacturing facilities. The estimated current annual production of herbal drugs is around Rs. 3500 crore. This section gives an overview of the rapidly growing Indian herbal industry followed by the legal parameters encompassing the manufacturing of herbal drugs.

The turnover of Ayush industry is estimated to be more than Rs 8,800 crore. The domestic market of Indian Systems of Medicine & Homoeopathy (ISM&H) is of the order of Rs 4,000 crore with a total consumption of all botanicals to a figure of 1,77,000 MT, which is expanding day by day. The total annual turnover of the ayurvedic drug manufacturing industry is estimated to be around Rs 3,500 crore. Besides this, there is also a growing demand for natural products including items of medicinal value/pharmaceuticals, food supplements and cosmetics in both domestic and international markets. India with its diversified biodiversity has a tremendous potential and advantage in this emerging area.

Phytochemical industry
The success of herbal extract and phytochemical industry lies in the quality and authenticity of raw herbs being used. Most of the supplies of herbs which cater the needs of herbal extract and ayurvedic industry come from the wild sources. Very limited data is present on the Indian phytochemical industry.  Chinese phytochemical industry is contributing towards nation economy. We need to set up regulatory council for Indian phytochemical industry so that potential phytochemicals extracted from medicinal plants can enter the international market. Phytochemical association was set up in Himachal Pradesh with purpose of exploiting medicinal flora for novel phytochemicals.

Potential medicinal plants for phytochemical
Disogenin containing Indian medicinal plants can be good source for promoting business and initiating efforts for reviving the Indian phytochemical industry. Disogenin, a steroid saponin, is used in synthesis of corticosteroids and sex hormones.

Costus speciosus: The whole plant is source of steroid saponin, disogenin (see table) used in synthesis of corticosteroids and sex hormones. The rhizome contains 2-4 per cent of disogenin on dry weight basis.
% of disogenin in various fresh plant parts of C. speciosus    
Rhizome    2.6%
Stem    0.65%
Leaves    0.37%
Flowers    1.2%

D. deltoidea occurs throughout North-West Himalayas at the altitude of 900-3000 meters. The plant is one of the richest sources of disogenin. It contains disogenin varying from 2-5% on dry weight basis.  

Trillidium govanianum is known only from scattered localities in the Himalayas. The plant is important commercially as the roots contain sesquiterpene glycoside trillarin, which on hydrolysis, yields disogenin.

Promoting cultivation of above suggested crops is beneficial for cultivators and phytochemical industry. Steroid containing medicinal plants is just one example how work can be initiated for making Indian phytochemical industry feasible.

Phytochemicals as nutraceuticals
Phytochemicals as nutraceuticals importance are bioactive constituents that sustain or promote health and occur at the intersection of food and pharmaceutical industries. Such substances may range from isolated nutrients, dietary supplements and specific diets to genetically engineered designer foods, herbal products, processed foods and beverages. The phytochemicals, either alone and/or in combination, have tremendous therapeutic potential in curing various ailments. The respective health benefits are based on science and ethics for health claims, functional foods and presence of certain phytochemicals.

(Author is a herbal consultant based in Mohali)