Determination of Saponins in Lupin Seed (Lupinus Angustifolius) Using High-Performance Liquid Chromatography: Comparison with a Gas Chromatographic Method

Anticancer properties and mechanism insights of α-hederin

α-Hederin is a natural bioactive molecule very abundant in aromatic and medicinal plants (AMP). It was identified, characterized, and isolated using different extraction and characterization technologies, such as HPLC, LC-MS and NMR. Biological tests have revealed that this natural molecule possesses different biological properties, particularly anticancer activity. Indeed, this activity has been investigated against several cancers (e.g., esophageal, hepatic, breast, colon, colorectal, lung, ovarian, and gastric). The underlying mechanisms are varied and include induction of apoptosis and cell cycle arrest, reduction of ATP generation, as well as inhibition of autophagy, cell proliferation, invasion, and metastasis. In fact, these anticancer mechanisms are considered the most targeted for new chemotherapeutic agents' development. In the light of all these data, α-hederin could be a very interesting candidate as an anticancer drug for chemotherapy, as well as it could be used in combination with other molecules already validated or possibly investigated as an agent sensitizing tumor cells to chemotherapeutic treatments.

Polyphenols, Saponins and Phytosterols in Lentils and Their Health Benefits: An Overview

The lentil (Lens culinaris L.) is one of the most important legumes (family, Fabaceae). It is a natural functional food rich in many bioactive compounds, such as polyphenols, saponins and phytosterols. Several studies have demonstrated that the consumption of lentils is potentially important in reducing the incidence of a number of chronic diseases, due to their bioactive compounds. The most common polyphenols in lentils include phenolic acids, flavan-3-ol, flavonols, anthocyanidins, proanthocyanidins or condensed tannins, and anthocyanins, which play an important role in the prevention of several degenerative diseases in humans, due to their antioxidant activity. Furthermore, lentil polyphenols are reported to have antidiabetic, cardioprotective and anticancer activities. Lentil saponins are triterpene glycosides, mainly soyasaponins I and βg. These saponins have a plasma cholesterol-lowering effect in humans and are important in reducing the risk of many chronic diseases. Moreover, high levels of phytosterols have been reported in lentils, especially in the seed coat, and β-sitosterol, campesterol, and stigmasterol are the most abundant. Beyond their hypocholesterolemic effect, phytosterols in lentils are known for their anti-inflammatory activity. In this review, the current information on the nutritional composition, bioactive compounds including polyphenols, saponins and phytosterols, and their associated health-promoting effects are discussed.

Saponins in pulses and their health promoting activities: A review

Saponins are a class of natural compounds present in pulses having surface active properties. These compounds show variation in type, structure and composition of their aglycone moiety and oligosaccharide chains. Saponins have plasma cholesterol lowering effect in humans and are important in reducing the risk of many chronic diseases. Moreover, they have shown strong cytotoxic effects against cancer cell lines. However, more epidemiological and clinical studies are required for the proper validation of these health promoting activities. Processing and cooking promotes the loss of saponins from foods. The effect of soaking, sprouting and cooking on the stability and bioavailability of saponins in pulses is an important area which should be thoroughly worked out for achieving desirable health benefits. In the present review, the structures, contents and health benefits of saponins present in pulses are discussed. Moreover, the effect of processing (of pulses) on the saponins is also highlighted.

Soya Saponins Induce Enteritis in Atlantic Salmon (Salmo salar L.)

Soybean meal-induced enteritis (SBMIE) is a well-described condition in the distal intestine of salmonids, and saponins have been implicated as the causal agent. However, the question remains whether saponins alone cause SBMIE. Moreover, the dose-response relationship has not been described. In a 10 week feeding trial with Atlantic salmon, a highly purified (95%) soya saponin preparation was supplemented (0, 2, 4, 6, or 10 g/kg) to two basal diets, one containing fishmeal as the major protein source (FM) and the other 25% lupin meal (LP). Saponins caused dose-dependent increases in the severity of inflammation independent of the basal diet, with concomitant alterations in digestive functions and immunological marker expression. Thus, saponins induced inflammation whether the diet contained other legume components or not. However, responses were often the same or stronger in fish fed the corresponding saponin-supplemented LP diets despite lower saponin exposure, suggesting potentiation by other legume component(s).

Saponins, classification and occurrence in the plant kingdom

Saponins are a structurally diverse class of compounds occurring in many plant species, which are characterized by a skeleton derived of the 30-carbon precursor oxidosqualene to which glycosyl residues are attached. Traditionally, they are subdivided into triterpenoid and steroid glycosides, or into triterpenoid, spirostanol, and furostanol saponins. In this study, the structures of saponins are reviewed and classified based on their carbon skeletons, the formation of which follows the main pathways for the biosynthesis of triterpenes and steroids. In this way, 11 main classes of saponins were distinguished: dammaranes, tirucallanes, lupanes, hopanes, oleananes, taraxasteranes, ursanes, cycloartanes, lanostanes, cucurbitanes, and steroids. The dammaranes, lupanes, hopanes, oleananes, ursanes, and steroids are further divided into 16 subclasses, because their carbon skeletons are subjected to fragmentation, homologation, and degradation reactions. With this systematic classification, the relationship between the type of skeleton and the plant origin was investigated. Up to five main classes of skeletons could exist within one plant order, but the distribution of skeletons in the plant kingdom did not seem to be order- or subclass-specific. The oleanane skeleton was the most common skeleton and is present in most orders of the plant kingdom. For oleanane type saponins, the kind of substituents (e.g. -OH, =O, monosaccharide residues, etc.) and their position of attachment to the skeleton were reviewed. Carbohydrate chains of 18 monosaccharide residues can be attached to the oleanane skeleton, most commonly at the C3 and/or C17 atom. The kind and positions of the substituents did not seem to be plant order-specific.

Triterpene glycosides of Lupinus angustifolius

Investigation of whole seeds of Lupinus angustifolius L. (Leguminosae) yielded the two triterpenoid saponins with branched monosaccharide chain 3 beta,21 beta,22 beta,24-tetrahydroxyolean-12-en-3-O-alpha-L-rhamnopyranosyl-(1-->3)-[alpha-L-rhamnopyranosyl-(1-->2)]-beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranoside (3) and 3 beta,21 beta,22 beta,24-tetrahydroxyolean-12-en-3-O-alpha-L-rhamnopyranosyl-(1-->3)-[alpha-L-rhamnopyranosyl-(1-->2)]-beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl-21-O-alpha-L-rhamnopyranoside (4) along with the known compounds soyasaponin I (1) and 3 beta,21 beta,22 beta,24-tetrahydroxyolean-12-en-3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl-21-O-alpha-L-rhamnopyranoside (2). The structures of the compounds were elucidated using hydrolysis, FAB-MS and extensive NMR experiments. Compounds 2-4 showed moderate antifungal activity against Candida albicans with MIC values of 25, 25 and 30 microg/ml, respectively. Only soyasaponin I was found weakly hemolytic (HC(50) >500 microg/ml).

A preliminary study on the effect of germination on saponin content and composition of lentils and chick peas

Two cultivars of chick peas (Cicer arietinum) and one cultivar of lentils (Lens culinaris) were subjected to germination in the dark for 6 days at 20 degrees C. Soyasaponin VI, also known as soyasaponin beta g, a DDMP- (2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one-) conjugated form of soyasaponin I, was the only saponin detected in both the unprocessed and germinated seed. No significant changes in saponin content were observed for chick peas or lentils after a 6-day germination.