Effects of various ginsenosides and ginseng root and ginseng berry on the activity of Pancreatic lipase

Protective effect of ginseng berry saponin conversion products on skin photodamage caused by UVB in vitro and in vivo

Ultraviolet (UV) B irradiation is closely related to skin aging and skin damage. Here, we report the photoprotective mechanism of action of ginseng berry rare saponins (GFRS) on UVB-induced damage to human keratinocytes and mouse skin. Several UVB irradiation-induced cytotoxicity and oxidative stress responses were assessed. GFRS preconditioning significantly improved HaCaT cell survival and reduced the levels of the DNA damage markers histone H2AX and cyclobutane pyrimidine dimer. Under oxidative stress, GFRS could reduce the transformation and loss of the mitochondrial membrane potential to the monomer form; effectively clear the expression of lipid reactive oxygen species, malondialdehyde, and other peroxides, and restore total superoxide dismutase, glutathione peroxidase, and catalase levels. The occurrence of ferroptosis after UVB induction was also studied. Erastin exacerbated the induced cellular iron overload, whereas GFRS and Fer-1 reversed this response to varying degrees. Mechanistically, GFRS activated the Nrf2/HO-1/GPX4 pathway and inhibited the phenomenon of ferroptosis in cells. Our findings were confirmed using a mouse model of UV induced skin injury. GFRS not only mitigated lipid peroxides and iron overload in tissues but also prevented skin barrier damage and collagen loss. Therefore, GFRS shows potential as a novel functional product as it protects the skin from UVB light-induced damage.

Comparative study on inhibitory effects of ginsenosides on human pancreatic lipase and porcine pancreatic lipase: structure-activity relationships and inhibitory mechanism

The inhibitory effects of twenty-six ginsenosides on human pancreatic lipase (hPL) and porcine pancreatic lipase (pPL) were studied. Study reveals that nine ginsenosides have moderate inhibitory effects against hPL, and good selectivity over pPL. By contrast, (S)-Rh2 showed good inhibitory effects on pPL over hPL. SAR analysis indicated that introduction of the O-glycosyl group(s) at C-3/C-7 site is unbeneficial for hPL inhibition, ginsenosides with A-skeleton is more beneficial than ginsenosides with B-/C-skeleton. Inhibition kinetic analysis indicated that Rg3 and (S)-Rh2 inhibited hPL-catalyzed DDAO-ol hydrolysis in a mixed manner. Molecular docking studies have confirmed that Rg3 and (S)-Rh2 inhibit hPL via many Pi-hydrogen interactions and hydrogen bonds with catalytic residues of hPL. These results indicated that pPL as an enzyme source could not fully represent the inhibitory effect of the tested compounds on hPL, and hPL should be used as far as possible to evaluate the inhibitory effect of PL.

A computational study to probe the binding aspects of potent polyphenolic inhibitors of pancreatic lipase

Pancreatic lipase (PL) is a keen target for anti-obesity therapy that reduces dietary fat absorption. Here, we investigated the binding patterns of 220 PL inhibitors having experimental IC50 values, using molecular docking and binding energy calculations. Screening of these compounds illustrated most of them bound at the catalytic site (S1-S2 channel) and a few compounds are at the non-catalytic site (S2-S3 channel/S1-S3 channel) of PL. This binding pattern could be due to structural uniqueness or bias in conformational search. A strong correlation of pIC50 values with SP/XP docking scores, binding energies (ΔGMMGBSA) assured the binding poses are more true positives. Further, understanding of each class and subclasses of polyphenols indicated tannins preferred non-catalytic site wherein binding energies are underestimated due to huge desolvation energy. In contrast, most of the flavonoids and furan-flavonoids have good binding energies due to strong interactions with catalytic residues. While scoring functions limited the understanding of sub-classes of flavonoids. Hence, focused on 55 potent PL inhibitors of IC50 < 5 µM for better in vivo efficacy. The prediction of bioactivity, drug-likeness properties, led to 14 bioactive compounds. The low root mean square deviation (0.1-0.2 nm) of these potent flavonoids and non-flavonoid/non-polyphenols PL-inhibitor complexes during 100 ns molecular dynamics runs (MD) as well as binding energies obtained from both MD and well-tempered metadynamics, support strong binding to catalytic site. Based on the bioactivity, ADMET properties, and binding affinity data of MD and wt-metaD of potent PL-inhibitors suggests Epiafzelechin 3-O-gallate, Sanggenon C, and Sanggenofuran A shall be promising inhibitors at in vivo conditions.Communicated by Ramaswamy H. Sarma.

Inhibitory Effects of Saponin-Rich Extracts from Pouteria cambodiana against Digestive Enzymes α-Glucosidase and Pancreatic Lipase

Pouteria cambodiana is a perennial plant that has a wide distribution in tropical regions. It is commonly referred to as 'Nom-nang' in the northern region of Thailand. The bark of this plant has been used for the purpose of promoting lactation among breastfeeding mothers. Moreover, P. cambodiana bark has a high nutraceutical potential due to the presence of saponins, which are secondary metabolites. The purpose of this study was to determine the optimal conditions for ultrasound-assisted extraction (UAE) of saponins from the bark of P. cambodiana and to assess the in vitro inhibitory activities of saponin-rich extracts. The most effective extraction conditions involved a temperature of 50 °C and a 50% concentration level of ethanol as the solvent, which allowed the extraction of saponin at a concentration of 36.04 mg/g. Saponin-rich extracts and their hydrolysates from P. cambodiana bark were evaluated for their ability to inhibit α-glucosidase and pancreatic lipase. The IC50 values for saponin- and sapogenin-rich extracts inhibiting α-glucosidase were 0.10 and 2.98 mg/mL, respectively. Non-hydrolysed extracts also had a stronger inhibitory effect than acarbose. In the case of pancreatic lipase, only the hydrolysed extracts exhibited inhibitory effects on pancreatic lipase (IC50 of 7.60 mg/mL). Thus, P. cambodiana bark may be an applicable natural resource for preparing ingredients for functional products with inhibitory activity against α-glucosidase and pancreatic lipase. The phenolic contents, saponin contents, and antioxidant activities of the dried extract stored at a low temperature of 25 °C for 2 months showed the best stability, with more than 90% retention.

Recent Advances in Yeast Recombinant Biosynthesis of the Triterpenoid Protopanaxadiol and Glycosylated Derivatives Thereof

Plant natural products are a seemingly endless resource for novel chemical structures. However, their extraction often results in high prices, fluctuation in both quantity and quality, and negative environmental impact. The latter might result from the extraction procedure but more often from the high amount of plant biomass required. With the advent of synthetic biology, producing natural plant products in large quantities using yeasts as hosts has become possible. Here, we focus on the recent advances in metabolic engineering of the yeasts species Saccharomyces cerevisiae and Yarrowia lipolytica for the synthesis of ginsenoside triterpenoids, namely, dammarenediol-II, protopanaxadiol, protopanaxatriol, compound K, ginsenoside Rh1, ginsenoside Rh2, ginsenoside Rg3, and ginsenoside F1. A discussion is provided on advanced synthetic biology, bioprocess strategies, and current challenges for the biosynthesis of ginsenoside triterpenoids. Finally, future directions in metabolic and process engineering are summarized and may help reify sustainable ginsenoside production.

Phytochemistry of ginsenosides: Recent advancements and emerging roles

Ginsenosides, a group of tetracyclic saponins, accounts for the nutraceutical and pharmaceutical relevance of the ginseng (Panax sp.) herb. Owing to the associated therapeutic potential of ginsenosides, their demand has been increased significantly in the last two decades. However, a slow growth cycle, low seed production, and long generation time of ginseng have created a gap between the demand and supply of ginsenosides. The biosynthesis of ginsenosides involves an intricate network of pathways with multiple oxidation and glycosylation reactions. However, the exact functions of some of the associated genes/proteins are still not completely deciphered. Moreover, ginsenoside estimation and extraction using analytical techniques are not feasible with high efficiency. The present review is a step forward in recapitulating the comprehensive aspects of ginsenosides including their distribution, structural diversity, biotransformation, and functional attributes in both plants and animals including humans. Moreover, ginsenoside biosynthesis in the potential plant sources and their metabolism in the human body along with major regulators and stimulators affecting ginsenoside biosynthesis have also been discussed. Furthermore, this review consolidates biotechnological interventions to enhance the biosynthesis of ginsenosides in their potential sources and advancements in the development of synthetic biosystems for efficient ginsenoside biosynthesis to meet their rising industrial demands.

The hydrolysis of saponin-rich extracts from fenugreek and quinoa improves their pancreatic lipase inhibitory activity and hypocholesterolemic effect

Saponins are promising compounds for ameliorating hyperlipidemia but scarce information exists about sapogenins, the hydrolyzed forms of saponins. Saponin-rich extracts and their hydrolysates from fenugreek (FE, HFE) and quinoa (QE, HQE), and saponin and sapogenin standards, were assessed on the inhibition of pancreatic lipase and interference on the bioaccessibility of cholesterol by in vitro digestion models. All extracts inhibited pancreatic lipase (IC₅₀ between 1.15 and 0.59 mg/mL), although the hydrolysis enhanced the bioactivity of HQE (p = 0.014). The IC₅₀ value significantly correlated to the saponin content (r = -0.82; p = 0.001). Only the hydrolyzed extracts showed a reduction of bioaccessible cholesterol (p < 0.001) higher than that of phytosterols (35% reduction). Sapogenin standards exhibited no bioactivities, protodioscin and hederacoside C slightly inhibited the lipase (around 10%) and protodioscin reduced the bioaccessible cholesterol (23% reduction, p = 0.035). The hydrolysis process of saponin-rich extracts enhances the bioactivity and allows developing multibioactive products against pancreatic lipase and cholesterol absorption simultaneously.