NATURAL DYES are derived from natural resources such as plants, insects, animals and minerals. These colours are exhibited by naturally occurring organic and inorganic molecules commonly called as pigments and their mixtures are due to the absorption of light in the visible region of 400-800 nm. From ancient times, natural dyes have been used as dying agents for wool, cotton, food, hair, nails, etc. However, with the advent of synthetic dyes the use of natural dyes was limited. This was because those synthetic dyes were fast in action and colour, easy to use and commercially available. However, with the passage of time, hazardous effects of synthetic dyes on humans and environment were known which again attracted scientists towards natural dyes as these dyes are economical, environment friendly and sustainable. Some of the natural dyes exhibit medicinal properties such as, turmeric, the brightest of naturally occurring yellow dyes is a powerful antiseptic and is used in healing of wounds on skin.
Khyber Pakhtunkhwa and adjacent tribal areas (FATA) are blessed with a lot of natural resources like rivers, minerals, natural gas, petroleum and forests, etc. The zone of the province towards north is cold receiving heavy snowfall in winters. The summers are pleasant with diverse floral biodiversity. On the other hand, southern part of the province is arid and hot in summers and relatively cold in winters with a scanty of rainfall. These diverse climatic conditions support the growth of a vast majority of plant species among which many are reported for their medicinal value.
According to some primitive research data, Khyber Pakhtunkhwa is blessed with 70 such plant species which have potential of commercial scale production of natural dyes. Some of the important and commonly available plant species having potential for commercial scale production of natural dyes is given below.
1. Safflower (Carthamus tinctorius L.) is an oil yielding crop having yellow and red dye in petals, grows well in hot climates and suitable for Southern region of KP. Its dye has antimicrobial potential and traditionally used in dyeing wool.
2. Indigo (Indigofera heterantha var. Gerardiana), blue and most important dye from leaves, extracted in water after fermenting the leaves. The dye is used in coloring wool, cotton and in production of ink. Medicinaly it has cooling sensation when applied on skin.
3. Henna (Lawsonia inermis L.), a red dye in water and greenish red in ethanol is obtained from leaves. The dye is used for dyeing hair, for staining nails, palms, soles, and in medicine. A currently published research article in Pakistan Journal of Botany showed that henna dye can be used for staining and visualizing plant tissues in light microscopy.
4. Rasaut (Berberis vulgaris L.), a yellow dye from wood, highly medicinal and having potential to be used in visualizing plant specimens under light microscope.
5. Turmeric (Curcuma longa L.), root yields yellow dye, highly medicinal and used as antiseptic.
6. Pomegranate (Punica granatum L.), bark of fruit yields yellow dye in water, highly medicinal, used in stomach disorders.
7. Jangali palak (Rumex dentatus L.), grows from plains to 3000 m.a.s.l, mostly in moist areas, its stem is a good source of red dye.
8. Indian Madder (Rubia cordifolia Hochst. ex A. Rich.), red pigment abundantly in root and stem, highly medicinal.
9. Sra zeal (Geranium wallichianum D.Don.), fruit and root yields yellow and red dyes, Astringent used in toothache and eye infection.
10.Bishop wood or paniala (Bischofia javanica), the trunk is a good source of red dye and have potential for dying wool and cotton fibers.
In spite of the above mentioned plants, a lot of other plant species are found in KP which has potential for the commercial scale production of dyes. More detailed studies and scientific investigations are needed to assess the real potential and availability of natural dye-yielding resources and for propagation of species in great demand on commercial scale. Biotechnological and other modern techniques are required to improve the quality and quantity of dye produced by plants.
Indigenous knowledge of extraction, processing and practice of using of natural dyes has diminished to a great extent among the new generations due to easy availability of cheap synthetic dyes. This is the reason that traditional knowledge of dye-making is now confined only among the surviving older people and few practitioners in the tribal communities. Therefore, further studies are needed to conserve this valuable pool of knowledge associated with tribal communities. Major plantation of dyes yielding plants will help in commercialization and market availability of natural dyes.