Successive extraction yields of raw, nano and fermented-nano materials
The effect of ultrafine grinding and fermentation of tested materials on the solubility of different types of phytochemical in petroleum ether, tetrahydrofuran and methanol, as well as total yield is illustrated in Fig. 1. The yields of petroleum ether, tetrahydrofuran and methanol extracts were 1.97, 1.07 and 2.74% for WB; 6.85, 1.83 and 15.36% for WG; 2.81, 1.86 and 2.19% for RB, respectively. Similar yields were reported by Oufnac (2006) and Wang et al. (1993). They attributed the higher yield of methanol to that methanol solvent possibly extracts not only lipids and small molecule polar compounds, but also some large molecule polar compounds, such as alcohol soluble proteins and carbohydrates. On the other hand, ultrafine grinding increased the yield for both tested materials and solvents. This could be due to increase the surface area of the produced nano-powders of tested materials. Also, fermentation process increased the solubility of tested materials in all solvents, except FNWG. The low yield values of FNWG, especially in methanol, could be explained by consumption of large portion of micro and macro-nutrients during the growth of yeast cells.
Phytochemical Analysis
The results of phytochemical analysis (total phenols, total flavonoids and total carotenoids) conducted on successive extracts of tested materials are presented in Table 1. As shown in this table, total phenolic contents in the investigated samples were the highest in WG, 3.00 mg gallic acid equivalent (GAE) per gram sample. Lower total phenolic contents were present in RB 2.65 mg GAE/g sample) and the lowest in WB 1.66 mg GAE/g sample. A similar phenolic content in wheat bran (1.24 mg GAE/g) and rice bran (2.5 mg GAE/g) had been reported by Zhu et al. (2010) and Lai et al. (2009). Ultrafine grinding significantly increased the phenolic contents of NWB and NRB (2.10 and 3.51 mg GAE, respectively) as compared to WB and RB, while this increase in NWG was not significant. Fermentation process did not significantly alter the phenolic content in FNWB or FNRB compared to its nano-forms, while phenolic content of FNWG significantly increased to 4.78 mg GAE/g. Katina et al. (2012) reported that the amounts of total phenolic content did not change in rice bran ferments, while Dordevic et al. (2010) reported that fermentation of wheat bran by both S. cerevisiae and Lactobacillus rhamnosus increased the phenolic content in wheat extracts. They explained the increase in the total phenolic content by the ability of fungi to degrade lignocellulosic materials due to their highly efficient enzymatic system. Xylanases, in particular, are one type of enzyme missing from S. cerevisiae which are important for release of phenolic compounds from cereal matrix (Mathew & Abraham, 2004). This could explain the inability of yeast to release the phenolic compounds from wheat and rice matrix.
Table 1 Phytochemicals of raw, nano and fermented-nano-materials
Sample
|
Total phenols
(mg GAE/g)
|
Total flavonoids
(mg CE/g)
|
Total carotenoids
(mg βCE/g)
|
WB
|
1.664G±0.103
|
0.588F±0.005
|
1.052EF±0.020
|
NWB
|
2.104F±0.032
|
1.256E±0.011
|
1.039F±0.006
|
FNWB
|
2.338F±0.099
|
2.038CD±0.029
|
1.021F±0.002
|
WG
|
3.003D±0.030
|
2.635B±0.036
|
1.984C±0.127
|
NWG
|
3.198CD±0.054
|
3.071AB±0.068
|
2.376B±0.107
|
FNWG
|
4.780A±0.293
|
3.539A±0.389
|
3.577A±0.190
|
RB
|
2.649E±0.006
|
1.206E±0.031
|
1.262E±0.004
|
NRB
|
3.513B±0.067
|
1.805D±0.006
|
2.076C±0.009
|
FNRB
|
3.389CB±0.072
|
2.566BC±0.324
|
1.583D±0.122
|
- Values in the same column followed by different letters are significantly different (p < 0.05)
WB- wheat bran, NWB- nano-wheat bran, FNWB- fermented-nano- wheat bran, WG- wheat germ, NWG- nano-wheat germ, FNWG- fermented-nano-wheat germ, RB- rice bran, NRB- nano-rice bran, FNRB- fermented-nano-rice bran.
Also, data in Table 1 showed that the total flavonoids content of WG (2.64 mg catachine equivalent (CE)/g) was significantly higher than those of WB and RB (0.59 and 1.21 mg CE/g, respectively). Ultrafine grinding significantly increased the flavonoids content of NWB and NRB to 1.26 and 1.81 mg CE/g, respectively, but its effect on NWG was not significant. Moreover fermentation process significantly increased the flavonoids contents of FNWB and FNRB to 2.04 and 2.57 mg CE/g, respectively. Also, the effect of fermentation process on FNWG flavonoids content was not significant. Similar results were reported by Zilic et al. (2012) for wheat genotypes, El Bedawey et al. (2010) for wheat germ and rice bran. Brewer et al. (2014) compared the flavonoids content of coarse, medium and fine wheat bran from the same wheat cultivar. The order of flavonoid content was determined as: fine > coarse ~ medium. Prabhu et al. (2014) mentioned that fermentation of rice bran by yeast resulted about 14% and 18% increase in flavonoid content after 24 and 48 h of fermentation. This was attributed to the increase in acidic value during fermentation that is liberating bound flavonoid components and making it more bioavailable.
Total carotenoids contents of investigated samples ranged from 1.02 to 3.58 mg β-carotene equivalent (βCE)/g (Table 1). Among the tested raw materials WG had the highest total carotenoids content (1.984 mg βCE/g). There were no significant differences between the carotenoids contents of WB and RB (1.05 and 1.26 mg βCE/g, respectively). Ultrafine grinding significantly increased the carotenoids contents of NWG and NRB to 2.38 and 2.08 mg βCE/g, respectively. This increase in NWB was not significant. Furthermore, fermentation process significantly increased the total carotenoids of FNWG which recorded the highest total carotenoids content (3.58 mg βCE/g) among all tested forms of the investigated materials. Also, the increase in total carotenoids contents of FNWB as a result of fermentation process was not significant. Zilic et al. (2012) found that the total yellow pigments in the brans of bread and durum wheat genotypes ranged from 4.66 to 6.62 mg βCE/kg, and from 8.65 to 12.55 mg βCE/kg, respectively.
Phenolic acids profiles of wheat and rice by-products
The phenolic acids (gallic, protocatechuic, gentistic, syringic, chlorogenic, caffeic, vanillic, ferulic, sinapic, p-coumaric, rosmarinic, trans-cinnamic acids and chyrsin) were investigated in cereal by-products and the concentrations of individual phenolic are shown in Table 2. Phenolic acids profile of WB, WG and RB was nearly similar. Among the tested phenolic acids, only gentistic and chlorogenic acids were not detected in WB and WG while, chlorogenic acid was not detected in RB under the experimental conditions. Ferulic and sinapic acids were the predominant phenolic acids in WB and WG while, ferulic and vanillic acids were the predominant phenolic acids in RB. Most of the ferulic and sinapic acids in WB were bound, with a concentration of 129.51 and 80.15 µg/g, respectively. While, the most of ferulic acid in WG was bound, with a concentration of 105.29 µg/g, but most of sinapic acid was conjugated, with a concentration of 127.48 µg/g. Most of the ferulic and vanillic acids in RB were bound, with a concentration of 147.96 and 56.15 µg/g, respectively.
Ultrafine grinding of raw WB and WG releases detectable free and conjugated amounts of gallic and protocatechuic acids. Also, NRB contained detectable free amounts of sinapic, p-coumaric, and rosmarinic acids which were not detected in RB. Moreover, ultrafine grinding of WB, WG and RB apparently increased the free, conjugated and bound forms of all identified phenolic acids except conjugated sinapic acid in WG and RB. This could be due to that ultrafine grinding increased phenolic acids accessibility by increasing the particle surface area of cell walls, and thus increasing the release of intra-cellular contents. Similar results were obtained by Van Craeyveld et al. (2009). They reported that the intensive grinding of wheat bran could partly solubilize the arabinoxylans, possibly contributing to the production of bioaccessible phenolic compounds, i.e. phenolics which are in conjugated or even free forms. While, Rosa et al. (2013) found that the mechanical treatment did not change the phenolic acids structuration state as the conjugated and free forms remained constant among the ground fractions. They mentioned that the conditions of grinding used (frequency and time) probably were not hard enough to break phenolic acids ester link.
Table 2 Phenolic acids profile of raw, nano and fermented-nano materials (µg/g)
Compound
|
Free
|
Conjugated
|
Bound
|
WB
|
NWB
|
FNWB
|
WB
|
NWB
|
FNWB
|
WB
|
NWB
|
FNWB
|
Gallic
|
ND
|
0.81
|
8.99
|
ND
|
6.44
|
10.96
|
13.07
|
2.88
|
2.03
|
Protochatchuic
|
ND
|
2.40
|
2.99
|
ND
|
0.77
|
1.20
|
5.67
|
10.79
|
6.22
|
Caffeic
|
ND
|
ND
|
0.63
|
ND
|
0.31
|
0.81
|
1.66
|
2.35
|
1.23
|
Syrngic
|
2.26
|
2.98
|
4.75
|
1.91
|
7.73
|
18.72
|
13.34
|
16.32
|
10.17
|
Vanillic
|
0.78
|
2.59
|
5.61
|
1.15
|
1.21
|
1.63
|
8.65
|
14.54
|
8.06
|
Ferulic
|
10.6
|
9.09
|
23.74
|
5.98
|
11.27
|
13.03
|
129.5
|
136.21
|
185.03
|
Sinapic
|
1.62
|
1.24
|
7.30
|
5.72
|
18.91
|
18.19
|
8015
|
79.27
|
57.89
|
P-Coumaric
|
ND
|
ND
|
10.02
|
0.41
|
0.99
|
0.78
|
3.19
|
3.64
|
7.42
|
Rosmarinic
|
0.84
|
3.36
|
4.29
|
0.98
|
4.04
|
4.77
|
23.19
|
29.04
|
9.81
|
Cinnamic
|
0.55
|
0.24
|
0.83
|
0.15
|
0.23
|
0.23
|
5.51
|
7.30
|
5.87
|
Chyrsin
|
1.73
|
1.87
|
4.42
|
1.14
|
1.52
|
1.54
|
9.72
|
10.34
|
16.61
|
|
WG
|
NWG
|
FNWG
|
WG
|
NWG
|
FNWG
|
WG
|
NWG
|
FNWG
|
Gallic acid
|
ND
|
1.24
|
16.60
|
7.59
|
7.98
|
12.78
|
ND
|
ND
|
ND
|
Protochatchuic
|
ND
|
0.60
|
7.38
|
4.20
|
2.21
|
5.49
|
ND
|
ND
|
ND
|
Caffeic acid
|
ND
|
ND
|
1.21
|
ND
|
ND
|
ND
|
ND
|
ND
|
ND
|
Syrngic acid
|
1.58
|
3.60
|
9.58
|
8.99
|
22.57
|
10.37
|
3.14
|
5.50
|
2.85
|
Vanillic acid
|
0.78
|
1.94
|
2.60
|
3.17
|
4.40
|
5.34
|
12.07
|
12.68
|
10.04
|
Ferulic acid
|
1.95
|
6.11
|
4.77
|
21.10
|
28.83
|
21.54
|
105.29
|
107.07
|
109.81
|
Sinapic acid
|
0.47
|
1.37
|
7.48
|
127.48
|
89.78
|
89.20
|
20.70
|
17.27
|
40.49
|
Coumaric acid
|
0.14
|
0.13
|
0.12
|
0.24
|
0.52
|
0.43
|
1.84
|
2.93
|
0.80
|
Rosmarinic
|
ND
|
1.44
|
6.78
|
1.88
|
2.02
|
1.84
|
6.28
|
5.91
|
3.07
|
Cinnamic acid
|
0.16
|
0.34
|
0.16
|
0.15
|
0.23
|
0.20
|
0.44
|
0.61
|
0.86
|
Chyrsin
|
1.65
|
4.80
|
4.42
|
ND
|
ND
|
ND
|
ND
|
ND
|
ND
|
|
RB
|
NRB
|
FNRB
|
RB
|
NRB
|
FNRB
|
RB
|
NRB
|
FNRB
|
Gallic acid
|
ND
|
ND
|
6.59
|
6.16
|
5.58
|
7.05
|
ND
|
ND
|
ND
|
Protochatchuic
|
2.71
|
13.58
|
13.31
|
ND
|
ND
|
ND
|
ND
|
ND
|
ND
|
Gentisic acid
|
ND
|
ND
|
ND
|
3.59
|
3.47
|
8.89
|
ND
|
ND
|
ND
|
Caffeic acid
|
0.94
|
1.06
|
1.80
|
ND
|
ND
|
ND
|
ND
|
1.06
|
1.26
|
Syrngic acid
|
0.94
|
1.91
|
2.59
|
ND
|
7.87
|
5.05
|
5.92
|
5.92
|
8.07
|
Vanillic acid
|
8.36
|
10.40
|
5.16
|
5.62
|
6.05
|
5.41
|
56.15
|
32.25
|
37.99
|
Ferulic acid
|
2.82
|
5.50
|
14.52
|
6.71
|
32.99
|
20.62
|
147.9
|
194.66
|
251.08
|
sinapic acid
|
ND
|
1.83
|
2.99
|
43.23
|
23.23
|
26.61
|
19.39
|
26.25
|
38.75
|
Coumaric acid
|
ND
|
4.57
|
8.40
|
1.16
|
1.25
|
1.94
|
4.95
|
6.45
|
12.58
|
Rosmarinic
|
ND
|
10.17
|
12.77
|
3.50
|
6.47
|
1.92
|
15.98
|
26.71
|
50.25
|
Cinnamic acid
|
1.10
|
1.11
|
0.81
|
0.42
|
0.31
|
ND
|
1.08
|
1.21
|
2.19
|
Chyrsin
|
ND
|
ND
|
ND
|
11.53
|
18.92
|
7.91
|
5.50
|
6.56
|
7.34
|
WB- wheat bran, NWB- nano-wheat bran, FNWB- fermented-nano- wheat bran, WG- wheat germ, NWG- nano-wheat germ, FNWG- fermented-nano-wheat germ, RB- rice bran, NRB- nano-rice bran, FNRB- fermented-nano-rice bran, ND- not detected.
On the other hand, the concentrations of soluble free and conjugated gallic, syringic, sinapic, p-coumaric, and rosmarinic acids of fermented nano-samples showed pronounced increases versus the raw and nano-samples. This indicates that yeast may produce hydrolytic enzymes capable of releasing soluble conjugated or insoluble bound phenolic acids from wheat bran. In contrast, soluble free ferulic and vanillic acids concentrations in FNWG and FNRB, respectively showed decreased values compared to NWG and NRB. This decrease indicates that yeast may be able to convert ferulic and vanillic acids to other compounds through enzymatic reactions. Interestingly, strains of S. cerevisiae have been reported to have a variety of phenolic acid biotransformation activities involving ferulic and vanillic acid derivatives (Priefert et al., 2001). This may partially explain the observed changes in soluble free phenolics. Furthermore, results showed that fermentation altered soluble conjugated and insoluble bound concentrations for most detected phenolic acids. Yeast treatment of WB and WG decreased insoluble bound concentrations for all measured phenolic acids versus nano-form, except for ferulic and p-coumaric acids. These results suggest that S. cerevisiae may have produced enzymes capable of releasing insoluble bound phenolic acids, thereby increasing its soluble free and or soluble conjugated phenolic acid contents. On contrast, fermentation of RB increased insoluble bound concentrations of all measured phenolic acids versus NRB. This could be due to the differences in lignocellulosic materials and phenolic acids profile of wheat and rice cultivars. Moore et al. (2007) and Chen et al. (2019) studied the effect of yeast and fungal fermentation on soluble free, soluble conjugated and insoluble bound phenolic acids of wheat and rice bran, respectively and found similar results.
Antioxidant activity of raw, nano and fermented-nano materials
The extracts of investigated samples were analyzed and compared for their IC50 values against DPPH• (Table 3). IC50 is the required concentration of sample antioxidants to scavenge 50% DPPH radicals in the reaction mixtures under the experimental conditions. The IC50 values ranged from 1.73 mg for WG to 0.51 mg for NRB, indicating that individual samples may significantly differ in their DPPH• radical scavenging capacities. The scavenging effect against DPPH• radical ranked the samples in the order of rice bran > wheat bran > wheat germ. Scavenging activity of all nano-materials slightly increased compared to raw materials. Also, the scavenging activity of FNWG increased compared to its nano-forms, while the scavenging activity of FNWB and FNRB decreased. This could be due to the ability of yeast to increase extracted phytochemicals. These results were in agreement with those of Moore et al. (2005), Mansour et al. (2013) and Shin et al. (2019). While, Prabhu et al. (2014) depicted that the fermented rice bran extract exhibited about 56% radical scavenging activity with 24 h of fermentation. They attributed this enhancement of scavenging activity to the liberation of bound polyphenolic and flavonoid content by the fermentative action of yeast.
All tested samples exhibited effectual radical cation scavenging activity ranged from 4.61 mM trolox equivalent (TE)/g WB to 8.27 mM TE/g NWB, as seen in Table, 3. There were no significant differences in ABTS•+ scavenging potential among WB, WG or RB. Ultrafine grinding significantly increased the scavenging activity of NWB and NRB to 8.27 and 8.08 mM TE/g, respectively. Also, the scavenging activity of FNWB and FNRB were significantly higher than those of WB and RB. On the other hand, neither ultrafine grinding nor fermentation significantly affected the scavenging activity of wheat germ. Moore et al. (2005) found that soft wheat grains had ABTS•+ scavenging activities varied from 14.3 to 17.6 µM TE/g. Also, wheat bran had 73.24 % ABTS radical scavenging activity (Shallan et al. 2014). Mahmoud et al. (2015) mentioned that 1µg/ml of wheat germ extract had ability to scavenging 70% from the ABTS•+ radicals.
The results of reducing power demonstrate the electron donor properties of tested samples thereby neutralizing free radicals by forming stable products (Table 3). The outcome of the reducing reaction is to terminate the radical chain reactions that may otherwise be very damaging. WB had the lowest reducing power (4.55 mM TE/g). There were no significant differences in reducing power of WG and RB (5.79 and 6.00 mM TE/g, respectively). Ultrafine grinding significantly increased the reducing power of NWB and NRB to 7.60 and 7.40 mM TE/g, respectively. While, the fermentation process only increased the reducing power of FNWG to 6.88 mM TE/g compared to 5.7 mM TE/g for both WG and NWG. Lai et al. (2009) found that the antioxidant activity of the methanolic extract of rice bran was 78% of reducing power. Singh et al. (2012) reported that the reducing power of Wheat bran was 2.532 mM ascorbic acid equivalent (AAE)/g.
Table 3 Antioxidant activity of raw, nano and fermented-nano-materials
Sample
|
DPPH
IC50 (mg/mL)
|
ABTS
(mM TE/g)
|
FRAP
(mM TE/g)
|
WB
|
1.682
|
4.613 C ±0.202
|
4.556 D ±0.197
|
NWB
|
1.080
|
8.269 A ±0.360
|
7.602 A ±0.248
|
FNWB
|
1.176
|
6.128 B ±0.365
|
5.788 C ±0.039
|
WG
|
1.730
|
6.311 B ±0.582
|
5.797 C ±0.126
|
NWG
|
1.432
|
6.343 B ±0.052
|
5.736 C ±0.030
|
FNWG
|
1.400
|
6.500 B ±0.409
|
6.886 B ±0.047
|
RB
|
1.331
|
6.429 B ±0.170
|
6.002 C ±0.098
|
NRB
|
0.505
|
8.082 A ±0.118
|
7.403 A ±0.178
|
FNRB
|
0.89
|
6.839 B ±0.096
|
7.354 A ±0.126
|
-Values in the same row followed by different letters are significantly different (p < 0.05)
WB- wheat bran, NWB- nano-wheat bran, FNWB- fermented-nano- wheat bran, WG- wheat germ, NWG- nano-wheat germ, FNWG- fermented-nano-wheat germ, RB- rice bran, NRB- nano-rice bran, FNRB- fermented-nano-rice bran.
Cytotoxic activity of raw, nano and fermented-nano materials
The effect of successive extracts of tested samples on proliferation of human colon cancer cell line HT-116 was investigated using MTT assay at 4 concentrations (10, 7.5, 5 and 2.5 mg/ml) and IC50 and IC90 were calculated using the probit analysis as shown in Table 4. Among the tested raw materials only RB extract was effective against cancer cell proliferation with IC50 values of 6.47. Cytotoxic activity of WB and WG successive extracts showed a dramatic inhibition drop against cancer cell growth from 63.8 and 82.6% at 10 mg/ml, respectively to 0% at 5 mg/ml. The anticancer activity of ultrafine ground samples increased compared to raw materials. Also, NRB extract was the most effective treatment with IC50 value of 4.10 mg/ml followed by 7.77 mg/ml for NWG and 14.30 mg/ml for NWB. Also, the extracts of FNWB and FNWG showed lower IC50 values compared to the extracts of raw and nano forms which indicate that fermentation process increased the anticancer activity of these materials. In this concern, some identified phenolic acids including p-coumaric, ferulic, and sinapinic acids have been previously shown to inhibit the growth of some cancer cell lines (Jaganathan, 2013; Peng et al., 2013). The antiproliferative activities of p-coumaric, ferulic, and sinapinic acids against HeLa, HCT116, and HT29 cancer cell lines were examined by Senawong et al. (2014). The MTT assay showed that ferulic, sinapinic and p-coumaric acids could inhibit the growth of tumor cells at millimolar concentrations. p-Coumaric acid exhibited the greatest anticancer activity against all tested cancer cell lines. Moreover, rice bran fermented products were found to arrest the cancer cell cycle, promote cancer cell apoptosis and enhance the chemo-preventive effects (Yu et al., 2019).
Table 4 Cytotoxic activity of raw, nano and nano-fermented materials
Sample
|
LC50
(mg/ml)
|
LC90
(mg/ml)
|
Remarks
(at 10 mg/ml)
|
WB
|
--------
|
--------
|
63.8%
|
NWB
|
8.90
|
14.30
|
72%
|
FNWB
|
5.96
|
8.14
|
100%
|
WG
|
--------
|
--------
|
82.6%
|
NWG
|
5.39
|
7.77
|
100%
|
FNWG
|
3.08
|
5.11
|
100%
|
RB
|
6.47
|
11.11
|
76.3%
|
NRB
|
2.63
|
4.10
|
100%
|
FNRB
|
1.62
|
4.23
|
100%
|
DMSO
|
--------
|
--------
|
1%
|
Negative control
|
--------
|
--------
|
0 %
|
WB- wheat bran, NWB- nano-wheat bran, FNWB- fermented-nano- wheat bran, WG- wheat germ, NWG- nano-wheat germ, FNWG- fermented-nano-wheat germ, RB- rice bran, NRB- nano-rice bran, FNRB- fermented-nano-rice bran, DMSO- dimethylsulphoxide, ---------- = 0 inhibition at concentration lower than 5mg/ml.
Correlation between antioxidants, antioxidant activity and cytotoxic activity of raw, nano and fermented-nano materials
Data in Table 5 showed high correlation between the techniques used for determining antioxidant activity. High negative correlations among IC50 determined based on DPPH assay and both ABTS and FRAP assays were found (r = -0.821 and 0.825, respectively, p < 0.01). Also, correlations among ABTS and FRAP assays were positively high (r = 0.997, p < 0.01). Connor et al. (2002) found high correlation among ORAC, FRAP, and methyl linoleate oxidation assays in blueberries. Awika et al. (2003) also found high correlation between ORAC, ABTS, and DPPH in sorghum and its products. Moreover, DPPH, ABTS and FRAP were highly correlated with both total phenols (r = -0.836, 0.998 and 0.992, respectively, p < 0.01) and total flavonoids (r = -0.808, 0.992 and 0.995, respectively, p < 0.01) of the tested materials (Table 5). Whereas, the correlation between antioxidant activity assay methods and total carotenoids was not significant (r = -0.441, 0.238 and 0.286, respectively). Both total phenols and total flavonoids showed high correlation with antioxidant activity as determined by all assays, which indicates that they are important contributors to antioxidant activity in tested extracts. Gil et al. (2002) found high correlation (r = 0.9, P < 0.05) between antioxidant activities determined by DPPH or FRAP assays and total phenols.
On the other hand, negative correlation between cytotoxic activity (IC50 value) and both total phenols and total flavonoids (r = -0.527 and -0.555, respectively, P < 0.05), while the correlation between cytotoxic activity and total carotenoids was not significant (r -0.028). Also, there was negative correlation between cytotoxic activity and both ABTS and FRAP (r = -0.534 and 0.539, respectively, P < 0.05). The highest positive correlation was found between cytotoxic activity and DPPH (r = 0.648, P < 0.01). For this reason, phytochemicals could contribute, at least in part, induced cytotoxic effect in the tested cell through its antioxidant activity.
Table 5 Correlation coefficient of antioxidants, antioxidant activity and cytotoxic activity of raw, nano and fermented-nano materials
Trait
|
TPH
|
TF
|
TC
|
DPPH
(IC50)
|
ABTS
|
FRAP
|
TF
|
0.986**
|
|
|
|
|
|
TC
|
0.264ns
|
0.27ns
|
|
|
|
|
DPPH (IC50)
|
-0.836**
|
-0.808**
|
-0.441ns
|
|
|
|
ABTS
|
0.998**
|
0.992**
|
0.238ns
|
-0.821**
|
|
|
FRAP
|
0.992**
|
0.995**
|
0.286ns
|
-0.825**
|
0.997**
|
|
CA (IC50)
|
-0.527*
|
-0.555*
|
-0.028ns
|
0.648**
|
-0.534*
|
-0.539*
|
TPH = total phenols, TF = total flavonoids, TC = total carotenoids and CA = cytotoxic activity. ns = non significant, * = Correlation is significant at p < 0.05 and ** = Correlation is significant at p < 0.01.