Anti-hyperglycemic and Anti-hyperlipidemic Effects of Lupinus albus in Type 2 Diabetic Patients: A Randomized Double-blind, Placebo-controlled Clinical Trial

Metabolomics and chemometrics depict the changes in the chemical profile of white lupine (Lupinus albus L.) bioactive metabolites during seed germination

The current study attempts to illustrate how the chemical and biological profile of white lupine seeds varies throughout the course of various germination days using UHPLC-QqQ-MS combined to chemometrics. Abscisic acid showed maximum level in the un-germinated seeds and started to decline with seed germination accompanied by an increase in the levels of gibberellins which were undetectable in un-germinated seeds. Coumaronochromones were the most prevalent constituents detected in un-germinated seeds while day 2 sprouts showed significant accumulation of flavones. The levels of alkaloids showed significant increase upon germination of the seeds reaching its maximum in day 14 sprouts. The OPLS model coefficients plot indicated that lupinalbin D and F, apigenin hexoside, kaempferol hexoside, albine, and hydoxylupanine showed strong positive correlation to the alpha amylase inhibitory activity of the tested samples while lupinalbin A, lupinisoflavone, lupinic acid and multiflorine were positively correlated to the inhibition of alpha glycosidase activity. The results obtained indicated that seed germination has a profound effect on the chemical profile as well as the in-vitro antidiabetic activity of lupine seeds.

A Lupinus angustifolius protein hydrolysate exerts hypocholesterolemic effects in Western diet-fed ApoE-/- mice through the modulation of LDLR and PCSK9 pathways

Lupin protein hydrolysates (LPHs) are gaining attention in the food and nutraceutical industries due to their several beneficial health effects. Recently, we have shown that LPH treatment reduces liver cholesterol and triglyceride levels in hypercholesterolemic mice. The aim of this study was to elucidate the effects of LPH treatment on the molecular mechanism underlying liver cholesterol metabolism in ApoE^-/- mice fed the Western diet. After identifying the composition of the peptide within the LPH mixture and determining its ability to reduce HMGCoAR activity in vitro, its effect on the LDLR and PCSK9 pathways was measured in liver tissue from the same mice. Thus, the LPH reduced the protein levels of HMGCoAR and increased the phosphorylated inactive form of HMGCoAR and the pHMGCoAR/HMGCoAR ratio, which led to the deactivation of de novo cholesterol synthesis. Furthermore, the LPH decreased the protein levels of SREBP2, a key upstream transcription factor involved in the expression of HMGCoAR and LDLR. Consequently, LDLR protein levels decreased in the liver of LPH-treated animals. Interestingly, the LPH also increased the protein levels of pAMPK responsible for HMGCoAR phosphorylation. Furthermore, the LPH controlled the PSCK9 signal pathway by decreasing its transcription factor, the HNF1-α protein. Consequently, lower PSCK9 protein levels were found in the liver of LPH-treated mice. This is the first study elucidating the molecular mechanism at the basis of the hypocholesterolemic effects exerted by the LPH in an in vivo model. All these findings point out LPHs as a future lipid-lowering ingredient to develop new functional foods.

Lupin-Derived Bioactive Peptides: Intestinal Transport, Bioavailability and Health Benefits

There is a renewed interest on the reliance of food-based bioactive compounds as sources of nutritive factors and health-beneficial chemical compounds. Among these food components, several proteins from foods have been shown to promote health and wellness as seen in proteins such as α/γ-conglutins from the seeds of Lupinus species (Lupin), a genus of leguminous plant that are widely used in traditional medicine for treating chronic diseases. Lupin-derived peptides (LDPs) are increasingly being explored and they have been shown to possess multifunctional health improving properties. This paper discusses the intestinal transport, bioavailability and biological activities of LDPs, focusing on molecular mechanisms of action as reported in in vitro, cell culture, animal and human studies. The potentials of several LDPs to demonstrate multitarget mechanism of regulation of glucose and lipid metabolism, chemo- and osteoprotective properties, and antioxidant and anti-inflammatory activities position LDPs as good candidates for nutraceutical development for the prevention and management of medical conditions whose etiology are multifactorial.

White Lupin as a Promising Source of Antioxidant Phenolics for Functional Food Production

Although white lupin is the oldest known legume in the history, it has been forgotten for many years. Now, the interest of food producers concerning white lupin is increased again. The aim of this study was to evaluate the total phenolic content (TPC), antioxidant activity (AA), and the content of selected phenolics in 11 white lupin cultivars. The determined TPC was in the interval 4260–5663 mg GAE/kg DM and the values of AA determined using DPPH•, ABTS•+, and FRAP methods were in the ranges 0.993–1.878, 5.496–7.924, and 1.328–1.741 μmol TE/g DM, respectively. Individual phenolics content (4-hydroxybenzoic acid, caffeic acid, trans-p-coumaric acid, trans-ferulic acid, myricetin, quercetin, apigenin, and genistein) were determined, too. Caffeic acid (442.9–766.2 mg/kg DM) and myricetin (11.2–21.2 mg/kg DM) are the dominant phenolics in the investigated lupin cultivars. Statistically significant differences in all investigated variables were observed between the tested cultivars except for quercetin. The obtained results show that the Astra and Nelly cultivars are a rich source of phenolic acids.

Lupin protein isolate improves insulin sensitivity and steatohepatitis in vivo and modulates the expression of the Fasn, Gys2, and Gsk3b genes

Although studies on lupin protein isolate (LPI) have indicated the presence of a preventive effect on insulin resistance (IR) and lipid disturbances, their influence on established pathological traits has received little attention. Here, we evaluated the in vivo effects of LPI on IR and steatohepatitis as well as its influence on genes involved in lipid and carbohydrate metabolism. We first induced IR and steatohepatitis in rats by maintaining them on a high-fat diet for 5 weeks. Thereafter, we administered LPI to the rats daily for 3 weeks. LPI improved insulin sensitivity (AUC: 6,777 ± 232 vs. 4,971 ± 379, p < .05, pre- vs. post-treatment values) and reduced glucose and triglyceride levels by one-third. In addition, LPI-treated rats exhibited attenuated steatohepatitis. At the molecular level, LPI treatment reduced liver Fasn gene expression substantially but increased Gys2 and Gsk3b levels. We concluded that the hypolipidemic and hypoglycemic activities of LPI may be caused by reduced liver lipogenesis and modulation of insulin sensitization mechanisms.

Quinolizidine alkaloids are transported to seeds of bitter narrow-leafed lupin

Narrow-leafed lupin (NLL, Lupinus angustifolius) is a promising legume crop that produces seeds with very high protein content. However, NLL accumulates toxic quinolizidine alkaloids (QAs) in most of its tissues, including the seeds. To determine the level of in situ biosynthesis in the seeds, we compared the accumulation of QAs with the expression of the biosynthetic gene lysine decarboxylase (LDC) in developing seeds and pods of a bitter (high-QA) variety of NLL. While QAs accumulated steadily in seeds until the drying phase, LDC expression was comparatively very low throughout seed development. In contrast, both QA accumulation and LDC expression peaked early in pods and decreased subsequently, reaching background levels at the onset of drying. We complemented these studies with MS imaging, which revealed the distribution patterns of individual QAs in cross-sections of pods and seeds. Finally, we show that a paternal bitter genotype does not influence the QA levels of F1 seeds grown on a maternal, low-QA genotype. We conclude that the accumulation of QAs in seeds of bitter NLL is mostly, if not exclusively, transported from other tissues. These results open the possibility of using transport engineering to generate herbivore-resistant bitter NLL varieties that produce QA-free seeds.