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

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.

llex paraguariensis decreases oxidative stress in bone and mitigates the damage in rats during perimenopause.

During perimenopause, oxidative stress increases, which may result in disruption of bone turnover, and consequently in osteoporosis. The use of antioxidants may be an effective nutritional approach to reducing osteoporosis in this period of life. Mate tea (MT) (Ilex paraguariensis), a typical and inexpensive beverage consumed in the Brazilian south-east, Argentina and Uruguay, increases antioxidant defense. Our hypothesis was that MT would decrease oxidative stress and mitigate bone deterioration. To test this, we analyzed oxidative stress markers of bone turnover, and local and systemic markers of bone metabolism of rats during natural perimenopause. Female Wistar rats (aged 16months) in proven perimenopause period received 20mg/kgBW/day of mate tea, by gavage (PM+MT Group, n=10) or water (PM Group, n=10). Female rats aged 4months (AD Group, n=10) received water. The treatment period was four weeks. MT minimized the deterioration of rat microarchitecture, characterized by increase in the bone trabecular area, number of osteocytes and areal bone mineral density. These results were accompanied by a lower level of malondialdehyde, an oxidative stress marker, in femoral tissue homogenate. Plasmatic tartrate-resistant acid phosphatase, a typical osteoclastic function marker, decreases after treatment, indicating a decrease in osteoclastic function. MT also modified the immunostaining pattern of bone metabolism markers, decreasing the receptor activator of nuclear factor kappa-B ligant (RANKL), superoxide dismutase isoform 2 (SOD2) and increasing osteoprotegerin (OPG), a decoy receptor for the RANKL, which positively modulates bone mass. These results suggested MT was capable of decreasing bone resorption by inhibiting the osteoclastogenesis in a RANKL-dependent signaling pathway activated by oxidative stress. Taken together, the results indicated that MT minimized bone loss in perimenopause and this effect is at least partly due to the decrease in oxidative stress, confirming our hypothesis.

Ilex paraguariensis supplementation may be an effective nutritional approach to modulate oxidative stress during perimenopause.

Perimenopause is a period in a woman's life that precedes menopause and is characterized by hormonal changes that result in increased oxidative stress. Since oxidative stress is associated with age-related diseases and perimenopausal symptoms including somato-vegetative manifestations, nutritional antioxidant supplementation may be an effective approach to minimizing this stress. Mate tea (MT) (Ilex paraguariensis), a typical and inexpensive beverage consumed in the Brazilian south-east, Argentina and Uruguay, increases antioxidant defense. We hypothesized that MT could minimize oxidative stress during perimenopause by modulating enzymatic antioxidant defense. To test this, we analyzed the lipid oxidative damage and antioxidant defense in erythrocytes and liver of rats, after MT treatment. Female Wistar rats (aged 16months) in proven perimenopause period received 20mg/kgBW/day of mate tea, by gavage (PM+MT group) or water (PM group). Female rats aged 4months (AD group) received water. Erythrocytes and liver were used to determine lipid oxidative damage, determined by malondialdehyde (MDA); superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) activities. Total plasma antioxidant capacity was examined by ferric reducing antioxidant power assay (FRAP) and estrogen by radioimmunoassay. MT increased FRAP and did not change estrogen levels. Increased SOD and GPx, and reduced MDA were observed in both tissues studied. Increased CAT activity was observed only in the liver. We confirmed the hypothesis that MT was capable of minimizing oxidative stress in this period of life by modulating antioxidant defense.