Pharmacological and Phytochemical Profile of Guizotia Abyssinica Cass – A Review Beyond its Culinary Utility

Introduction

Folklore medicine known as the ‘Traditional medicine’ existed before, exists now and will exist tomorrow and forever. Traditional herbal medicines and their preparations have been widely used for thousands of years in developing and developed countries owing to their natural origin and lesser side effects or dissatisfaction with synthetic drugs.¹ There are many plants used in folklore practices but not included in the classic literature. These plants play a major role in the lives of tribal and rural people by helping in relieving ailments, particularly in remote parts of developing countries. The ethnic and rural people of India have preserved a large bulk of traditional knowledge about medicinal uses of plants of their locality. This treasure of knowledge is handed down from generation to generation orally and is extensively used for the treatment of common diseases and conditions. The indigenous method of preparation maintains its own unique methodology. Furthermore the traditional folk healers treat with kindness, grace,  patience and tolerances, which plays a vital role in healing process.² Non documentation of such oral traditional knowledge about the medicinal plants along with urbanization and loss of green wealth could become a grave problem, with greater probability of losing some valuable botanicals, if not given any importance at least now

Guizotia abyssinica Cass.^3,4 of Compositae family is an erect, stout, branched annual plant, commonly known as Ramtil or Niger plant. It is a popular source of oil seed crop cultivated mainly in different parts of Ethiopia and India.⁴ The black coloured seeds of the plants are commonly found in households of South India like Karnataka, Maharashtra, Madhya Pradesh, Andhra Pradesh used for culinary preparations like dry chutney, sweets, as accompaniment with other food articles and as a source of edible oil.^5,6 These widely used seeds, possessing valuable therapeutic and nutritional properties, but less studied or scientifically documented is an example of the folklore medicine. The present paper is intended for comprehensive review on the literature of the plant and documents the pharmocological and phytochemical profile of Guizotia abyssinica Cass.

Plant profile

Baagoe (1974) presented a taxonomic revision of the genus based on morphological traits for the Guizotia.⁷

Nomenclature⁸

Guizotia: In honour of M. Guizot, the great French Minister Linn. Abyssinicca: Native of Abyssinia, Horn of Africa.

Taxonomical position⁷

Kingdom - Planatae

Phylum - Angiospermae

Class - Dicotyledoneae

Subclass - Sympetalae

Order - Campunulales

Family - Compositae

Tribe - Heliantheae

Sub tribe - Corepsidinae

Genus - Guizotia

Species - abyssinica

Vernacular names

English: Niger, Niger seed, Niger seed oil, Ramtil oil, Kerasani seeds, Surguja

Ethiopian: 

Amharic - Nog, Nuk, Nook, Noog(The plant), Nehigue (The oil),

Tigrinya and Sahinya - Neuk, Nuhk, Nehug

Orimigna, Galignya - Nuga, Nughi

Kaffinya - Nughio

Gumuzinya - Gizkoa

Indian

Assamese : Sorguja

Bengali : Ramtil, Surguja, sirguja, sarguza

Bhopal : Rameli

Gujarati : Kharasani, Kesani, Ramtal, Kaltel, Ramtal

Hindi : Ramtil, Kala til, Jagni

Kannada : Hucchellu, Gurellu

Marathi : Karale, Khurasani, Karla

Oriya : Alashi

Punjabi : Ramtil

Tamil : Kattellu, Uchellu, Payel

Telugu : Verinuvvulu,Valesulu, Ulasi^3,4.6.9

Local name and its derivation

Guizotia abyssinica Cass. plant is the source of oil seeds grown in Southern part of India. These seeds are termed as Niger seeds, commonly identified as Gurellu / Hucchellu in Northern Karnataka. Botanically these are the fruits of the plant termed as achene. The seeds are black coloured, obovoid and source of the oil similar to seeds of Tila (Black Sesame Seeds). The Tila (Sesame Seeds) recognised as Ellu in the Karnataka region, Guizotia abyssinica Cass seed termed as Hucchellu / Gurellu look alike

Morphological features

Guizotia abyssinica Cass. is an annual dicotyledon plant. Epigeal germination takes place with pale brown hypocototyls and cotyledons, remaining for long period in the seedling herb (Figure 1).

Leaves: A small first paired leaves appear and the successive leaves initially and later are larger with varying colour from light green to dark green and have smooth surface. They are opposite, sessile, subcordate or ovate – lanceolate, serrate, sub scabrous, up to 22 cm long, involucre with ovate, biseriate scales (Figure 2).

Stem: The stem is smooth or slightly rough, hollow and easily breakable, usually either moderately or well branched.

Flowers: The flowers are yellow, conspicuous, in solitary or clustered heads, arranged in corymbs, with heads of 40-60 tubular hermaphroditic florets, surrounded by a marginal row of ligulate florets. The receptacle is semi-spherical, 1-2 cm in diameter and 0.5-0.8 cm high and enclosed by two rows of involucral bracts. The capitulum includes six to eight fertile female ray florets with narrowly elliptic, obovate ovules. The stigma has 2 mm long two curled branches. The disk florets are yellow to orange in colour containing yellow anthers and densely hairy stigma (Figure 3).

Flowering in each head lasts for 7-8 days, probably cross pollinated by the bees. About 40 fruits termed as achenes are produced in each head. These achenes are black in colour, with a white to yellow scar over the base and top. They bear a hard testa and white embryo^10,11-13 (Figure 4).

Origin and distribution

It was believed to have originated from Ethiopia where it was domesticated in 2000 BC. It is largely found in the Ethiopian Highland of west of Rift valley. It was taken to India by the immigrants probably in the third millen- nium along with other crops like finger millets.⁹

It is cultivated in various parts of India, such as Andhra Pradesh, Madhya Pradesh, Orissa, Maharashtra, Bihar, Karnataka, Nagar Haveli, West Bengal etc. Madhya Pradesh is the largest among them. Bidar, Bijapur, Gul- barga, Gadag, Bagalkot, Haveri, Dharwad are the major districts of distribution in Karnataka.⁴

Useful Parts: Seeds, seed oil, leaves and roots.^2-15

Extraction of Guizotia abyssinica Cass. seed oil

Guizotia abyssinica Cass. seed oil is pale yellow, has nutty taste and a pleasant odour. Traditionally it is ex- tracted in Ethiopia through a combination of warming, grinding and mixing with hot water, followed by centrif- ugation in an ‘ensera’ (a container made of Clay). Af- ter an hour of centrifugation on smooth soft surface, the pale yellow oil settles over the meal. The seeds are also crushed in small cottage expellers and large oil mills. The meal remaining after extraction of the oil using Ethiopian expellers, contains 6 -12% oil depending on expeller. In India, the oil is extracted by bullock – pow- ered local ‘Ghani’ and rotary mills (cottage expellers) or in mechanized expellers and hydraulic presses in large industrial areas.^4,14 

Uses

Culinary uses

Cold pressed seed oil and refined hot pressed oil in fresh state is used locally for edible purpose.^15-17 In Ethiopia, seeds are used at household level to make oil, to make paste known as ‘litlit’ and also paste mix with snack, which is commonly given to a large family to subdue appetite at extra meal hour. The seed paste is mixed with other roasted cereal or applied on flat bread or ‘injera’ used during special occasions, especially in Northern Ethiopia. The flour or the meal from the oil press is also used to smoothen the heated baking clay pan before baking as ‘masesha’.¹⁸ In Ethiopia, ‘Wot’ is prepared by warming the seed in kettle over an open fire, crushed with a pestle in a mortar and then mixed with crushed pulses. The seeds are crushed and mixed with roasted cereals to prepare ‘Chibto’, a preferred food for young boys.^14,18 The seeds are used for making chutneys and condiments. A spicy preparation called Chutney prepared by mixing red chilli powder with roasted and pounded seed is a common preparation in rural areas of India. These seeds are parched with pulses as snack food. It is fried in ghee, can accompany other foods to enhance their palatability and nutritional quality.⁴

Agro Forestry uses

The plant of Guizotia abyssinica Cass. is fed to sheep, silage can be fed to cattle. The green stalks and leaves of plant are used as green manure to increase the organ- ic soil matter. The dried plant contains nitrogen 0.20, potash (K2O) 0.85, and phosphoric acid (P2O5) 0.11%. The seeds are sometimes fed to cage birds. These are fa- vourites of finches especially Goldfinch and Greenfinch, referred or sold as thistle seed. Niger seedcake is utilized for feeding cattle or as manure. It has a high manorial value and gives good results when applied to sugar cane crops.⁴

Industrial uses

The oil contains stearic or palmitic acid and is employed for making soap and illuminate. The soap made from it is white and soft. The oil is almost odourless and absorbs the characteristic fragrance of flowers. This oil is used in cosmetic industry. The seed oil is often used as a sub- stitute or as an adulterant for other oils as it is relatively low in cost. The seed oil is a semi-drying oil used to a limited extent as paint oil.⁴ 

Ethno medicinal uses

Guizotia abyssinica Cass. seeds are roasted and pounded into flour, boiled, inhaled and drunk as a remedy for common cold. A preparation named ‘Tej’ which is a mixture of Guizotia abyssinica Cass. seed sprouts mixed with garlic is used to treat cough. A thick paste of leaves and root made with water is applied to joints in rheumatism, arthritis and to treat burns. The seeds are used for birth control. Seed oil is applied for healing of burns. Seed paste and seed oil are applied to treat microbial infections. The seeds are used as poultice, applied to the surface of the body to relieve pain, itching, swelling, inflammation, abscesses, boils etc.² Reports are available regarding the use of seed oil for birth control and in the treatment of syphilis.^2,18

Phytochemical Profile

Guizotia abyssinica Cass. seeds are reported to contain nutritional components like oil (30-40%), proteins (10- 25%), soluble sugars (12-18%), crude fibre (10-20%) and moisture (10-11%).⁹ The fixed oil is a mixture of triglycerides, lauric, palmitic, palmitoleic, stearic, oleic, linoleic and arachidic acids. The unsaponifiable matter is said to be the mixture of sigmasterol n-triacontne and lupeol.³

The seed oil has typical fatty acid composition of Compositae plant family with linoleic acid as dominant fatty acid. The characteristics of Indian variety seed oil are different from those of the African variety. The latter is reported to be richer in Linoleic acid (70%) than the Indian. The linoleic acid content is approximately 55% in seeds grown in India with a corresponding increase in oleic acid content. The components of fatty acids of the oil are myristic (including capric and lauric acids) 1.7-3.4; palmatic 5.0-6.4; stearic 2.0-4.9; oleic 31.1-38.9; linoleic 51.6-54.3%; arachidic acids. The components glycerides are trilinolien 2.0, oleodilinolien 40, dioleodililinilien 30, mitodililinolien 6.0, palmito oleolinolien 11.0, stearodilineolien 2 and sterooleolinolein 4%.^19,20,21

As reported, the total lipid of the seed oil is triacylglycerides and 0.7-.8% of polar lipids account for the lipid content. The amount of total tocopherol is 720 -935 µg/g oil in which α – tocopherol is 90%, 3-5% is ɤ-tocopherol and β–tocopherol is only 1%. High levels of α– tocopherol being antioxidant improves the stability of the seed oil. The total sterol consists of 38-43% β, 14% campesterol,14% stigmasterol, 5-7% of 5 avenasterol and 4% of 7 avenasterol.²²

The amino acid composition of the seed protein showed a deficiency in tryptophan. The lipoprotein concentration is isolated from seeds using hot water/ ethanol, sodium chloride solution extraction (Eklund 1971a,1971b). This lipoprotein has 4% moisture, 12% ash, 46% protein, 20% fat, 7% crude fibre and 11% soluble carbohydrate. The lipoprotein has 400 kcal/100g of energy content.²³

The seed meal/cake remaining after oil extraction contains approximately 30% protein and 23% crude fibre. Overall compositions of oil, protein and crude fibre content of the seed are affected by the thickness of the hull; thicker the hull, less is the oil & protein and more is the crude fibre. The chemical composition and nutritive value of the seed cake is crude protein 32.74 on basis of dry matter; ether extract 4.42; crude fibre 17.62; N- free extract 31.45; total ash 13.75; calcium (CaO) 0.84, Phosphorous (P2O5) 2.55%; digestible nutrients – crude protein 32.74; ether extract 4.38; total carbohydrate 6.80; total digestible nutrients 49.4; and starch equivalent 43.3lb/100lb.⁴

Ariel part of the plant showed the presence of nin flavonoids (-) – liquiritigenin, (-)-7,3’,4’-trihydroxy flavanone,(-)-7,8,3’,4’-tetrahydroxyflavanone,7,3’,4’- trihydroxyflavone, quercentin, isoliquiritigenin, butein, okanin and 3,2’4’- trihydroxy-4,3’-dimethoxychalcone.²⁴

Investigations regarding the phytoconstituents of ethanolic extract of seeds reported the presence of tannins, terpanoids, alkaloids, flavonoids, cardiac glycosides and steroids.^25-27

Pharmacological Profile

The pharmacological properties concerning the ethno medical claims were investigated scientifically and major database of the activities has emerged. Dwivedi Sumeet et al., assessed the in vitro anthelminthic activity in earthworms with aqueous extract and ethanolic extract of leaves and seeds, reported a significant anthelmintic activity of the aqueous extract compared to ethanolic extract.²⁸ The acute toxicity test in albino rats has not exhibited any toxic effect. On screening, the anti- inflammatory activity of aqueous and ethanolic extract was found to be significant with p <0.01.²⁹

Amin N et al., conducted a study to determine the antimicrobial, antifungal and cytotoxic activity of the ethnolic extract of seeds of Guizotia abyssinica Cass. The antibacterial activity against the strains like Bacillus subtilis, Streptococcus aureus, Streptococcus abony, Escherichia coli, Pseudomonas aerugiosa was assessed. Inhibitory activity against all the microorganisms with higher antibacterial effect against E. coli, S. abony and B. subtilis was observed.

Ethanolic extracts of Guizotia abyssinica Cass. seed when tested against pathologic fungi like Alternaria solani, Lasiodiploidia theobromae, Rhizopus spp., and Aspegillus niger, exhibited good antifungal activity except against Alternaria solani. Ethanolic extracts of seeds of Guizotia abyssinica Cass. evaluated for cytotoxic activity on c2c12 (Mouse, Muscle cell line) and HEK293T(Human embryonic kidney cell line) showed remarkable cytotoxic effect²⁹ Hirvey Swati et al., studied anti-diabetic activities of ethanolic extract of Guizotia abyssinica Cass. seed using in vitro and in vivo methods and reported significant in vivo anti-diabetic activity supported by the in vitro study.³⁰

Antioxidant activity of methanol and n-hexane extracts of leaves and seeds of Guizotia abyssinica Cass. have been assayed for total antioxidant capacity, total phenolic content, 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, reducing power and lipid peroxidation activities. All the activities showed a significant increase in antioxidant potential with increase in concentration of the extract. The total methanol and n– hexane extracts showed higher reducing power and the percentage inhibition of linoleic acid lipid peroxidation was considerable compared to the standard n-propyl gallate. Antioxidant activity of the plant extracts are not limited to phenolic compounds, and can also be attributed to other secondary metabolites such as volatile oils, carotenoids and vitamins.³¹

Discussion and Conclusion

Guizotia abyssinica Cass. is a commonly cultivated plant for its culinary use. Leaves or the whole plant has utility in agroforestry and industries. The seeds and seed oil have been used for culinary purpose because of nutritional potentiality. Several ethno-medical claims regarding medical properties ignited the vision of scientific validation about pharmacological properties of the plants. This review about phytochemical and pharmacological profile provides scientific data about the qualitative and quantitative assay of the seeds and seed oil, demonstrating the presence of fatty acids like linoleic acids, oleic acids, lupeol, and presence of healthy lipids. The pharmacological profile indeed provides the preliminary validation for the pharmacological properties mentioned in the ethno medicine. Different research protocols can be framed based on the preliminary literary studies which can widen the pharmacological perspective of Guizotia abyssinica Cass

Conflict of Interest

Nil

Acknowledgement

Authors are obliged to President, Dr. D. Veerendra Heggade, SDM Educational Society and Shri G S Patil Chairman Rajiv Gandhi Education Society for constant support. Authors are indebted to Dr. Mamatha Principal SDM Udupi for Guidance and support.