Some Analytical Characteristics of Moringa Oleifera Leaves and Seeds Affected by Gamma Irradiation ( 575 )

ABSTRACT

KEYWORDS

Some Analytical Characteristics of Moringa Oleifera Leaves and Seeds Affected by Gamma Irradiation Aly, A.A.*1, Maraei, R.A.1* and Ali, H.G.M.2

Received: 09/09/2014

Accepted: 20/11/2014

Available on line: 01/12/2014

E.mail:alrahman_27israa@yahoo.com

Flavonoids, HPLC, Moringa Oleifera, Phenolics and Scavenging Activity.

J. Nucl. Tech. Appl. Sci, Vol. 2, No. 5, PP. 575 : 587 (2014)

Journal of

NUCLEARTechnology in Applied ScienceISSN 2314-8209 e-ISSN 2314-8217

1. Atomic Energy Authority, National Centre for Radiation Research and Technology, Natural Products Dept., Nasr City, P.O Box 29, Nasr City, Cairo– Egypt.

2. Atomic Energy Authority, Nuclear Research Center, Inshase, Egypt.* Corresponding author

Moringa oleifera is an important multipurpose tropical tree under-recognized for its nutritional and medicinal properties. Antioxidants play an important role in inhibiting and scavenging free radicals, thus provid-ing protection to human against infections and degenerative diseases. Leaves and seeds of M. oleifera were subjected to different gamma rays dose levels (0, 5, 10 and 15 kGy) and the content of phenolics, flavo-noids, antioxidants activity and the profile of phenolics and flavonoids by HPLC were evaluated. The obtained data indicated that the pheno-lics and flavonoids content increased gradually by increasing irradiation doses in the seeds and leaves extract. Scavenging activity was increased gradually by increasing irradiation dose levels. Regarding to HPLC analysis of phenolic and flavonoid compounds it was shown that irra-diation stimulated the biosynthesis of some phenolic compounds such as, chlorogonic, caffeic, salycilic, ellagic and p-OH-benzoic, as well as rosmarinic, naringin and hyperoside for flavonoids. This study showed that gamma irradiation is an effective tool for enhancing the phenolic compounds and antioxidant activity of M. oleifera.

INTRODUCTION

Recently, more attention has been given in medicinal plants of therapeutic potentials as antioxidants in reducing free radical induced tissue injury. The synthetic antioxidants have restriction for use, as they are suspected to be car-cinogenic.

Aly, A.A et al.( 576 ) J. Nucl. Tech. Appl. Sci., Vol. 2, No. 5

Therefore, the importance of searching for and exploiting natural antioxidants has increased greatly in present years. Many studies have indicated that phenolic compounds play a crucial role in oxidative scavenging (Mateos et al., 2005). Living cells may generate free radicals and other reactive oxygen spe-cies by-products as a results of physiological and biochemical processes.

Free radicals can cause oxidative damage to lip-ids, proteins and DNA, eventually leading to many chronic diseases, such as cancer, diabetes, aging, and other degenerative diseases in human beings (Har-man, 1998). Plants are endowed with free radical scavenging molecules, such as vitamins, terpenoids, phenolic acids, lignins, stilbenes, tannins, flavo-noids, quinones, coumarins, alkaloids, amines, beta-lains, and other metabolites, which have antioxidant activity (Zheng and Wang, 2001).

Studies have shown that many of these antioxi-dant compounds possess anti-inflammatory, antiath-erosclerotic, antitumor, antimutagenic, anticarcino-genic, antibacterial and antiviral activities (Sala et al., 2002; Charoensin and Wongpoomchai, 2010; Berkovich et al., 2013).

The ingestion of natural antioxidants has been associated with reduced risks of cancer, cardiovas-cular disease, diabetes, and other diseases associated with ageing (Veerapur et al., 2009). The antioxida-tive effect is mainly due to phenolic compounds such as phenolic acids, phenolic diterpens, anthocyanins, cumarins and flavonoids (Cai et al., 2004).

Phenolics are antioxidants with redox properties, which allow them to act as reducing agents, hydro-gen donators, and singlet oxygen quenchers (Pietta, 2000).

They have also metal chelation properties (Rice-Evans et al., 1997). Flavonoids, the most common group of polyphenolic compounds that are found ubiquitously in plants. These are widely distrib-uted in plant fulfilling many functions. Flavonoids and other plant phenolics are especially common in leaves, flowering tissues and woody parts such as

stems and barks. Also, are important in plant for nor-mal growth development and defense against infec-tion and injury (Kähkönen et al., 1999).

Moringaceae is a single-genus family with 14 known species and Moringa oleifera Lam. is the most widely known and utilized species. It is a small or medium-sized tree, about 10 m high, cultivated throughout the world. However, M. oleifera is indig-enous to many countries in Africa, Southeast Asia, the Pacific and Caribbean islands, and South Ameri-ca (Morton, 1991).

This rapidly-growing tree was utilized by the ancient Egyptians, Romans and Greeks, it is now ex-tensively cultivated and has become naturalized in numerous locations in the tropics (Fuglie, 2001). Its seeds have shown analgesic (Sutar et al., 2008) and antipyretic activities. Also, its leaves have shown wound healing (Hukkeri et al., 2006), analgesic (Rao and Ojha, 2003), and hepatoprotective (Sel-vakumar and Natarajan, 2008).

Gamma irradiation is considered as effective method of food processing to reduce microbial load and to extend the shelf life of product without any detrimental effect on food quality. Gamma irradia-tion (10 kGy) has also increased phenolic acid con-tent in cinnamon and clove while phenolic content in nutmeg remained unaltered (Variyar et al., 1998).

There are several reports on effect of irradiation processing on total phenolic content and antioxidant activity from several plant and food products. Al-though, some studies reported that, gamma irradia-tion does maintain or enhance the antioxidant prop-erties; there are a few examples wherein the antioxi-dant properties of the plant material were decreased (Alothman et al., 2009).

Therefore, in the present study, total phenolics and flavonoids of the unirradiated and irradiated leaves and seeds extract of Moringa oleifera were evaluated. In addition, the antioxidant activity were determined as well as the identification of the pheno-lic and flavonoid profiles as the main active antioxi-dant was carried out.

Some Analytical Characteristics of Moringa Oleifera Leaves and Seeds Affected by Gamma Irradiation ( 577 )

MATERIALS AND METHODS

Plant materials

Leaves and seeds of moringa plant (Moringa oleifera) were obtained from the Orman Botanical Garden, Ministry of Agriculture, Giza, Egypt. After the removal of seeds coat, the leaves and seeds were air dried and crushed into a coarse powder using a laboratory blender. The analysis of this investigation samples were carried out in the Natural Products Dept. National Center for Radiation Research and Technology, Atomic Energy Authority, Nasr City, Cairo-Egypt.

Irradiation treatments

Dry leaves and seeds powder of M. oleifera were exposed to gamma irradiation with four doses (0.0, 5, 10 and 15 kGy) in a 60Co gamma radiation chamber (10400 CI [26/3/1988] 60Co with a dose rate of : 2.25 Gy/min) at the National Center of Radiation Research and Technology, Atomic Energy Authority, Nasr City, Cairo-Egypt.

Plant extraction

One gram of dry samples was macerated in 10-20 ml 80% ethanol for 24 hours at 0˚C. The alcohol was clarified and the remained tissue re-extracted with 10-20 ml 80% ethanol for three times. At the end, clarified extract was completed to 100 ml using 80% ethanol. This extraction used for determing the phenolics and flavonoids content, antioxidant activi-ties using DPPH radical, reducing power assay and lipid peroxidation. As well as HPLC analysis for the phenolics and flavonoids profile.

Total phenolic content

The phenolic contents were determined accord-ing to the method of Shahidi and Naczk (1995) using the Folin–Denis reagent. Phenolics content of the samples were calculated on the basis of the standard curve of gallic acid (GA). The results were expressed as mg/g of GA equivalent of dry weight of the samples.

Total flavonoids content

Total flavonoids content were determined in the leaves and seeds by the aluminum chloride colori-metric assay as described by Marinova et al. (2005). The absorbance was measured against the blank at 510 nm. Total flavonoids were expressed as mg quercetin equivalent /g dry weight.

Determination of antioxidant activities

1. DPPH radical

The radical scavenging activities of the sample extracts against 2,2- Diphenyl-1-picryl hydrazyl (DPPH) radical was determined as described by Gulluce et al. (2004) at 517 nm. L- Ascorbic acid was used as the positive control. The radical scav-enging activity was calculated using the following formula:

A control - A sample% Scavenging activity = x 100 A control

Where: A control is the absorbance of the DPPH solution.

Asample is the absorbance of the solution when the sample extract was added.

2. Inhibition of lipid peroxidation

Inhibition of lipid peroxidation was determined according to Yoden et al. (1980). The absorbance of the sample was read at 532 nm against the blank. The inhibition of lipid peroxidation was calculated from the following equation: A control - A sample

% Inhibition of lipid peroxidation = x 100 A control

Where: A control is the absorbance of the solution without sample extract.

Asample is the absorbance of the solution when the sample extract was added.

3. Reducing power assay

Reducing power was determined according to

Aly, A.A et al.( 578 ) J. Nucl. Tech. Appl. Sci., Vol. 2, No. 5

the method of (Oyaizu, 1986). The absorbance of the sample was read at 700 nm against the blank. A higher absorbance indicates a higher reducing pow-er. L- Ascorbic acid was used as positive control.

Identification of phenolic and flavonoid compounds by HPLC

The identification of the phenolic and flavonoid compounds from treated and untreated leaves and seeds extract were performed by HPLC according to Christine et al. (1999) in Food Technology Institute, Agricultural Research Center, Giza-Egypt. HPLC was equipped with a Hewlett- Packard 1050 pho-todiode array detector (Agilent Technologies, Palo Alto, Calif., U.S.A) with Hewlett- Packard HPLC ChemStation software and autosampler, using a PDS-column C18, 5 micron (150 mm x 4.6 mm, op-erated at 45ºC. The solvent system used was gradient of A (acetic 2.5%), B (acetic 8%) and C (acetoni-trile). The solvent flow rate was 1.0 ml/min and the ingection volume was 50 µl. Phenolic compounds were calculated by external standard calibration at 280 nm. The external standard substances were gal-lic, protocatechoic, catechein, catechol, chlorogonic, caffeic, vanillic, caffeine, salycilic, ellagic, couma-rin, cinnamic, ferullic and p-OH-benzoic. Also, the external standard substances for flavonoid com-pounds were naringin, rosmarinic, rutin, quercitrin, hyperoside, naringenin, luteolin, quercetin, hespere-tin, kaempferol and apigenin. Phenolic and flavonoid compounds were expressed as (mg/100g DW).

Statistical analysis

Data were subjected to statistical analysis using the analysis of variance method and the means of treatments were compared by using the least signifi-cant difference (L.S.D) at 0.05 level of probability according to Duncan (1955) Multiple Range test.

RESULTS AND DISCUSSION

Phenolic content

Phenolic compounds are known to act as antiox-

idants not only because of their ability to donate hy-drogen atoms or electrons but also because of their stable radical intermediates, which prevent the oxi-dation of various food ingredients, particularly fatty acids and oils (Nakatani, 2000). Data presented in Fig. (1) indicated that the phenolic content increased gradually by increasing irradiation doses in all ex-tracts until the high dose level 15 kGy which gave the highest phenolics content (1.538 mg/g DW) in seeds when compared with the control (1.365 mg/g DW). While, the amount of phenolics content at the dose level 10 kGy in the leaves extract was (19.40 mg/g DW), in comparison with control (13.93 mg/g DW). These results are in agreement with those of Zhu et al. (2010) who found that γ-irradiation up to 30 kGy increased the phenolic compounds in rice grain and a significant increase in total phenolic compounds of velevet beans seeds (Bhat et al., 2007). Moreover irradiation of almond skins with dose levels of 4.0, 8.0, or 12.0 kGy increased total phenolics (Harri-son and Were, 2007). This increase in total phenolic content is related to phenylalanine ammonia-lyase activity (PAL) (EL-Samahy et al., 2000), Phenyl-alanine ammonia-lyase (PAL) is the key enzyme for the metabolism of phenolics. It catalyzes the deamination of L-phenylalanine to yield ammonia and trans-cinnamic acid from which phenolic com-pounds are produced. Increasing the total phenolic in irradiated tamarind juice has also been reported by Lee et al. (2009). Such increase in total pheno-lic is due to the release of phenolic compounds from glycosidic components and the degradation of larger phenolic compounds into smaller ones by gamma ir-radiation as suggested by Harrison and Were (2007). Also, this increase in total phenolic content may be associated with changes in the molecular conforma-tion as a result of irradiation treatment (Kumari et al., 2009). The differences in the effect of irradiation on total phenolic content (increase or decrease) may be due to plant type, geographical and environmental conditions, state of the sample (solid or dry), pheno-lic content composition, extraction solvent, extrac-tion procedures, temperature, dose of gamma irra-diation, etc. (Khattak et al., 2008).

Some Analytical Characteristics of Moringa Oleifera Leaves and Seeds Affected by Gamma Irradiation ( 579 )

Flavonoids content

Flavonoids as one of the most diverse and wide-spread group of natural compounds are probably the most important natural phenolic. These compounds possess a broad spectrum of chemical and biological activities including radical scavenging properties. The data graphically illustrated in Fig. (2) showed that, flavonoids content in leaves and seeds ex-tract (mg/g DW) in response to gamma irradiation treatment, the used different irradiation dose levels caused significant increase in flavonoids content.

The high contents of flavonoids (3.223 mg/g DW) were detected under the influence of irrradiation dose level 15 kGy in the seeds extract, while in the leaves extract the highest content of flavonoids was (19.40 mg/g DW) which given by the dose level of 10 kGy. Generally, it could be concluded that, gam-ma rays increased gradually the flavonoids content, whereas, the flavonoids content in the unirradiated treatment were 2.580 mg/g DW in seeds extract and 17.40 mg/g DW in leaves extract. These results are in concomitant with those reported by Antognoni et al. (2007) on passiflora, an increase in total flavo-noid content by gamma irradiation was also reported by (Hussein et al., 2011). Flavonoid biosynthesis, which is a significant step in the phenylpropanoid pathway, is the conversion of phenylalanine to cin-namic acid in the presence of PAL as catalyst. The activity of PAL affects the flavonoid synthesis in response to irradiation (gamma and UV-B stress) whereas the flavonoids alleviate the damage induced by the irradiation stress. For instance, the flavonoid content of soybean seedlings increases in response to UV-B radiation (Peng and Zhou, 2008). Also, ir-radiation of Arabidopsis caused increases in the fla-vonoids levels, which accumulated in the aerial parts of the plants (Lois, 1994). The phenolic compounds act as free radical terminators (Kessler et al., 2003) and mechanism of action of flavonoid are through scavenging or chelating process (Bajpai et al., 2005). Consumption of M. oleifera leaves and seeds as vegetable are likely to be benefit by scavenging and reducing free radicals in the body.

Fig (1): Phenolics content (mg/g DW) of Moringa ole-ifera (leaves and seeds) from unirradiated and irradiated samples.Results are expressed as means ± standard errors (SE). Bars with different letters are significantly different at (p < 0.05).

Aly, A.A et al.( 580 ) J. Nucl. Tech. Appl. Sci., Vol. 2, No. 5

Antioxidant activities

Scavenging activity on DPPH radical

DPPH is a relatively stable free radical. The as-say is based on the measurement of the scavenging ability of antioxidants towards the stable radical DPPH. This method allows estimation of hydrogen radical donating ability of the extract. Data present-ed in Fig. (3) showed scavenging activity on DPPH radical in leaves and seeds extract. The obtained re-sults indicated that the scavenging activity increased gradually by increasing irradiation dose level and reached to the maximum increase in the highest dose level 15 kGy which gave the highest scavenging ac-tivity (15.04%) in seeds and 10 kGy in leaves extract (86.07%). These results are in agreement with those of Vicente et al. (2005) on peppers, Khattak and Simpson (2010) on Glycyrrhiza glabra and Jo et al. (2003) who reported that doses between 10 and 20 kGy applied to ethanol extracts of green tea leaves gave rise to a significant increase in DPPH radical-scavenging ability. The destructive processes of oxi-dation and γ-irradiation are capable of breaking the chemical bonds of polyphenols, thereby releasing soluble phenols of low molecular weights, leading to an increase of antioxidant-rich phenolics (Adamo et al., 2004).

Positive correlation between phenolics and flavonoids content and antioxidant activity (by DPPH radical) in leaves extract

Data presented in Fig. (4 and 5) showed positive correlation between phenolics, flavonoids content and antioxidant activity respectively, in leaves ex-tract. The results indicated that the antioxidant activ-ity increased gradually by increasing phenolics and flavonoids content. Regarding the relation between scavenging activities of extract and total phenolic, flavonoid contents, it could be noticed that scaveng-ing activity increased with increasing total phenolic and flavonoid contents. Such observed data revealed

Fig (2): Flavonoids content (mg/g DW) of Moringa ole-ifera (leaves and seeds) from unirradiated and irradiated samples. Results are expressed as means ± standard errors (SE). Bars with different letters are significantly different at (p < 0.05).

Fig (3): Percentage of scavenging activity by DPPH radi-cal of Moringa oleifera (leaves and seeds) from unirradi-ated and irradiated samples.Results are expressed as means ± standard errors (SE). Bars with different letters are significantly different at (p < 0.05).

Some Analytical Characteristics of Moringa Oleifera Leaves and Seeds Affected by Gamma Irradiation ( 581 )

a correlation between total phenolics, flavonoids content and the scavenging activity of extract. A positive correlation between phenolics and antioxi-dants has also been suggested (Huang et al., 2005; Harrison and Were, 2007). The antioxidant activity of phenolics is mainly due to their redox properties, which allow them to act as reducing agents, hydro-gen donors, and singlet oxygen quenchers (Rice-Ev-ans et al., 1996). Moreover, Barbosa et al. (2006) found a high correlation between antioxidant activ-ity and flavonoids content showing the importance of flavonoids as antioxidant agents with potential in reducing the risk of chronic diseases.

Inhibition of lipid peroxidation

In general, the recorded data indicated that there was a significant and gradual increase in inhibition of lipid peroxidation with increasing the irradiation

dose level. Concerning of moringa leaves, there were significant increases in inhibition of lipid peroxida-tion percentage for the other extracts from 89.3% to 90.74% with increasing irradiation dose level from 5 to 15 kGy, respectively, in comparison with the control (88.77%). Additionally, there was significant increase in inhibition of lipid peroxidation percent-age from 77.50% to 80.81% with increasing the dose level from 5 to 15 kGy, respectively in comparison with the untreated sample (control) 77.17% of seeds.

This is consistent with Maraei (2012) who re-ported that there was significant and gradual increase in inhibition of lipid peroxidation with increasing the irradiation dose level in lavender plantlets.

Fig (4): The R values (correlation coefficients) between antioxidant activities (by DPPH) and Phenolics content in leaves extract.

Fig (5): The R values (correlation coefficients) between antioxidant activities (byDPPH) and flavonoids content in leaves extract.

Fig (6): Inhibition percentage of lipid peroxidation of Mo-ringa oleifera (leaves and seeds) from unirradiated and ir-radiated samples.Results are expressed as means ± standard errors (SE). Bars with different letters are significantly different at (p < 0.05).

Aly, A.A et al.( 582 ) J. Nucl. Tech. Appl. Sci., Vol. 2, No. 5

Reducing power

Generally, the data indicated that there was a slight increase in reducing power by increas-ing irradiation dose level. The highest applied irradiation dose level 15 kGy gave the highest reducing power (0.148 and 0.553) compared to the control (0.179 and 0.660) in leaves and seeds extract, respectively. These results are in agree-ment with those of Fan and Thayer (2002) on apple juice and Suhaj and Horváthová (2007) on clove (Syzygium aromaticum) and ginger (Zingiber officinale). During irradiation, re-ductants and novel new antioxidants may be formed (Dubery et al., 1999). The redox state of ions and compounds may also be changed by irradiation. For example, the hydrated electrons (e aqueous

-) formed from water radiolysis can re-act strongly with metal ions (such as Fe3+) and reduce them to lower redox states (Fe2+). The measurement of ferric reducing antioxidant power (FRAP) values is based on compounds’ ability to reduce Fe3+ to Fe2+. Therefore, the in-crease in FRAP values may be due to the change in the redox state of metal ions, formation of reductants, and/or formation of new antioxi-dants. The exact compound(s) that contributes to FRAP values remains to be elucidated. The disappearance of elevated FRAP values during storage suggests that the compounds are not stable (Fan and Thayer, 2002).

HPLC analysis for phenolic and flavonoid compounds

The ethanolic extracts of phenolic and flavonoid compounds from leaves and seeds of moringa were identified by comparison of their retention times and UV spectra with those of known standards. Data pre-sented in Tables (1 and 2) show the contents of these phenolic and flavonoid compounds. Among fourteen identified phenolic compounds, gallic, protocatecho-ic, catechein, catechol, chlorogonic, caffeic, vanil-lic, caffeine, salycilic, ellagic, coumarin, cinnamic, ferullic and p-OH-benzoic. Irradiation stimulated the biosynthesis of some phenolic compounds such as, chlorogonic, caffeic, salycilic and ellagic in leaves and p-OH-benzoic in seeds. Meanwhile, protocat-echoic appeared in the irradiated treatments only at 10 and 15 kGy in leaves. On the other hand, gal-lic and chlorogenic were appeared in seeds at dose level 15 kGy. There were some other phenolic com-pounds which increased in irradiated treatments than in unirradiated. The highest content of chlorogonic was detected under the influence of irradiation dose level 5 kGy. Regarding the flavonoid compounds, irradiation stimulated the biosynthesis of some fla-

Fig (7): Reducing power of Moringa oleifera (leaves and seeds) from unirradiated and irradiated samples.Results are expressed as means ± standard errors (SE). Bars with different letters are significantly different at (p < 0.05).

Some Analytical Characteristics of Moringa Oleifera Leaves and Seeds Affected by Gamma Irradiation ( 583 )

vonoid compounds such as, Rosmarinic in leaves extract and naringin and hyperoside in seeds extract. Meanwhile, there were some other flavonoid com-pounds which increased in irradiated treatments than in unirradiated one such as quercitrin and naringenin

in leaves extract. Gamma irradiation may modify some enzymes in moringa leaves and, resulting in enhanced or decreased synthesis of phenolic acids. Thus, it is plausible that gamma irradiation lead to synthesis of phenolic acids.

Table (1) Phenolic compounds profile (mg/100g DW) using HPLC of Moringa oleifera (leaves and seeds) from unirradiated and irradiated samples.

Phenoliccompound

Irradiation treatments (kGy)Leaves Seeds

0 5 10 15 0 5 10 15Gallic 10.11 4.15 7.65 4.91 - - - 0.043

Protocatechoic - - 7.33 6.01 - - - -Catechein 91.66 102.89 89.09 89.66 - - - -Catechol 18.76 - 25.70 21.60 - - - -

Chlorogonic 398.81 461.06 355.73 380.49 - - - 14.49Caffeic 5.51 14.35 15.46 - 1.37 0.173 0.25 -Vanillic 13.38 11.57 8.58 14.03 0.75 0.22 0.61 1.17Caffeine 6.38 6.02 - 5.81 - - 0.234 -Salycilic 100.02 95.06 113.14 104.50 24.62 21.56 7.96 13.99Ellagic 93.20 121.60 148.78 113.83 - - - -

Coumarin 11.68 7.35 9.05 11.96 1.84 1.52 1.39 0.98Cinnamic 21.37 18.96 19.08 20.68 - - - -Ferullic - - - - 3.14 - 0.31 -

P-OH-benzoic - - - - 30.78 - 32.97 -

Table (2) Flavonoid compounds profile (mg/100g DW) using HPLC of Moringa oleifera (leaves and seeds) from unirradiated and irradiated samples.

FlavonoidsIrradiation treatments (kGy)

Leaves Seeds0 5 10 15 0 5 10 15

Naringin - - - - - - 2.33 3.83Rosmarinic 11.82 13.31 12.62 9.88 - 0.346 0.234 0.215

Rutin 28.03 24.13 21.07 15.09 2.21 0.203 0.304 0.376Quercitrin 5.056 - 6.061 5.45 - 0.574 0.180 0.110Hyperoside - - - - - - 0.557 1.58Naringenin 3.43 3.83 3.18 2.32 0.844 0.284 0.126 -

Luteolin - 22.77 18.75 - 1.80 0.693 0.821 1.16Quercetin 3.82 8.003 7.83 2.57 - 0.904 0.654 0.269Hesperetin 24.62 21.35 4.38 2.58 2.21 0.716 0.273 -Kaempferol - - - - 1.60 0.138 0.069 -

Apigenin - - 6.62 1.22 1.29 0.441 0.498 0.581

Aly, A.A et al.( 584 ) J. Nucl. Tech. Appl. Sci., Vol. 2, No. 5

These results are in agreement with those of Silva et al. (2012) on leaves of Echinodorus macro-phyllus. Zhu et al. (2010) found that gamma irradia-tion with dose levels 6 and 8 kGy significantly (p < 0.05) increased phenolic acids in black rice. Thus, it is plausible that gamma irradiation may disrupt the phenolic acids resulting in a reduction of the content, and activate some enzyme inducing the synthesis of the phenolic acids. The balance of the disruption and synthesis may depend on the irradiation dose level. However, further biochemical data are needed to support this hypothesis.

CONCLUSION

From the results obtained in the present study, it is concluded that ethanolic extract of leaves and seeds of Moringa oleifera which contains pheno-lics, flavonoids, exhibits antioxidant and free radi-cal scavenging activities. Also, gamma irradiation increased the antioxidant activity, as well as it have been established that there was a relationship be-tween total phenolic, flavonoid contents and the free radical scavenging activity. These in vitro assays in-dicate that this plant extracts are significant source of natural antioxidant, which might be help in prevent-ing the progress of various oxidative stresses. There-fore, further investigations need to be carried out to isolate and identify the antioxidant compounds pres-ent in the plant extract.

Acknowledgement: This work was supported by the Atomic Energy Authority.

REFERENCES

• Adamo, M.; Capitani, D.; Mannina, L.; Cristinzio, M.; Ragni, P.; Tata, A. and Coppola, R. (2004): Truffles decontamination treatment by ionizing radia-tion. Rad. Physics. Chem., 71: 165.

• Alothman, M.; Bhat, R. and Karim, A.A. (2009): Effects of radiation processing on phytochemicals and antioxidants in plant produce. Trends Food Sci. Technol., 20 (2): 201.

• Antognoni, F.; Zheng, S.; Pagnucco, C.; Baraldi, R.; Poli, F. and Biondi, S. (2007): Induction of fla-

vonoid production by UV-B radiation in Passiflora quadrangularis callus cultures. Fitoterapia, 78: 345.

• Bhat, R.; Sridhar, K. R. and Yokotani, K.T. (2007): Effect of ionizing radiation on antinutritional features of velvet bean seeds (Mucuna pruriens). Food Chem., 103: 860.

• Bajpai, M.; Pande, A.; Tewari, S.K. and Prakash, D. (2005): Phenolic contents and antioxidant activity of some food and medicinal plants. Int. J. Food. Sci. Nut., 56(4): 287.

• Barbosa, A.C.L.; Hassimotto, N.M.A.; Lajolo, F.M. and Genovese, M.I. (2006): Teores de isoflavo-nas capacidade antioxidante da sojae produtos deriva-dos. Cienc. Tecnol. Aliment Campinas, 26(4): 921.

• Berkovich, L.; Earon, G.; Ron. I.; Rimmon, A.; Vexler, A. and Lev-Ari, S. (2013): Moringa oleifera aqueous leaf extract down-regulates nuclear factor- kappaB and increases cytotoxic effect of chemother-apy in pancreatic cancer cells. BMC Compl. Altern. Med., 13:212.

• Cai, Y.; Luo, Q.; Sun, M. and Corke, H. (2004): Antioxidant activity and phenolic compounds of 112 traditional Chinese medicinal plants associated with anticancer. Life. Sci., 74, 2157.

• Charoensin, S. and Wongpoomchai, R. (2010): Mutagenic and antimutagenic actvities of aqueous extract of Moringa oleifera leaves. Thai. J. Toxicol., 25(2):97.

• Christine, E.L.; John, R.L. and Jane, E.L. (1999): Changes in anthocyanin, flavonoid and phenolic acid concentrations during development and storage of colored potato (Solanum tuberosum L) tubers. J. Sci. Food. Agric., 79: 311.

• Dubery, I.A.; Louw, A.E. and Heerden, F.R. (1999): Synthesis and evaluation of 4-(3-methyl-2-butenoxy) isonitrosoacetophenone, a radiation-induced stress metabolite in citrus. Phytochem., 50: 983.

• Duncan, D.B. (1955). Multiple range and multiple ’F’ tests. Biometrics, 11: 1.

• EL-Samahy, S.K.; Youssef, B.M.; Askar, A.A. and Swailam, H.M.M. (2000): Microbiological and chemical properties of irradiated mango. J. Food Saf., 20: 139.

Some Analytical Characteristics of Moringa Oleifera Leaves and Seeds Affected by Gamma Irradiation ( 585 )

• Fan, X. and Thayer, D.W. (2002): γ-radiation influ-ences browning, antioxidant activity, and malondial-dehyde level of apple juice. J. Agric. Food Chem., 50: 710.

• Fuglie, L.J. (2001): The Miracle Tree: Moringa oleif-era: Natural Nutrition for the Tropics. Training Man-ual.Church World Service, Dakar, Senegal.

• Gulluce, M.; Sokmen, M.; Sahin, F.; Sokmen, A.; Adiguzel, A. and Ozer, H. (2004): Biological activi-ties of the essential oil and methanolic extract of Mi-cromeria fruticosa (L) Druce ssp serpy llifolia (Bieb) PH davis plants from the Eastern Anatolia region of Turkey. J. Sci. Food Agric., 84: 735.

• Harman, D. (1998): Aging: phenomena and theories. Ann. NY Acad. Sci., 854: 1.

• Harrison, K. and Were, L.M. (2007): Effect of gamma irradiation on total phenolic content yield and antioxidant capacity of almond skin extracts. Food Chem., 102: 932.

• Huang, D.; Ou, B. and Prior, R.L. (2005): The chemistry behind antioxidant capacity assays. J. Ag-ric. Food Chem., 53: 1841.

• Hukkeri, V.I.; Nagathan, C.V.; Karandi, R.V. and Patil, B.S. (2006): Antipyretic and wound healing activities of Moringa oleifera Lam. in rats. Ind. J. Pharm. Sci., 68(1):124.

• Hussein, S.Z.; Yusoff, K.M.; Markpol, S. and Yu-sof, I.A.M. (2011): Antioxidant capacities and total phenolic contents increase with gamma irradiation in two types of Malaysian honey. Molecules., 16:6378.

• Jo, C.; Son, J.H.; Son, C.B. and Byun, M.W. (2003): Functional properties of raw and cooked pork patties with added irradiated, freeze-dried green tea leaf extract powder during storage at 4ºC. Meat, Sci., 64:13.

• Kähkönen, M.P.; Hopia, A.I.; Vuorela, J.H.; Rau-ha, J.P.; Pihlaja, K.; Kujala, T.S. and Heinonen, M. (1999): Antioxidant activity of plant extracts con-taining phenolic compounds. J. Agric. Food Chem., 47: 3954.

• Kessler, M.; Ubeaud, G. and Jung, L. (2003): Anti and pro-oxidant activity of rutin and quercetin deriva-tives. J. Pharm. Pharmacol., 55: 131.

• Khattak, K.F. and Simpson, T.J. (2010): Effect of gamma irradiation on the antimicrobial and free radi-cal scavenging activities of Glycyrrhiza glabra root. Rad. Physics Chem., 79: 507.

• Khattak, K.F.; Simpson, T.J. and Ihasnullah (2008): Effect of gamma irradiation on the extraction yield, total phenolic content and free radical-scaveng-ing activity of Nigella sativa seed. Food Chem., 110: 967.

• Kumari, N.; Kumar, P.; Mitra, D.; Prasad, B.; Ti-wary, B.N. and Varshney, L. (2009): Effects of ion-izing radiation on microbial decontamination, pheno-lic contents, and anti-oxidant properties of triphala. J. Food Sci., 74 (3): M109.

• Lee, J.W.; Kim, J.K.; Srinivasan, P.; Choi, J.; Kim, J.H.; Han, S.B.; Kim, D. and Byun, M.W. (2009): Effect of gamma irradiation on microbial analysis, antioxidant activity, sugar content and color of ready-to-use tamarind juice during storage. LWT-Food Sci. Technol., 42: 101.

• Lois, R. (1994): Accumulation of UV-absorbing fla-vonoids induced by UV-B radiation in Ambidopsis thaliana L. Planta, 194: 498.

• Maraei, R.W. (2012): Influence of gamma radiation on biologically active compounds in lavender (La-vandula multifida) plant using tissue culture. Ph.D. thesis, Faculty of Agriculture, Ain Shams University.

• Marinova, D.; Ribarova, F. and Atanassova, M. (2005): Total phenolic and total flavonoids in Bul-garian fruits and vegetables. J. Uni. Chem. Technol. Metal, 40(3): 255.

• Mateos, R.; Goya, L. and Bravo, L. (2005): Metab-olism of the olive oil phenols hydroxytyrosol, tyro-sol, and hydroxytyrosyl acetate by human hepatoma hepG2 cells. J. Agric. Food Chem., 53: 9897.

• Morton, J.F. (1991): The horseradish tree, Moringa pterigosperma (Moringaceae)-A boon to arid lands? Econ. Bot., 45:318.

• Nakatani, N. (2000): Phenolic antioxidants from herbs and spices. Biofac., 13: 141.

• Oyaizu, M. (1986): Studies on products of brown-ing reactions: Antioxidative activities of products of browning reaction prepared from glucosamine. Jap.

Aly, A.A et al.( 586 ) J. Nucl. Tech. Appl. Sci., Vol. 2, No. 5

J. Nut., 44: 307.

• Peng, Q. and Zhou, Q. (2008): Effect of lanthanum on the flavonoids in the soybean seeding under ultra-violet-B stress: II effect on content of flavonoids. J. Agro-Environ. Sci., 27: 462.

• Pietta, P.G. (2000): Flavonoids as antioxidants. J. Nat. Prod., 63: 1035.

• Rao, C.V. and Ojha, S.K. (2003): Analgeslc effect of Moringa oleifera Lam leaf extract on rats. Second World Congress on Biotechnological Developments of Herbal Medicine. Lucknow. India 10 NBRI. P 42. MAPA - 02-911.

• Rice-Evans, C.A.; Miller, N.J. and Paganga, G. (1997): Antioxidant properties of phenolic com-pounds. Trends Plant Sci., 2: 152.

• Rice-Evans, C.A.; Miller, N.J. and Paganga, G. (1996): Structure-antioxidant activity relationships of flavonoids and phenolic acids. Free Radic. Biol. Med., 20(7): 933.

• Sala, A.; Recio, M.D.; Giner, R.M.; Manez, S.; Tournier, H.; Schinella, G. and Rios, J.L. (2002): Antiinflammatory and antioxidant properties of He-lichrysum italicum. J. Pharm. Pharmacol., 54(3): 365.

• Selvakumar, D. and Natarajan, P. (2008): Hepato-protective activity of Moringa oleifera Lam. leaves in carbon tetrachloride induced hepatotoxicity in albino rats. Pharma Mag., 4(13): 97.

• Shahidi, F. and Naczk, M. (1995): Methods of anal-ysis and quantification of phenolic compounds. Food phenolic: sources, chemistry, effects and applications (pp. 287). Technomic Publishind Company, Inc: Lan-caster.

• Silva, T.M.; Dias, M.D.; Pereira, M.T.; Takahashi, J.A.; Ferraz, V.P.; Piló-Veloso, D. and Alcântara, A.F.C. (2012): Effect of the γ-radiation on phenol

fractions obtained from the leaves of Echinodorus macrophyllus Mich. Rad. Physics Chem., 81(1): 22.

• Suhaj, M. and Horváthová, J. (2007): Changes in antioxidant activity induced by irradiation of clove (Syzygium aromaticum) and ginger (Zingiber offici-nale). J. Food Nut. Res., 46(3): 112.

• Sutar, N.G.; Bonde, C.G.; Patil, V.V.; Narkhede, S.B.; Patil, A.P. and Kakad, R.T. (2008): Analge-sic activity of seeds of Moringa oleifera Lam. Int. J. Green Pharm., 2(2): 108.

• Variyar, P.; Bandyopadhyay, C. and Thomas, P. (1998): Effect of gamma irradiation on the phenolic acids of some indian spices. Int J. Food Sci. Technol., 33: 533.

• Veerapur, V.P.; Prabhakar, K. R.; Parihar, V.P.; Kandadi, M.R.; Ramakrishana, S.; Mishra, B.; Satish, R.B.S.; Srinivasan, K.K.; Priyadarsini, K.I. and Unnikrishnan, M.K. (2009): Ficus rac-emosa stem bark extract: A potent antioxidant and a probable natural radioprotector. evid based comple-ment Alternat. Med., 6(3): 317.

• Vicente, A.R.; Pineda, C.; Lemoine, L.; Civello, P. M.; Martinez, G.A. and Chaves, A.R. (2005): UV-C treatments reduce decay, retain quality and al-leviate chilling injury in pepper. Posthar Biol. Tech-nol., 35: 69.

• Yoden, K.L.; Iio, T. and Tabata, T. (1980): Mea-surement of thiobarbituric acid value in tissue ho-mogenate solutized with sodium dodecyl sulphate. Yakugaku Zasshi, 100: 553.

• Zheng, W. and Wang, S.Y. (2001): Antioxidant ac-tivity and phenolic compounds in selected herbs. J. Agric. Food Chem., 49(11): 5165.

• Zhu, Y.; Cai, F.; Bao, J. and Corke, H. (2010): Ef-fect of γ-irradiation on phenolic compounds in rice grain. Food Chem., 120: 74.

Some Analytical Characteristics of Moringa Oleifera Leaves and Seeds Affected by Gamma Irradiation ( 587 )

بعض اخلصائص التحليلية ألوراق وبذور املورينجا املتأثرة بأشعة جاما

أمينه عبد احلميد على1 – رباب وحيد مرعى1 – هدى مجال حممد على2

وذلك اهلامة األغ��راض متعددة استوائية شجرة هى (Moringa oleifera) املورينجا شجرة نظرا للخصائص الغذائية والطبية هلا. تلعب مضادات األكسدة دورا هاما يف تثبيط و نظافة الشقوق

احلرة وبالتالي توفري احلماية لإلنسان ضد االلتهابات واألمراض.

فى هذه الدراسة مت تعريض أوراق وبذور شجرة املورينجا M. oleifera جلرعات خمتلفة من أشعة جاما ( 0 و 5 و 10 و 15 كيلو جراى ) ومت تقديرحمتوى الفينوالت والفالفونويدات ، ونشاط مضادات

.HPLC األكسدة و كذلك تقدير الفينوالت والفالفونويدات بأستخدام جهاز

وأشارت النتائج اليت مت احلصول عليها أن احملتوى الفينولي والفالفونويدات قد زاد تدرجييا بزيادة جرعات اإلشعاع يف مستخلص البذور و األوراق. وكذلك زاد Scavenging activity تدرجييا بزيادة مستويات اجلرعة اإلشعاعية. وفيما يتعلق بالتحليل بواسطة HPLC للفينول و الفالفونويد أظهرت chlorogonic, caffeic, مثل: الفينولية املركبات بعض ختليق على حفز التشعيع أن النتائج

,salycilic, ellagic and p-OH-benzoic

الدراسة rosmarinic, naringin and hyperoside للفالفونويد وقد أظهرت وكذلك M. oleifera أن أشعة جاما هى أداة فعالة لتعزيز املركبات الفينولية والنشاط املضاد لألكسدة فى

)2014( ، 587 : جملد 2 ، عدد 5 ، ص 575

مجــــلة

التقنيــات النــوويــة فى العلوم التطبيقية

يصدرها

اجلمعية امل�شرية للعلوم الإ�شعاعية وتطبيقاتها

املوقع اإللكتروني www.esrsa.com

البريد اإللكتروني esrsa@live.com

مجـــــــــلد 1

عدد 1 (2013)

قسم املنتجات الطبيعية – املركز القومى لبحوث وتكنولوجيا اإلشعاع – هيئة الطاقة الذرية.. 1هيئة الطاقة الذرية – مركز البحوث النووية – أنشاص.. 2

Aly, A.A et al.( 588 ) J. Nucl. Tech. Appl. Sci., Vol. 2, No. 5