ANTIMICROBIAL AND ANTIOXIDANT EVALUATION OF DIFFERENT SOLVENT EXTRACTS OF MEDICINAL PLANT : FAGONIA MOLLIS DELILE

The present study was aimed to evaluation of the medicinal uses of Fagonia mollis by studying some active constituents, antioxidants and antimicrobial activities. Fagonia mollis Delile was collected from different sites from Tabuk, Saudi Arabia. The phytochemical analysis of the aerial parts of F. mollis indicated that the plant is rich in secondary compounds. F. mollis exhibited the highest content of tannins and saponins (19.9±1.68 and 16.8±1.32, mg/g D. W., respectively), followed by phenolics (11.6±0.72 mg/g D. W.), flavonoids (8.6±0.82 mg/g D. W.) and then alkaloids (5.6±0.64 mg/g D. W.). In the DPPH test system, the crud extract of F. mollis, with an IC50 value of 1.51 mg ml−1, but higher than that of the positive control catechol (0.37 mg ml−1). In the present study the petroleum ether and methylene chloride extracts of F. mollis inhibit all pathogenic bacteria with different rates. Ethyl acetate extract has no effect on both Escherichia coli and Klebsiella pneumonia, while the acetone inhibited all the bacteria except Escherichia coli and Staphylococcus aureus. Methyl alcohol extract of plant on tested bacteria proved a broad spectrum antimicrobial potential. On the other hand, petroleum ether extract inhibited the growth of Candidia albicans and Mucor spp (8 and 9.3 mm, respectively), but has no effect on the Aspergillus fumigatus and A. niger. The methylene chloride, Ethyl acetate and methyl alcohol extracts had no antifungal activities against all the pathogenic fungi. Acetone extract inhibited the growth of A. fumigatus (10.2 mm) but has no effect on the others. The above results revealed that F. mollis have an excellent anti-bacterial activity and can be used for disease therapy.


INTRODUCTION
Use of wild desert plants in medicine as antimicrobial agents and their cultivation is not a new practice, it has been common in many countries all over the world.The wild medicinal plants growing in the desert region of USA, Mexico, India, Egypt, Saudi Arabia and many other countries can be a good source for cultivating vast areas in the desert with the least ecological consequences in addition to the conservation of such resource [1].The secondary metabolites or biochemical compounds are the basis of medicinal action in plants, and which can solve many disease conditions in human body [2,3].
The genus Fagonia consists of many plants and are common in many of the countries [21,22].The species from Fagonia exhibit some morphological differences and consists of shrubs, shrublets or herbs with some of its peculiar characters [23].Fagonia mollis is a genus of flowering plants in the family Zygophyllaceae.It is a perennial, glabrescent, hairy low shrub, which reaches up to 20-40 cm, with a woody base.Stems are many, branched, angular, and striate with stipular spines.Leaves are 3-foliolate with ovate-elliptic leaflets with mucronatespinulose apex; the terminal leaflet is longer and broader than the 2 laterals.Flowers are pink and the fruit is an obconical-obovoid [24,25].
Previous phytochemical study of this plant revealed the presence of flavonoid [26] and saponins [27].Mahmoud and Gairola [28] study the traditional knowledge and use of medicinal plants (F.mollis) in the Eastern Desert of Egypt, revealed the aerial part uses in psychological fears.Therefore, the goal of the present work is to evaluation of the medicinal uses of F. mollis in Tabuk, Saudi Arabia by studying some active constituents, antioxidants and antimicrobial activities Tabuk (Tabuk is located in the Northern part of Saudi Arabia), Saudi Arabia during the period of May 2017.The identification of species was done according to Boulos [25].It was dried at room temperature and grinded into a powder using a blender.Ten gram of dried plant powder was extracted using different solvents (Methanol, hexane, petroleum ether and ethyl acetate) by socking overnight with periodical shacking.The solution was filtered and evaporated to dryness.The dried residue was dissolved in dimethyl sulfoxide (DMSO) and kept at-20 °C for future use [29].

Phytochemical analysis
Fagonia mollis was collected and prepared as previously mentioned.Total phenolics, flavonoids and alkaloids were estimated using spectrophotometric techniques adapted by Harborne [30], Sadasivam and Manickam [31] and Boham and Kocipai-Abyazan [32], respectively.Tannins were determined according to Van-Buren and Robinson [33], while Saponin content was estimated by the method adopted by Obadoni and Ochuko [34].

Antibacterial activity
Antibacterial activity of the extracts was determined against five bacterial strains, three gram-positive i.e., Streptococcus pyogenes, Staphylococcus aureus and Bacillus subtilis and two gram-negative i.e., Klebsiella pneumoniae and Escherichia coli using the disc diffusion method.A sterile paper disc (5 mm in diameter) was socked in the crude extract of the studied plant and then placed over the surface of the inoculated nutrient agar in antibacterial assay [36].All Petri dishes were incubated at 37 °C for 24 h.After incubation, the diameter of inhibition zone (cm) was measured for recording the clear zone and compared with the DMSO as a control.Experiments were performed in triplicate and mean inhibitory zone was calculated.The standard antibiotic of ampicillin and clotrimazole were used for comparison with the tested plant extracts.

Antifungal activity
Antifungal activity against three fungal strains (Aspergillus fumigatus, Aspergillus niger, Candida albicans and Mucor spp.) was determined by the disc diffusion [36].Filter paper discs (5 mm in diameter) are prepared before use and sterilized in an autoclave for 20-30 min.A sterile paper disc is wetted in the solution of crude extract (100 μl) and then placed over the surface of the inoculated PDA in the antifungal assay described by Culture plates were incubated at 28 °C for 72 h and zones of inhibition was recorded around the paper disc.

Phytochemical constituents
In plants, secondary metabolites are not related to the normal growth and development, but are useful in defense mechanism of plants against environmental stresses and diseases [37,38].The phytochemical analysis of the aerial parts of F. mollis indicated that the plant is rich in secondary compounds.F. mollis exhibited the highest content of tannins and saponins (19.9±1.68 and 16.8±1.32,mg/g D. W., respectively), followed by phenolics (11.6±0.72 mg/g D. W.), flavonoids (8.6±0.82mg/g D. W.) and then alkaloids (5.6±0.64 mg/g D. W.) (fig.1).
The phytochemical analysis of F. mollis in this study are relatively agree with those mentioned by Sajid et al. [39] and Saeed et al. [40] on F. cretica from Pakistan, but higher than those reported by Eman et al. [41] and Hussain et al. [42] on Fagonia arabica and F. cretica, respectively.Comparing the obtained results to that for other plant species of the Egyptian flora, revealed that the phytochemical analysis of F. mollis agree with that obtained by Alghanem and El-Amier [43] on Pergularia tomentosa (Solanaceae) growing in arid region.While it higher than that attained by El-Amier et al. [19] on some wild Aizoaceae species.

Antioxidant activity
In plants, antioxidants are the radical scavengers and are involved in defense mechanism of plants [44,45].The antioxidant activity of the different concentration of methanolic extract of the F. mollis is presented in table 1.The DPPH assay is used to measure the antioxidant activity [46].In the DPPH test system, free radicalscavenging activity of the crud extract of F. mollis, with an IC50 value of 1.51 mg ml −1 , but higher than that of the positive control catechol (0.37 mg ml −1 ).
There are previous reports about terpenoids and saponins of genus Fagonia [27,[47][48].Phenolics and tannins are major compounds providing antioxidant activity [49].Therefore, several studies reported that the antioxidant activity of the Fagonia could be attributed to chemical composition and concentration level [50][51][52].

Antimicrobial activity assessment
Microbial contaminations including multidrug-safe strains are among the main sources of death around the world.Healthcare system across the globe has been suffering from an extraordinary burden in terms of looking for the new and stronger antimicrobial compounds [53].In the present study the petroleum ether and methylene chloride extracts of F. mollis inhibit all pathogenic bacteria with rates (fig.2).Ethyl acetate extract has no effect on both Escherichia coli and Klebsiella pneumonia but inhibited others.The acetone inhibited all the bacteria except Escherichia coli and Staphylococcus aureus.Methyl alcohol extract of plant on tested bacteria proved a broad spectrum antimicrobial potential.Similar results have been determined for various extracts of F. indica [54], F. cretica [39,55] and F. olivieri [56].
On the other hand, petroleum ether extract inhibited the growth of Candidia albicans and Mucor spp (8 and 9.3 mm, respectively), but has no effect on the Aspergillus fumigatus and A. niger (fig.2).The methylene chloride, Ethyl acetate and methyl alcohol extracts had no antifungal activities against all the pathogenic fungi.Acetone extract inhibited the growth of A. fumigatus (10.2 mm) but has no effect on the others.In another study, Fagonia extracts exhibited a pronounced antibacterial and antifungal activity [61,56].

Fig. 1 :
Fig. 1: Concentrations of the active organic compounds (mg/g dry weight) estimated in Fagonia mollis

Fig. 2 :
Fig. 2: Antimicrobial activity of different extract of Fagonia mollis and standard antibiotic.The recorded value is mean value of 3 replicates