Phytochemical Studies of Dysophylla myosuroides (Roth.) Benth. In. Wall. and Talinum cuneifolium (Vahl.) Willd

Dysophylla myosuroides and Talinum cuneifolium are medicinal plants used for different diseases. The present work was aimed to screen these medicinal plants for phytochemical studies. The dry powder of plant parts were extracted with different solvents by using soxhlet apparatus. Leaves of Dysophylla myosuroides revealed the presence of flavonoids, phenols, glycosides, terpenoids, saponins, steroids and volatile oils and absence of alkaloids, lignin, tannins, quinones and fixed oils. Whereas, tubers and leaves of Talinum cuneifolium showed that the presence of flavonoids, glycosides, saponins and steroids and absence of alkaloids, phenols, lignin, tannins, terpenoids, quinones, fixed oils and volatile oils. Both the plants showed variation in the synthesis of secondary metabolites. Dysophylla myosuroides accumulates more number of secondary metabolites than that of Talinum cuneifolium. Methanol and hexane are found to be efficient solvents for Talinum cuneifolium and Dysophylla myosuroides, respectively. Tuber of Talinum cuneifolium synthesized more number of secondary metabolites than that of leaves, methanol the most efficient solvent to extract the phytochemicals from tuber and leaves of Talinum.

INTRODUCTION

Plant synthesizes a wide variety of chemical compounds which can be sorted by their chemical class, biosynthetic origin and functional groups into primary and secondary metabolites. Primary metabolites comprise sugars, amino acids, proteins and carbohydrates while secondary metabolites consist of alkaloids, flavonoids, saponins, tannins and steroids so on (Parekh and Chanda, 2007; Kumar et al., 2009). Secondary metabolites do not seem to be vital to the immediate survival of the organism that produces them. These are not an essential part of the process of building and maintaining living cells. With the development of natural product chemistry, the potential of chemotaxonomy is now becoming increasing by obvious. The application of chemical data to systematic has received serious attention of a large number of biochemists and botanists during the last three decades (Sharanabasappa et al., 2007).

Phytochemical constituents are the basic source for the establishment of several pharmaceutical industries. The constituents present in the plant play a significant role in the identification of crude drugs. Phytochemical screening is very important in identifying new sources of therapeutically and industrially important compounds like alkaloids, flavonoids, phenolic compounds, saponins, steroids, tannins, terpenoids etc. (Akindele and Adeyemi, 2007; Liu, 2003). Previously the crude drugs were identified by comparison only with the standard descriptions available but recently due to advancement in the field of pharmacognosy various techniques have been following for the standardization of crude drugs (Savithramma et al., 2010).

Medicinal herbs have been use in one form or another under indigenous systems of medicine. Dubey et al. (2004) mentioned that the complete phytochemical investigations of medicinal plants of India should be carried out because these secondary metabolites are responsible for medical activity of the plant. Qualitative and quantitative phytochemical analysis was carried out in 53 plants of western region of India by Vaghasiya et al. (2011). Recent reports of the usefulness of phytochemicals for medicinal and therapeutic purposes and also taxonomic elucidation of plant species were studied by Ibrahim et al. (2007), Njoku and Akumefula (2007), Rasool et al. (2010), Jana and Shekhawat (2010), Karthishwaran et al. (2010), Oseni and Akindahunsi (2011), Ganesh and Vennila (2011) and Shafaei et al. (2011). Number of plants were screened for secondary metabolites for their medicinal values by Bhakuni et al. (2001) Artemisia annua, Rani and Naidu (1998) Nardostachys jatamamsi, Bazylko and Strzelecka (2007) Thymus vulgaris, Stajner et al. (2006) Allium giganteum, Bae et al. (2007) Cephalotaxus koreana, Savithramma et al. (2010) Boswellia ovaliofoliolata, Santhi et al. (2011) Nerium oleander and Momordica charantia, Nwokocha et al. (2011) Jatropha and Nawagish et al. (2007) Lawsonia inermis. Identification of biologically active compounds is an essential requirement for quality control and dose determination of plant based drugs. A medicinal herb can be viewed as a synthetic laboratory as it produces and contains a number of chemical compounds. The medicinal properties of plants can be determined by the presence of one or more plant natural products (Vinoth et al., 2011).

For the present study two species of medicinal plants were selected. Dysophylla myosuroides is common on open rocky crevices in hill slopes of Tirumala (Chetty et al., 2008). It is belongs to the family Lamiaceae, the local healers and tribals used to cure ailments and leaf extract is used for relieving anxiety and stimulation of brain (Savithramma, 2003). Talinum cuneifolium (Portulacaceae) is a green leaf vegetable, it is rich vitamin A and minerals content (National Institute of Science Communication, 2004). Indian System of Medicine (ISM) refers that the leaves and roots are medicinally important parts. The supplementation of the leaves are used in treatment of diabetic, mouth ulcer and aphrodisiac, roots are used for cough, gastritis, diarrhoea and pulmonary tuberculosis (Janapati et al., 2008). Several species of medicinal plants were screened for secondary metabolites, such studies are not performed so far in these plants though they are widely using for medicinal purpose. Hence in the present study these two taxa were selected for phytochemical screening.

MATERIALS AND METHODS

Leaves of Dysophylla myosuroides and leaves and tubers of Talinum cuneifolium collected from the Tirumala hills, Chittoor district Andhra Pradesh, India in December 2010. The leaves and tubers were air dried for 15 days and kept in the hot air oven at 60°C for 24 to 48 h and ground to fine powder. These powders extracted with different solvents by using soxhlet apparatus. The preliminary tests, for the detection of secondary metabolites were carried out with hexane, ethyl acetate and methanolic extracts. Soxhlated dry residue of extracts of 500 mg was dissolved in 100 mL of the respective solvents and filtered through Whatman No. 1 filter paper. Thus, the filtrates obtained were used as test solution for the following preliminary phytochemical studies.

The following methods are used to test the flavonoids (Peach and Tracey, 1956), steroids (Gibbs, 1974), terpenoids and tannins (Treare and Evans, 1985), glycosides (Kokate et al., 1999), saponins and alkaloids (Gibbs, 1974), phenols (Gibbs, 1974) quinones and lignins (Gibbs, 1974) fixed oils and volatile oils.

RESULTS AND DISCUSSION

Preliminary phytochemical analysis of leaf extracts of Dysophylla myosuroides revealed that the pharmacological actions of crude drugs and other therapeutically active constituents were more in hexane extract which include flavonoids, phenols, steroids, glycosides and saponins. Ethyl acetate extract was rich in flavonoids, phenols, steroids, glycosides. The constituents which exhibited positive reaction in methanolic crude drug extract were phenols, saponins and steroids (Table 1).

Table 1:	Preliminary screening of secondary metabolites from leaf extracts of Dysophylla myosuroides, tuber and leaf extracts of Talinum cuneifolium
+: Presence, -: Absence

The test for the presence of terpenoids in fresh leaf material of Dysophylla revealed the presence of diterpenoids in it. Plant based drugs contain a mixture of multiple components which serve the effective control of diseases. Flavonoids are to be synthesized by plants in response to microbial infection. Flavonoids, tannins and terpenoids are attributed for analgesic and anti-inflammatory activities. Apart from this tannins contribute property of astringency i.e., faster the healing of wounds and inflamed mucous membrane (Okwu and Josiah, 2006).

Preliminary phytochemical analysis of all the tuber extracts of Talinum cuneifolium, revealed that the maximum number of the compounds were reported in methanolic extract which was rich in flavonoids, steroids, glycosides and saponins. Whereas, ethylacetate extract was rich in flavonoids, steroids and glycosides. Hexane extract showed positive results only for flavonoids. Steroids were found to be present in leaves and tuber of the selected plants. It should be noted that the steroidal compounds are of importance and interest in pharmacy due to their relationship with sex hormones (Santhi et al., 2011). The qualitative analysis of phytochemicals in the leaf crude extracts of Talinum cuneifolium, illustrates that methanolic extract which was rich in flavonoids, steroids, glycosides and saponins. Hexane extract rich in steroids and glycosides whereas steroids are present in ethyl acetate extract. Phenols are found in the leaves of Dysophylla myosuroides which are helpful to improve self immunity and important in pharmaceutical applications.

According to previous studies, roots of Strychnons potatorum (Mallikharjuna et al., 2007), leaves of Bauhinia recemosa (Sharanabasappa et al., 2007), methanolic extract of roots and leaves of Hyptis suaveolens (Nwobu et al., 2010), ethanolic extract of Thymus fontanesii and Laurus nobilis (Haddouchi et al., 2011) and Rumex vesicarius (Hariprasad and Ramakrishnan, 2011), aqueous extracts of Echiumpynanthum pommel (Chouche et al., 2011), Cardiospermum halicacabum (Patil et al., 2011), root tuber of Curculigo (Agrahari et al., 2010), leaves of Nerium and Momordica (Santhi et al., 2011), leaves, bark, root and galls of Pistacia (Uddin et al., 2011) and leaves, stem, roots and seeds of Jatropha (Nwokocha et al., 2011) rich in secondary metabolites.

In order to promote Indian herbal drugs, there is an urgent need to evaluate the therapeutic potentials of the drugs as per WHO guidelines (WHO, 2000). Patwardhan et al. (2004) mentioned that 30% of drugs selling in the world’s market is based on natural products. Traditional indigenous medicine is limited to small tribal and geographical areas called “little traditions” are an excellent repository of knowledge about medicinal properties of botanical sources. Kamboj (2000) stated that the bioactive extract should be standardized on the basis of phytochemical compounds. Phytochemical screening of medicinal plants is very important in identifying new sources of therapeutically and industrially important compounds. It is imperative to initiate urgent steps for screening of plants for secondary metabolites. In the present communication an attempt has been made to assess the status of phytochemical properties in leaves and tuber of Dysophylla myosuroides and Talinum cuneifolium which will be beneficial in standardization of drug discovery and development. These two species are used by people extensively to improve the health status and also use in pharmaceutical and nutraceutical products of commercial importance.

CONCLUSION

Dysophylla myosuroides and Talinum cuneifolium, thus appear to be rich in secondary metabolites and widely used in traditional medicine to combat and cure various ailments. The anti-inflammatory, antispasmodic, antianalgesic and diuretic properties of these two plants can be attributed to their high flavonoids, steroids, glycosides and saponins. Exploitation of these pharmacological properties involves further investigation of these active ingredients for the implementation techniques of extraction, purification, separation, crystallization and identification.