Printer Friendly

Antimicrobial and Antioxidant activity of Citharexylum Spinosum.

Byline: Muhammad Ajaib, Taskeen Mehak, Sidra Fareed, Shahnaz Perveen and Shazia Shah

Summary: The antimicrobial and antioxidant potential of different parts of Citharexylum spinosum L. was evaluated. The antimicrobial activity was estimated by agar well diffusion method. The maximum antibacterial activity (44.5 +- 0.5 mm) was observed by methanolic bark extract against Staphylococcus aureus while the minimum activity (10.5 +- 0.5 mm) was exhibited by the chloroform leaves extract against Staphylococcus aureus. The highest antifungal activity (41.83 +- 0.76 mm) reported by distilled water extract of leaves against A. niger while petroleum ether extract of bark showed minimum activity (11.16 +- 0.28 mm) against A. oryzae. The most resistant value of MIC was observed at concentration of 0.3125 mg/mL of methanol leaves extract against B. subtilis and P. aeruginosa.

The antioxidant potential was analyzed by using five techniques included total phenolic content (TPC), total flavanoids content (TFC), ABTS, metal chelating activity, and DPPH free radical scavenging activity. The results displayed that petroleum ether bark extract showed maximum TPC value (60.24 +- 0.03 ug/mL). Petroleum ether extract of bark exhibited maximum TFC value (1350.07 +- 0.01 ug/mL). ABTS results showed that distilled water extract of bark exhibited maximum TEAC value (7.92 +- 0.06 mm). Metal chelating results showed that maximum % inhibition (64.2 +- 0.05 %) was observed by distilled water extract of bark. The highest scavenging effects (82.59 +- 0.66 %) was observed by chloroform extract of leaves. The phytochemical analysis of Citharexylum spinosum L showed the presence of alkaloids, tannin, terpenoids, saponins, reducing sugar, anthraquinones, cardiac glycosides and flavonoids.

Keywords: Citharexylum spinosum L., Antioxidant activity, MIC, Antimicrobial activity, Phytochemical screening.

Introduction

Pakistan has sufficient resources of plants which have therapeutic properties and more than 1,000 species have been reported which have medicinal values and used to cure various diseases [1]. According to world health organization medicinal plants would be the best source to obtain a variety of drugs. The antimicrobial properties of many plants have been investigated by a number of researchers worldwide [2]. Various medicinal plants are used for the treatment of different diseases and also used as food along with their medicinal benefits, evaluating their nutritional significance can help to understand the worth of these plants species [3-4]. There is a need to discover new antimicrobial agents with diverse chemical structures and novel mechanisms of action for new and re-emerging infectious diseases [5].

Energy is generated in the form of ATP inside the cell, oxygen existent within the individual is consumed and as a consequence free radicals are formed. These free radicals are produced in the result of the redox mechanisms occurring in cell. These constitute singlet oxygen (O2-), hydroxyl radical (OH-) and hydrogen peroxide (H2O2) which are called as reactive oxygen species (ROS). ROS are constructive for cellular feedbacks as well as for the appropriate performance of the immune system, provided that they are occurring in minor or moderate concentrations [6]. In addition to their individual effects, antioxidants interact in synergistic ways and have sparing effect in which one may protect another against oxidative destruction. These justify the overwhelming interest in finding naturally occurring antioxidants for use in foods or medicinal materials to replace synthetic antioxidants [7].

Previously antimicrobial and antioxidant potential of essential oil and flower extracts of C. spinosum are reported [8-9]. In view of these studies, we have selected Citharexylum spinosum L. for detailed studies. It is commonly known as fiddlewood or spiny fiddlewood. The family verbenaceae includes 90 genera and 3000 species. It contains a large number of economically and medicinally important plants. C. spinosum is used for making furniture, musical instruments such as guitars. It is native to Guyana, Venezuela, Caribbean, Suriname and Southern Florida.

Experimental

Plant Material

Citharexylum spinosum was collected from the Botanic Garden, Government College University, Lahore and identified from Dr. Sultan Ahmad Herbarium GC University Lahore with a voucher no. GC. Herb. Bot. 2943.

Microorganisms

Four bacterial strains including two Gram positive (Bacillus subtilis and Staphylococcus aureus), two Gram negative (Pseudomonas aeruginosa and Escherichia coli), and two fungal strains (Aspergillus niger and Aspergillus oryzae) were selected as test microorganism for microbial study. All these bacterial strains were obtained and identified from Department of Pathology, Punjab Institute of Cardiology, Jail Road, Lahore. Fungal strains were obtained from The Institute of Industrial Biotechnology and Microbiology, GC University, Lahore.

Standard Discs

Standard discs were used to draw a comparison between antimicrobial potential of extracts and that of other commercially available antibiotics. The antibiotic discs were amikacin, cephalaxin and erythromycin, while griseoflavin and terbinafine were used as the antimycotic discs.

Extraction

The leaves and barks of plant material Citharexylum spinosum L. were dried at room temperature, ground to powder and soaked in solvents (petroleum ether, chloroform, methanol and water) according to polarity. The extracts were concentrated under reduced presure on a rotary evaporator.

Phytochemical Analysis

Plant extracts were analyzed qualitatively for different phytochemicals following the procedure accepted by Ayoola et al. [10]. Draggendroff's, Mayer's test, Salkowski test, Fehling's test and Keller-Killiani test were performed for the detection of alkaloids, terpenoids, reducing sugars and cardiac glycosides. The extracts were also tested for the presence of saponins, flavonoids and anthraquinones.

Antimicrobial Activity

Preparation of Culture Media

In accordance with protocol adopted by Cruick-Shank et al. culture media were prepared [11]. For the preparation of 1L PDA medium, 39 g of PDA was dissolved in distilled water and final volume was raised up to 1L. For the preparation of nutrient agar medium, 8 g of NB and 14 g of agar were dissolved in distilled water and final volume was made up to 1L. The pH of PDA medium and nutrient medium was maintained at 5.6 +- 0.2 and 6.8 +- 0.2, respectively. Media so prepared was autoclaved for 15 min at 120 degC and 15 lb/psi pressure. Under the aseptic condition of laminar air flow, 20 mL of medium was poured in each plate and then solidified at room temperature.

Agar Well Diffusion Method

Agar well diffusion technique of Jorgensen et al. was employed for antimicrobial activity [12]. According to this technique, dilute inoculum of tested bacteria and fungi were spread in the Petri plates containing desired media, standard hole was made in the center of all Petri plates using cork borer no. 4 and 1mL of crude extract was filled in the hole in the laminar air flow. Each plate was labeled, covered with cling film and placed in incubator at 35 +- 2 degC and 25 +- 2 degC for 24 and 48 h for determination of antibacterial and antifungal activity, respectively. After incubation, diameter of inhibited zone was measured with the help of transparent ruler or vernier calipers in mm.

Minimum Inhibitory Concentration (MIC)

Minimum inhibitory concentration was determined by agar dilution method in accordance to Joshua et. al., [13]. Five dilutions 10 mg/mL, 5 mg/mL, 1.25 mg/mL, 0.625 mg/mL and 0.3125 mg/mL were made for the aqueous extracts of leaf and bark. Methanol extracts were selected for this evaluation. Potato dextrose agar and nutrient agar were prepared according to the standard method. In laminar air flow hood, 18 mL of autoclaved media was poured in each plate and 2 mL of extract was added and mixed well to ensure even distribution. A ratio of 9:1 was maintained between medium and extract. Media (containing extract) was solidified and then the inoculum (fungal or bacterial) was streaked on the surface of medium. The inoculated plates were incubated at temperature of 35 +- 2 degC for 24 h. After incubation plates were observed for the growth of test organisms.

Antioxidant Activity

Total Phenolic Content

The total phenolic content (TPC) for each plant extract was calculated by the method of Makkar et al., [14]. A supersaturated solution of sodium carbonate was prepared. To 40 uL of sample add 3.16 mL of double distilled water and 200 uL of Folin-ciocalteu reagent, mixed them well and allowed it to stay for 8 min. Then add 600 uL of sodium carbonate solution and allow it to incubate at 400 degC for 30 min and note its absorbance at 765 nm. Total phenolic contents were calculated from the standard curve and expressed as mg/g equivalents of gallic acid which were derived for standard calibration curve.

Y = 0.057 X Where,

Y = Sample absorbance

X = TPC value

Total Flavanoids Content

Total flavanoids content (TFC) of plant fractions were determined by method developed by Dewanto et al., [15]. 0.25 mL of plant sample/quercetin standard solution was mixed with 1250 uL of distilled water in a test tube and then 75 uL of NaNO2 solution was added. After 5 min 0.5 mL of 1M NaOH was added and raised the volume with distilled water to a final volume of 2.5 mL. The absorbance of this sample solution was measured at 510 nm. TFC contents were determined from the standard curve of quercetin and expressed as mg of quercetin equivalents per gram of sample.

Y = 0.0029X-0.0022

Where,

Y = Sample absorbance

Xn = TFC value

ABTS Activity

Evaluation of antioxidant ABTS*+ assay was carried out by Re et al., method [16]. 7 mM solution of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) was prepared in double distilled water which generated ABTS*+ while reacting with 2.45 mM potassium persulfate after 24 h on standing under dark. The ABTS*+ stock solution was diluted with PBS buffer of pH 7.4 or methanol to an absorbance of 0.70 + 0.02 at 734 nm. For the evaluation of antioxidant activity, added 10 uL of sample to 2.99 mL of diluted solution of ABTS*+ (A = 0.70+ 0.02) and noted the change in absorbance after every 1 min interval for 8 min. Appropriate solvent blank was run in parallel. All the samples were run in triplicate and mean values of absorbance were calculated. A dose response curve of trolox was prepared by plotting its absorbance at 734 nm and % age inhibition for each sample was calculated by using following formula.

% age inhibition (at 734 nm) = (1-Af /Ao) X 100

where Ao = absorbance of ABTS radical cation and

Af = absorbance after sample addition.

Y = 11.37 X + 0.97 where,

Y = Sample absorbance

X (ABTS value) = ?

Table-2: Zone of inhibition produced by standard antibiotic and antifungal discs against test microbes.

Microbial###Standard###Concentration of###Zone of

strains###discs###standard discs (ug)###Inhibition (mm)

E. coli###Amikacin###20###16.9 +- 0.9

P. aeruginosa Erythromycin###20###15.3 +- 0.57

B. subtilis###Cephalaxin###20###19 +- 1.02

S. aureus###Amikacin###20###18.3 +- 1.15

A. niger###Griseofulvin###20###20.6 +- 1.53

###Terbinafine###20###21 +- 2.64

A. oryzae###Griseofulvin###20###22.6 +- 1.15

###Terbinafine###20###20.3 +- 2.52

Metal Chelating Activity

Metal chelating activity was determined by the method described by Dinis et al., [17]. The reaction mixture was prepared by mixing 100 uL of sample with 0.05 ml of FeSO4 and 0.2 mL of 5 mM ferrozine and raised its volume to 4 mL with double distilled ethanol. Allow this reaction mixture to stand for 10 min at room temperature. Then noted the absorbance of the solution at 562 nm. The results were expressed as the % age of bound iron which can be calculated from the formula shown below or in terms of EDTA standard.

% age bound iron= [(Acontrol - Asample)/Acontrol]

DPPH Radical Scavenging Activity

The DPPH radical scavenging activity of the plant extracts was examined by comparison with known antioxidant, i.e. butylated hydroxytoluene (BHT) following the method of Lee et al. [18]. Plant extract mixed with 3 mL of 0.01 mM methanolic solution of DPPH. The mixture was shaken vigorously and allowed to stand at room temperature for 1 h. Absorbance was measured at 517 nm in the spectrophotometer. The percent of DPPH decoloration of the sample was calculated according to following formula:

% scavenging activity = Acontrol - Asample/Acontrol x 100

Results and Discussion

Phytochemical tests of C. spinosum were carried out for qualitative analysis of compounds. Petroleum ether and distilled water extracts of leaves indicated the presence of all phyto-constituents except tannins. The petroleum ether and distilled water extracts of bark revealed the presence of all eight phyto-constituents (reducing sugar, terpenoids, flavonoids, anthraquinones, alkaloids, tanins, saponins, and cardiac glycosides). The chloroform extract of bark was proved to contain all phyto-constituents except flavonoids, whereas the methanol extract of bark contain reducing sugar, terpenoids, anthraquinones, tanins, and saponins (Table-1).

Table 1: Phytochemical tests of bark and leaves extracts of C. spinosum L.

Plant Parts###Solvents###Phytochemical constituents

###Reducing sugars###Terpenoids###Flavonoids###Anthraquinones###Alkaloids###Tannins###Saponins###Cardiac glycosides

###Petroleum###+###+###+###+###+###+###+###+

###ether

Bark###Chloroform###+###+###-###+###+###+###+###+

###Methanol###+###+###+###-###-###+###+###+

###Distilled water###+###+###+###+###+###+###+###+

###Petroleum###+###+###+###+###+###+###+###+

###ether

Leaves###Chloroform###+###+###+###+###-###_###+###-

###Methanol###+###+###-###+###-###+###+###-

###Distilled water###+###+###+###+###+###+###+###+

Table-3: Zone of inhibition produced by bark and leave extracts of C. spinosum against bacterial strains.

###Plant Parts###Solvents###Zone of inhibition (mm)

###E. coli###P. aeruginosa###B. subtilis###S. aureus

###Bark###Petroleum ether###19.16 +- 0.76###16.16 +- 1.04###14.16 +- 0.28###34.16 +- 1.04

###Chloroform###38 +- 1.0###16.5 +- 0.5###14.5 +- 0.5###11.5 +- 0.5

###Methanol###29.5 +- 0.5###27.16 +- 1.04###30 +- 1.0###44.5 +- 0.5

###Distilled water###29 +- 1.0###29.5 +- 0.5###27.16 +- 1.04###29.16 +- 0.76

###Leaves###Petroleum ether###29 +- 1.0###11.5 +- 0.5###11.5 +- 0.5###11.5 +- 0.5

###Chloroform###37.16 +- 0.76###11.16 +- 1.25###11.16 +- 0.28###10.5 +- 0.5

###Methanol###27 +- 1.0###24.16 +- 0.76###28.5 +- 0.5###29.8 +- 0.76

###Distilled water###35.83 +- 0.76###34.16 +- 1.04###39.16 +- 0.76###31.5 +- 0.5

###LSD###1.498###1.519###1.158###1.144

Antibacterial and antifungal potential of plant extracts were carried out by using four bacterial strain (E. coli, P. aeruginosa, B. subtilis, and S. aureus) and two fungal strain (A. niger and A. oryzae). The standard discs were used for comparison between antimicrobial potential of extracts and commercially available antibiotics (Table-2). The maximum zone of inhibition (44.5 +- 0.5 mm) showed by methanol bark extract against S. aureus, while the minimum activity (10.5 +- 0.5 mm) was exhibited by the chloroform leaves extract of C. spinosum against Staphylococcus aureus. Leaves extract of C. spinosum exhibited antibacterial activity between 39.16 +- 0.76 mm to 10.5 +- 0.5 mm. The distilled water extract of leaf expressed maximum antibacterial activity (39.16 +- 0.76 mm) against B. subtilis (Table-3).

The antimycotic potential of C. spinosum L. was evaluated against A. niger and A. oryzae (Table-4). The distilled water extract of leaves displayed maximum activity (41.83 +- 0.76 mm) against A. niger while petroleum ether extract of bark showed minimum activity (11.16 +- 0.28 mm) against A. oryzae. The maximum zone of inhibition of distilled water extract of leaves (41.83 +- 0.76 mm) against A. niger while minimum activity of chloroform extract of leaves of 14 +- 0.5 mm against A. niger.

MIC (minimum inhibitory concentration) of methanolic extracts of bark and leaves extracts of C. spinosum L. was performed. The extracts of C. spinosum L. exhibited variations in their activity against bacterial and fungal strains (Fig. 1 and 2). The methanol extract of bark showed minimum concentration (1.25 mg/mL) against P. aeruginosa, while methanol extract of leaves showed minimum concentration. (0.625 mg/mL) against P. aeruginosa.

Methanol extract of leaves showed minimum concentration (0.3125 mg/mL) against B. subtilis while methanol extract of bark showed minimum concentration. (1.25 mg/mL) against B. subtilis.

Table-4: Inhibition zones exhibited by bark and leaves extracts of C. spinosum against fungal strains.

Plant Part

###Solvents###Zone of Inhibition

###A. niger###A. oryzae

###Petroleum ether###15.8 +- 0.72###11.16 +- 0.28

###Bark

###Chloroform###11.33 +- 0.28###20+-0.5

###Methanol###31.83 +- 0.76###24+-0.5

###Distilled Water###33.83 +- 0.76###30+-1.0

###Petroleum ether###20.16 +- 0.76###25+-0.5

###Leaves

###Chloroform###14 +- 0.5###29+-0.5

###Methanol###26.66 +-1.52###29+-0.5

###Distilled Water###41.83 +- 0.76###40+-0.5

###LSD###1.437###0.983

The comparison between the activities of antifungal drugs (griseofulvin) showed that the leaves and bark extracts of C. spinosum L may serve as an effective antifungal source. Antibacterial standard drugs amikacin, cephalaxin, and erythromycin showed zone of inhibition below 20 mm, whereas the activity of all of the plants extracts (except methanol leaves against B. subtilis) was quite higher than standard drugs.

Antioxidant potential of different parts of Citharexylum spinosum L was performed by using five different methods including total phenolic content, total flavonoid content, ABTS assay, metal chelating, and DPPH activity.

Bark and leaves extracts of C. spinosum were subjected to total phenolic content (Table-5) to assess their possible antioxidant potentials. The results demonstrated that petroleum ether bark extract showed maximum TPC value (60.24 +- 0.03 ug/mL) and distilled water extract of leaves showed minimum TPC value (18.46 +- 0.03ug/mL).

Table-5: Total Phenolic Content (TPC) of C. spinosum.

###Plant Part###Solvents###GAE (ug/ml)

###Bark###Petroleum ether###60.24 +- 0.035

###Chloroform###25.77 +- 0.02

###Methanol###28.55 +- 0.035

###Distilled water###27.15 +- 0.04

###Leaves###Petroleum ether###26.35 +- 0.02

###Chloroform###30.05 +- 0.03

###Methanol###29.05 +- 0.03

###Distilled water###18.46 +- 0.03

###LSD###0.055

Bark and leaves extracts of C. spinosum were subjected for determining total flavonoid content to assess their possible antioxidant potentials (Table-6). The results showed that petroleum ether bark extract exhibited maximum TFC value (1350.07 +- 0.01 ug/mL) and distilled water leaves extract showed minimum TFC value (62 391.1 +- 0.01 ug/mL).

Table-6: Total Flavonoid Content (TFC) of C. spinosum.

Plant Parts###Solvents###Quercetein (mg/l)

###Bark###Petroleum ether###1350.07 +- 0.01

###Chloroform###894.19 +- 0.01

###Methanol###856.62 +- 0.02

###Distilled water###458.35 +- 0.015

###Leaves###Petroleum ether###860.06 +- 0.025

###Chloroform###462.46 +- 0.015

###Methanol###1109.37 +- 0.01

###Distilled water###391.1 +- 0.01

###LSD###0.026

Bark and leaves extracts of Citharexylum spinosum were subjected to total flavonoid content to assess their possible antioxidant potentials (Table-7). The results showed that distilled water bark and leaves extract showed maximum TEAC value. 7.92 +- 0.06 mm and chloroform leaves extract exhibited minimum TEAC value (2.53 +- 0.05 mm).

Table-7: ABTS Assay of C. spinosum.

###Plant Part###Solvent###TEAC Value (mm)

###Petroleum ether###7.50 +- 0.05

###Bark

###Chloroform###3.27 +- 0.05

###Methanol###4.92 +- 0.04

###istilled water###7.92 +- 0.06

###Petroleum ether###4.33 +- 0.04

###Chloroform###2.53 +- 0.05

###Leaves

###Methanol###6.76 +- 0.05

###Distilled water###7.92 +- 0.05

###LSD###0.090

Bark and leaves extracts of C. spinosum were subjected to metal chelating activity to determine their possible antioxidant potentials (Table-8). The results showed that distilled water bark extract showed maximum % inhibition of ferrozine-ferrous complex formation value (64.2 +- 0.05% ) and petroleum ether bark extract exhibited minimum % inhibition value (1.38 +- 0.04%).

Table-8: Metal Chelating Activity of C. spinosum.

Plant Part###Solvents###% Inhibition

###Petroleum ether###1.38 +- 0.04

###Chloroform###3.09 +- 0.06

Bark

###Methanol###30.82 +- 0.06

###Distilled water###64.2 +- 0.05

###Petroleum ether###10.30 +- 0.025

###Chloroform###1.46 +- 0.05

Leaves

###Methanol###12.58 +- 0.065

###Distilled water###40.78 +- 0.04

LSD###0.091

Bark and leaves extracts of C. spinosum were subjected to DPPH free radical scavenging activity to assess their possible antioxidant potential (Table-9). The IC50 values were calculated and compared with standard antioxidant (butylated hydroxytoluene). Lower absorbance had indicated higher free radical scavenging activity.

Table-9: DPPH activity of C. spinosum.

Plant Part###Solvents###% DPPH remaining

Bark###Petroleum ether###66.13 +- 0.35

###Chloroform###69.96 +- 0.33

###Methanol###32.72 +- 0.56

###Distilled water###88.92 +- 0.08

Leaves###Petroleum ether###61.75 +- 0.09

###Chloroform###82.59 +- 0.66

###Methanol###75.70 +- 0.72

###Distilled water###69.92 +- 0.32

Conclusion

Phytochemical screening of bark and leaves extracts of C. spinosum L was concluded that almost all the extracts contained most of the phytochemicals. The antibacterial activity was considerably more remarkable than antifungal activity. The petroleum ether extracts of bark and leaves were concluded to be most effective against all four bacterial strains. S. aureus was most susceptible against all the crude extracts of the plant material C. spinosum L. The crude extracts showed high antimicrobial potential than the standard drugs. In case of antifungal activity, the methanol extract of bark was most promising against A. niger. The antifungal activity of crude extracts of plant against A. oryzae was satisfactory. The antioxidant assays also showed remarkable results. The leaves and bark extracts of C. spinosum can be concluded as important source of antimicrobial as well as antioxidant agents.

References

1. A. Mushtaq, Q. Rahmatullah, A. Muhammad, A. K. Mir, and Z. Muhammad, Traditional Herbal Remedies used for the Treatment of Diabetes from District Attock (Pakistan), Pak. J. Bot., 41, 2777 (2009).

2. H. M Adamu, O. J. Abayeh, M. O. Agho, A. L. Abdullahi, A. Uba, H. U. Dukku, and B. M. Wufem, An Ethnobotanical Survey of Bauchi State Herbal Plants and Their Antimicrobial Activity, J. Ethnopharmacol., 99, 1 (2005).

3. M. Pandey, A. B. Abidi, S. Singh, and R. P. Singh, Nutritional Evaluation of Leafy Vegetable Paratha, J. Hum. Ecol., 19, 155 (2006).

4. I. Hussain, F. A. Khan, H. Khan, Shafiq ur Rehman, and Badrullah, Antimicrobial, Phytochemical and Fluorescence Studies on Tribulus teresstris, J. Pharm. Res., 4, 1556 (2011).

5. R. Rojas, B. Bustamante, J. Bauer, I. Ferrandez, J. Alban, and O. Lock, Antimicrobial Activity of Selected Peruvian Medicinal Plants, J. Ethnopharmacol, 88, 199 (2003).

6. M. Ajaib, F. Boota, K. M. Khan, S. Perveen, and S. Shah, Clerodendrum splendens: A Potential Source of Antimicrobials, J. Chem. Soc. Pak., 36, 763 (2014a).

7. M. Ajaib. S. Q. Wahla, K. M. Khan, S. Perveen, and S. Shah, Firmiana Simplex: A Potential Source of Antimicrobials, J. Chem. Soc. Pak., 36, 744 (2014b).

8. A. Wei, and T. Shibamoto, "Antioxidant Activities and Volatile Constituents of Various Essential Oils," J. Agric. Food Chem. 55, 1737 (2007).

9. A. Mar and P. Pripdeevech, "Chemical Composition and Antibacterial Activity of Essential Oil and Extracts of Citharexylum spinosum Flowers from Thailand," Nat. Prod. Commun. 9, 707 (2014).

10. G. A. Ayoola, H. A. B. Coker, S. A. Adesegun, A. A. Adepoju-Bello, K. Obaweya, E. C. Ezennia, and T. O. Atangbayila, Phytochemical Screening and Antioxidant Activities of Some Selected Medicinal Plants Used For Malaria Therapy in Southwestern Nigeria, Trop. J. Pharm. Res., 7, 1019 (2008).

11. R. Cruick-Shank, J. P. Dugid, B. P. Marininon and R. H. Swain, Screening of Some Greek Aromatic Plants for Antioxidant Activity, Phytother. Res., 17, 194 (1975).

12. J. H. Jorgensen and J. D. Turnidge, Susceptibility test methods: Dilution and Disk Diffusion mrthods. In: Murray, P. R., E. J. Baron, J. H. Jorgensen, M. L. Landry and M.A. Pfaller (Eds.), J. Clin. Microbiol.. 9th ed. ASM Press, Washington p. 1152 (2007).

13. M. Joshua and M. Takudzwa, Antibacterial Properties of Mangifera Indica on Staphylococcus aureus, Afr. J. Clin. Experimental Microbiol., 14, 62 (2013).

14. H. P. S. Makkar, M. Blummel, N. K. Borowy and K. Becker, Gravimetric Determination of Tannins and Their Correlation with Chemical and Protein Precipitation Methods, J. Sci. Food and Agric., 61, 161 (1993).

15. V. Dewanto, X Wu, K. K. Adom, R. H. Liu, Thermal Processing Enhances the Nutritional Value of Tomatoes by Increasing Total Antioxidant Activity, J. Agric. Food Chem., 50, 3010 (2002).

16. R. Re, N. Pellegrini, A. Proteggente, A. Pannala, M. Yang, C. Rice-Evans, Antioxidant Activity Applying an Improved ABTS Radical Cation Decolorization Assay, Free Radic Biol Med., 26, 1231 (1999).

17. T. C. P. Dinis, V. M. C. Madeira, and M. L. M. Almeida., Action of Phenolic Derivatives (Acetaminophen, Salycilate and 5-Aminosalucilate) as Inhibitors of Membrane Lipid Peroxidation and as Peroxyl Radical Scavengers, Arch. Biochem. Biophys., 315, 161 (1994).

18. S. K. Lee, H. M. Zakaria, H. S. Cheng, L. Luyengi, E. J. C. Gamez, R. Mehta, A. D. Kinghorn, and M. J. Pezzuto, Evaluation of the Antioxidant Potential Of Natural Products, Combinat. Chem. High Through put Screen., 1, 35 (1998).
COPYRIGHT 2017 Asianet-Pakistan
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2017 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Publication:Journal of the Chemical Society of Pakistan
Article Type:Report
Date:Apr 30, 2017
Words:4504
Previous Article:Gamma Irradiation Effect on Mixed Dye Film; its Possible Use as a Radiation Dosimeter.
Next Article:Design and Anticancer Evaluation of Novel Norcantharidin Derivatives with 3D-QSAR studies.
Topics:

Terms of use | Privacy policy | Copyright © 2019 Farlex, Inc. | Feedback | For webmasters