1. Introduction

The intake of food and supplementsare utilized in the body for maintenance of good health, growth and energy[1]. A balanced diet mainly consists of macro nutrients, micro nutrients and water. The macronutrients include carbohydrates, fats and proteins whereas the micronutrients are vitamins and minerals. All these are very essential factors for normal functioning of the body[1]. The conventional food plants provides most of these nutrients and they are becoming less available to the middle and lower class people in the society due to the economic constrain and other factors such as increasing population[2], so more people from these classes are now incorporating the non conventional food (wild) plants into their daily mealwhich not only they provide nutrients but also used traditionally for treatment of various ailments[3].As available and cheap as they are thousands of these wild plants are yet to be discovered.

Chancapiedrais a wild edible plant belongs to the family ofEuphorbiaceacephyllanthus, and belongs to species ofNiruriamarus. It is synonyms to Phyllanthuscarolinianus, P. sellowianusP. fraternus,P. kirganella,P. lathyroides, Nymphanthusniruri. It is commonly called Chancapiedra in Spain. In Brazil the plant is known as Quebra- pedraorArranca-pedras, carry-me-seed, gale-wind grass, quinine weed which translates to as Stone– breaker[4]. The Hausas of the north Nigeria called itGerontsunsaye.ChancaPiedra is a small, erect, annual herb that grows 30-40cm in height. Itis indigenous to the rainforest of the Amazon and other tropical areas throughout theworld, including Bahamas, Southern India, Africa and China. Phyllanthusniruriis quite prevalent in the Amazon,some tropical areas in Africa and also include some wet rainforest, growing and spreading freely (much like a weed).P. amarus and P. sellowianus are closely related to Phyllanthusniruriin appearance, phytochemical structure and history of use, but typically are found in dry tropical climate of India, Brazil and even Florida and Texas[5].

The ChancaPiedraplant has a long history in herbal medicine in every tropical country where it grows. It is employed to similar condition worldwide. The plant is used for the treatment of numerous illness which includes; colic, diabetes, malaria, dysentery fever, flu, tumors, jaundice, and dyspepsia, and also considered as analgesic, and as an aperitif, carminative, digestive, laxative, stomachic, it expels worms, stone from kidneys, increase urination, relieves pain, protect liver, reduces inflammation, treat viral infections, its aids digestion, reduces blood sugar, lowers blood pressure, lowers cholesterol.The natural remedy is usually just standard infusion or weak decoction of the whole plant or its aerial parts[5]. Chancapiedra plant has been subjected to phytochemical research to determine the active constituents and their pharmacological activities, it was revealed that it is a rich source of photochemical including many which have been found only in the Phyllanthus genus many of the active constituents are glycosides, flavonoids, alkaloids, tannins and phenylpropanoids, lipids, sterols and flavones found in the leaf, steam and root of the plant[6]. This plant has shown a promising utilization in the pharmaceutical industries but not much has been done on it nutritional aspect.

2. Materials and Methods

Sampling and sample treatment: Chancapiedra plants were collected from Zuru local government inKebbi State and identified by a taxonomist at Botany department in Kebbi State University of Science and Technology, Aliero. They were sun dried for threedays and blended into fine powder with a blender machine, sieved and stored in a covered plastic container for further uses. All reagents were of analytical reagent grade unless otherwise stated. Distilled water was used in the preparation of solutions and dilution unless otherwise stated while the proximate composition, mineral composition and anti-nutritive component determinations unless otherwise stated were carried out in triplicates.

Proximate analysis: The estimation of the various food parameters inChancapiedra plant was carried out using the following methods.

Determination of moisture content: This is a measure of the % moisture lost due to drying at a temperature of 105℃. 2g of the fresh plants of Chancapiedra was weighed (W₁) into preweighed crucible (W₀) and placed into a hot drying oven at 105℃ for 24 hours. The crucible was removed, cooled in a desiccator and weighed. The process of drying, cooling and weighing were repeated until a constant weight (W₂) was obtained andthe weight loss due to moisture was obtained by the equation[6].

(i)

WhereW₀ = Weight of the empty crucible, g

W₁=Weight of fresh sample + empty crucible, g

1. W₂=Weight of dried sample + empty crucible, g

2. Determination of ash content: This is a measure of the residue remaining after combustion of the dried sample in a furnace at a temperature of 600℃ for 3 hours. 2g of the powdered plants sample of Chancapiedrawas weighed (W₁) into preweighed empty crucible (W₀) and placed into a Lentonfurnace at 600℃ for 3 hours. The ash was cooled in a desiccator and weighed (W₂). The weight of the ash was determined by the difference between the powdered leaves sample, preweighed crucible and the ash in the crucible[7]. Percentage ash was obtained by equation ii.

(ii)

WhereW₀=Weight of empty crucible, g

W₁=Weight of crucible + powder sample, g

W₂=Weight of crucible + ash sample, g

Determination of crude lipids: The crude lipid content in the sample of Chancapiedra was extracted using soxhlet extraction.The powder sample (2g) was weighed (W₀) into a porous thimble and covered with a clean white cotton wool. Petroleum ether (200cm³) was poured into a 250cm³ extraction flask, which was previously dried in the oven at 105℃ and weighed (W₂). The porous thimble was placed into the soxhlet and the rest of the apparatus was assembled. Extraction was done for 5 hours,the thimble was removed carefully and the extraction flask was placed in a water bath so as to evaporate the petroleum ether and then dried in the oven at a temperature of 105℃ to completely free the solvent and moisture. The flask was then cooled in a desiccator and reweighed (W₁). The percentage crude lipid was calculated using the equation below

(iii)

Where W₀=Weight of sample, g

W₁=Weight of flask + oil, g

W₂=Weight of flask, g

Determination of crude fiber content: 2g of powder sample of Chancapiedrawas weighed (W₀) into a 1 dm³ conical flask. Water (100cm³) and 20cm³ of 20% H₂SO₄ were added and boiled gently for 30 minutes. The content was filtered through Whatmann No. 1 filter paper. The residue was scrapped back into the flask with a spatula. Water (100cm³) and 20cm³ of 10% NaOH were added and allowed to boil gently for 30 minutes. The content was filtered and the residue was washed thoroughly with hot distilled water, then rinsed once with 10% HCl and twice with ethanol and finally three times with petroleum ether. It was allowed to dry and scrapped into the crucible and dried overnight at 105℃ in an air oven. It was then removed and cooled in a desiccator. The residue was weighed (W₁) and ashed at 600℃ for 90 minutes in a Lenton muffle furnace. It was finally cooled in a desiccator and weighed again (W₂)⁶. The percentage crude fiber was calculated using equation viii.

(iv)

WhereW₀=weight of sample, g

W₁=weight of dried residue, g

W₂=weight of ash residue, g

Determination of crude protein content: The crude protein of the Chancapiedrasample was determined using the micro – Kjeldahlmethod[8]. The principle of this method is based on the transformation of protein and that of the other nitrogen containing organic compounds, other than nitrites and nitrates into ammonium sulphate by acid digestion.

(v)

(vi)

(vii)

(viii)

The sample (2g) was weighed along with 20cm³ of distilled water into a micro – Kjeldahl digestion flask. It was shaken and allowed to stand for sometime. One tablet of selenium catalyst was added followed by the addition of 20cm³ concentrated sulphuricacid. The flask was heated on the digestion block at 100℃ for 4 hours until the digest became clear. The flask was removed from the block and allowed to cool. The content was transferred into 50cm³ volumetric flask and diluted to the mark with water. An aliquot of the digest (10cm³) was transferred into another micro-Kjeldahl flask along with 20cm³ of distilled water, and placed in the distilling outlet of the micro – Kjeldahl distillation unit. A conical flask containing 20cm³ of boric acid indicator was placed under the condenser outlet. Sodium hydroxide solution (20cm³, 40%) was added to the content in the Kjeldahl flask by opening the funnel stopcock. The distillation start and the heat supplied were regulated to avoid sucking back. When all the available distillate was collected in 20cm³ of boric acid, the distillation was stopped. The nitrogen in the distillate was determined by titrating with 0.01M of H₂SO₄, the end point was obtained when the colour of the distillate changed from green to pink.

Crude protein is a measure of nitrogen in the sample. It was calculated by multiplying the total nitrogen content by a constant, 6.60. This is based on the assumption that, proteins contain about 16%N which includes both true protein and non – protein N and does not make a distinction between available or unavailable protein[6]. The crude protein was calculated using equation ix

% crude protein = %N x 6.60 (ix)

The nitrogen content of the sample is given by the formula below.

(x)

Where Tv=Titre value of acid (cm³)

Na=Concentration or normality of acid

V₁=Volume of digest and distilled water used for dilutingthe digest (50cm³).

V₂=Volume of aliquot used for distillation (10cm³)

G=Original weight of sample used, g

Determination of carbohydrates: The James’s method[7] was adopted where the total proportion of carbohydrate in the plant sample was obtained by calculation using the percentage weight method. That is by subtracting the % sum of food nutrients: % protein, % crude lipids, % crude fiber and % ash from 100%.This is done by using the equation below.

% C_x(H₂O)_y = 100% - (% crude protein

+ % crude lipid + % crude fiber + % ash) (xi)

Estimation of energy value: The sample calorific value was estimated (in kcal) by multiplying the percentages of crude protein, crude lipid and carbohydrate by the recommended factors (2.44, 8.37 and 3.57 respectively) used in vegetables analysis[9]

Mineral analysis: The triple acid digestion method was employed. The powder plant sample (2.0g) was weighed into a micro-Kjeldahl digestion flask to which 24cm³ of mixture of concentrated HNO₃, H₂SO₄, and 60% HClO₄ (9:2:1 v/v) were added. The flask was put on a heating block and digested to a clear solution, it was cooled and the content wastransferred into a 50cm³ volumetric flask and made-up to the volume mark with distilledwater[10]. The solution was used for determination of mineral elements; calcium, magnesium, potassium, iron, sodium, manganese, zinc and phosphorus.

Minerals analysis using atomic absorption spectrometry (AAS): calcium, magnesium, potassium, iron, sodium, manganese and zinc were analyzed using atomic absorption spectrometry (AAS). The method[11] gives a good precision and accuracy. The principle of the method is based on nebulising a sample solution into an air acetylene flame where it is vaporized. Elemental ions were then atomized and the atoms then absorb radiation of a characteristic wavelength from a hallow-cathode lamp. The absorbance measured, is proportional to the amount of analyte in the sample solution.

Determination of phosphorus: The clear supernatant solution (2cm³) after digestion was placed into 50cm³ volumetric flask. 2cm³ of extracting solution was added, followed by 2cm³ of ammonium molybdate solution. Then distilled water was added to make-up to 48cm³. The content was properly mixed, and 1cm³ of dilute stannous chloride solution was added and mixed again. 1cm³ of distilled water was added to make-up to 50cm³mark and left to stand for 5minutes. The percentage absorbance on thespectrophotometer at 660nm wavelength was used to determine the concentration of phosphorus[12].

Determination of Oxalates content:To 1g of the powder plant sample, 75cm³ of 1.5M H₂SO₄ was added. The solution was carefully shaken on a mechanical shaker for 1 hour and then filtered using Whattman No.1 filter paper. The filtrate (25cm³) was then collected and titrated against 0.1M KMnO₄ solution till a faint pink colourthat persisted for 30 seconds appeared. 1cm³ of 0.1M KMnO₄ = 0.00450g oxalic acid[13].

Determination of phytates content: The powder sample (4g) was soaked in 100cm³ of 2% HCI for 3 hours and filtered. The filtrate (25cm³), 5cm³ of 0.3% NH₄SCN and 53.5cm³ of water were mixed together and titrated against standard FeCl₃ solution (containing 0.00195g Fe/cm³) until a brownish yellow colour which persisted for 5 minutes appeared. Phytin – phosphorus (cm³ Fe = 1.19 mg phytinphosphorus) was determined and phytate content was calculated by multiplying the value of phytin - phosphorous by 3.55[14].

Determination of tannins content: The powder sample (5g) was weighed into a 100cm³ volumetric flask. 50cm³ of distilled water was added and shaken for 1 hour on a mechanical shaker. This was filtered into a 50cm³ volumetric flask and made up to the mark with water. 5cm³ of the filtrate was pipette out into a test tube and mixed with 3cm³ of 0.1 M FeCI₃ in 0.1M HCI and 3cm³ of 0.008M potassium ferrocyanide. The absorbance was measured using a spectrophotometer at 520nm wavelength, within 10min. A blank sample was prepared the colour was developed the same as the sample and absorbance read at the same wavelength. A standard was prepared using tannic acid[15]. Tannins concentration was calculated in (mg/dl) using the absorbance table and the equation below

Determination of Nitrate content: 100grams of the powder sample was weighed into a 15cm³centrifuge tube and 10ml of distilled water was added. The suspension was incubated at 45℃ for an hour. 2 cm³ of the extract was pipette into 50 cm³ volumetric flask and mixed thoroughly with 8 cm³ of the 50% w/v salicylic acid – H₂SO₄ reagent and was allowed to stand for 20 minutes. 19 cm³ of 2N NaOH was slowly added to raise the pH above 12. The content was cooled at room temperature and its absorbance was measured at 410nm with spectrophotometer.Nitrate concentration was calculated in (mg/100g) using the absorbance table and the equation below[16].

(xiii)

Determination of cyanogenic glycosides: This is based on the reaction between alkaline picrate and hydrogen cyanide (HCN) resulting in an orange colour which is measured at 490nm.The lipid free sample (2.0g) was dissolved in 10cm³ of water allowed to stand for 24hours, it was then filtered and 1.0cm³ of filtrate was pipette into a test tube, 4cm³ of alkaline picrate solution was added and incubated for 5 minutes in a water bath at 90℃. The test tube was cooled to room temperature and absorbance of the solution was recorded at 490nm[8]. The concentration of cyanide in the sample was determined from the table of standards for cyanide and their absorbance below[8].

(xiv)

3. Results and Discussion

The results of the various analyses conducted on the sample are presented in Tables 1, 2 and 3

Proximate compositionThe result revealed that the moisture content 0.03± 0.06% is lower than those of some common Nigerian leafy vegetables such as Xanthosemsagittifolum 14.7%, Vernonia amygdaline27.4% and Adansoniadigitata 9.5%[17]. The plant has low moisture content below the value of 15% above which was reported to have favour microbial activities during storage[18]. The low moisture content of the sample is an indication that they have good storage property with minimum fungal and bacterial attack [18].

Table 1. Proximate composition of Chancapiedra plant

Table 2. Mineral composition of Chancapiedra plant

Table 3. Anti-nutritive factors ofChancapiedra plant

The ash content of the sample is a measure of its mineral content. The ash of the plant content of was found to be 5.55± 0.014%, the valve obtained is higher compared to 1.8% reported in sweet potato leaves[9], but lower than 19.61% in Amaranthushybridusleaves¹⁹, 10.83% in water spinach leaves and 18.00% Balsam apple leaves[19] A plant material intended for feed formulation should have ash content not more than 2.5%[18].

The crude proteins content in the sample is 9.52±0.02% is higher compared to 6.30% in water spinach[21], 4.6% in Monordicafoecide leaves consumed in Swaziland[22] but lower compared with 11.29% in balsam apple leaves[23], 24.85% in sweet potatoes leaves[24]. The recommended dietary allowance (RDA) for children, adult males, adult females, and pregnant women are 28, 63, 50, 60g of protein daily[25]. For 100g of Chancapiedraprovide 0.34g, 0.15g, 0.19g, 0.15g of proteins respectively, this indicate that the plant is a poor source of daily proteins.

The plant contained 3.15±0.014 crude lipid, which is lower than 11% in water spinach leaves[26], 12% in Senna obtusfollan²⁶but higher when compared to spinach leaves (0.3%) and Chaya leaves (0.4%) and 1.60% in Amaranthushybridus leaves[19]. Consumption of dietary fat and oils are the principle sources of energy but should not exceed the daily recommended dose of not more than 30 calories[27,28] so as to avoid obesity and other related diseases. One gram of lipid provides 8.37kcal, which indicates that 100g of Chancapiedra should provide about 0.26kcal.

The crude fiber content 17.10± 0.14 is high compared to 7.20% in sweet potatoes leaves[24], 13% in Tribubusterrestris (Tsaida) leaves[28], dietary fiber helps to reduce serum cholesterol level, risk of coronary heart disease, colon and breast cancer and hypertension[25]. The recommended daily allowance (RDA) for fiber is 18-35g[29] that means 100g of Chancapiedra can provide 0.17g of daily fiber for the body.

The carbohydrate content of the Chancapiedra is considered high 64.31± 0.18 compared to some other leafy vegetables like Tribulusterrestris (Tsaida) 55.67%²⁸, 54.20% in water spinach leaves[21] but lower than 82.8% in Corchorustridens leaves[9]. The main function of carbohydrate and lipid is to provide the body with energy. The carbohydrate content per 100g of Chancapiedraprovides279.18kcal of energy on dry weight which is within 248.8 – 307.1 kcal/100g reported in some Nigeria leafy vegetables[30]. That meansChancapiedra can serve as a good source of energy for the body.

MineralsThe result of minerals analyses of Chancapiedra plant in table 2 imply that manganese content is higher in the plant compared to other minerals while sodium has the lowest content. The potassium content of Chancapiedra 12.10± 0.10mg/100g is high compared with 6.42mg/100g found in Diospyrosmespiliformis[31]but lower compared to 220.00± 7.8mg/100g in Cassiasiamea leaves[32]. The recommended daily allowance (RDA) of potassium is 2000mg for adults[33] and the plant contributed 0.6% to R.D.A meaning the plant cannot provide the body with the dietary potassium.

The sodium content of Chancapiedra 0.44± 0.35mg/100g is low compared with 5.00± 0.6mg/100g reported in Tribulusterrestrisleaves[28]and 45mg/100g in Sennaobtustolla [26]. The sodium content is low. It contributes 0.08% RDA while the RDA value of sodium for adults is 500mg[33]. Despite the low sodium content in Chancapiedra it could be a good source of food for hypertensive patients.

The calcium content in the plant 25.58±1.03mg/100g is high compared with the calcium content 3.05mg/100g of Diospyrosmespiliformis(L)[31] and 17.95± 2.00mg/100g in Cassiasiamealeaves[32] but lower than 941mg/100g in Momordicabalsamina L. leaves[23]. The RDA values of calcium for adult men with 3000kcal/day; recommended energy intake is 1200mg[33] and Chancapiedra can only contribute 0.85% to the RDA. The values indicate that for calcium which is needed for growth and maintenance of bones, teeth and muscle[34], Chancapeidra, cannot contribute meaningful amount of dietary calcium.

The phosphorus content 15.42± 3.05mg/100g is high compared with the phosphorus content of Diospyrosmespiliformis (L) 1.0mg/100g[31] but lower than 166-460 mg/100g found in some green leafy vegetable consumed in Sokoto[35]. The RDA value for phosphorus is 1200mg for adult male[33], Chancapiedra plant is a poor source of phosphorus since it contributes 1.2% to RDA and phosphorus, like calcium is required for growth, maintenance of bones, teeth and muscles[34].

Magnesium is an important mineral element in connection with circulatory diseases such as ischemic heart disease and calcium metabolism in bones[36]. The magnesium content of the plant is 25.85± 4.03mg/100g which is high compared with2.56mg/100g in Diospyrosmespiliformis(L) and low when compared with magnesium content 400.00 ± 00.00 mg/100 in Cassia siamealeaves[32] the RDA value for magnesium in adult male is 350mg[33] and Chancapiedracontribute 7.3% to the RDA. This implies that the plant is a poor source of magnesium.

Iron is required for haemoglobin formation and its deficiency leads to anemia[34]. The iron content of Chancapiedra is 3.1± 0.03mg/100g which is higher than 2.80± 0.7 mg/100g in T.terrestrisleaves[28] andin some cultivated vegetables such as spinach (1.6mg/100g) lettuce (0.7 mg/100g) and cabbage (0.3mg/100g)[34] but lower than 70.00 ± 0.80mg/100g in Cassiasiamaeleaves[32]. The RDA value for iron for a male adult is 10-15mg[33]. The plant contribute 31%-20% of iron to the RDA, this shows Chancapiedra can provide the daily iron requirement for a male adult when the anti-nutrient agents are ignored.

The zinc content of Chancapiedra 0.45± 1.05mg/100g was found to the high when compared to 0.023mg/100g in Diospyrosmespiliformis(L)[31] but lower when compared to 6.85± 1.00mg/100g in Cassiasiamealeaves[32]. Zinc plays a vital role in gene expression, regulation of cellular growths and participates as a co-factor of enzymes responsible for carbohydrates, proteins and nucleic acids metabolism[37]. The RDA value of zinc for a male adult is 12-15mg[33] Chancapiedra contributes 3.7%-3% to the RDA. This shows that Chancapiedra plant is a poor source of zinc.

Manganese is a micro element essential for human nutrition. It acts as in activator for many enzymes[38]. The manganese content in Chancapiedra 1.27±0.02 which is higher than 0.98mg/100g reported in some locally green leafy vegetables[39] but lower than 11.6mg/100g in Balsam apple (MormordicaBalsamina L.) leaves[23]. The RDA value for manganese is 2-5mg/100g to a male adult[33] Chancapiedra contribute 63.5%-25.4% of manganese to the RDA. Chancapiedra is a good source of manganese.

Anti-nutritive FactorsThe oxalate content of Chancapiedra was found to 5.344± 0.4mg/100g dry matter. This value is higher when compared to 02.20±0.07mg/100g in Borassusaethiopum⁴⁰ but lower when compared to those reported for dehulled seeds of African locust beans (695mg/100g) and (851mg/100g) in seed kernel of Blanitesaegytitia[41]. The level of oxalate in the Chancapiedra plant is within physiological tolerance level of 2-5g.Oxalate can bind to calcium present in food thereby rendering calcium unavailable for normal physiological and biochemical roles. Oxalate present in food is insoluble, it may also precipitate around soft tissue such as the kidney, causing kidney stones[42].

The phytate content of the plant 27.58±1.70mg/100g which is higher compared to 8.24mg/100g in Cassiasiamealeaves[32] but lower than 392.23mg/100g in egg plant leaves[43]. It is also lower when compared to some common cereals such as maize 348mg/100g, millet 104mg/100g. Soya beans 808mg/100g⁵.Phytic acid can bind to mineral element such as calcium, zinc, magnesium, iron and manganese to form complexes that are indigestible, thereby decreasing the bioavailability of these elements for absorption[44]. The low phytate content in the plant indicate that the consumption of the plant will not affect the bioavailability of minerals especially calcium and zinc for absorption.

Cyanogenic glycosides content of the plant is 16.1±0.14 mg/100g. This Substance can be very poisonous when consumed in large amount. Although, moderately it is lower than the toxic level of 35mg/100g dry weight and 20 mg/HCN equivalent per kg sample recommended by standard organization of Nigeria (SON)

Nitrate content in the plant was found to be 22.42± 0.028 mg/100g. This is below acceptable daily intake level of 3.7mg/kg body weight equivalent of 220mg for 60kg person[45].

The tannins content in the plant is 15.2± 0.13mg/100g. This value is higher when compared to 7.40±0.14mg/100g in Balaniteaegyptiaca and 4.83±0.15 mg/100g in Vitexdonianan[40] but higher than 0.93+0.11 mg/100g in Parkiabiglobosa[41]. Tannins in food impose an astringent taste affecting palatability, reduce the intake of the food and consequently body growth. Tannins can bind to both exogenous and endogenous proteins including enzymes of the digestive tract, thereby affecting the utilisation of protein[40].

4. Conclusions

The Chancapiedra plant cannot provide the entire nutrient required by human system. Yet, it contains some essential nutrients like carbohydrate, iron and manganesewhich if utilized can serve as an alternative source of nutrients. It is quite safe for consumption since it contains low anti- nutritive agents such as the oxalate, phytate, cyanide and tannins contents.