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ORIGINAL ARTICLE
Year : 2019  |  Volume : 15  |  Issue : 60  |  Page : 156-163  

Optimization of ultrasonic-assisted extraction of bioactive compounds from Sargassum henslowianum using response surface methodology


1 Department of Pharmaceutical Engineering, College of Pharmacy, Guangdong Pharmaceutical University, Guangzhou; State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Hainan, Haikou, China
2 Department of Pharmaceutical Engineering, College of Pharmacy, Guangdong Pharmaceutical University, Guangzhou, China

Date of Submission08-Jul-2018
Date of Decision16-Aug-2018
Date of Web Publication23-Jan-2019

Correspondence Address:
Yongguang Bi
College of Pharmacy, Guangdong Pharmaceutical University, Guangzhou 510006
China
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/pm.pm_347_18

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   Abstract 


Background: Sargassum henslowianum has become an important source for the food industry as well as medicinal applications. In recent years, varieties of bioactive components in S. henslowianum and its activities have reported. However, the optimized extraction conditions of polysaccharides and polyphenols in S. henslowianum was unknown, and their activities need to be explored more. Objective: This study was to optimize the ultrasound-assisted extraction of polysaccharides and polyphenols from S. henslowianum and test the biological activity of the extract. Materials and Methods: Response surface methodology was used to optimize extraction conditions, and the antioxidant activity of the extracts was evaluated by radical scavenging assay, α-Glucosidase inhibition, and cytotoxicity on MCF-7. Results: The optimal conditions of extracting polysaccharides were shown as following: ultrasonic time for 40 min, ultrasonic power for 330 W, solid-to-liquid ratio for 1:36 g/mL, the extraction yield reached 12.63% under above parameters. The optimum conditions of ultrasonic-assisted extraction of total polyphenols were as following: ultrasonic time for 102 min, ultrasonic power for 377 W, alcohol concentration for 62%, under these conditions, the extraction yield reached 11.45%. Besides, the extracts of polyphenols possessed stronger activity. Conclusion: This study provides the scientific guidance for further exploitation and utilization of S. henslowianum.
Abbreviations used: RSM: Response Surface Methodology; BBD: Box-Behnken Design; ANOVA: Analysis of variance

Keywords: Bioactivity, response surface methodology, Sargassum henslowianum, ultrasonic extraction


How to cite this article:
Bi Y, Lu Y, Yu H, Luo L. Optimization of ultrasonic-assisted extraction of bioactive compounds from Sargassum henslowianum using response surface methodology. Phcog Mag 2019;15:156-63

How to cite this URL:
Bi Y, Lu Y, Yu H, Luo L. Optimization of ultrasonic-assisted extraction of bioactive compounds from Sargassum henslowianum using response surface methodology. Phcog Mag [serial online] 2019 [cited 2019 Feb 21];15:156-63. Available from: http://www.phcog.com/text.asp?2019/15/60/156/250604





SUMMARY

  • Response surface methodology was used to optimize extraction conditions, and the antioxidant activity of the extracts was evaluated by radical scavenging assay, α-Glucosidase inhibition, and cytotoxicity on MCF-7. The optimal conditions of extracting polysaccharides were shown as following: ultrasonic time for 40 min, ultrasonic power for 330 W, a solid-to-liquid ratio for 1:36 g/mL, the extraction yield reached 12.63% under above parameters. The optimum conditions of ultrasonic-assisted extraction of total polyphenols were as following: ultrasonic time for 102 min, ultrasonic power for 377 W, alcohol concentration for 62%, and the extraction yield reached 11.45% under these conditions. Besides, the extracts of polyphenols possessed stronger activity.



   Introduction Top


Sargassum henslowianum, which belongs to genus of brown seaweed, fucales, sargassaceae family, grows on low-tide zone rocks, and extensively distributes in Hong Kong and Guangdong province. However, the utilization of S. henslowianum is restricted, and only a small part play a role as the raw materials of feed, algae and pharmaceutical industry.[1] In recent years, a wealth of bioactive components such as meroterpenoids, phlorotannins, polysaccharides, dietary fiber, and phytosterols have been identified in S. henslowianum[2] and the pharmacological properties such as internal heat, infections, laryngitis, anticancer, antibacterial, antifungal, antiviral, and anti-inflammatory have been recognized.[3],[4],[5],[6] Consequently, extensive attention has been paid to its health care value and medicinal value. The polysaccharides in S. henslowianum mainly consist of fucoidan, alginate, and laminaran, which possess a wide range of biological activity, such as anticancer, anti-inflammatory, anticoagulant, and hypolipidemic.[7],[8] The polyphenols of fucophlorethols, fuhalols, and phlorethols were proved in S. henslowianum, and the anticoagulant and antioxidant activities have been reported.[9] To further develop the marine resources and expand application range of S. henslowianum, it is necessary to optimize extraction conditions of bioactive components.

Maceration and percolation are considered as traditional methods to extract biological active compounds from plant materials. To obtain higher quality biological active compounds efficiently, different methods such as ultrasonic-assisted extraction have been reported.[10] Owing to the cavitation, mechanical and thermal effects of ultrasound, the release, diffusion, and dissolution of the active substances in the cells are accelerated.[11] Ultrasonic-assisted extraction possesses the advantage of high efficiency, time-saving, and environmental kindness compared to classical heating extraction and Soxhlet extraction.[12]

The objective of this study was to investigate the optimum ultrasonic-assisted extraction process of polysaccharides and polyphenols and study the biological activity of the extracts from many aspects. Response Surface Methodology (RSM) was applied to analyze the relationship between factors and response value. Moreover, diphenyl picryl hydrazinyl (DPPH), hydroxyl radical scavenging, α-Glucosidase inhibition, and cytotoxicity on MCF-7 assay were used to investigate the activity of polysaccharides and polyphenols from S. henslowianum.


   Materials and Methods Top


Materials

S. henslowianum were purchased from Zhanjiang (Guangdong, China). Glucose and gallic acid standards were from Mann Stewart Biological Technology Co. Ltd. (Chengdu, China). α-Glucosidase was purchased from Sigma Chemical Co., (America). Other reagents were analytical reagent and from Fu Chen Chemical Reagent Factory (Tianjin, China). This article does not contain any studies with human or animal subjects.

Preparation of calibration curve of glucose

The calibration curve of glucose was determined by the phenol-sulfuric acid method.[13] Briefly, different concentrations of glucose solution (0.02, 0.04, 0.06, 0.08, 0.1, 0.12 mg/mL) were prepared, and 1.0 mL was taken into test tube. Then, 1.0 mL 5% phenol solution was added slowly under the conditions of ice water bath, shaken, 5 mL sulfuric acid was added immediately and the mixture was shaken for 5 min. The resulting solution in boiling water bathed for 10 min and in water bath for 20 min. The absorbance was measured at 490 nm using UV-Vis spectrophotometer (752, Shanghai, China). The standard curve was prepared with the concentration of glucose as the abscissa and the absorbance value as the ordinate.

Preparation of calibration curve of gallic acid

The calibration curve of gallic acid was determined by Folin–Ciocalteu reagent.[14] Briefly, different concentrations of gallic acid solution (0.02, 0.04, 0.06, 0.08, 0.1, 0.12 mg/mL) were prepared. 0.5 mL Folin was added and reacted for 5 min, and then added 1.5 mL 20% sodium carbonate solution. The mixture was incubated for 30 min at room temperature. The absorbance was measured at 763 nm by UV-Vis spectrophotometer (752, Shanghai, China). The standard curve was prepared with the concentration of gallic acid as the abscissa and the absorbance value as the ordinate.

Extraction of polysaccharides and polyphenols

The S. henslowianum were ground into powder by a pulverizer (DFY-600, Wenling, China) and passed through 40 mesh sieve. 1.0 g powder was used to extract target compounds with ultrasonic cleaner (KQ-400DB, Dongguan, China) under different conditions. After the extraction process, the supernatant was collected by filtration. The content of polysaccharides and polyphenols in the extract were determined by the method shown in the above section. The extraction rate was calculated by the following formula:



Where C (mg/mL) is the concentration of Sargassum polysaccharide or polyphenols, V (mL) is the volume of extraction, W (g) is the quality of Sargassum powder.

Single-factor test

Single-factor test was used to provide a guide for the experimental design of RSM. In this test, one factor was changed while the other factors were kept constant, so the influence of each factor on extraction rate was revealed. The extraction factors of polysaccharides included extraction time (X1), ultrasonic power (X2) and solid-to-liquid ratio (X3); and of polyphenols included extraction time (X1), ultrasonic power (X2), and alcohol concentration (X3).

Experimental design of response surface methodology

Box-Behnken Design with three-level-three-factor was employed to optimize the extraction yield of polysaccharides and polyphenols.[15] The independent variables were coded at three levels including-1, 0 and 1, and the extraction yield was deemed to the response. The experiment was designed using Design-Expert software version 8.0.5. The variables and their levels were shown in [Table 1] for polysaccharides and [Table 2] for polyphenols. Each trial was performed in triplicate. A second-order polynomial was obtained by the experimental data,[16] and the form was shown as follows:
Table 1: Factors and levels for polysaccharides and central composite design with the independent variables

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Table 2: Factors and levels for polyphenols and central composite design with the independent variables

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Where Y is extraction yield, β0, βi, βii, and βij represent the interception, linear coefficient, quadratic coefficient, and interaction coefficient, respectively.

Antioxidant activity assay

Diphenyl picryl hydrazinyl radical scavenging assay

The extracts of seaweed polysaccharides and polyphenols were obtained according to the optimal conditions, respectively. The DPPH free radical scavenging activity of polysaccharides and polyphenols extracted from S. henslowianum was analyzed using the method described by this[17] with minor modification. Briefly, 5 mL extracts at the different concentration of 0.1, 0.2, 0.3, 0.4, and 0.5 mg/mL was mixed with 5 mL of 0.04 mg/mL DPPH-ethanol solution respectively, and then reacted at room temperature for 30 min. The absorbance was measured at 517 nm.



Where Ai is the absorbance of the sample, Aj is the absorbance of the mixture of ethanol and sample, A0 is the absorbance of the control solution.

Hydroxyl radical scavenging assay

The method proposed by this[18] was used to investigate the scavenging effect of seaweed polysaccharides and polyphenols on hydroxyl radical with a minor modification. Briefly, the reaction solution contained 2 mL Fe2+ (1.5 mmol/L), 1 mL salicylic acid (3 mmol/L), 2 mL H2O2 (0.3%), and different concentrations of seaweed polysaccharides or polyphenols. The mixtures were incubated for 30 min at 37°C, and the absorbance was measured at 510 nm.



Where Ai is the absorbance of the sample solution, A0 is the absorbance of control solution (water instead of the sample), Ai0 is the absorbance value of the sample under identical condition as Ai with water instead of H2O2.

α-glucosidase inhibition

The α-Glucosidase inhibition activity of the extracts from S. henslowianum was measured by this.[19] Briefly, 100 μL phosphate buffer (PH 6.8), 20 μL α-Glucosidase and 10 μL sample solution in different concentration were added into 96-well plate in sequence, then the mixture was stored in 37°C for 15 min and acarbose as a positive control. Followed by adding 20 μL PNPG and incubating at 37°C for 20 min. The OD value was measured at 405 nm using microplate reader (ST-360, Shanghai, China).

3- [4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay

MCF-7 cells (5 × 104 cells/well) were treated with S. henslowianum extracts whose concentration were in the range of 50–1600 μg/mL, and then processed cells were incubated for 24 h. Cell viability was measured by ELISA plate reader using 3- [4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay.[20] Each point set three replicated trials, and the results were averaged.


   Results and Discussion Top


Effect of extraction time on extraction yield

To investigate the effect of extraction time on extraction yield of polysaccharides, extraction time ranged from 10 to 60 min while the ultrasonic temperature, solid-to-liquid ratio, and ultrasonic power were fixed at 40°C, 1:25, and 280 W, respectively. With the increasing of ultrasonic time, the extraction yield of polysaccharides increased and reached a plateau at 40 min and then decreased slightly, as shown in [Figure 1]a. While for polyphenols, extraction time varied from 20 to 100 min, and the ultrasonic temperature, alcohol concentration, and ultrasonic power were 60°C, 60%, and 400 W, respectively. [Figure 2]a exhibits that with the increasing of extraction time from 20 to 100 min, the content of polyphenols increased, and then tended to descend. Initially, the content of the target compound in the extraction solvent was in low level and the extension of time is beneficial to the dissolution of the target compound. However, the structure of polysaccharides and polyphenols were destroyed as time prolonged. Considering the economic benefit, the extraction time should not be chosen for a long time but a moderate time.[21],[22]
Figure 1: Effects of different parameters on the extraction yield of polysaccharides ([a]: Extraction time, [b]: Ultrasonic power, [c]: Solid-to-liquid ratio)

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Figure 2: Effects of different parameters on the extraction yield of polyphenols ([a]: Extraction time, [b]: Ultrasonic power, [c]: Alcohol concentration)

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Effect of ultrasonic power on extraction yield

Ultrasonic power changed in the range of 160 W and 360 W while the ultrasonic time, temperature, and solid-to-liquid ratio were set as 30 min, 40°C, and 1:25 to extract polysaccharides. For polyphenols, ultrasonic power changed in the range of 200 and 400 W and the extraction time, temperature and alcohol concentration were set as 60 min, 60°C, and 60%. According to the results of [Figure 1]b and [Figure 2]b, with the increasing of ultrasonic power, the extraction rate of polysaccharides and polyphenols rise rapidly and then dropped. Furthermore, the extraction rate reached maximum value when the ultrasonic power was 280 W for polysaccharides and 320 W for polyphenols. The destructive effect of ultrasound on the cell wall was beneficial to the dissolution of compound, however, once the power was too high, the damage of ultrasound for the target compound was enhanced obviously. Hence, it is necessary to investigate the optimal ultrasonic power.[23],[24],[25]

Effect of solid-to-liquid ratio on extraction yield of polysaccharides

The value of solid-to-liquid ratio was chosen including 1:15, 1:20, 1:30, 1:35, and 1:40. Others were fixed as the followings: ultrasonic time 30 min, temperature 40°C, and ultrasonic power 280 W. [Figure 1]c shows that with the increasing of extraction solvent, the extraction rate of polysaccharides increased rapidly and then tended to be stable. With a small volume of extraction solvent, the polysaccharide dissolved in the solution to reach saturation easily, which leads to low extraction rate. The increasing of solvent was beneficial to the dissolution and diffusion of polysaccharides and caused a significant increase in the extraction yield.[26],[27],[28]

Effect of alcohol concentration on polyphenols yield

The value of alcohol concentration was chosen including 30%, 40%, 50%, 60%, 70%, and 80%. Other parameters were fixed as the followings: ultrasonic time 60 min, temperature 60°C, and ultrasonic power 400 W. [Figure 2]c indicates that under the condition of 60% ethanol, the extraction rate reached the highest value, the main reason was that the polarity between 60% ethanol and polyphenols was similar, which was beneficial to the dissolution of polyphenols.[29] Therefore, it is significant to choose the appropriate solvent for higher extraction yield.

Response surface analysis test

In the single factor test, extraction variables of polysaccharides (extraction time, ultrasonic power, and solid-to-liquid ratio) and polyphenols (extraction time, ultrasonic power, and alcohol concentration) were investigated, respectively. Under these results, the Center Combination Design (CCD) was used to optimize the ultrasonic extraction conditions, which included factorial point and zero point and zero-point experiments were repeated six times to estimate the experimental error.

Optimization of extraction conditions of polysaccharides

[Table 1] and [Table 2] represent the result of CCD experiments of polysaccharides and polyphenols respectively, and the second-order polynomial obtained by the experimental data was expressed by the following equation as an indication of coded factors.





Where Ypolysaccharides is the extraction yield of polysaccharides, X1, X2, X3 represent the independent variables of extraction time (min), ultrasonic power (W), and solid-to-liquid ratio (g/mL) for equation (5); for equation (6), where Ypolyphenols is the extraction yield of polyphenols, X1, X2, X3 represent the independent variables of extraction time (min), ultrasonic power (W), and alcohol concentration (%).

The validity of the model was tested using analysis of variance (ANOVA) and the result of ANOVA for quadratic polynomial model of extraction of polysaccharides and polyphenols were shown in [Table 3] and [Table 4], respectively.
Table 3: Results of analysis of variance for the fitted quadratic polynomial model of extraction of polysaccharides

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Table 4: Results of analysis of variance for the fitted quadratic polynomial model of extraction of polyphenols

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Analysis of response surface

Results of ANOVA for the fitted quadratic polynomial model of extraction of polysaccharides were shown in [Table 3]. The value of R2 was 98.78%, indicating that 98.87% of the variables (extraction time, ultrasonic power, and solid-to-liquid ratio) could be explained using the model obtained by the experiment. The R2Pred of 90.54% was in reasonable agreement with the R2Adj of 97.68%. The value of R2Adeq was 24.242, which was >4, indicated an adequate signal. Above data certified that this model could be used to navigate the design space. Quadratic regression model F-value of 89.93 implied the model was significant. Values of “Prob > F” <0.05 indicated the term was significant. In this case, independent variables (X2, X3), interaction coefficient (X2 X3), and quadratic terms (X12, X22, X32) were significant. Results of ANOVA for the fitted quadratic polynomial model of extraction of polyphenols were shown in [Table 4], the value of R2 was 99.09%, which meant that 99.09% of the variables (extraction time, ultrasonic power, and alcohol concentration) could be explained using the model obtained by the experiment. The R2Pred of 93.77% was in reasonable agreement with the R2Adj of 98.28%. The value of R2Adeq was 27.949, which was >4, indicated an adequate signal. Above data certified that this model can be used to navigate the design space. Quadratic regression model F-value of 121.60 implied the model was significant. The values of “Prob > F” <0.05 indicated the term was significant. In this case, independent variables (X2, X3), interaction coefficient (X2 X3), and quadratic terms (X12, X22, X32) were significant.

The three-dimensional profiles of polysaccharides and polyphenols were shown in [Figure 3] and [Figure 4], respectively, which illustrated the relationship between dependent variables and the independent. In addition, different shapes represent different interactions (the greater the bending amplitude of the response surface plots, the variables more significant). [Figure 3]c was the steepest response surface plot, which meant that the variable of solid-to-liquid ratio was more significant than extraction time and ultrasonic power and this result was shown in [Table 3]. [Figure 4]c was the steepest response surface plot, which meant that the variable of alcohol concentration was more significant than extraction time and ultrasonic power. This result was in agreement with the result in [Table 4].
Figure 3: Response surface plots showing the effect of different variables on the extraction rate of polysaccharides ((a) Extraction time and ultrasonic power, (b) Extraction time and solid-to-liquid ratio, (c) Ultrasonic power and solid-to-liquid ratio)

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Figure 4: Response surface plots showing the effect of different variables on the extraction rate of polyphenols ((a) Extraction time and ultrasonic power, (b) Extraction time and alcohol concentration, (c): Ultrasonic power and alcohol concentration)

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Optimization of the extraction condition and validation

Through the model was obtained by experiment, the optimum conditions of extraction polysaccharides from S. henslowianum were as follows: extraction time for 40.1 min, ultrasonic power for 330.88 W, solid-to-liquid ratio for 1:36.43, and in consideration of the actual operation, the best extraction process was modified to extraction time 40 min, ultrasonic power 330 W, solid-to-liquid ratio for 1:36. Under the above condition, the extraction yield reached 12.63% (n = 3), which approached predicted value of 12.92%.

For polyphenols, the optimum conditions were shown as following: extraction time for 102.33 min, ultrasonic power for 377.12 W, alcohol concentration for 62.75%, and considering the actual operation, the extraction condition was modified to extraction time 102 min, ultrasonic power 377 W, alcohol concentration 63%. Under these conditions, the extraction yield reached 11.45% (n = 3), which was close to the predicted value of 11.72%.

Antioxidant activity analysis

DPPH and hydroxyl radical scavenging assay were applied to investigate the antioxidant activity of polysaccharides and polyphenols extracted from S. henslowianum, and the results were shown in [Figure 5]a and [Figure 5]b. The DPPH and hydroxyl radical scavenging ability increased with the increase in concentrations of polysaccharides and polyphenols. Polyphenols possessed stronger scavenging activity on both DPPH and hydroxyl radical by comparing the results. Furthermore, both extracts showed good scavenging activity on DPPH and hydroxyl radical in the same concentration.
Figure 5: Activities of polysaccharides and polyphenols. (a) Diphenyl picryl hydrazinyl; (b) hydroxyl radical; (c) Inhibitory activity of polysaccharides and polyphenols on MCF-7

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α-glucosidase inhibition

In this experiment, the inhibition rate of S. henslowianum extracts to α-Glucosidase was measured by enzyme dynamic experiment, and the value of IC50 was used to compare the ability of two different extracts inhibiting α-Glucosidase. According to the OD value, the IC50 value of polysaccharides, polyphenols, and acarbose was 1844.6, 832.7, and 1256.2 μg/mL. It was easy to get the conclusion that S. henslowianum polyphenols possessed the stronger inhibitory activity of α-Glucosidase than polysaccharides and positive control, which meant that polyphenols had a potential hypoglycemic value.

3- [4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay

[Figure 5]c summarizes the result of MTT assay, which indicated that increasing dose inhibited proliferation of cells more. By calculation, the IC50 of polysaccharides, polyphenols was 776 and 288 μg/mL, this phenomenon proved polyphenols possessed a stronger inhibitory effect on MCF-7.


   Conclusion Top


RSM was applied to optimize ultrasonic-assisted extraction conditions of S. henslowianum polysaccharides and polyphenols and both models obtained through this study can be used to predict the experimental value. The optimal conditions for extracting polysaccharides were as following: ultrasonic time for 40 min, ultrasonic power for 330 W, solid-to-liquid ratio for 1:36, and the extraction yield reached 12.63% under these parameters. The optimum conditions for ultrasonic-assisted extraction of total polyphenols were as following: ultrasonic time for 102 min, ultrasonic power for 377 W, and alcohol concentration for 62%. Under these conditions, the extraction yield reached 11.45%. The antioxidant assay, α-Glucosidase inhibition, and MTT assay indicated that polyphenols possessed stronger activity than polysaccharides. This study provides scientific guidance for further exploitation and utilization of S. henslowianum.

Acknowledgments

This work is supported by the Open Project Program of the State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, Hainan, China (No. 2018002), Guangdong Provincial Oceanic and Fishery Bureau-marine fisheries science and technology and industrial development projects (No. A201501C11) and Guangdong Province Science and Technology Project (No. 2016A020210133).

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
   References Top

1.
Yu Z, Zhu X, Jiang Y, Luo P, Hu C. Bioremediation and fodder potentials of two Sargassum spp. in coastal waters of Shenzhen, South China. Mar Pollut Bull 2014;85:797-802.  Back to cited text no. 1
    
2.
Cuong HD, Thuy TT, Huong TT, Ly BM, Van TT. Structure and hypolipidaemic activity of fucoidan extracted from brown seaweed Sargassum henslowianum. Nat Prod Res 2015;29:411-5.  Back to cited text no. 2
    
3.
Wong CK, Ooi VE, Ang PO. Protective effects of seaweeds against liver injury caused by carbon tetrachloride in rats. Chemosphere 2000;41:173-6.  Back to cited text no. 3
    
4.
Zemkewhite WL, Ohno M. World seaweed utilization: An end-of-century summary. J Appl Phycol 1999;11:369-76.  Back to cited text no. 4
    
5.
Chen SH, Wang WM, Liu H, Li CL, Liu CY. Study on the purification and lowing hyperlipidemia activity of fucoidan from Sargassum henslowianum. Food Fermn Ind 2010;36:28-31.  Back to cited text no. 5
    
6.
Wong KH, Cheung PC. Effect of fiber-rich brown seaweeds on protein bioavailability of casein in growing rats. Int J Food Sci Nutr 2003;54:269-79.  Back to cited text no. 6
    
7.
Hou Z. Researches on antitumor activity of alginate from Sargassum henslowianum. Food Sci 2001;22:95-7.  Back to cited text no. 7
    
8.
Hwang PA, Chien SY, Chan YL, Lu MK, Wu CH, Kong ZL, et al. Inhibition of lipopolysaccharide (LPS)-induced inflammatory responses by Sargassum hemiphyllum sulfated polysaccharide extract in RAW 264.7 macrophage cells. J Agric Food Chem 2011;59:2062-8.  Back to cited text no. 8
    
9.
Liu L, Heinrich M, Myers S, Dworjanyn SA. Towards a better understanding of medicinal uses of the brown seaweed Sargassum in traditional Chinese medicine: A phytochemical and pharmacological review. J Ethnopharmacol 2012;142:591-619.  Back to cited text no. 9
    
10.
Gazeran S, Tajalli F, Sani AM. Effect of ultrasonic extraction on qualitative parameters of saffron edible extract. J Essent Oil Bear Plants 2016;19:1286-91.  Back to cited text no. 10
    
11.
Saleh MA, Berto DA, Padilha PM. Ultrasound-assisted extraction of Na and K from swine feed and its application in a digestibility assay: A green analytical procedure. Ultrason Sonochem 2013;20:1353-8.  Back to cited text no. 11
    
12.
Skowyra M, Falguera V, Gallego G, Peiró S, Almajano MP. Antioxidant properties of aqueous and ethanolic extracts of Tara (Caesalpinia spinosa) pods in vitro and in model food emulsions. J Sci Food Agric 2014;94:911-8.  Back to cited text no. 12
    
13.
Li JW, Ding SD, Ding XL. Optimization of the ultrasonically assisted extraction of polysaccharides from Zizyphus jujuba cv. jinsixiaozao. J Food Eng 2007;80:176-83.  Back to cited text no. 13
    
14.
Ramić M, Vidović S, Zeković Z, Vladić J, Cvejin A, Pavlić B, et al. Modeling and optimization of ultrasound-assisted extraction of polyphenolic compounds from Aronia melanocarpa by-products from filter-tea factory. Ultrason Sonochem 2015;23:360-8.  Back to cited text no. 14
    
15.
Maran JP, Manikandan S, Nivetha CV, Dinesh R. Ultrasound assisted extraction of bioactive compounds from Nephelium lappaceum L. fruit peel using central composite face centered response surface design. Arab J Chem 2017;10:S1145-57.  Back to cited text no. 15
    
16.
Chen W, Wang WP, Zhang HS, Huang Q. Optimization of ultrasonic-assisted extraction of water-soluble polysaccharides from Boletus edulis mycelia using response surface methodology. Carbohydr Polym 2012;87:614-9.  Back to cited text no. 16
    
17.
Cheung YC, Siu KC, Wu JY. Kinetic models for ultrasound-assisted extraction of water-soluble components and polysaccharides from medicinal fungi. Food Bioprocess Tech 2013;6:2659-65.  Back to cited text no. 17
    
18.
Spigno G, Tramelli L, Faveri DM. Effects of extraction time, temperature and solvent on concentration and antioxidant activity of grape marc phenolics. J Food Eng 2007;81:200-8.  Back to cited text no. 18
    
19.
Matsui T, Ueda T, Oki T, Sugita K, Terahara N, Matsumoto K. α-glucosidase inhibitory action of natural acylated anthocyanins. 1. Survey of natural pigments with potent inhibitory activity. J Agric Food Chem 2001;49:1948-51.  Back to cited text no. 19
    
20.
Chidambara Murthy KN, Jayaprakasha GK, Patil BS. Apoptosis mediated cytotoxicity of citrus obacunone in human pancreatic cancer cells. Toxicol In Vitro 2011;25:859-67.  Back to cited text no. 20
    
21.
Kushwaha SC, Kates M. Modification of phenol-sulfuric acid method for the estimation of sugars in lipids. Lipids 1981;16:372-3.  Back to cited text no. 21
    
22.
Ainsworth EA, Gillespie KM. Estimation of total phenolic content and other oxidation substrates in plant tissues using folin-ciocalteu reagent. Nat Protoc 2007;2:875-7.  Back to cited text no. 22
    
23.
Minjares-Fuentes R, Femenia A, Garau MC, Candelas-Cadillo MG, Simal S, Rosselló C, et al. Ultrasound-assisted extraction of hemicelluloses from grape pomace using response surface methodology. Carbohydr Polym 2016;138:180-91.  Back to cited text no. 23
    
24.
Vieira GS, Cavalcanti RN, Maa M, Hubinger MD. Chemical and economic evaluation of natural antioxidant extracts obtained by ultrasound-assisted and agitated bed extraction from jussara pulp (Euterpe edulis). J Food Eng 2013;119:196-204.  Back to cited text no. 24
    
25.
Wang R, Chen P, Jia F, Tang J, Ma F, Xu B. Characterization and antioxidant activities of polysaccharides from Panax japonicus C.A. Meyer. Carbohydr Polym 2012;88:1402-6.  Back to cited text no. 25
    
26.
Smirnoff N, Cumbes QJ. Hydroxyl radical scavenging activity of compatible solutes. Phytochemistry 1989;28:1057-60.  Back to cited text no. 26
    
27.
Zhu CP, Zhai XC, Li LQ, Wu XX, Li B. Response surface optimization of ultrasound-assisted polysaccharides extraction from pomegranate peel. Food Chem 2015;177:139-46.  Back to cited text no. 27
    
28.
Zhang DY, Wan Y, Xu JY, Wu GH, Li L, Yao XH, et al. Ultrasound extraction of polysaccharides from mulberry leaves and their effect on enhancing antioxidant activity. Carbohydr Polym 2016;137:473-9.  Back to cited text no. 28
    
29.
Maran JP, Priya B. Ultrasound-assisted extraction of polysaccharide from Nephelium lappaceum L. Fruit peel. Int J Biol Macromol 2014;70:530-6.  Back to cited text no. 29
    


    Figures

  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4]



 

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