Proximate and mineral analysis of delonix regia leaves and roots

Medicinal plants serves as therapeutic agents as well as raw materials for the manufacture of modern medicines due to the presence bioactive chemicals (phytochemicals) and nutrients (protein, carbohydrates, fats, amino acids etc.). Among the potential medicinal plants is Delonix regia, therefore this study was carried out to determine the proximate and mineral composition in the plant (leaf and root). The result on proximate analysis of Delonix regia leaf (DRL) showed that it contained moisture (8.10 %), dry matter (91.90 %), crude protein (18.77 %), crude fibre (9.85 %), ether extract (1.33 %), ash (5.21 %), nitrogen free extract (56.74 %), carbohydrates (78.54 %) and energy (1703.5 kj/100 g) while Delonix regia root (DSR) contained moisture, dry matter, crude protein, crude fibre, ether extract, ash, nitrogen free extract, carbohydrates and energy at 9.60 %, 90.40 %, 10.63 %, 7.44 %, 2.71 %, 9.30 %, 60.32 %, 90.18 % and 1814 kj/100g respectively. Mineral analysis showed that DSR contained higher concentrations of calcium, phosphorus, potassium, zinc, magnesium, sodium, copper, iron and cobalt at 95.43 mg/100g, 40.77 mg/100g, 100.4 mg/100g, 7.21 mg/100g, 14.21 mg/100g, 41.22 mg/100g, 10.2 mg/100g, 1.10 mg/100g and 0.05 mg/100g relative to calcium (77.31 mg/100g), phosphorus (40.35 mg/100g), potassium (51.60 mg/100g), zinc (3.21 mg/100g), magnesium (10.35 mg/100g), sodium (33.18 mg/100g), copper (7.35 mg/100g) and iron (1.89 mg/100g) established in DRL. It was concluded that DRL and DSR contains various nutrients and phytochemicals that produce definite physiological action on the body of animals.


Introduction
Medicinal plants contains phytochemical constituents which are used for the treatment of various human and livestock health disorders all over the world from ancient times to the present day (Oluwafemi et al., 2020;Kavita et al., 2013). WHO (2014) reported that there are over 250, 000 species of medicinal plants and more than 80 % people from developing countries relies on herbal medicines for better health. Medicinal plants have also been reported to been reported to be relatively cheap, efficient and safe . Phytochemical constituents posses important pharmacological properties like antimicrobial, anti-inflammatory, antifungal, antiviral, antioxidant, anti-nociceptive, antithrombotic, hepatoprotective, antidiabetic, chemopreventive and cytotoxic effects (Joy et al., 2019;Manita and Gaurav, 2020).
Delonix regia is a leguminous plant belonging to the family Caesalpiniaceae. It is found in mostly found in countries like India, Pakistan, Afghanistan, Brazil, Mexico, China, Nigeria, Senegal, Ghana, South Africa, Cameroon, Togo, Congo, Sudan, Kenya, Tanzania, Rwanda and Mudagaska (Ogunkoya et al., 2006). The tree can grow up to a height of 9.1 -18.0 meters with wide spreading umbrella like canopy, the leaves are characterized by long stalks with numerous flowers of about 12 mm long, pods are flat, woody, dark brown, 61 cm long and about 5.1 cm wide (Abulude et al., 2018;Aluyor et al., 2009;Rani et al., 2011;Bake et al., 2014).The plant is rich in phytochemicals such as: saponins, alkaloids, carotene, hydrocarbons, phytotoxins, flavonoids, tannins, steroids, carotenoids, galactomannon, lupeol, β-sitosterol, terpenoids, glycosides and carbohydrates, essential minerals, fatty acids and amino acids in leaves, flowers, bark and roots (Ujowundu et al., 2008;Oyedeji et al., 2017). Traditionally, the leaves and stem bark are used for the prevention and treatment of fever, constipation, inflammation, arthritis, hemoplagia, piles, boils, pyorrhea, scorpion bite, bronchitis, asthma and dysmenorrhoea (Rani et al., 2011;Abulude et al., 2011;Banso and Adeyemo, 2006). In view of these abundant potential, a study was carried out to examine the proximate and mineral analysis in Delonix regia leaf and roots.

Site of experiment
The experiment was carried out at Sumiltra Research Institute, Gujarat, India in the month of September to December, 2019.
Plant collection and preparation Delonix regia leaves and roots were collected from Sumitra research farm, Gujarat, India. It was identified and authenticated by a crop taxonomist (Singh. Ram), washed with clean running tap water to remove dirt's, cut differently into pieces and allowed to dry under shade to retain the bioactive chemicals in the samples. The dried samples were individually crushed into powder using a pulverizer and stored in a well labeled air tight container for further analysis. Delonix regia leaf, stem bark and root were abbreviated as DRL and DSR respectively.
Measurements Proximate analysis Crude fibre, crude protein, moisture, ether extract and moisture content were determined according with the official methods of the association of official analytical chemist (AOAC, 2000) and all samples were evaluated in triplicates.
Statistical analysis The analyses were done in triplicates and the data obtained were expressed as mean ± standard error of the means (mean ± S.E.M). The data were subjected to one way analysis of variance (ANOVA) and differences between samples were determined Duncan multiple range test (Duncan, 1955). Significant was declared if P ≤ 0.05. Table 1 reveals the proximate composition of Delonix regia leaf (DRL) and root (DSR). DRL contained moisture, dry matter, crude protein, crude fibre, ether extract, ash, nitrogen free extract, carbohydrates and energy at 8.10 %, 91.90 %, 18.77 %, 9.85 %, 1.33 %, 5.21 %, 56.74 %, 78.54 % and 1703.5 (Kj/100g) respectively. DSR contained dry matter (90.40 %), moisture (9.60 %), crude protein (10.63 %), crude fibre (7.44 %), ether extract (2.71 %), nitrogen free extract (60.32 %), ash (9.30 %), carbohydrates (90.18 %) and energy (1814.1 Kj/100g). The moisture values obtained in DRL and DSR is higher than the values reported for Daniellia oliveri stem bark (6.25 %), Piliostigma thonngii root (8.34 %), Urena lobata leaf (7.21 %), Carpolobia lutea leaf (8.84 %) but lower than those recorded for Centella asiatica (9.96 %), Carpolobia lutea root (9.55 %), Eugenia caryophllata (4.55 %) and Sida cuta leaves (54.82 %). Low moisture content in a sample improves the shelf life of a sample Kader et al., 2014). The crude protein value of DRL (18.77 %) obtained in this study is contrary to the findings of Alagbe et al. (2018), this could be attributed to differences in species, age of plant, method of processing as well as geographical location. Audu et al. (2018) also reported a crude protein value of 12.81 % in Balanites aegyptiaca root. DRL and DSR crude protein (CP) values were lower than the values of Veronia amgydalina leaf (30.02 %) and Indigofera tinctoria leaf (30.53 %) reported by Abiodun et al. (2017) and . The low CP values in DRL and DSR is an indication that the sample cannot be used as a protein supplement in animal feed (NRC, 1994). Crude fibre values reported in this experiment is comparable to those recorded for Physostigma venenosum leaves (7.91 %) and Sida acuta leaves (8.04 %) by Aihiokhai  Volume 3, Issue X, October 2020 | with 5.21 %, this signifies that DSR contained more minerals (Adebowale and Bayer, 2002;. According to Olanipekun et al. (2016); Onyeka (2008) carbohydrates are responsible in energy provision for metabolism of living organisms and it's produced by plants during photosynthesis. Low level of carbohydrates in diets of animals could lead to hypoglycaemia (Vasudevan and Sreekumari, 2007). Fats play a vital role in energy production, aids in structural functioning of cells, transportation of essential vitamins and improves palatability of feeds (Aiyesanmi and Oguntokun, 1996;. Energy value reported in DRL and DSR was higher than the values obtained for Jatropha curcas leaf and root (1514.77 kj /100 g) and (602.93 kj /100 g) reported by Atamgba et al. (2015).  Table 2. DRL contained calcium (77.31 mg/100g), phosphorus (40.35 mg/100g), potassium (51.60 mg/100g), zinc (3.21 mg/100g), magnesium (10.35 mg/100g), sodium (33.18 mg/100g), copper (7.35 mg/100g), iron (1.89 mg/100g), cobalt (0.07 mg/100g) and selenium (0.09 mg/100g). Delonix regia root (DSR) contained calcium, phosphorus, potassium, zinc, magnesium, sodium, copper, iron, cobalt and selenium at 95.43 mg/100g, 40.77 mg/100g, 100.4 mg/100g, 7.21 mg/100g, 14.21 mg/100g, 41.22 mg/100g, 10.2 mg/100g, 1.10 mg/100g, 0.05 mg/100g and 0.04 mg/100g. The mineral composition in this study revealed that DSR contained a higher concentration compared to DRL. However, all values were within the World Health Organization guidelines (WHO, 1991). Calcium value in DRL and DSR higher lower than values reported for Culcasia scandens leaf (10.80 mg/100g), Albizia lebbeck leaf (16.0 mg/100g) reported by Uraku (2017); Labaran et al. (2016). Calcium provides animal's bone with rigidity and support (Ibrahim et al., 2001), deficiency of calcium causes tetany (Vasidevan and Sreekumari, 2007). Copper is a powerful pro-oxidant and catalyzes the oxidation of unsaturated fats and oils as well as ascorbic acid (Uzama et al., 2012). Potassium assists in the regulation of electrolyte, water and acid base in the body and muscle function (Indrayan et al., 2009). Iron is responsible for haemoglobin formation, regulation of the central nervous system and oxidation of protein, fats and carbohydrates (Adeyeyi and Okokiti, 1999). Phosphorus is an essential component of phospholipids, nucleic acids, phosphoproteins (casein), high energy phosphate esters (ATP), hexose phosphates, creatine phosphate, and several key enzymes Vasidevan and Sreekumari, 2007). Zinc is an active component or cofactor for many important enzyme systems zinc plays a vital role in lipid, protein, and carbohydrate metabolism; being particularly active in the synthesis and metabolism of nucleic acids (RNA) and proteins (Uzama et al., 2012;Musa et al., 2020). Magnesium is key in enzyme activation, magnesium (like calcium) stimulates muscle and nerve irritability (contraction), is involved in the regulation of intracellular acid-base balance, and plays an important role in carbohydrate, protein and lipid metabolism (Beldi et al., 2006). It has also been suggested that selenium participates in the biosynthesis of ubiquinone (coenzyme Q; involved in cellular electron transport) and influences the absorption and retention of vitamin E (Abdennour et al., 2004). Sodium plays a fundamental role in the regulation of plasma volume, acid-base balance, nerve action and muscle contraction (Akpanyung, 2005;. Cobalt is an integral component of cyanocobalamin (vitamin B12), and as such is essential for red blood cell formation and the maintenance of nerve tissue (Chia et al., 1992).

Conclusion
The study was a scientific validation that Delonix regia contains essential minerals, nutrients and some chemical substances that produce definite physiological action on the body of human and animals. Medicinal plants are safe, cheap and effective and are could also be used in future to bridge the gap between food safety and production in livestock. Funding: This research received no external funding.
Conflicts of Interest: The authors declare no conflict of interest.