Simple and reliable methods for the determination of three steroidal glycosides in the eight species of Solanum by reversed-phase HPLC coupled with diode array detection

Ethnomedicinal Usage, Phytochemistry and Pharmacological Potential of Solanum surattense Burm. f

Solanum surattense Burm. f. is a significant member of the Solanaceae family, and the Solanum genus is renowned for its traditional medicinal uses and bioactive potential. This systematic review adheres to PRISMA methodology, analyzing scientific publications between 1753 and 2023 from B-on, Google Scholar, PubMed, Science Direct, and Web of Science, aiming to provide comprehensive and updated information on the distribution, ethnomedicinal uses, chemical constituents, and pharmacological activities of S. surattense, highlighting its potential as a source of herbal drugs. Ethnomedicinally, this species is important to treat skin diseases, piles complications, and toothache. The fruit was found to be the most used part of this plant (25%), together with the whole plant (22%) used to treat different ailments, and its decoction was found to be the most preferable mode of herbal drug preparation. A total of 338 metabolites of various chemical classes were isolated from S. surattense, including 137 (40.53%) terpenoids, 56 (16.56%) phenol derivatives, and 52 (15.38%) lipids. Mixtures of different parts of this plant in water-ethanol have shown in vitro and/or in vivo antioxidant, anti-inflammatory, antimicrobial, anti-tumoral, hepatoprotective, and larvicidal activities. Among the metabolites, 51 were identified and biologically tested, presenting antioxidant, anti-inflammatory, and antitumoral as the most reported activities. Clinical trials in humans made with the whole plant extract showed its efficacy as an anti-asthmatic agent. Mostly steroidal alkaloids and triterpenoids, such as solamargine, solanidine, solasodine, solasonine, tomatidine, xanthosaponin A-B, dioscin, lupeol, and stigmasterol are biologically the most active metabolites with high potency that reflects the new and high potential of this species as a novel source of herbal medicines. More experimental studies and a deeper understanding of this plant must be conducted to ensure its use as a source of raw materials for pharmaceutical use.

Solanum dulcamara L. Berries: A Convenient Model System to Study Redox Processes in Relation to Fruit Ripening

The present study provides, for the first time, a physicochemical and biochemical characterization of the redox processes associated with the ripening of Solanum dulcamara L. (bittersweet) berries. Electron Paramagnetic Resonance Spectroscopy (EPRS) and Imaging (EPRI) measurements of reactive oxygen species (ROS) were performed in parallel with the tissue-specific metabolic profiling of major antioxidants and assessment of antioxidant enzymes activity. Fruit transition from the mature green (MG) to ripe red (RR) stage involved changes in the qualitative and quantitative content of antioxidants and the associated cellular oxidation and peroxidation processes. The skin of bittersweet berries, which was the major source of antioxidants, exhibited the highest antioxidant potential against DPPH radicals and nitroxyl spin probe 3CP. The efficient enzymatic antioxidant system played a critical protective role against the deleterious effects of progressive oxidative stress during ripening. Here, we present the EPRI methodology to assess the redox status of fruits and to discriminate between the redox states of different tissues. Interestingly, the intracellular reoxidation of cell-permeable nitroxide probe 3CP was observed for the first time in fruits or any other plant tissue, and its intensity is herein proposed as a reliable indicator of oxidative stress during ripening. The described noninvasive EPRI technique has the potential to have broader application in the study of redox processes associated with the development, senescence, and postharvest storage of fruits, as well as other circumstances in which oxidative stress is implicated.

High-Performance Liquid Chromatography-Mass Spectrometry Analysis of Glycoalkaloids from Underexploited Solanum Species and Their Acetylcholinesterase Inhibition Activity

Solanum glycoalkaloids are gaining increased scientific attention due to their bioactive potential in the defense of plants against pests and pathogens. The comprehensive glycoalkaloid profiling from the leaves, stems, and roots of seven underexploited Solanum species (S. caripense, S. melanocerasum, S. muricatum, S. nigrum, S. quitoense, S. retroflexum, and S. sisymbriifolium) was conducted using high-performance liquid chromatography-time-of-flight mass spectrometry. A total of 51 glycoalkaloids were shared among the studied Solanum species, with concentrations ranging from 7 to 5.63 × 105 ng g-1. Based on the glycoalkaloid composition, plants were separated into two clusters, Cluster 1 (S. melanocerasum, S. nigrum, and S. retroflexum) and Cluster 2 (S. caripense, S. muricatum, S. quitoense, and S. sisymbriifolium). The inhibition activity of glycoalkaloid extracts on acetylcholinesterase showed a half-maximal inhibitory concentration (IC50), ranging from 0.4 (S. nigrum stems) to 344.9 µg mL-1 (S. sisymbriifolium leaves), that was not directly correlated to the total glycoalkaloid contents. This suggests that the composition of glycoalkaloids in the plant extract, rather than the total concentration, is a driver of biological activity. The study provides a framework for the bioprospecting of underexploited Solanum species for exploring bioactive glycoalkaloids and other compounds with potential pesticidal activities for the development of green bioformulation. This is the first comprehensive report on the glycoalkaloid profiles of S. retroflexum.

Risk assessment of glycoalkaloids in feed and food, in particular in potatoes and potato-derived products

The European Commission asked EFSA for a scientific opinion on the risks for animal and human health related to the presence of glycoalkaloids (GAs) in feed and food. This risk assessment covers edible parts of potato plants and other food plants containing GAs, in particular, tomato and aubergine. In humans, acute toxic effects of potato GAs (α-solanine and α-chaconine) include gastrointestinal symptoms such as nausea, vomiting and diarrhoea. For these effects, the CONTAM Panel identified a lowest-observed-adverse-effect level of 1 mg total potato GAs/kg body weight (bw) per day as a reference point for the risk characterisation following acute exposure. In humans, no evidence of health problems associated with repeated or long-term intake of GAs via potatoes has been identified. No reference point for chronic exposure could be identified from the experimental animal studies. Occurrence data were available only for α-solanine and α-chaconine, mostly for potatoes. The acute dietary exposure to potato GAs was estimated using a probabilistic approach and applying processing factors for food. Due to the limited data available, a margin of exposure (MOE) approach was applied. The MOEs for the younger age groups indicate a health concern for the food consumption surveys with the highest mean exposure, as well as for the P95 exposure in all surveys. For adult age groups, the MOEs indicate a health concern only for the food consumption surveys with the highest P95 exposures. For tomato and aubergine GAs, the risk to human health could not be characterised due to the lack of occurrence data and the limited toxicity data. For horses, farm and companion animals, no risk characterisation for potato GAs could be performed due to insufficient data on occurrence in feed and on potential adverse effects of GAs in these species.

The application of an aqueous two-phase system combined with ultrasonic cell disruption extraction and HPLC in the simultaneous separation and analysis of solanine and Solanum nigrum polysaccharide from Solanum nigrum unripe fruit

An aqueous two-phase system was used in conjunction with ultrasonic cell disruption to extract and separate solanine (mainly solasonine and solamargine) and Solanum nigrum polysaccharide from Solanum nigrum unripe fruit. The optimized conditions of the present study were determined by a single-factor experiment and a multifactor experiment. The concentration of ethanol was set at 60% and the duration of the ultrasonic cell disruption extraction was 50 min. In the ethanol-K₂CO₃ aqueous two-phase separation system, the concentration of ethanol was 36%, the concentration of K₂CO₃ was 0.21 mg·mL^-1, and the temperature was 15 °C. The solasonine and solamargine were determined by high-performance liquid chromatography, and the Solanum nigrum polysaccharide was determined by an ultraviolet-visible spectrophotometer in accordance with the phenol-sulfuric acid method. xUnder optimized conditions, the average extraction efficiencies of solasonine, solamargine and Solanum nigrum polysaccharide were 95.86%, 95.95% and 96.95%, respectively, and the average separation efficiencies of solasonine, solamargine and Solanum nigrum polysaccharide were 2.07 mg·g^-1, 2.05 mg·g^-1 and 8.15 mg·g^-1, respectively.

Reverse-phase HPLC method for the quantification of two antihyperglycemic glycolipids in Oplismenus burmannii

Glycolipids and sphingolipids are well known for their diverse biological activities like anticancer, anti-inflammatory, antistress, anti-HIV, hepatoprotective and antimicrobial. The present study deals with the activity-guided isolation and characterization of two antihyperglycemic glycolipids, (2S)-1,2-di-O-octadecanoyl-3-O-[α-d-galctopyranosyl-(1'' → 6')-O-β-d-galactopyranosyl] glycerol (1) and 1-O-β-d-glucopyranosyl-(2S,3S,4R,8E)-2-[(2R)-2-hydroxy-tetracosanoylamino]-2,3,4-octadecanetriol-8-ene (2) from Oplismenus burmannii and the development of a simple and validated reverse-phase HPLC analytical method for their quantification in the methanolic extracts of O. burmannii. The marker compounds 1 and 2 were isolated from the methanolic extract of O. burmannii and characterized on the basis of their spectroscopic data. Their antihyperglycemic potential was evaluated by determining their glucose uptake-stimulating potential in L6-GLUT4myc myotube cells. Finally, these analytes were separated on a Waters Spherisorb ODS 2 column with a binary gradient of methanol and water at a constant flow rate of 0.8 mL/min and detected using a photodiode array detector at 230 nm. The calibration curve was linear (r(2)  > 0.999) over 1.2 orders of magnitude with acceptable accuracy, reproducibility and recovery (98.16-100.50%). The limits of detection and quantification for 1 and 2 were 1.36, 4.11 and 1.11, 3.35 µg/mL respectively. The method is simple, accurate, precise and selective and may be routinely used for the quality control analysis of whole plant extract of O. burmannii for these two glycolipids.