• Biomolecules & Therapeutics
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• v.21 no.2
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• pp.153-160
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• 2013

We screened the pharmacological effects of a 50% ethanol extract of Yacon tubers and leaves on spermatogenesis in rats. As a result, we found that Yacon tuber extracts increased sperm number and serum testosterone level in rats. It has been reported that the crude extract of Yacon tubers and leaves contain phenolic acids, such as, chlorogenic acid, ferulic acid and caffeic acid by HPLC/MS analysis. We were interested in the contributions made by phenolic acid, particularly chlorogenic acid of Yacon tuber extract to the spermatogenic activity. After administering Yacon tuber extract or chlorogenic acid to rats for 5 weeks, numbers of sperm in epididymis were increased by 34% and 20%, respectively. We also administered ferulic acid, which has been reported to be a metabolite of chlorogenic acid and a constituent of Yacon tuber extract to investigate its spermatogenic activity in rats. Yacon tuber extract and ferulic acid increased sperm numbers by 43% and 37%, respectively. And, Yacon tuber extract, and chlorogenic acid showed significantly inhibition effect of testoeterone degradation in rat liver homogenate. We considered that the spermatogenic effect of Yacon tuber extract might be related to phenolic compounds and their inhibitory effect of testosterone degradation. Yacon showed the possibility as ameliorable agents of infertility by sperm deficiency and late onset hypogonadism syndrome with low level of testosterone.

• YAKHAK HOEJI
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• v.53 no.5
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• pp.250-258
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• 2009

Male reproductive function seems to have deteriorated considerably in the past 4 to 5 decades. It was observed a significant decline in mean sperm counts from $113{\times}10^6/ml$ in 1940 to $66{\times}10^6/ml$ in 1990; a fall of $0.94{\times}10^6/ml/year$. We reported that Yacon tuber extracts have spermatogenic effects in rat. In the present study, we tested the spermatogenic effect of Yacon tuber extracts in healthy male volunteers. Subjects were assigned randomly to the control group and the Yacon ethanol extracts administered group (each 12 subjects). And, placebo or Yacon tuber extracts (100 ml) were administered two times daily, by oral for 3 months. Sperm numbers, biochemical parameters and hormone levels were recorded before starting administration, then every month. The Yacon tuber extracts administered group showed significant time dependant increases in according to administration period. Especially, the numbers of sperm increased by 54% after 3 months of administration. And, in Yacon tuber extracts administered group, testosterone and estradiol level were significantly higher than placebo group. On the other hands, Yacon tuber extracts didn't show any toxicity in glucose and lipid metabolism and liver and kidney function. The results of the present study suggest that Yacon tuber extract is a possible therapeutic for the treatment of sperm deficiency.

• Natural Product Sciences
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• v.14 no.2
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• pp.73-80
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• 2008

The authors screened the pharmacological effects of 50% ethanol extracts of Yacon on spermatogenesis in rats. Numbers of sperm in animals treated with 25, 50, or 100 mg/kg/day for 6 weeks of Yacon tuber extracts (YTE) were approximately 1.51, 1.61 and 1.78 times higher, respectively, than in the untreated control group. Moreover, the spermatogenic effect of Yacon leaf extract was found to be $1.03{\sim}1.38$ times higher than that of YTE. The ameliorative effect of Yacon tuber extracts on 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induced toxicities in the rat were also investigated. Rats were assigned to three groups (6 rats/group), a control group, a TCDD exposed group, and a group treated with Yacon tuber extract (YTE) after TCDD exposure (TCDD/YTE group). 40 ${\mu}g/kg$ of TCDD was injected i.p., and 200 mg/kg/day of YTE was also administered for 4 weeks by oral gavage. The TCDD/YTE group showed a significant increase in sperm number as compared with the TCDD exposed group. In conclusion, TCDD induced testicular toxicity was significantly ameliorated by YTE. The results of the present study suggest that Yacon extract is a possible therapeutic for the treatment of spermatogenic disorder.

• YAKHAK HOEJI
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• v.57 no.4
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• pp.241-249
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• 2013

We reported previously that the extracts of Yacon tuber and leaf have spermatogenic activity and testosterone level increasing effect in men. The aim of this study was to investigate the mechanism of testosterone level increasing effect of Yacon tuber and leaf extracts. In this study, we found that Yacon leaf extracts and chlorogenic acid, a constituent of Yacon extracts showed significantly inhibition effect of testosterone degradation in rat liver homogenate. We suggest that this could be a part of direct mechanism about increasing effect of testosterone level. Futhermore, we evaluated the inhibition effect of testosterone metabolism of Torilis japonica and Coix lacryma-jobi have been reported as $5{\alpha}$-reductase inhibitor. The inhibition ratio of testosterone metabolism of these were Torilis japonica>Coix lacryma-jobi>Yacon. We also evaluated the benign prostatic hyperplasia (BPH) score with the preparation composed of these natural product, Yacon pill. It showed the decreased the BPH score in men. Rats with BPH showed significantly increased dihydrotestosterone (DHT) levels in the serum; however, Yacon pill extracts treated rats showed significant reduction of DHT levels compared with the BPH group. Conclusively, Yacon pill showed the possibility as ameliorable agents of BPH symptoms.

• Biomedical Science Letters
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• v.26 no.3
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• pp.201-209
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• 2020

The effect of mulberry leaves and yacon tuber extracts (MYE) on antioxidant was tested in this study. The present study investigated the in vivo effects of the anti-oxidative effect of MYE on catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), glutathione peroxidase (GSH-Px), and thiobarbituric acid reactive substances (TBARS). The seven-day acclimation of the mice was divided into six groups: Normal diet group (NOR), high fat diet group (HFD), high fat diet with 0.5% hydroxycitric acid group diet group for positive group (HHCA), high fat diet with 1% mulberry leaf and 1% yacon diet group (MYE-1), high fat diet with 3% mulberry leaf and 3% yacon group (MYE-3) and high fat diet with 5% mulberry leaf and 5% yacon group (MYE-5). The effect of serum antioxidant in the catalase of MYE-1, MYE-3, and HHCA comparing to HFD by 31.0%, 27.7% and 45.2%, respectively (P<0.05~0.01). The effect on hepatic antioxidant in the catalase of HFD was significantly increased 3.7 (77.3%) times than that of NOR (P<0.01). But, the activities of catalase were decreased significantly in MYE-1, MYE-3, MYE-5 and HHCA by 21.7%, 24.2%, 24.9%, and 28.8% compared to HFD, respectively. GSH-Px was significantly decreased in MYE-1, MYE-3, MYE-5 and HHCA by 15.5%, 37.1%, 23.4%, and 23.7% compared to HFD, respectively (P<0.05). The activities of CAT, SOD, GST, GSH-Px, and TBARS were more significantly decreased in MYE-1 and MYE-3 than those of HFD and HHCA. MYE have shown significant effects on anti-oxidative function against high fat diet.

• Biomolecules & Therapeutics
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• v.17 no.3
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• pp.256-262
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• 2009

Smallanthus sonchifolius (Yacon, Asteraceae) was originally cultivated in South America and used in food and traditional medicine by Andean inhabitants. Yacon is potentially beneficial for the management of diabetes and is composed of fructooligosaccharides, proteins, minerals and phenolic compounds. The aim of this study was to investigate the hypoglycemic effect of Yacon tuber extract (YTE) and its constituent, chlorogenic acid (CGA), in streptozotocin (STZ)-induced diabetic rats. In this study, a HPLC method was developed for simultaneous determination of major active phenolic components, CGA and caffeic acid in YTE. We investigated the hypoglycemic effect of YTE and CGA in STZ-induced diabetic rats and studied glucose tolerance test (GTT). The effect of orally administered multiple doses of YTE and CGA on plasma biochemical parameters was examined using diabetic rats. We also measured free radical scavenging activity by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Oral administration of YTE (200 mg/kg) and CGA (10 mg/kg) for 6 weeks produced a significant hypoglycemic effect in STZ-induced diabetic rats. YTE and CGA-treated groups exhibited significantly decreased plasma glucose surge during the GTT. Total cholesterol (TC) and triglyceride (TG) concentrations were significantly decreased by 33% and 49%, respectively, in YTE-treated rats. TC and TG concentrations were also significantly decreased by 26 % and 41%, respectively, in CGA-treated rats. In the DPPH assay, free radical scavenging activity of CGA was similar to that of vitamin E, a positive control. This study suggests that YTE and its constituent, CGA, may be a useful option for management of hyperglycemia and diabetic nephropathy.

• Korean Journal of Weed Science
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• v.32 no.2
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• pp.98-106
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• 2012

This research has been carried out to find out the highest effect on insecticidal, fungicidal and herbicidal activities in leaves, stem and tuber extracts of yacon (Smallanthus sonchifolius) and extraction methods such as water, boiling water and methanol. Characteristics of potential herbicidal components among extraction methods were investigated by solvent fractions such as hexane, chloroform, ethyl acetate, butanol, and water. Generally, methanol extract was the best on inhibition of germination rate, plant height, and root length in cucumber and barley. On the other hand, the inhibition effect on growth in cucumber and barley was the best in tuber among plant parts of yacon. Inhibition of germination rate, plant height, and root length in cucumber and barley in solvent fractions was the best in water fraction, but there were no differences in other fractions. Digitaria sanguinalis L. and Solanum nigrum L. by 5 and 10% extractions of yacon tuber were controlled by more than 70~80% and 95~100%, respectively. However, there was no inhibition effect on foliar treatment in cucumber and barley as affected by 5 and 10% extractions of yacon tuber. Mortality of green peach aphid (Myzus persicae Sulzer) was 50% at 3 days after treatment of 5% extracts of yacon leaves. Mortality of brown plant hopper (Nilaparvata lugens Stal) was only 24% in 5% extracts of stems and leaves with midrib, but was 57% in 5% extracts of leaves without midrib. There was no fungicidal effect on anthracnose (Colletotrichum truncatum), wilt disease (Fusarium oxysporum), verticillium wilt (Verticillium dahliae), bacterial blight (Xanthomonus oryzae) in 5% extracts of yacon leaves.

• Biomedical Science Letters
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• v.26 no.2
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• pp.101-108
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• 2020

There has been a lot of interest in medicinal effects for hyperlipidemia from the natural product since the therapy of atherosclerosis has emerged as social concern. Rats were acclimated to the feeding environment for one week and induced to obesity with high fat diet during 4 weeks until their body weight were more than 30% of normal range. To evaluate the effect of hyperlipidemia of mulberry leaf of Morus alba and yacon tuber of Smallanthus sonchifolia extracts (MLYT), 1%, 3%, 5% of MLYT were treated to Sprague-Dawley rats. Aspartate transaminase (AST) was significantly increased 26.2% in high fat diet group (G2) compared to normal diet group (G1) (P<0.05). But AST were significantly decreased in high fat diet with 0.5% hydroxycitric acid diet group (G3) and all the MLYT treated groups compared to G2. Total cholesterol, low-density lipoprotein (LDL), triglycerides and phospholipids were observed significant improvements in the MLYT-treated groups (P<0.05). These improvements in liver and feces were further supported by the lipid content. MLYT remarkably suppressed the level of lipid peroxidation caused by high-fat diet in rats. The level of 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase activity. As a result, the proper combination of mulberry leaves and yacon tuber extract will have a synergistic effect on hyperlipidemia. These results indicate that MLYT could be a candidate for the improvement of hyperlipidemia.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.3
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• pp.240-244
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• 1993

Yacon(Polymina sonchifolia POEPP), an indigenous Andean natural resource food plant, was imported as a new root crop from New Zealand in 1986. However the chemical composition and planting system of it have not been research in Korea. The experimental results for the optimum planting densities and mulching effect are as follows. Height of the main stem of yacon was grown linear from July to October, is showed more fast growth as density increased, and showed highest in 70 ${\times}$ 55cm density. The tiller was bubed 3 month after planting but there was no significant difference among mulching, non-mulching condition and planting density. The fresh weight of root of mulching condition was heavier than that in non-mulching condition and 70 ${\times}$ 40cm mulching condition. In mulching treatment, number of roots in dense planting were more than that in sparse planting. The effect of mulching was not shown significantly in root diameter and root length.

• Korean Journal of Plant Resources
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• v.10 no.1
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• pp.17-23
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• 1997

This experiment was conducted to investigate the effect of planting date and planting density on the growth and yield characters of yacon (Polymnia sonchifolia POEPP) and to establish cultivation method in the middle region of Korea. An introduced variety of yacon was used. Seeding dates were from April 5 to April 7,and seedlings were trasplanted three times on the May 25, june 5, and June 15 with the intervals of 10 days. Planting densities were 80(width) $\times$ 35(distance) cm, 80 $\times$ 45cm, and 80 $\times$ 55cm. Plant height was not significant among planting dates, but was longer in the order of 80 $\times$ 55cm, 80 $\times$ 35cm, and 80 $\times$ 35cm among planting densities. Fresh weight of top part was heavier as the planting dates were faster and planting densities were narrower. Total yeid of tuber had no significant among planting dates and was higher in the density with 80 $\times$ 45cm and had the same tendency in the yeild of commercial goods. Correlation coefficient between plant height and yeild of commercial goods was highly positive(r= 0.927**).