Yacon roots (Smallanthus sonchifolius) improve oxidative stress in diabetic rats

Effects of yacon on carbohydrates and lipid metabolism, oxidative-nitrative stress markers changes in rats with experimental metabolic syndrome

Background and aim

Smallanthus sonchifolius (Poepp. and Hendl.) H. Robinson, commonly known as yacon, is a medicinal species recognized for its therapeutic properties. The hypoglycemic and hypolipidemic effects of yacon root tubers have been well-documented across various models of metabolic syndrome. However, research on the effects of biologically active compounds derived from yacon leaves remains limited. The aim of the study was to evaluate the hypoglycemic, hypolipidemic and antioxidant effects of an aqueous extract of yacon leaves under the fructose-induced experimental metabolic syndrome.

Experimental procedure

In the study were used male Wistar white rats, in which metabolic syndrome was induced by consuming a 10 % fructose solution. Animals were given an aqueous extract of yacon leaves at a dose of 500 mg per kilogram of body weight for seven and fourteen days following the establishment of metabolic syndrome. Hypoglycemic (glucose and glycosylate hemoglobin concentrations) and hypolipidemic (plasma cholesterol, triglycerides, low-density lipoproteins and high-density lipoproteins levels) effects and antioxidant activity (activity of superoxide dismutase, catalase, glutathione peroxidase, NO-synthase, the content of nitrite anion (NO₂‾) and nitrate anion (NO₃‾), content of carbonyl groups and thiobarbituric acid reactive substances) of extract were then evaluated.

Results

The 14 days use of aqueous extract of yacon for the treatment of fructose-induced metabolic syndrome leads to a decrease of animals' body weight (59.94 %), glucose concentration (10.33 %), glycosylated hemoglobin content (61.58 %), blood plasma triglycerides (50.35 %), cholesterol (24.46 %), low-density lipoproteins (21.56 %), as well as to increase in high-density lipoproteins concentration (29.29 %), paraoxonase activity (56.03 %). In animals with experimental MetS yacon cause oxidative-nitrative stress indicators normalization: increase in SOD (47.85 %) and GPO activity (16.55 %); decrease in TBARS content (23.77 %) and proteins oxidative modification products of neutral character (52.56 %); decrease in NOS activity (12.30 %), which was accompanied by a decrease in nitrate content (10.44 %).

Conclusions

The aqueous extract of yacon demonstrates significant hypoglycemic and hypolipidemic effects in a fructose-induced model of experimental metabolic syndrome, contributing to the normalization of both prooxidant and antioxidant states in rat erythrocytes.

Fructooligosaccharides Ameliorate Renal Injury and Dysfunction Through the Modulation of Gut Dysbiosis, Inhibition of Renal Inflammation, Oxidative Stress, Fibrosis, and Improve Organic Anion Transporter 3 Function in an Obese Rat Model

SCOPE

High-fat diet (HFD) consumption causes obesity and gut dysbiosis which induces kidney injury. It has been reported that prebiotics improve gut dysbiosis and insulin sensitivity and decelerate the progression of kidney disease. This study investigates the impact of fructooligosaccharides (FOS) on renoprotection and the prevention of gut dysbiosis and intestinal barrier injury in obese rats.

METHODS AND RESULTS

Wistar rats are treated with HFD for 16 weeks. Then, the HFD fed rats (HF) are given FOS 1 g day-1 (HFFOS1), 2 g day-1 (HFFOS2), or metformin 30 mg kg-1 day-1 (HFMET), by intragastric feeding for 8 weeks. Blood, urine, feces, kidney, and intestine are collected to determine the metabolic changes, gut dysbiosis, and the expression of proteins involved in kidney and intestinal injury. FOS can attenuate insulin resistance and hypercholesterolemia concomitant with the inhibition of renal inflammation, oxidative stress, fibrosis, and apoptosis, which are related to the deceleration of the overexpression of renal Toll-like receptor 4 (TLR4) and NADPH oxidase (NOX4). Moreover, FOS shows a greater efficacy than metformin in the reduction of the intestinal injury and loss of tight junction proteins induced by HFD.

CONCLUSION

FOS may be used as a supplement for therapeutic purposes in an obese condition to improve intestinal integrity and prevent renal complications.

Effects of Smallanthus sonchifolius Flour on Metabolic Parameters: A Systematic Review

Smallanthus sonchifolius, popularly known as yacon, is a member of the Asteraceae family. Due to its medicinal and edible value, yacon is consumed by different populations. Yacon is unique due to its high fructo-oligosaccharide and inulin content, as well as flavonoids, sesquiterpene lactones, and phenolic acids. Roots can be used to produce flour, which is less perishable and can be applied in various industrial products. This systematic review focuses on the effects of yacon flour on metabolic parameters. PubMed, Cochrane, Embase, Science Direct, Scopus, Web of Science, and Google Scholar databases were consulted, and PRISMA guidelines were followed in the selection of the studies. In total, 526 articles were found in the databases, and of these, only 28 full texts were eligible for inclusion. After applying the inclusion and exclusion criteria, seven studies were finally included. The results showed that the use of yacon flour can reduce glycemia, HbA1c, advanced glycation ends, plasma lipids, body fat mass, body weight, and waist circumference and improve intestinal microbiota and the antioxidant status. Further exploration of the effects of yacon flour is warranted, and additional clinical trials are necessary to determine the optimal daily consumption levels required to assist in improving metabolic parameters.

The impact of prebiotic fructooligosaccharides on gut dysbiosis and inflammation in obesity and diabetes related kidney disease

Obesity is an extensive health problem worldwide that is frequently associated with diabetes. It is a risk factor for the development of several diseases including diabetic nephropathy. Recent studies have reported that gut dysbiosis aggravates the progression of obesity and diabetes by increasing the production of uremic toxins in conjunction with gut barrier dysfunction which then leads to increased passage of lipopolysaccharides (LPS) into the blood circulatory system eventually causing systemic inflammation. Therefore, the modification of gut microbiota using a prebiotic supplement may assist in the restoration of gut barrier function and reduce any disturbance of the inflammatory response. In this review information has been compiled concerning the possible mechanisms involved in an increase in obesity, diabetes and kidney dysfunction via the exacerbation of the inflammatory response and its association with gut dysbiosis. In addition, the role of fructooligosaccharides (FOS), a source of prebiotic widely available commercially, on the improvement of gut dysbiosis and attenuation of inflammation on obese and diabetic conditions has been reviewed. The evidence confirms that FOS supplementation could improve the pathological changes associated with obesity and diabetes related kidney disease, however, knowledge concerning the mechanisms involved is still limited and needs further elucidation.

Influence of Smallanthus sonchifolius (Yacon) on the Activity of Antidepressant Drugs in Mice

Depression is one of the most common mental disorders in the world that negatively affects the daily functioning of patients. Numerous studies are currently being conducted to examine the antidepressant potential of innovative synthetic compounds and herbal substances. Yacon, Smallantchus sonchifolius, belongs to plants with numerous health-beneficial properties. Yacon-based products are regarded as a functional food. In our study, we attempted to check whether administration of Yacon tuber extract would have an antidepressant effect in the forced swim test (FST) in mice and whether its intake could influence the activity of conventional antidepressant drugs with different mechanisms of action, i.e., imipramine hydrochloride, fluoxetine hydrochloride, and reboxetine mesylate. The spontaneous locomotor activity of the tested mice was also investigated to eliminate any false-positive results. We demonstrated that an intragastric administration of the Yacon tuber extract at a dose of 100 mg/kg induced the antidepressant-like behavior in the FST in mice and that a combined administration of the sub-effective doses of the Yacon extract (50 mg/kg) with imipramine hydrochloride (7.5 mg/kg), fluoxetine hydrochloride (20 mg/kg), or reboxetine mesylate (5 mg/kg) significantly reduced the immobility time of animals in this behavioral test. The obtained results were not affected by the increased locomotor activity of the tested subjects. In conclusion, our findings suggest that Yacon tuber extract is promising as an alternative mood-improving product since it possesses an antidepressant potential and it can acts synergistically with conventional antidepressant drugs.

Effects of yacon flour associated with an energy restricted diet on intestinal permeability, fecal short chain fatty acids, oxidative stress and inflammation markers levels in adults with obesity or overweight: a randomized, double blind, placebo controlled clinical trial

Objective

Yacon flour is rich in bioactive compounds (phenolic compounds and fructooligosaccharides (FOS)), and may therefore reduce the risk of diseases associated with excess body weight. However, its effect on fecal short chain fatty acids (SCFA), intestinal permeability, oxidative stress and inflammation markers has not been studied in adult humans with excess body weight. Thus, we evaluated the effect of the consumption of yacon flour on these variables.

Methods

Twenty-six excess body weight (30.4 ± 2.4 kg/m²) adults (31.3 ± 8.5y) were randomized to one of two groups (yacon flour or control; n = 13) on a double blind clinical trial. Subjects received a breakfast drink containing or not yacon flour (25g) associated with an energy restricted diet, for six weeks. The flour chemical characterization, FOS and total phenolics contents were evaluated. Antioxidant capacity was evaluated in vitro and in vivo (plasma). Intestinal permeability, fecal SCFA, oxidative stress and inflammatory markers also were evaluated in vivo.

Results

Yacon flour was well tolerated. It presented an in vitro and in vivo antioxidant capacity, increased plasma total antioxidant capacity (Δ_YAC: 49.16 (-4.20; 156.63)) and reduced protein carbonyl concentrations (Δ_YAC: -0.98 (-1.54; -0.42)). A reduction in SCFAs was observed in both groups (Δ_acetic: -3.16 (-5.07; -0.95) vs. -1.05 (-2.65; 1.11); Δ_propionic: -1.05 (-2.60;-0.38) vs. -0.41 (-2.08; 0.09); Δ_butyric -0.75 (-1.38; -0.04) vs. -0.28 (-0.98; 0.11), for YAC and CON, respectively). Other variables did not change.

Conclusion

The yacon flour increased the plasma antioxidant capacity, decreased oxidative stress and SCFAs in adults with obesity or overweight.

Yacón (Smallanthus sonchifolius) prevented inflammation, oxidative stress, and intestinal alterations in an animal model of colorectal carcinogenesis

BACKGROUND

Yacón (Smallanthus sonchifolius) roots store carbohydrate in the form of prebiotic fructooligosaccharides (FOS), which improve intestinal health. Yacon has the potential to prevent the intestinal barrier alterations associated with colorectal cancer (CRC). This study aimed to investigate the preventive effects of yacón flour (YF) on alterations promoted by CRC induced by 1,2-dimethylhydrazine in rats.

RESULTS

CRC increased tumor necrosis factor alpha levels (group CY = 10.2 ± 0.72; group C = 9.6 ± 1.0; group Y = 5.8 ± 0.54; group S = 5.95 ± 0.6 pg mL^-1 ) and short-chain fatty acid production, and decreased total antioxidant capacity (group CY = 4.7 ± 0.72; group C = 3.3 ± 0.3; group Y = 4.1 ± 0.47; group S = 6.7 ± 0.78 U mL^-1 ). Furthermore, YF treatment reduced intraluminal pH (group CY = 6.45 ± 0.47; group C = 7.65 ± 0.44; group Y = 6.75 ± 0.46; group S = 8.13 ± 0.2), lactulose/mannitol ratio, tumor necrosis factor-alpha (TNF-α)/interleukin (IL)-10 ratio, and increased secretory immunoglobulin A (group CY = 9.48 ± 1.46; group C = 10.95 ± 3.87; group Y = 15.95 ± 7.36; group S = 9.19 ± 1.52), but did not affect IL-10, IL-12, and TNF-α levels nor the IL-12/IL-10 ratio.

CONCLUSION

YF as a source of fructooligosaccharides may help to maintain the integrity of intestinal health, which is altered in induced CRC in rats. © 2020 Society of Chemical Industry.

A Sustainable Wholesome Foodstuff; Health Effects and Potential Dietotherapy Applications of Yacon

A sustainable food supply is an ever-growing public and planetary health concern influenced by food culture, food practices, and dietary patterns. Globally, the consumption of plant foods that offer physiological and biochemical benefits is increasing. In recent years, products made from yacon (Smallanthus sonchifolius) tubers and leaves, e.g., in the form of syrup, powder, and herbal tea, have steadily emerged with scientific evidence to validate their possible health claims. Yacon was introduced to New Zealand in 1966, and its products can now be produced on a commercial scale. This paper reviews literature published mainly in the last 10 years concerning the health-related properties of yacon as a wholesome foodstuff and its bioactive components, e.g., fructooligosaccharides. Literature was sourced from Web of Science, PubMed, EBSCO Health, and Google Scholar up to June 2019. The potential markets for yacon in the field of food technology and new dietotherapy applications are discussed. Furthermore, the unique features of New Zealand-produced yacon syrup are introduced as a case study. The paper explores the scientific foundation in response to the growing public interest in why and how to use yacon.

Smallanthus sonchifolius (Yacon) Flour Improves Visceral Adiposity and Metabolic Parameters in High-Fat-Diet-Fed Rats

Smallanthus sonchifolius (yacon), a native plant of South America, was observed to improve lipid profile in rodents and humans. This study aimed to investigate the antiobesity properties of yacon roots in a high-fat-diet (HFD) model and the underlying mechanisms. A total of 30 Wistar male rats were divided into five groups (n=6): the standard chow diet (SD) group was fed a SD; the HFD group was fed a HFD; and the HFD Y340 and HFD Y680 groups were fed a HFD plus yacon flour (340 and 680 mg FOS/kg b. w./day, respectively). HFD Y340 and HFD Y680 rats exhibited marked attenuation of weight gain, a decrease in visceral fat pad weight, a restoration of the serum lipid profile and atherogenic index in a dose-dependent manner, being the higher dose more effective (p < 0.05). In addition, we found that HFD Y680 rats showed lower glucose and insulin levels, improved glucose tolerance, and insulin sensitivity (p < 0.5). A downregulation of several adipocyte specific-transcription factors, including peroxisome proliferator-activated receptor gamma2 (PPAR-γ2), CCAAT/enhancer binding protein a (C/EBP-a) and activating protein (aP2) mRNA levels, was determined in the visceral adipose tissue of HFD Y680 rats (p < 0.05). An improvement of adipokine profile in HFD Y680 rats and decreased serum proinflammatory cytokine levels (p < 0.05) were determined by ELISA. Decreased macrophage infiltration and F4/80 and MCP-1 expression in the visceral adipose tissue of HFD Y680 rats (p < 0.5), together with a higher pAkt/Akt expression (p < 0.05) were also observed by immunofluorescence and immunoblotting. A significant increase in glucagon (Gcg) and PYY mRNA levels in distal ileum of HFD Y680 rats (p < 0.05) were also detected. In the second approach, we determined that yacon supplementation potentiates the effects of the HFD reversion to a standard diet. In conclusion, yacon showed antiobesity properties by inhibiting adipogenesis and improving the visceral adipose tissue function.

Phytochemical Properties and Nutrigenomic Implications of Yacon as a Potential Source of Prebiotic: Current Evidence and Future Directions

The human gut is densely populated with diverse microbial communities that are essential to health. Prebiotics and fiber have been shown to possess the ability to modulate the gut microbiota. One of the plants being considered as a potential source of prebiotic is yacon. Yacon is an underutilized plant consumed as a traditional root-based fruit in South America. Yacon mainly contains fructooligosaccharides (FOS) and inulin. Therefore, it has bifidogenic benefits for gut health, because FOS are not easily broken down by digestive enzymes. Bioactive chemical compounds and extracts isolated from yacon have been studied for their various nutrigenomic properties, including as a prebiotic for intestinal health and their antimicrobial and antioxidant effects. This article reviewed scientific studies regarding the bioactive chemical compounds and nutrigenomic properties of extracts and isolated compounds from yacon. These findings may help in further research to investigate yacon-based nutritional products. Yacon can be considered a potential prebiotic source and a novel functional food. However, more detailed epidemiological, animal, and human clinical studies, particularly mechanism-based and phytopharmacological studies, are lacking for the development of evidence-based functional food products.

Antioxidant and Hepatoprotective Potentiality of Randia dumetorum Lam. Leaf and Bark via Inhibition of Oxidative Stress and Inflammatory Cytokines

Randia dumetorum Lam. (RD) (Rubiaceae) is traditionally used by some tribes of Assam and Manipur of North East India for the treatment of liver ailments. In this context, to scientifically validate this indigenous traditional knowledge, we have evaluated the antioxidant and hepatoprotective activity of RD leaf and bark. The methanol extracts of RD leaf and bark were evaluated for in vitro antioxidant activity which exhibited good antioxidant activity in terms of reducing power assay, total antioxidant assay and DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging assay. Total phenolic and flavonoid content were found to be 112 ± 3.24 mg and 138 ± 2.46 mg gallic acid equivalents/g extract and 2.6 ± 0.26 mg and 3.34 ± 0.31 mg rutin equivalents/g extract respectively for RD leaf and bark methanol extracts. The in vivo hepato protective activity of the RD leaf and bark extract was evaluated against carbon tetrachloride (CCl4) induced hepatic damage in male wistar rats. CCl4 administration induced hepatic damage in rats resulted in increased levels of aspartate transaminase, alanine transaminase, alkaline phosphatase, lactate dehydrogenase, thiobarbituric acid reacting substances, albumin, bilirubin, TNF-α, IL-1β and decreased levels of total protein and antioxidant enzymes like superoxide dismutase, catalase, and glutathione reductase. RD leaf and bark methanol extracts pre-treatment exhibited protection against CCl4 induced hepatotoxicity by reversing all the abnormal parameters to significant levels. Histopathological results revealed that RD leaf and bark extracts at 400 mg/kg protects the liver from damage induced by CCl4. The results of this study scientifically validate the traditional use of RD leaf and bark for the treatment of liver ailments.