Phytochemical Analysis of Daucus Carota and Zingiber officinale Samples Collected from Gwarimpa Abuja Nigeria

This study aims at determining the phytochemical potentials of Daucus carota and Zingiber officinale collected from a location in Abuja, FCT. Standard laboratory procedures were employed to achieve the objectives. To ascertain the presence of phytochemical components which may be responsible for the healing and ethno-medicinal properties, a qualitative and quantitative screening of the extracts of the sampled plants was conducted. Daucus carota and Zingiber officinale were collected from Kado Bimko market, Gwarinpa, Abuja in October, 2016. Vegetable samples were washed, chopped into uniform sizes and dehydrated into powder form in preparation for further analysis. The phytochemical screening of chemical constituents of the vegetable extracts were carried out to confirm if they contain some notable phytochemicals in them, the result obtained showed some differences in the two samples tested, tannins, alkaloids, flavonoids, Terpenes, steroids, Anthraquinones, and resins were present in zingiber officianale sample while daucus carota showed presence of tannins, saponins, flavonoids, glycosides, terpenes, steroids, phenols, and resins. The presence of these important plant constituents suggests that these vegetables could be potential sources of phytochemicals, which are responsible for their curative and healing properties. This however confirms that they can be used in drug development and treatment and management of various diseases in Nigeria.


Introduction
Phytochemical is a broad term meaning plant (phyto) chemical referring to a wide variety of compounds that occur naturally in plants. It has been demonstrated that fruits, vegetables and grains exert a protective effect against the development of chronic diseases [20,11,9,10] This protective role can be mainly attributed to the phytochemicals in them, which are defined as bioactive nonnutrient compounds in fruits, vegetables, grains, and other plants [19]. So far, about 10,000 phytochemicals have been identified, and still a large percentage remains unknown. These identified phytochemicals include tannins, flavones, terpenoids, steroids, saponins, and alkaloids [3]. According to world health organization [18], up to 80% of the world's population in underdeveloped countries relies on traditional medicine practices for their primary health care needs [18]. Traditional medicines have been accorded greater acceptance in Africa because of unavailability, unwanted side effects and high costs associated with orthodox medicines, inadequate health facilities and healthcare professionals coupled with inadequate training of health workers [14]. The search for new plant derived chemicals to replace synthetic drugs should thus be a priority in future efforts towards sustainable development [1].
Ginger (Zingiber officinale) is a flowering plant whose rhizome, ginger root is widely used as a spice or a folk medicine. It grown mostly in Kaduna, Gombe, Bauchi, Benue, Nassarawa, states of Nigeria. It has been used for over 2000 years for treating diabetes, High blood pressure, cancer, fitness and many other illnesses [2]. The consumption of ginger led to reduction in blood cholesterol and also served as a potential anti inflammatory and antithrombotic agent [12]. Some health benefits of ginger include: antimicrobial, anti-ulcer, anti-cholinergic, antioxidant, antiinflammatory, anti-cramp, anti-rheumatic and analgesic properties. It improves blood circulation, helps with cholesterol regulation and hypotensive properties [6].
Carrot (Daucus carota) is a root vegetable, usually orange in colour, though purple, black, red, white, and yellow cultivars exist [15]. They are widely cultivated in the northern parts of Nigeria in Zaria, Sokoto, Kano, and Plateau states. Carrots are a domesticated form of the wild carrot, native to Europe and south-western Asia. The plant probably originated in Persia and was originally cultivated for its leaves and seeds. Most of the benefits of carrots can be attributed to their beta-carotene and fibre content. According to the USDA nutrient data, these root vegetables are also a good source of antioxidants, potassium, vitamin K, vitamin C, niacin, and vitamin [17,7]. Has shown that the presence of α-and β-carotene in blood has a protective effect against atherosclerosis. [13] has demonstrated that high carotenoid diets are associated with a reduced risk of heart disease. The main physiological function of carotenoids is as precursor of vitamin A [13] Carotenoids also act as free-radical scavengers and are very important for health [4,5].

Plant Materials
Fresh carrots (Daucus carota) and ginger (Zingiber officianale) used for this study were collected from Kado-Bimko market, Gwarinpa Abuja.

Sample Preparation
The Carrots and Ginger were washed under running tap water, chopped into uniform sizes and dried in an oven at 60° celcius until adequately dehydrated. With the aid of mortar, pestle, miller, grinder, these plant parts were homogenized to fine powder and stored in airtight bottles or containers for phytochemical analysis.

Extraction of Plant Materials
The plant samples were macerated separately in Ethanol (solvent) for 24 hours. After which it was filtered using suction filtration. The filtrate of each sample was further concentrated using the Rotary Evaporator at reduced temperature and pressure. The concentrated extracts were finally dried on the water bath and transferred to sample bottles for further analysis.

Preliminary Phytochemical Screening of Different Extracts Samples
Chemical tests for the screening and identification of bioactive chemical constituents in the plant extracted were carried out using standard procedure.

Test for Tannins
3g of the powdered samples were boiled in 50ml of distilled water for 1 minute on a hot plate. The mixture was filtered and the resulting filtrate was used to carry out the following test for tannins.
i. Lead Sub-Acetate Test To 1ml of the extract, 3 drops of lead sub-acetate solution was added. Production of brown precipitate indicates the presence of tannins.
ii. Ferric Ammonium Citrate Test To 1ml of the water extract, 0.25% ferric ammonium citrate solution. To the mixture, sufficient solid sodium acetate was added to adjust the solution of pH 8 using an indicator paper. This was boiled on a water bath and filtered. A dark green precipitate indicates the presence of tannins.

Test for Saponins
i. Froth Test To a small quantity of the powdered sample, 95% ethanol was added and boiled. The mixture was filtered and 2.5ml of the filtrate was added to 10ml of diluted water in a test tube. The test tube was stoppered and shaken vigorously for about 30 seconds. It was then allowed to stand for half an hour. Persistent homogenous froth is indicative of the presence of saponins.
ii. Fehling's Solution Test To 2ml of the samples extract, an equal amount of Fehling's solution. A bluish-green precipitate shows the presence of saponin glycoside.

Test for Alkaloids
An extract was prepared by macerating 3g of the powdered samples in 50ml methanol. The extract was evaporated to dryness. 0.5g of the residue was mixed with 10ml of the 1% aqueous hydrochloric acid on a water bath.
1ml each of the filtrate was treated with a few drops of the following reagents: 1. Mayer's reagent (potassium mercuric iodine solution) 2. Dragendorff's reagent (potassium bismuth iodine solution) 3. Wagner's reagent (solution of iodine in potassium iodide) 4. 10% tannic acid solution (a solution of picric acid) Turbidity or precipitation with all of these reagents is indicative of the presence of alkaloids in the extract.

Test for Flavonoids
5g of the powdered sample was completely de-tanned with acetone. The residue was extracted in warm water after evaporating the acetone on a water bath. The mixture was filtered and the filtrate was used for the following tests: 1. Sodium Hydroxide Test 5ml of 10% sodium hydroxide was added to an equal volume of the de-tanned water extract. A yellow solution indicates the presence of flavonoids.
2. Shinoda Test 0.5g of the powdered sample was extracted in ethanol by boiling on a water bath for 5 minutes, filtered and cooled. To the filtrate was added four pieces of magnesium filing followed by a few drops of concentrated hydrochloric acid. A pink or red color indicates the presence of flavonoids [8].
3. Amyl Alcohol Test 3g of the powdered sample was macerated in 50ml of 1% hydrochloric acid and filtered. The filtrate was used for the following tests: 4. 4ml of the filtrate was shaken with 5ml of amyl alcohol. Production of a yellow color indicates the presence of free flavonoid aglycones. 5. 10ml of the filtrate was shaken with 7ml of amyl alcohol and the mixture was transferred into a separating funnel. The amyl alcohol layer was discarded and the aqueous layer boiled with 10ml of 10% hydrochloric acid for 2minutes. The acidic solution was cooled and divided into two portions. The first portion was shaken with amyl alcohol. Production of a yellow color indicates the presence of combined flavonoid. To the second portion, magnesium turning were added and the color of the solution was observed Production of a red color indicates the presence of flavanone and flavonol glycoside.

Test for Glycosides
i. Test for Cardiac Glycosides 0.5g of the powdered sample was boiled with 10ml of 95% alcohol for 2 minutes. The resulting mixture was filtered and cooled. The filtrate was diluted with water and three drops of strong solution of lead sub-acetate was added. This was mixed thoroughly and filtered. The filtrate divided into two portions; one portion was kept for further test and the other portion was extracted with 5ml of chloroform in a separating funnel. The lower chloroform layer was divided into two evaporating dishes, evaporated to dryness and used for the following tests: ii. Keller-killani Test for Deoxy Sugars One of the chloroform residues was dissolved in 1ml of glacial acetic acid containing a trace of ferric chloride solution. The mixture was carefully poured on the surface of 1ml of Sulphuric acid already contained in a test tube to form a separate layer. A reddish-brown color at the interface of the liquid indicates the presence of digitoxase.
iii. Legal Test for Cardenolide Aglycone The second chloroform residue was dissolved in a few drops of pyridine and a few drops of 20% sodium hydroxide was added. A deep red color indicates the presence of cardenolide aglycone [16].
iv. Kedde Test for Free or Combined Cardenolide Aglycone The reserved filtrate was treated with 1ml of 2% solution of 3, 5 dinitrobenzoic acid in alcohol. The solution was made alkaline with 5% sodium hydroxide. A purple-blue color indicates the presence of the free or combined cardenolide aglycone. [16]

Test for Terpenes and Sterols
5g of the powdered sample was extracted by the maceration with 50ml of ethanol (95%), filtered and the filtrate was evaporated to dryness. The residue was dissolved in 10ml of anhydrous chloroform and then filtered. The filtrate was divided into two equal portions and the following tests were carried out.
i. Liebermann-Burchard Test The first portion of the chloroform solution from the above was mixed with 2ml of acetic anhydride, followed by the addition of 1ml of concentrated Sulphuric acid down the wall of the test tube to form a lower layer. The formation of reddish-violet colour at the junction of the two liquids and a green colour in the chloroform layer indicates the presence of terpenes.
ii. Salkowski's Test The second portion of the solution was mixed with 2ml of concentrated Sulphuric acid carefully s that the acid forms a lower layer. A reddish-brown color at the interface indicates the presence of a steroid.

Test for Resins
15ml of petroleum ether extract was made using 0.1g of the powdered sample and filtered into a test tube. An equal volume of copper acetate solution was added and shaken vigorously then allowed to separate. A green color indicates the presence of resins.

Tests for Anthraquinones Derivatives
Borntrager's Tests (To show for the presence of free and/or combined anthraquinones): 0.5g of the powdered sample was boiled with 10ml of 10% hydrochloric acid for 2 minutes. The extract was filtered. To the filtrate, an equal volume of chloroform was added, the test tube was inverted a couple of times avoiding vigorous shaking. The solution was transferred into a separating funnel and the two layers were allowed to separate. The lower chloroform layer was poured into a clean test tube and the ammonia solution was added shaken. The two layers were again allowed to separate. A bright pink color in the upper aqueous layer indicates the presence of free and/or combined anthraquinones.

Phytochemical Screening
The results of the phytochemical screening of the plant samples were studied, analyzed and presented in Tables 1  and 2. Table 1shows all the metabolites that were tested for in this sample. Negative signifies absence of while positive signifies presence of particular constituents or metabolites. Zingiber officianale showed presence of Alkaloids, Tannins, Flavonoids, Terpenes, Steroids, Resins and Anthraquinones and absence of Phenols, Glycosides and Saponins.

Conclusion
In the present study, the result of phytochemical screening of all samples analysed were found to contain notable constituents of medicinal importance, Both samples showed presence of Tannins, Steroids, Resin, and Flavonoids. The therapeutic effects of these medicinal plants can justifiably be attributed to, among others, the flavonoids, alkaloids, steroids, terpenes, phenols, anthraquinones, tannins, and saponins present. It could therefore be inferred that these secondary metabolites contain bioactive constituents and medicinal properties which can be effective nutraceuticals and as natural supplements.