Evaluation of biological activities of a groundnut (Apios americana Medik) extract containing a novel isoflavone

Groundnut (Apios americana Medik) Extract Enhances the Osteoblast Differentiation of MC3T3-E1 Cells

The effects of groundnut ( Apios americana Medik) extract on osteoblast differentiation were examined using MC3T3-E1 cells. MC3T3-E1 cells were treated with the crude extract along with other differentiating reagents. The alkaline phosphatase (ALP) activity of cells cultured in a differentiation medium supplemented with 0.01% crude groundnut extract was 1.5‐1.6 times higher than that of cells cultured in a differentiation medium without the extract. Crude groundnut extract was further separated into aqueous and methanol fractions. The methanol fraction enhanced ALP activity, osteocalcin, integrin-binding sialoprotein, and type I collagen expression, and calcium mineralization. Conversely, the aqueous fraction did not show such effects. Groundnut extract may enhance osteoblast differentiation, and this effect is likely conferred by water insoluble substance(s).

Effects of Isolated Isoflavones Intake on Health

BACKGROUND

Isoflavones are naturally occurring flavonoids, commonly found in the food consumed for centuries in the East-Asian population, characterized by a structure able to exert nonsteroidal estrogen-like activity on human cells. They have attracted researcher interest all around the word, following the results obtained in epidemiological and clinical studies. The involvement of isoflavones and their metabolites in various biological processes suggests that they can influence several metabolic pathways and can influence the gene expression at epigenetic level, involving effects that probably are due to early life exposure. They show positive health effects on several diseases, especially in the prevention of coronary heart and neurological diseases, hormone-related cancers, osteoporosis, and postmenopausal symptoms.

METHODS

We have performed a critical evaluation of available literature trough a structured search of bibliographic databases about isoflavones health promoting properties, risk assessment and mechanisms of action. In addition, we supplied useful information on their biochemical properties, sources and bioavailability.

RESULTS

Although these molecules have been the subjects of numerous researches, their role for the wellness of the human organism remains controversial. Moreover, there are substantial inconsistencies between the results obtained by epidemiologic studies conducted on Eastern population, which found high health promoting properties, and Western clinical trials, which found much less positive effects.

CONCLUSION

Further epidemiologic studies and well-designed prospective human studies are to determine the beneficial effects of isoflavones exposure, as well as establishing its safe therapeutic.

Improvement in post-partum uterine involution in rats treated with Apios americana

OBJECTIVE

Apios americana, a plant used as a staple ingredient of native American diets, has various properties, including anti-cancer, anti-hyperglycemic, hypotensive, and anti-inflammatory activity. In Japan, Apios is used as a post-natal medication. After parturition, women undergo a period of recovery as they return to pre-pregnancy conditions. However, few health products that aid post-partum recovery are on the market. We explored whether Apios can accelerate the post-partum recovery process, in particular the involution of the uterus.

METHODS

Female rats kept in individual cages were mated with two male rats, with the exception of the control group (female rats without mating, on basal diet; n=6). After delivery, rats were divided into five groups based on their diet: basal diet (model; n=6); basal diet+oral intake at 5.4 g/kg of Chanfukang granules (a Chinese patent medicine preparation for post-partum lochia) (positive; n=6); basal diet containing 10% Apios powder (low; n=6); basal diet containing 20% Apios powder (medium; n=6); basal diet containing 40% Apios powder (high; n=6). Five days later, uteri and spleens were weighed. Uterus and spleen indices for each rat were calculated by dividing visceral weight by the total weight. Hormone and cytokine concentrations were measured using enzyme-linked immunosorbent assay (ELISA). Histological analysis of uteri was completed using hematoxylin and eosin (H&E) staining. Expression of matrix metalloproteinases and inhibitors in uteri was measured by western blotting.

RESULTS

Our results showed that Apios treatment reduced the post-partum uterus index and regulated the hormone concentrations. Moreover, we found that the process of uterine involution was accelerated, based on morphological changes in the uterus. In addition, our results indicated that Apios alleviated the inflammatory response induced by the involution process. Transforming growth factor β was also found to be regulated by Apios. There were significant downregulation of matrix metalloproteinases and upregulation of their inhibitors by Apios, which suggested that Apios increased the rate of the collagen clearance process.

CONCLUSIONS

These results, based on experimental observations at the molecular and protein levels, verified our hypothesis that Apios can improve uterine involution, and demonstrated the potential application of Apios in post-partum care.

Differential Accumulation of Anthocyanins in Dendrobium officinale Stems with Red and Green Peels

Dendrobium officinale stems, including red and green stems, are widely used as a dietary supplement to develop nutraceutical beverages and food products. However, there is no detailed information on pigment composition of red and green stems. Here, we investigated the content and composition of pigments in red and green stems by Ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry and assessed the differential accumulation of anthocyanins at the molecular level. The color of peels in red stems was caused by the presence of anthocyanins in epidermal cells unlike the peels of green stems. The glucoside derivatives delphinidin and cyanidin are responsible for the red color. Within the D. officinale anthocyanidin biosynthetic pathway, DoANS and DoUFGT, coding for anthocyanidin synthase and UDP-glucose flavonoid-3-O-glucosyltransferase, respectively, are critical regulatory genes related to the differential accumulation of anthocyanidin. These findings provide a more complete profile of pigments, especially anthocyanin, in D. officinale stems, and lay a foundation for producing functional foods.

Anti-Inflammatory Effect of Lupinalbin A Isolated from Apios americana on Lipopolysaccharide-Treated RAW264.7 Cells

Apios americana, a leguminous plant, is used as food in some countries. Although the biological activities of Apios extract have been reported, there have been no reports about the anti-inflammatory mechanism of lupinalbin A on the RAW264.7 cells. In this study, we investigated the anti-inflammatory effect of A. americana lupinalbin A on lipopolysaccharide (LPS)-treated RAW264.7 cells. Lupinalbin A significantly inhibited nitric oxide production and inducible nitric oxide synthase expression in LPS-treated RAW264.7 cells. The expression of cytokines, including interleukin-6, tumor necrosis factor-α, and chemokine of monocyte chemoattractant protein, was reduced under lupinalbin A exposure in LPS-treated RAW264.7 cells. In addition, lupinalbin A significantly decreased LPS-induced interferon (IFN)-β production and STAT1 protein levels in RAW264.7 cells. Taken together, these results suggest that A. americana lupinalbin A exerts anti-inflammatory effects via the inhibition of pro-inflammatory cytokines and blocking of IFN-β/STAT1 pathway activation.

Effects of C-Glycosides from Apios americana Leaves against Oxidative Stress during Hyperglycemia through Regulating Mitogen-Activated Protein Kinases and Nuclear Factor Erythroid 2-Related Factor 2

Main components of Apios americana leaves extract (ALE) were flavonoid C-glycosides, including vitexin (46.7%), schaftoside (18.9%), and orientin (4.32%). In vitro, ALE restored glucose consumption, glucose uptake, and glycogen content in glucose-induced hepatic cells. Exposure of HepG2 cells to high glucose resulted in reactive oxygen species and O₂^- accumulation, while ALE alleviated these increases by 47 ± 0.68 and 68 ± 0.74%, respectively. Glucose increased c-Jun N-terminal kinase (JNK) and decreased extracellular signal-regulated kinases 1 and 2 (ERK1/2) and p38 phosphorylation, while ALE reduced p-JNK and p-p38 but not p-ERK1/2, accompanied by nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1, and NAD(P)H quinine oxidoreductase 1 downregulation. In vivo, the lifespan of Caenorhabditis elegans was more violently shortened by paraquat under hyperglycemia, while ALE protected this damage in N2 worms (2.6 times extension) but not in daf-16 mutants. Furthermore, p38/PMK-1 and Nrf2/SKN-1 expressions in worms were suppressed by glucose, which were reversed by ALE treatment. These results suggest that ALE prevents glucose-induced damage via regulating specific mitogen-activated protein kinases and Nrf2 pathways.

Antioxidative and Antidiabetic Effects of Natural Polyphenols and Isoflavones

Many polyphenols that contain more than two phenolic hydroxyl groups are natural antioxidants and can provide health benefits to humans. These polyphenols include, for example, oleuropein, hydroxytyrosol, catechin, chlorogenic acids, hesperidin, nobiletin, and isoflavones. These have been studied widely because of their strong radical-scavenging and antioxidative effects. These effects may contribute to the prevention of diseases, such as diabetes. Insulin secretion, insulin resistance, and homeostasis are important factors in the onset of diabetes, a disease that is associated with dysfunction of pancreatic β-cells. Oxidative stress is thought to contribute to this dysfunction and the effects of antioxidants on the pathogenesis of diabetes have, therefore, been investigated. Here, we summarize the antioxidative effects of polyphenols from the perspective of their radical-scavenging activities as well as their effects on signal transduction pathways. We also describe the preventative effects of polyphenols on diabetes by referring to recent studies including those reported by us. Appropriate analytical approaches for evaluating antioxidants in studies on the prevention of diabetes are comprehensively reviewed.

Rapid method for the determination of 14 isoflavones in food using UHPLC coupled to photo diode array detection

A rapid method for the determination of 14 types of isoflavones in food using ultra-high performance liquid chromatography (UHPLC) was validated in terms of precision, accuracy, sensitivity and linearity. The UHPLC separation was performed on a reverse-phase C18 column (particle size 2 μm, i.d. 2 mm, length 100 mm) using a photo diode array detector that was fixed to 260 nm. The limits of detection and quantification of the UHPLC analyses ranged from 0.03 to 0.33 mg kg(-1). The intra-day and inter-day precision of the individual isoflavones were less than 11.77% and calibration curves exhibited good linearity (r(2) = 0.99) within the tested ranges. These results suggest that the rapid method used in this study could be available to determine of 14 types of isoflavones in a variety of food such as soy bean, black bean, red bean and soybean paste.

Potential risk of isoflavones: toxicological study of daidzein supplementation in piglets

As a main component of soy isoflavones, daidzein is rich in soy-derived products, which are widely used as feed ingredients in farm animals. However, little research has been conducted on the side effects of dietary daidzein, especially in young animals. In this study, the safety of daidzein was evaluated. Results show that ingesting 400 mg/kg of dietary daidzein for 70 days is associated with a lower average daily weight gain (kilogram) (0.47 ± 0.03 vs 0.54 ± 0.04, P < 0.05) and a higher splenic damage index (1.00 ± 1.10 vs 0.00 ± 0.00, P < 0.05) in young pigs compared with control. Female pigs receiving 200 and 400 mg/kg daidzein showed reduced serum testosterone levels (ng/L) on days 35 and 70 compared with the control group (day 35, 246 ± 74 and 224 ± 20 vs 362 ± 48, P < 0.05; day 70, 252 ± 38 and 219 ± 77 vs 374 ± 38, P < 0.05). Daidzein residue (μg/kg) in pig livers increased (243 ± 80 vs 142 ± 47, P < 0.05, day 70). These results suggest that dietary supplements of 400 mg/kg of daidzein negatively affect the weight gain and splenic morphology of pigs.