Yacon (Smallanthus sonchifolius) Leaf Extract Attenuates Hyperglycemia and Skeletal Muscle Oxidative Stress and Inflammation in Diabetic Rats

Abstract

The effects of hydroethanolic extract of Yacon leaves (HEYL) on antioxidant, glycemic, and inflammatory biomarkers were tested in diabetic rats. Outcome parameters included glucose, insulin, interleukin-6 (IL-6), and hydrophilic antioxidant capacity (HAC) in serum and IL-6, HAC, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in soleus. The rats (10/group) were divided as follows: C, controls; C + Y, HEYL treated; DM, diabetic controls; and DM + Y, diabetic rats treated with HEYL. Diabetes mellitus was induced by administration of streptozotocin. C + Y and DM + Y groups received 100 mg/kg HEYL daily via gavage for 30 d. Hyperglycemia was improved in the DM + Y versus DM group. Insulin was reduced in DM versus C group. DM rats had higher IL-6 and MDA and lower HAC in the soleus muscle. HEYL treatment decreased IL-6 and MDA and increased HAC in DM rats. DM + Y rats had the highest CAT activity versus the other groups; GPx was higher in C + Y and DM + Y versus their respective controls. The apparent benefit of HEYL may be mediated via improving glucoregulation and ameliorating oxidative stress and inflammation, particularly in diabetic rats.

Antihyperglycemic and diabetic wound healing activity of smallanthus sonchifolius leaves extract

“…Yacon leaves extract attenuates hyperglycemia, oxidative stress and inflammation in diabetic rats [5]. A decoction of yacon leaves reduced blood glucose level in streptozotocin induced diabetic rats and increased the insulin concentration [6].…”

Recovery of Cardiac Remodeling and Dysmetabolism by Pancreatic Islet Injury Improvement in Diabetic Rats after Yacon Leaf Extract Treatment

“…In summary, there is extensive evidence that the hyperglycemia established in the diabetic condition is associated with the generation of reactive oxygen species (ROS) and a weakening of the antioxidant defense, resulting in enhanced oxidative stress [ 13 , 34 ]. Indeed, the activity of several antioxidant enzymes is decreased in the diabetic heart in both rats and humans [ 13 , 35 , 36 ]. Here, we have demonstrated that the activity of the antioxidant enzymes catalase, superoxide dismutase, and glutathione peroxidase is decreased in the diabetic group and MDA concentration is elevated in cardiac tissue (Figures 2(a) – 2(d) ), indicating an oxidative stress process.…”

“…The solvents were evaporated to dryness under low pressure (45°C) using a rotary evaporator in a vacuum system to afford the crude Yacon leaf extract (YLE). More information about the plant material, production of leaf extract, and phytochemical characterization can be found in a previous study of our group [ 13 ].…”

“…The animals received YLE (100 mg/kg body weight/day constituted in 1 mL of 0.9% saline) for gavage for 30 days after the 7th day of the established diabetic condition. The dose of the treatment was selected based on a previous study conducted by our team [ 13 ], where 3 different doses were tested (Y25, Y50, and Y100) and the highest dose presented a better glycemic control ( Figure 1 ). Control animals were given the same volume of saline.…”

“…Yacon ( Smallanthus sonchifolius ) is a perennial plant originally cultivated in the Andean highlands of South America, and its tubers are commonly used as food [ 11 ]. A number of studies have demonstrated the presence of large amounts of phenolic compounds in extracts from Yacon leaves and tubers [ 12 , 13 ]. So, since diabetic cardiomyopathy is tightly related to oxidative stress—originally from persistent hyperglycemia and the metabolic shift in the cardiac tissue [ 14 , 15 ], the treatment with Yacon leaves can be useful in diminishing oxidative damage and decreasing or preventing the progression of diabetic cardiomyopathy.…”