Introduction

Medicinal plants are now getting more attention than ever before because they have the potential of myriad benefits to society, especially in the line of medicine and pharmacological. The medicinal value of these plant lies in bioactive phytochemical constituents that produce definite physiological action1. The detection of active principles in medicinal plants plays a strategic role in the phytochemical investigation of crude plant extracts and is very important with regards to their potential pharmacological effects27. Medicinal plants contain both organic and inorganic constituents, and many medicinal plants are found to be rich in one or more individual elements, thereby providing a possible link to the therapeutic action of the medicines3430. Trace elements play a vital role in the formation of bioactive chemical constituents in medicinal plants and are therefore responsible for both their medicinal and toxic properties28. Thus, a quantitative estimation of minor and trace element can be important in determining the effectiveness and toxicity of the medicinal plants in treating various diseases and to understanding pharmacological actions.

Cochlospermum planchonii, a West African species can be up to 0.5 – 1.5m in height and growing from Guinea region to Cameroon153. It has various medicinal applications in different parts of Africa. In Ivory Coast, the root is used to treat schiotomiasis, jaundice, fever and back pains while in Senegal, it is used to treat jaundice, intestinal worms, bilhariasis and hepatitis7. The fresh root of the plant is also used as a concoction together with fresh stem bark of E. senegalensis for the treatment of stomach disorder, typhoid and urinary tract infection37. Information on the phytochemical and mineral constituent of this plant is however very scanty in literature. The present study was therefore carried out to evaluate the phytochemical and mineral compositions of the root of the plant.

Materials and Methods

Plant material and authentication

The plant samples obtained from the traditional herb seller at ‘Oja-oba’ Market, Ilorin, Nigeria were authenticated at the Forestry Research Institute of Nigeria (FRIN), Ibadan, Nigeria. A voucher specimen (F.H.I 99093) was deposited at the herbarium of the institute. The plant materials were washed and air dried to a constant weight for two weeks. Thereafter, the samples were milled into powder with mechanical blender (Thomas Willey Machine, UK) and stored in an air-tight bottle till used for analysis.

Phytochemical Screening

Qualitative evaluation were carried out using chemical test on the samples following standard procedure for identification of the constituents as described by Harbone (1973); Trease and Evans38 and Sofowora35. The quantification of the detected phytochemicals was carried out as described for saponins8, flavonoids, tannins, steroids, triterpenes, phenolics and phlobatannins10, alkaloids12, anthraquinones17.

Mineral Analysis

The multiple-nutrient wet acid digestion method described by AOAC2 was used for the mineral evaluation of the sample. Calcium, sodium and potassium levels were determined by Flame photometric method on Jenway Digital Flame Photometer (PFP7 Model) using filters corresponding to each mineral element. Determination of Pb, Cd, Cu, Mg, Se, Fe, and Mn was carried out with Atomic Absorption Spectrophotometer (AAS) Buck 211 Model.

Results

The result of the phytochemical screening (Table 1) revealed the presence of several phytochemicals, prominent among which are saponins (7.58 %), alkaloids (2.92 %), Phenolics (3.16 %) and steroids (0.89 %). The mineral analysis of C. planchonii (Table 2) showed its rich content of elements like Na (3.08 × 104mg/kg), K(8.25 × 104 mg/kg), Fe (91.4 mg/kg), Ca (26.80mg/kg), and Mg (32.80mg/kg) among others. The plant also contains minute amount of Pb (1.00 mg/kg) and Cd (0.20mg/ kg).

Table 1: Phytochemical components of Cochlospermum planchonii root.

Table 2:Some mineral constituents of Cochlospermum planchonii root.

Discussion

Tannins, saponins, phenolics, alkaloids and flavonoids have been suggested to be involved in anti bacterial and anti-viral activities, while tannins and flavonoids are thought to be responsible for anti-diarrheal activity11. Investigations of mode of action indicate that tannins and flavonoids increase colonic water and electrolyte reabsorption while other phytochemicals act by inhibiting intestinal mobility11. This explains the anti-diarrheal use of C. planchonii root in traditional medicine. In addition, tannin has astringent properties, hastens the healing of wounds and inflamed mucous membrane. Plants with tannins are used for healing of wounds, varicose ulcers, hemorrhoids, frost- bite and burns1418. The biological functions of flavonoids include protection against allergies, inflammation, platelets aggregation, microbes, ulcer and tumour25. They are free radical scavengers, super antioxidants and potent water soluble thus preventing oxidative damage and have strong anti-cancer activity31. Thus, the acclaimed anti-inflammatory and wound healing uses of C. planchonii root extract may be attributed to flavonoids and tannins.

Saponins has been shown to affect sex hormones like oxytocin which is implicated in the onset of labour in women and subsequent release of milk25. Studies have shown that saponins have antitumor and anti-mutagenic activities and can lower the risk of human cancers, by preventing cancer cells from growing. They seem to react with the cholesterol rich membranes of cancer cells, thereby limiting their growth and viability. Rao and Sung29 found that saponins may help to prevent colon cancer. Anti- hyperglycemic potential of saponins has also been reported19 and26. The presence of saponin in C. plachonii root may explain its use as an anti-diabetic agent. The saponin may be responsible for the anti-hyperglycemic activity of aqueous extract of C. planchonii root and its effectiveness in reverting some of the disorders of metabolism associated with diabetes metabolism reported by Yakubu et al41. The high saponin content may however be conferring possession of heamolytic property. This can influence the use of the plant in folk medicine a cholesterol binding agent.

Phenolic compounds have antimicrobial properties. Phenol and phenolic compounds have been extensively used in disinfections and remain the standards which other bacteriacides are compared24. Alkaloids are the most efficient therapeutically significant plant substance23. Pure isolated alkaloids and the synthetic derivatives are used as the basic medicinal agent because of their analgesic, anti-plamodic and bacterial properties where they showed marked physiological effects when administered to animals23. This may justify the use of C. planchonii root extract in the treatment of pain, malaria, and enteric fever in folk medicine.

The presence of phlobatannins may suggests diuretic property on the plant4. Steroid in modern clinical studies have supported the role of C. planchonii as anti- inflammatory and analgesic agent34. Anthraquinones have wide application as immunosuppressive, immunostimulant, anti-ulcer, antioxidant36 and anti-microbial activity40.

The elements K, Na, Ca, Mg, and Cl are some of the macronutrients which are essential to human health and nutrition42. Sodium acts with other electrolytes especially potassium in the intracellular space to regulate the osmotic pressure and maintain proper water balance within the body. It is required for glucose absorption and transportation of other nutrients across cell membranes5. In addition, normal functioning of the nervous system depends on sodium. Potassium also plays an important role in the regulation of acid base balance in the cell, water retention and is essential for protein biosynthesis by ribosomes32. Calcium is the main constituent of the skeleton and is important for regulating many vital cellular activities such as neuromuscular transmission muscle contraction, hormonal actions, blood clotting and other cellular mortility2132.

Magnesium is involved in over 300 enzymatic reactions in the body396, including glycolysis, the Kreb cycle, creatine phosphate formation, nucleic acid synthesis, amino acid activation, cardiac and smooth muscle contractibility, cyclic AMP formation, and protein synthesis. Magnesium is also important in the proper utilization of vitamins B and E and functions with other minerals such as calcium, sodium and potassium in maintaining fluid and electrolyte balance5.

Copper is an essential trace element for humans and animals. The ability of copper to easily accept and donate electrons explains its important role in oxidation-reduction reactions and scavenging free radicals16. The main function of iron is in the transport of oxygen to the tissue (haemoglobin) and is also involved in the processes of cellular respiration32. Manganese plays an important role in a number of physiologic processes, as a constituent of multiple enzymes and an activator of other enzymes22. A number of manganese-activated enzymes play important roles in the metabolism of carbohydrates, amino acids, and cholesterol. It is also thought to aid in the maintenance of epithelia tissue21. Although selenium is a toxic heavy metal, it is very important for human health. Together with Vitamin E, selenium helps the immune system produce antibodies. Selenium binds with toxic metals like mercury and is involved in promotion of normal body growth and fertility9.

In conclusion the results obtained from this analysis supports that the aqueous extract of Cochlospermum planchonii root is a very rich source of phytochemicals and mineral elements which justify the various therapeutic uses attributed to it in folklore medicine. However the presence of trace amount of lead and cadmium however calls for caution because of their toxicity.