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. 2020 Dec 31;25(4):375–379. doi: 10.3746/pnf.2020.25.4.375

Protective Effects of Anthocyanin Extract from Purple Sweet Potato (Ipomoea batatas L.) on Blood MDA Levels, Liver and Renal Activity, and Blood Pressure of Hyperglycemic Rats

Ervika Rahayu Novita Herawati 1,✉, Umar Santosa 2, Suharwadji Sentana 1, Dini Ariani 1
PMCID: PMC7813593  PMID: 33505931

Abstract

There has been a dynamic progression in the study of purple sweet potatoes, particularly in regard to their antioxidant compounds, such as anthocyanins. Antioxidants can reduce oxidative stress due to hyperglycemia, therefore research into the protective effects of hyperglycemia is essential. This study was conducted to investigate the protective effects of anthocyanin extracts from purple sweet potatoes on blood malondialdehyde (MDA) levels, liver and renal activity, and blood pressure in hyperglycemic rats. Anthocyanin from purple sweet potato (APSP) was extracted with ethanol-citric acid 3% solvent. Twenty-four rats were split into four experimental groups: (i) healthy rats; (ii) hyperglycemic rats without anthocyanin treatment; (iii) hyperglycemic rats treated with APSP extract at a dose of 50 mg/kg; and (iv) hyperglycemic rats treated with APSP extract at a dose of 100 mg/kg. Rats received treatment for 35 days. The results showed that consumption of APSP significantly reduced levels of MDA in the blood, and liver and renal systems. APSP could reduce the urea and creatinine levels, which are indicative of improved renal function. In addition, APSP could decrease serum glutamate oxalacetate transaminase and serum glutamate pyruvate transaminase levels, indicative of protective activity of the extract on liver, and decrease systolic blood pressure. Accordingly, it was concluded that APSP could be developed as a functional food for treatment of diabetes.

Keywords: anthocyanin extract, antioxidant activity, hyperglycemic, MDA, purple sweet potato

INTRODUCTION

Sweet potato is a healthy food recommended by the Food and Agriculture Organization of the United Nations, due to the presence of beneficial metabolites such as β-carotene, anthocyanins, vitamins (B1, B2, C, and E), and minerals (Ca, Mg, K, and Zn) (Kim et al., 2012). Purple sweet potato (PSP) is a variety of sweet potato rich in anthocyanins. The anthocyanins in PSP are mostly 3,5-diglucosidederivatives of cyanidin or peonidin, and caffeoyl, feruloyl, and p-hydroxybenzoyl (Liu et al., 2017). Anthocyanins have attracted lots of attention because of their potential biological and pharmacological benefits. For example, anthocyanin from PSP has many antioxidant activity (Zhang et al., 2009; Wu et al., 2012; Hu et al., 2016), anti-cancer (Lim et al., 2013), antidiabetic (Matsui et al., 2002; Jang et al., 2012; Zhao et al., 2013; Jang et al., 2019), anti-inflammatory (Wang et al., 2010), and hepatoprotective activities (Sun et al., 2014; Wang et al., 2014a; Wang et al., 2014b).

Many varieties of sweet potato are grown in Indonesia, including PSP. PSP (Ipomoea batatas L.) contains the antioxidant anthocyanin, which can decrease blood glucose levels in hyperglycemic rats (Herawati and Santoso, 2013). However, the protective effects of anthocyanin extracts from PSP in rats (e.g., on liver and renal system) has not been reported. The protective effects of anthocyanin extracts on the liver can be investigated by analysis of serum marker enzymes [serum glutamate oxalacetate transaminase (SGOT) and serum glutamate pyruvate transaminase (SGPT)], and the protective effects on the renal system can be investigated by analysis of urea and creatinine levels. Therefore, the purpose of this study was to investigate the protective effects of anthocyanin extracts from PSP on blood malondialdehyde (MDA) levels, liver and renal function, and blood pressure in hyperglycemic rats.

MATERIALS AND METHODS

Materials and extract preparation

Local PSPs were obtained from Srigading, Sanden, Bantul, Yogyakarta, Indonesia. PSPs were processed into flour following the method by Herawati and Santoso (2013). PSP tubers were peeled, washed with clean water, sliced into small pieces, and dried using a cabinet dryer at 50∼ 60°C for 12 h. The dried slices were milled using a hammer mill and sieved using a 1 mm sieve. The flour was then packed inside bags and stored at room temperature.

PSP powder was extracted following on the method developed by Matsui et al. (2001). The flour were extracted using a solvent (4:1 ratio of ethanol to citric acid 3%) for 2 h at 40°C on a hot plate. Then, the extract was filtered by Whatman paper and evaporated using a rotary vacuum evaporator for 12 h at 50°C.

Animals

Eight-week-old male Sprague-Dawley rats (200∼250 g) were obtained from Gadjah Mada University, Yogyakarta, Indonesia. Rats were housed in cages under standard conditions of 26°C, a relative humidity of 60% and with a 12-h light/dark cycle. Rats were fed a standard pellet diet with water available ad libitum.

The experimental design was approved by the Medical and Health Research Ethics Committee (MHREC), Faculty of Medicine, Gadjah Mada University, Ministry of National Education (Reference number: KE/FK/361/EC). The animals were used after 9 days acclimatization to the laboratory environment, and were fasted overnight before experiments.

Experimental design

A total of 24 male rats were randomly divided into four experimental groups of six rats: (i) healthy rats; (ii) hyperglycemic rats without anthocyanin treatment; (iii) hyperglycemic rats treated with anthocyanin extract at a dose of 50 mg/kg; and (iv) hyperglycemic rats treated with anthocyanin extract at a dose of 100 mg/kg. The grouping of rats was based on simple random sampling of taking any rat into a group. First, rats were acclimatized for 9 days with a standard pellet diet (AIN-93 M) and ad libitum water. Hyperglycemic was then induced in rats by single intraperitoneal injection of alloxan 120 mg/ kg body weight (Farsani et al., 2016; Mostafavinia et al., 2016; Rahimi-Madiseh et al., 2017; Abdullah et al., 2018). Five days after administration of alloxan, fasting blood glucose levels were examined. Anthocyanin extracts were given to two experimental groups of hyperglycemic rats for 35 days. No samples were lost during the study. After 35 days of treatment, all rats were sacrificed using ether anesthesia. We then performed in vivo analysis of (i) MDA, a product of lipid oxidation, in the blood, and liver and renal systems, (ii) SGOT and SGPT levels, (iii) urea and creatinine levels, and (iv) systolic blood pressure (SBP).

Chemical analyses

Serum sample were obtained by sinus orbitalis. For MDA analysis, thiobarbituric acid reactive concentrations were determined by spectrophotometric analysis (Ohkawa et al., 1979). The reaction between thiobarbiturate and MDA forms a pink chromogen, the absorbance of which can be measured at a wavelength of 532 nm (Jovanović et al., 2013). Enzymatic kits were used to determine urea and creatinine levels, and SBP was measured with a tail-cuff plethysmography sphygmomanometer.

Statistical analysis

Data were expressed as means±standard error (SE). All statistical analyses were performed using the SPSS version 16 (SPSS Inc., Chicago, IL, USA). The results were analyzed using an one way analysis of variance (ANOVA), followed by Duncan’s multiple range post-hoc test to determine significant differences between groups (P-values <0.05).

RESULTS AND DISCUSSION

This section is organized as follows: (i) analysis of MDA levels; analysis of serum marker enzymes (SGOT and SGPT), indicative of protective effects on the liver; (iii) analysis of urea and creatinine levels, indicative of protective effects on the renal system; and (iv) analysis of SBP.

MDA levels

Our results showed that PSP powder has a water content of 5.28% and anthocyanin content of 91.86 mg/100 g of flour or 96.98 mg/100 g dry weight. In contrast, the extract contains 8.31 mg/g anthocyanin and exhibits antioxidant activity (i.e., capturing free radical activity) of 79.61%, as determined by DPPH assays (Herawati and Santoso, 2013). Two experimental groups received anthocyanin. The levels of MDA in the blood, liver, and renal system after 35 days are shown in Table 1.

Table 1.

Malondialdehyde (MDA) levels in rats after 35 days of treatment

Treatment group Blood MDA (mmol/L) Liver MDA (nmol/g) Renal MDA (nmol/g)
Healthy 2.32±0.14a 3.55±0.23a 2.97±0.12a
Hyperglycemic 8.38±0.22d 9.61±0.18d 8.75±0.13d
Hyperglycemic+low dose APSP extract 3.52±0.11c 5.85±0.19c 4.17±0.17c
Hyperglycemic+high dose APSP extract 2.78±0.13b 4.36±0.12b 3.78±0.20b
Open in a new tab

Data are mean±standard deviation.

The same letter (a-d) in the same column, indicates samples are not significantly different at a significance level of 95%. In this table, each group has different letters under same column indicator, and are therefore significantly different. The same letters in different column are not connected.

APSP: anthocyanin from purple sweet potato.

MDA levels are indicative of lipid oxidation. Our results showed that MDA levels in the blood, liver, and renal system were significantly enhanced in hyperglycemic rats. Indeed, hyperglycemic induced oxidative stress and increased levels of lipid peroxide and MDA. This damages the structure and fluidity of membrane, thereby impairing membrane functions. However, MDA was significantly decreased in the blood, liver and renal system of hyperglycemic rat that received anthocyanin extracts. Anthocyanin in PSP tubers has antioxidant activity, which prevents oxidative stress in blood and organs, and decreases levels of MDA. Administration of PSP aqueous extracts, which contain anthocyanin, can therefore decrease levels of MDA (Jawi et al., 2008; Satriyasa, 2016).

Anthocyanins may attenuate diabetic renal injury via suppression of reactive oxygen species, and protect mitochondrial function (Wei et al., 2018). Administration of anthocyanins enhances antioxidant function and decreases oxidative stress, thus decreases levels of MDA. Anthocyanins are phenolic compounds that have the ability to inhibit the formation of free radicals and catalytic metal for chelating redox reactions, thereby increasing total antioxidant capacity (Roussel et al., 2009). Anthocyanins (e.g., cyanidin and peonidin) can inhibit oxidation of low density lipoproteins in a concentration-dependent manner (Yi et al., 2010). Our results showed that MDA levels in the blood, liver, and renal system decreased by a greater extent in rats that received a high dose of APSP compared with a low dose of APSP. Similarly, in mice fed a high-fat diet, administration of anthocyanin from PSP reduced the level of oxidative stress-associated advanced glycation endproducts receptors and thioredoxin interacting proteins (Shan et al., 2014).

A limitation of this study is that it only investigates the effect of one polyphenol (anthocyanin) in PSP. Other components, such as copigments, may also have roles in reducing hyperglycemic by inhibiting a-glucosidase enzymes and by exhibiting antioxidant activity (Esatbeyoglu et al., 2017). Although copigments are present at a lower quantity than anthocyanin, we recommend it is investigated in future studies.

Protective effect of anthocyanin

The protective effect of anthocyanin extracts on the liver can be analyzed using serum marker enzymes. Both SGOT and SGPT are clinical indicators of liver damage. Hyperglycemic damages hepatocytes, causing GTP and GOT enzyme to enter the blood circulation and, consequentially, elevating blood SGPT and SGOT levels. In this study, administration of APSP significantly decreased SGOT and SGPT levels in hyperglycemic rats (Table 2). At the higher experimental dose (100 mg/kg) APSP extracts significantly decrease SGOT and SGPT levels to a greater extent than the lower dose (50 mg/kg), indicating greater protective activity on the liver. Anthocyanin compounds can improve hepatocyte function, thereby decreasing levels of SGPT and SGOT.

Table 2.

Serum marker enzymes in rats after 35 days of treatment (unit: U/L)

Treatment group SGOT SGPT
Healthy 18.69±0.23a 22.19±0.43a
Hyperglycemic 38.56±0.31d 45.30±0.47d
Hyperglycemic+low dose APSP 24.28±0.32c 27.95±0.37c
Hyperglycemic+high dose APSP 20.61±0.32b 25.57±0.32b
Open in a new tab

Data are mean±standard deviation.

The same letter (a-d) in the same column, indicates samples are not significantly different at a significance level of 95%. In this table, each group has different letters under same column indicator, and are therefore significantly different. The same letters in different column are not connected.

APSP: anthocyanin from purple sweet potato.

SGOT, serum glutamate oxalacetate transaminase; SGPT, serum glutamate pyruvate transaminase.

Consistent with our results, previous studies have reported that anthocyanin decreases SGOT and SGPT in diabetic mice (Alli et al., 2017; Ranjan et al., 2017). For example, anthocyanin in the form of cyanidin 3-caffeoyl-p-hydroxybenzoylsophoroside-5-glucoside inhibited hepatic glucose secretion in hyperglycemic mice. Furthermore, anthocyanin extracts reduced cardiac cell inflammation and hypertrophy, and attenuated cardiac fibrosis to protect cardiac function (Liu et al., 2015; Chen et al., 2016).

Urea and creatinine level

High levels of urea and creatinine in hyperglycemic rats is indicative of impaired renal function. Indeed, diabetic people often have high amounts of nitrogen compounds (urea and creatinine) in plasma and urine, resulting from decreased protein synthesis and increased muscle proteolysis (Gray and Cooper, 2011). In a previous study, consumption of PSP (i.e., anthocyanin) reduced body weight and the ratio of urine albumin to creatinine in high fat diet mice (Esatbeyoglu et al., 2017). In the current study, urea and creatinine levels significantly decreased after administration of APSP compared with hyperglycemic rats (Table 3). These results are indicative of improved renal activity, possibly induced by bioactive compounds present in APSP extracts. Bioactive compounds have positive effects on reducing kidney failure and extracellular dehydration (Alezandro et al., 2013; Amaya-Cruz et al., 2015). Previously, Pérez-Beltrán et al. (2017) reported fruit rich anthocyanin puree decreased levels of plasma glucose, urea, and creatinine in hyperglycemic rats.

Table 3.

Urea and creatinine level in rats after 35 days of treatment (unit: mg/dL)

Treatment group Urea Creatinine
Healthy 14.60±0.45a 0.46±0.01a
Hyperglycemic 73.58±1.79d 3.81±0.07d
Hyperglycemic+low dose APSP 37.53±2.45c 0.94±0.01c
Hyperglycemic+high dose APSP 26.85±0.81b 0.74±0.03b
Open in a new tab

Data are mean±standard deviation.

The same letter (a-d) in the same column, indicates samples are not significantly different at a significance level of 95%. In this table, each group has different letters under same column indicator, and are therefore significantly different. The same letters in different column are not connected.

APSP: anthocyanin from purple sweet potato.

Blood pressure

Consumption of APSP extracts decreased the SBP of hyperglycemic rats (Table 4). These results are consistent with those from other studies investigating the antihypertensive activity of anthocyanin. Anthocyanin exhibits a vasoprotective effect by relaxing the isolated rings of the aorta, an effect compatible with the relaxing vascular effect induced by several antihypertensive compounds (Guzmán-Gerónimo et al., 2017). Phenolic compounds such as flavonoids and anthocyanins may decrease blood pressure through antagonizing Ca, inhibiting angiotensin converting enzymes and activating endothelial nitric oxide synthase (Mohtashami et al., 2019).

Table 4.

Systolic blood pressure in rats after 35 days of treatment (unit: mmHg)

Treatment group Systolic blood pressure
Healthy 99.8±1.72a
Hyperglycemic 139.17±2.04d
Hyperglycemic+low dose APSP 116.67±2.80c
Hyperglycemic+high dose APSP 106.50±1.87b
Open in a new tab

Data are mean±standard deviation.

The same letter (a-d) in the same column, indicates samples are not significantly different at a significance level of 95%. In this table, each group has different letters under same column indicator, and are therefore significantly different. The same letters in different column are not connected.

APSP: anthocyanin from purple sweet potato.

In conclusion, consumption of APSP significantly decreased the levels MDA in the blood, liver and renal system in hyperglycemic rats. Furthermore, APSP reduced urea and creatinine levels, which are indicative of improved renal activity. In addition, ASAP decreased SGOT and SGPT levels, indicative of protection of the liver protective, and lowered SBP. Therefore, APSP may be developed as a functional food for treatment of diabetes with additional health benefits.

Footnotes

AUTHOR DISCLOSURE STATEMENT

The authors declare no conflict of interest.

References

  1. Abdullah KM, Alam MM, Iqbal Z, Naseem I. Therapeutic effect of vitamin B3 on hyperglycemia, oxidative stress and DNA damage in alloxan induced diabetic rat model. Biomed Pharmacother. 2018;105:1223–1231. doi: 10.1016/j.biopha.2018.06.085. [DOI] [PubMed] [Google Scholar]
  2. Alezandro MR, Granato D, Genovese MI. Jaboticaba (Myrciaria jaboticaba (Vell.) Berg), a Brazilian grape-like fruit, improves plasma lipid profile in streptozotocin-mediated oxidative stress in diabetic rats. Food Res Int. 2013;54:650–659. doi: 10.1016/j.foodres.2013.07.041. [DOI] [Google Scholar]
  3. Alli K, Thirupathi AT, Rao KNV, Begum A, Agey S, Dutt R. Antidiabetic activity of the methanolic extract of the leaves of Basella rubra L. against alloxan induced diabetes in albino rats. World J Pharm Pharm Sci. 2017;6:1295–1308. doi: 10.20959/wjpps20174-8896. [DOI] [Google Scholar]
  4. Amaya-Cruz DM, Rodríguez-González S, Pérez-Ramírez IF, Loarca-Piña G, Amaya-Llano S, Gallegos-Corona MA, et al. Juice by-products as a source of dietary fibre and antioxidants and their effect on hepatic steatosis. J Funct Foods. 2015;17:93–102. doi: 10.1016/j.jff.2015.04.051. [DOI] [Google Scholar]
  5. Chen YF, Shibu MA, Fan MJ, Chen MC, Viswanadha VP, Lin YL, et al. Purple rice anthocyanin extract protects cardiac function in STZ-induced diabetes rat hearts by inhibiting cardiac hypertrophy and fibrosis. J Nutr Biochem. 2016;31:98–105. doi: 10.1016/j.jnutbio.2015.12.020. [DOI] [PubMed] [Google Scholar]
  6. Esatbeyoglu T, Rodríguez-Werner M, Schlösser A, Winterhalter P, Rimbach G. Fractionation, enzyme inhibitory and cellular antioxidant activity of bioactives from purple sweet potato (Ipomoea batatas) Food Chem. 2017;221:447–456. doi: 10.1016/j.foodchem.2016.10.077. [DOI] [PubMed] [Google Scholar]
  7. Farsani MK, Amraie E, Kavian P, Keshvari M. Effects of aqueous extract of alfalfa on hyperglycemia and dyslipidemia in alloxan- induced diabetic Wistar rats. Interv Med Appl Sci. 2016;8:103–108. doi: 10.1556/1646.8.2016.3.5. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Gray SP, Cooper ME. Diabetic nephropathy in 2010: alleviating the burden of diabetic nephropathy. Nat Rev Nephrol. 2011;7:71–73. doi: 10.1038/nrneph.2010.176. [DOI] [PubMed] [Google Scholar]
  9. Guzmán-Gerónimo RI, Alarcón-Zavaleta TM, Oliart-Ros RM, Meza-Alvarado JE, Herrera-Meza S, Chávez-Servia JL. Blue maize extract improves blood pressure, lipid profiles, and adipose tissue in high-sucrose diet-induced metabolic syndrome in rats. J Med Food. 2017;20:110–115. doi: 10.1089/jmf.2016.0087. [DOI] [PubMed] [Google Scholar]
  10. Herawati ERN, Santoso U. Pengaruh konsumsi ekstrak antosianin ubi jalar ungu (Ipomoea batatas L.) terhadap glukosa darah, status antioksidan darah, dan gambaran histopatologis pankreas tikus hiperglikemia induksi aloksan. Universitas Gadjah Mada; Yogyakarta, Indonesia: 2013. Master's thesis. [Google Scholar]
  11. Hu Y, Deng L, Chen J, Zhou S, Liu S, Fu Y, et al. An analytical pipeline to compare and characterise the anthocyanin antioxidant activities of purple sweet potato cultivars. Food Chem. 2016;194:46–54. doi: 10.1016/j.foodchem.2015.07.133. [DOI] [PubMed] [Google Scholar]
  12. Jang HH, Kim HW, Kim SY, Kim SM, Kim JB, Lee YM. In vitro and in vivo hypoglycemic effects of cyanidin 3-caffeoyl-p-hydroxybenzoylsophoroside-5-glucoside, an anthocyanin isolated from purple-fleshed sweet potato. Food Chem. 2019;272:688–693. doi: 10.1016/j.foodchem.2018.08.010. [DOI] [PubMed] [Google Scholar]
  13. Jang HH, Park MY, Kim HW, Lee YM, Hwang KA, Park JH, et al. Black rice (Oryza sativa L.) extract attenuates hepatic steatosis in C57BL/6 J mice fed a high-fat diet via fatty acid oxidation. Nutr Metab. 2012;9:27. doi: 10.1186/1743-7075-9-27. https://doi.org/10.1186/1743-7075-9-27 . [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Jawi IM, Suprapta DN, Subawa AAN. The extract of purple sweet potato decrease blood and liver MDA of mice after intense physical activity. Indones Vet J. 2008;9:65–72. [Google Scholar]
  15. Jovanović JM, Nikolić RS, Kocić GM, Krstić NS, Krsmanović MM. Glutathione protects liver and kidney tissue from cadmium- and lead-provoked lipid peroxidation. J Serb Chem Soc. 2013;78:197–207. doi: 10.2298/JSC120214053J. [DOI] [Google Scholar]
  16. Kim HW, Kim JB, Cho SM, Chung MN, Lee YM, Chu SM, et al. Anthocyanin changes in the Korean purple-fleshed sweet potato, Shinzami, as affected by steaming and baking. Food Chem. 2012;130:966–972. doi: 10.1016/j.foodchem.2011.08.031. [DOI] [Google Scholar]
  17. Lim S, Xu J, Kim J, Chen TY, Su X, Standard J, et al. Role of anthocyanin-enriched purple-fleshed sweet potato p40 in colorectal cancer prevention. Mol Nutr Food Res. 2013;57:1908–1917. doi: 10.1002/mnfr.201300040. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Liu X, Xiang M, Fan Y, Yang C, Zeng L, Zhang Q, et al. A root- preferential DFR-like gene encoding dihydrokaempferol reductase involved in anthocyanin biosynthesis of purple-fleshed sweet potato. Front Plant Sci. 2017;8:279. doi: 10.3389/fpls.2017.00279. https://doi.org/10.3389/fpls.2017.00279 . [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Liu Y, Tan D, Shi L, Liu X, Zhang Y, Tong C, et al. Blueberry anthocyanins-enriched extracts attenuate cyclophosphamide-induced cardiac injury. PLoS One. 2015;10:e0127813. doi: 10.1371/journal.pone.0127813. https://doi.org/10.1371/journal.pone.0127813 . [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Matsui T, Ebuchi S, Kobayashi M, Fukui K, Sugita K, Terahara N, et al. Anti-hyperglycemic effect of diacylated anthocyanin derived from Ipomoea batatas cultivar Ayamurasaki can be achieved through the α-glucosidase inhibitory action. J Agric Food Chem. 2002;50:7244–7248. doi: 10.1021/jf025913m. [DOI] [PubMed] [Google Scholar]
  21. 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;49:1948–1951. doi: 10.1021/jf001251u. [DOI] [PubMed] [Google Scholar]
  22. Mohtashami R, Fallah Huseini H, Nabati F, Hajiaghaee R, Kianbakht S. Effects of standardized hydro-alcoholic extract of Vaccinium arctostaphylos leaf on hypertension and biochemical parameters in hypertensive hyperlipidemic type 2 diabetic patients: a randomized, double-blind and placebo-controlled clinical trial. Avicenna J Phytomed. 2019;9:44–53. [PMC free article] [PubMed] [Google Scholar]
  23. Mostafavinia A, Amini A, Ghorishi SK, Pouriran R, Bayat M. The effects of dosage and the routes of administrations of streptozotocin and alloxan on induction rate of type 1 diabetes mellitus and mortality rate in rats. Lab Anim Res. 2016;32:160–165. doi: 10.5625/lar.2016.32.3.160. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Ohkawa H, Ohishi N, Yagi K. Assay for lipid peroxides in animal tissues by thiobarbituric acid reaction. Anal Biochem. 1979;95:351–358. doi: 10.1016/0003-2697(79)90738-3. [DOI] [PubMed] [Google Scholar]
  25. Pérez-Beltrán YE, Becerra-Verdín EM, Sáyago-Ayerdi SG, Rocha-Guzmánc NE, García-López EG, Castañeda-Martínez A, et al. Nutritional characteristics and bioactive compound content of guava purees and their effect on biochemical markers of hyperglycemic and hypercholesterolemic rats. J Funct Foods. 2017;35:447–457. doi: 10.1016/j.jff.2017.06.022. [DOI] [Google Scholar]
  26. Rahimi-Madiseh M, Heidarian E, Kheiri S, Rafieian-Kopaei M. Effect of hydroalcoholic Allium ampeloprasum extract on oxidative stress, diabetes mellitus and dyslipidemia in alloxan-induced diabetic rats. Biomed Pharmacother. 2017;86:363–367. doi: 10.1016/j.biopha.2016.12.028. [DOI] [PubMed] [Google Scholar]
  27. Ranjan B, Kumar R, Verma N, Mittal S, Pakrasi PL, Kumar RV. Evaluation of the antidiabetic properties of S-1708 mulberry variety. Pharmacogn Mag. 2017;13:S280–S288. doi: 10.4103/pm.pm_490_16. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Roussel AM, Hininger I, Benaraba R, Ziegenfuss TN, Anderson RA. Antioxidant effects of a cinnamon extract in people with impaired fasting glucose that are overweight or obese. J Am Coll Nutr. 2009;28:16–21. doi: 10.1080/07315724.2009.10719756. [DOI] [PubMed] [Google Scholar]
  29. Satriyasa BK. Aqueous extract of purple sweet potato tubers decrease MDA and increase SOD2 in kidney of diabetic rats. Bali Med J. 2016;5:29–32. doi: 10.15562/bmj.v5i2.273. [DOI] [Google Scholar]
  30. Shan Q, Zheng Y, Lu J, Zhang Z, Wu D, Fan S, et al. Purple sweet potato color ameliorates kidney damage via inhibiting oxidative stress mediated NLRP3 inflammasome activation in high fat diet mice. Food Chem Toxicol. 2014;69:339–346. doi: 10.1016/j.fct.2014.04.033. [DOI] [PubMed] [Google Scholar]
  31. Sun H, Mu T, Liu X, Zhang M, Chen J. Purple sweet potato (Ipomoea batatas L.) anthocyanins: preventive effect on acute and subacute alcoholic liver damage and dealcoholic effect. J Agric Food Chem. 2014;62:2364–2373. doi: 10.1021/jf405032f. [DOI] [PubMed] [Google Scholar]
  32. Wang J, Tong X, Li P, Liu M, Peng W, Cao H, et al. Bioactive components on immuno-enhancement effects in the traditional Chinese medicine Shenqi Fuzheng Injection based on relevance analysis between chemical HPLC fingerprints and in vivo biological effects. J Ethnopharmacol. 2014a;155:405–415. doi: 10.1016/j.jep.2014.05.038. [DOI] [PubMed] [Google Scholar]
  33. Wang W, Li J, Wang Z, Gao H, Su L, Xie J, et al. Oral hepatoprotective ability evaluation of purple sweet potato anthocyanins on acute and chronic chemical liver injuries. Cell Biochem Biophys. 2014b;69:539–548. doi: 10.1007/s12013-014-9829-3. [DOI] [PubMed] [Google Scholar]
  34. Wang YJ, Zheng YL, Lu J, Chen GQ, Wang XH, Feng J, et al. Purple sweet potato color suppresses lipopolysaccharide-induced acute inflammatory response in mouse brain. Neurochem Int. 2010;56:424–430. doi: 10.1016/j.neuint.2009.11.016. [DOI] [PubMed] [Google Scholar]
  35. Wei J, Wu H, Zhang H, Li F, Chen S, Hou B, et al. Anthocyanins inhibit high glucose-induced renal tubular cell apoptosis caused by oxidative stress in db/db mice. Int J Mol Med. 2018;41:1608–1618. doi: 10.3892/ijmm.2018.3378. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. Wu TY, Tsai CC, Hwang YT, Chiu TH. Effect of antioxidant activity and functional properties of Chingshey purple sweet potato fermented milk by Lactobacillus acidophilus, L. delbrueckii subsp. lactis, and L. gasseri strains. J Food Sci. 2012;77:M2–M8. doi: 10.1111/j.1750-3841.2011.02507.x. [DOI] [PubMed] [Google Scholar]
  37. Yi L, Chen CY, Jin X, Mi MT, Yu B, Chang H, et al. Structural requirements of anthocyanins in relation to inhibition of endothelial injury induced by oxidized low-density lipoprotein and correlation with radical scavenging activity. FEBS Lett. 2010;584:583–590. doi: 10.1016/j.febslet.2009.12.006. [DOI] [PubMed] [Google Scholar]
  38. Zhang ZF, Fan SH, Zheng YL, Lu J, Wu DM, Shan Q, et al. Purple sweet potato color attenuates oxidative stress and inflammatory response induced by D-galactose in mouse liver. Food Chem Toxicol. 2009;47:496–501. doi: 10.1016/j.fct.2008.12.005. [DOI] [PubMed] [Google Scholar]
  39. Zhao JG, Yan QQ, Lu LZ, Zhang YQ. In vivo antioxidant, hypoglycemic, and anti-tumor activities of anthocyanin extracts from purple sweet potato. Nutr Res Pract. 2013;7:359–365. doi: 10.4162/nrp.2013.7.5.359. [DOI] [PMC free article] [PubMed] [Google Scholar]

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