Instability and Structural Change of 4-Methylsulfinyl-3-butenyl Isothiocyanate in the Hydrolytic Process

Non-enzymatic degradation of aliphatic Brassicaceae isothiocyanates during aqueous heat treatment

Glucosinolate-derived isothiocyanates are valuable for human health as they exert health promoting effects. As thermal food processing could affect their levels in a structure dependent way, the stability and reactivity of 12 Brassicaceae isothiocyanates during aqueous heating at 100 °C and pH 5-8 were investigated. The formation of their corresponding amines and N,N'-dialk(en)yl thioureas was quantified. Further, the potential to form odor active compounds was investigated by HRGC-MS-olfactometry. A strong structure-reactivity relationship was found and shorter side chains and electron withdrawing groups increase the reactivity of isothiocyanates. 3-(Methylsulfonyl)-propyl isothiocyanate was least stable. The main products are the corresponding amines (up to 69% recovery) and formation of N,N'-dialk(en)yl thioureas is only relevant at neutral to basic pH values. Apart from allyl isothiocyanate also 3-(methylthio)propyl isothiocyanate is precursor to many sulfur-containing odor active compounds. Thus, the isothiocyanate-structure affects their levels but also contributes to the flavor of boiled Brassicaceae vegetables.

Novel pH-sensitive gellan gum-ε-polylysine hydrogel microspheres for sulforaphene delivery

BACKGROUND

This study aimed to improve the stability and utilization of sulforaphene (SFE) and to enhance the intestinal stability and pH-sensitive release of SFE in the gastrointestinal tract. To achieve this objective, calcium chloride (CaCl2) was used as a crosslinking agent to fabricate novel SFE-loaded gellan gum (GG)-ε-polylysine (ε-PL) pH-sensitive hydrogel microspheres by using the ionic crosslinking technique.

RESULTS

The molecular docking results of GG, ε-PL, and SFE were good and occurred in the natural state. The loading efficiency (LE) of all samples was above 70%. According to the structural characterization results, GG and ε-PL successfully embedded SFE in a three-dimensional network structure through electrostatic interaction. The swelling characteristics and in vitro release results revealed that the microspheres were pH-sensitive, and SFE was mainly retained inside the hydrogel microsphere in the stomach, and subsequently released in the intestine. The result of cytotoxicity assay showed that the hydrogel microspheres were non-toxic and had an inhibitory effect on human colon cancer Caco-2 cells.

CONCLUSION

Thus, the hydrogel microspheres could improve SFE stability and utilization and achieve the intestinal targeted delivery of SFE. © 2024 Society of Chemical Industry.

Optimization of cultivar, germination time and extraction for radish sprout extract with high sulforaphene content

BACKGROUND

Cruciferous vegetable sprout has been highlighted as a promising functional material rich in bioactive compounds called isothiocyanates (ITCs) and it can be grown in very short periods in controlled indoor farms. However, because ITCs content depends on multiple factors such as cultivar, germination time and myrosinase activity, those variables need to be controlled during germination or extraction to produce functional materials enriched in ITCs. Sulforaphene (SFEN), an ITC found primarily in radishes (Raphanus sativus L.), exerts beneficial effects on obesity. However, the optimal germination and extraction conditions for radish sprout (RSP) to increase SFEN content remain unascertained, and the extract's anti-obesity effect has yet to be evaluated.

RESULTS

The present study found that the SFEN content was highest in purple radish sprout (PRSP) among the six cultivars investigated. Optimal SFEN content occurred after 2 days of PRSP germination (2 days PRSP). To maximize the dry matter yield, total ITCs and SFEN contents in RSP extract, we found the optimal conditions for extracting PRSP [27.5 °C, 60 min, 1:75.52 solute/solvent (w/v), no ascorbic acid] using response surface methodology. Consistent with high SFEN content, 2 days PRSP extract significantly outperformed 3 days or 4 days PRSP extract in inhibiting lipid accumulation in 3T3-L1 cells. Moreover, 2 days PRSP extract suppressed adipogenesis and lipogenesis-related protein expression.

CONCLUSION

Regarding the cultivar, germination time and extraction conditions, optimally produced PRSP extract contains high SFEN content and exerts anti-obesity effects. Thus, we suggest PRSP extract as a potent functional material for obesity prevention. © 2024 Society of Chemical Industry.

Micro-grinding-based production for sulforaphene-enriched radish seeds extract via facilitating glucosinolates-myrosinase reaction, and evaluation of its anti-adipogenic effects

Sulforaphene (SFEN), an isothiocyanate (ITC) abundant in radish (Raphanus sativus) seeds (RS), has many health benefits, including anti-obesity effects. SFEN content is affected by multiple factors during processing, such as glucoraphenin (GLE) (the precursor of SFEN) availability, myrosinase (essential for conversion from GLE to SFEN) activity, and SFEN stability. We examined the physiochemical-properties and anti-adipogenic effects of SFEN-enriched RSE produced by two processes, roasting and micro-grinding. The roasting process lowered SFEN content and myrosinase activity over 50 °C. However, among micro-grinding conditions, smaller particle size (#2 grind, ≈11.31 μm) more effectively increased SFEN content in RS compared to larger particles (#1 grind, ≈ 179.50 μm) by accelerating available GLE and myrosinase release from RS. Grind #2 also effectively inhibited the adipogenesis of 3T3-L1 pre-adipocytes compared to #1. Thus, micro-grinding can be suggested for producing SFEN-enriched RSE with anti-adipogenic activity as a functional material for obesity prevention or treatment.

Qualitative and quantitative analysis of the component variations of Raphani Semen during the stir-frying process and elucidation of transformation pathways of multiple components

Raphani Semen (RS) encompasses two distinct application forms in Chinese clinical practice: raw RS (RRS) and stir-fried RS (SRS). They exhibit divergent drug properties and effects, as described in traditional Chinese medicine theory known as "Sheng shu yi zhi, sheng sheng shu jiang". The dissimilarity in RS's drug properties is intrinsically linked to alterations in its internal components during the stir-frying process. Previous studies have demonstrated that stir-frying renders myrosinase inactive, thereby preventing the enzymatic hydrolysis of glucosinolates in RS. However, the precise enzymatic hydrolysis pathway and products of glucosinolates remain unclear. Furthermore, it remains uncertain whether other components undergo changes influenced by endogenous enzymes. The objective of this study is to systematically analyze the chemical components disparities between RRS and SRS using high-performance liquid chromatography coupled with time-of-flight mass spectrometry (HPLC-TOF-MS). Additionally, it seeks to elucidate the potential transformation pathways of multiple components from an enzymatic hydrolysis perspective. We have developed a sensitive and efficient high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (HPLC-QQQ-MS) method for quantifying the content of 5 characteristic components, including glucoraphenin, sinapine thiocyanate, sulforaphene, sinapic acid, and 3',6-disinapoylsucrose. Based on retention time and MS spectra, we have identified 19 characteristic components in both SRS and RRS, encompassing glucosinolates and sulfur-containing derivatives, oligosaccharide esters, and small-molecule phenolic acids. Notably, 18 of these components undergo changes during the enzymatic hydrolysis process, leading to the identification of 4 transformation pathways: glucoraphenin, 6-sinapoylglucoraphenin, 3',6-disinapoylsucrose and β-D-(3,4-disinapoyl) furanofructosyl-α-D-(6-sinapisoyl) glucoside, along with 3'-O-sinapoyl-6-O-feruloylsucrose. Quantitative analysis reveals significant differences, including lower levels of glucoraphenin in RRS compared to SRS, higher sulforaphene and sinapic acid levels in RRS, while sinapine thiocyanate and 3',6-disinapoylsucrose remain unchanged before and after stir-frying. The results of this study highlight distinct chemical compositions between RRS and SRS. Additionally, the method of characterization and content determination constructed in this paper has strong practical value and provides a useful approach for comprehensively evaluating the chemical composition and quality of RS.

Effects of Sulforaphene on the Cariogenic Properties of Streptococcus Mutans In Vitro and Dental Caries Development In Vivo

Sulforaphene (SFE) is a common nutritional supplement with antibacterial, anti-cancer, and anti-inflammatory effects. However, the effects of SFE on the cariogenicity of Streptococcus mutans and dental caries have not been reported. The objectives of this study were to investigate the caries-controlling potential of SFE. The effects of SFE on S. mutans were investigated using the broth microdilution method, crystal violet staining, SEM observation, acid tolerance assays, lactic acid quantification, and polysaccharide measurements. A rat caries model was established to evaluate the caries-controlling effects and biocompatibility of SFE in vivo. SFE inhibited S. mutans growth and biofilm formation. Furthermore, SFE restrained the cariogenic properties of S. mutans, including its acid production, acid tolerance, and extracellular polysaccharide production, without affecting the bacterial viability at sub-inhibitory levels. In the rat caries model, SFE significantly arrested the onset and development of dental caries. Moreover, no visible hemolytic phenomenon or cytotoxicity was detected in the SFE groups. After four weeks of SFE treatment, all rats remained in apparent good health with no significant differences in weight gain; their hemogram and biochemical parameters were normal; no pathological changes were observed in the oral mucosa, liver, or kidneys. In conclusion, SFE was safe and inhibited the development of caries effectively.

Enhancing stability and bioavailability of sulforaphene in radish seed extracts using nanoemulsion made with high oleic sunflower oil

The effect of nanoemulsions on the stability and bioavailability of sulforaphene (SFEN) in radish seed extract (RSE) was investigated. Four types of oil were used as lipid ingredients of the nanoemulsions: soybean, high oleic acid sunflower, coconut, and hydrogenated palm oils. SFEN in RSE nanoemulsions showed greater stability to temperature, acid, and alkaline conditions than SFEN in RSE suspended in water (RSE-S). Particularly under alkaline conditions, the half-life of SFEN in the nanoemulsion with high oleic sunflower oil (RSE-HOSO) was 8 times longer than that of RSE-S. Furthermore, in the pharmacokinetics study, it was observed that AUC0-8 increased and oral clearance (CL/F) decreased significantly in rats orally administered RSE-HOSO compared with RSE-S (p < 0.05). This study indicates that the type of oil used in nanoemulsions affects the stability and bioavailability of SFEN in RSE. These results may provide a guideline for the development of functional foods containing RSE.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01304-2.

Traditional uses, phytochemistry, transformation of ingredients and pharmacology of the dried seeds of Raphanus sativus L. (Raphani Semen), A comprehensive review

ETHNOPHARMACOLOGICAL RELEVANCE

Raphani Semen (Lai Fu-zi in Chinese, RS), the dried seeds of Raphanus sativus L., is a traditional Chinese herbal medicine. RS has long been used for eliminating bloating and digestion, antitussive, expectorant and anti-asthmatic in clinical treatment of traditional Chinese medicine.

AIM OF THE STUDY

This review provides a critical and comprehensive summary of traditional uses, phytochemistry, transformation of ingredients and pharmacology of RS based on research data that have been reported, aiming at providing a basis for further study on RS.

MATERIALS AND METHODS

The search terms "Raphani Semen", "the seeds of Raphanus sativus L." and "radish seed" were used to obtain the information from electronic databases such as Web of Science, China National Knowledge Infrastructure, PubMed and other web search instruments. Traditional uses, phytochemistry, transformation of ingredients and pharmacology of RS were summarized.

RESULTS

RS has been traditionally used to treat food dyspeptic retention, distending pain in the epigastrium and abdomen, constipation, diarrhea and dysentery, panting, and cough with phlegm congestion in the clinical practice. The chemical constituents of RS include glucosinolates and sulfur-containing derivatives, phenylpropanoid sucrosides, small organic acids and derivatives, flavone glycosides, alkaloids, terpenoids, steroids, oligosaccharides and others. Among them, glucosinolates can be transformated to isothiocyanates by plant myrosinase or the intestinal flora, which display a variety of activities, such as anti-tumor, anti-inflammatory, antioxidant, antibacterial, treatment of metabolic diseases, central nervous system protection, anti-osteoporosis. RS has a variety of pharmacological activities, including treatment of metabolic diseases, anti-inflammatory, anti-tumor, antioxidant, antibacterial, antihypertensive, central nervous system protection, anti-osteoporosis, etc. This review will provide useful insight for exploration, further study and precise medication of RS in the future.

CONCLUSIONS

According to its traditional uses, phytochemistry, transformation of ingredients and pharmacology, RS is regarded as a promising medical plant with various chemical compounds and numerous pharmacological activities. However, the material bases and mechanisms of traditional effect of RS need further study.

The degradation kinetics and mechanism of moringin in aqueous solution and the cytotoxicity of degraded products

In this work, we investigated the degradation of moringin (4-[(α-l-rhamnosyloxy)benzyl]-isothiocyanate), a major bioactive isothiocyanate (ITC) found in moringa seeds (Moringa oleifera Lam), at various food processing conditions. Moringin degrades rapidly to several water-soluble products via a pseudo-first-order kinetics. By analyzing the reaction products, the degradation mechanism was found to be through hydrolyzing to (A) 1-O-(4-hydroxymethylphenyl) α-l-rhamnopyranoside (rhamnobenzyl alcohol RBA) or (B) rhamnobenzylamine. The formed amine further reacts with moringin to form N,N'-bis{4-[(α-l-rhamnosyloxy)benzyl]}thiourea (di-rhamnobenzyl thiourea, DRBTU). In addition, moringin isomerizes to 4-[(α-l-rhamnosyloxy)benzyl]thiocyanate (RBTC), which further reacts with moringin to form S,N-bis{4-[(α-l-rhamnosyloxy)benzyl]}-dithiocarbamate (DRBDTC). Furthermore, pH was found to have an effect on the degradation of moringin. RBA and RBTC were major degraded products in neutral and acidic conditions while thiourea (DRBTU) was in alkaline condition. Although moringin showed higher cytotoxicity to cancer cells, its degraded products showed very weak or no activities, suggesting that the isothiocyanate group of ITCs is essential for their cancer chemoprevention activities.

The Influence of Red Cabbage Extract Nanoencapsulated with Brassica Plasma Membrane Vesicles on the Gut Microbiome of Obese Volunteers

The aim of the study was to evaluate the influence of the red cabbage extracts on the bioaccessibility of their isothiocyanates, and their effect on the intestinal microbiota using a dynamic model of human digestion treated with the gut microbiome of obese adults. The elicitation of red cabbage plants with methyl jasmonate (MeJA) duplicated the content of glucosinolates (GSLs) in the plant organs used for elaborating the encapsulated formula. The use of plasma membrane vesicles, according to a proper methodology and technology, showed a high retention of sulforaphane (SFN) and indol-3-carbinol (I3C) over the course of the 14-day digestion study. The microbiome was scarcely affected by the treatments in terms of microbiota composition or the Bacteroidetes/Firmicutes ratio, but a 3 to 4-fold increase was observed in the production of butyric acid with the encapsulated extract treatment. Based on our pilot red cabbage extract study, the consumption of this extract, mainly encapsulated, may play a potential role in the management of obesity in adults.

Glucosinolates and phenolic compounds rich broccoli extract: Encapsulation by electrospraying and antitumor activity against glial tumor cells

Gliomas, intracranial malignant tumors, are aggressive, asymptomatic and difficult to treat due to their degree of infiltration, alternatives are needed to treat the disease. In this sense, natural compounds from the specialized metabolism of plants can act to control the disease. Glucosinolates and phenolic compounds, present in broccoli, have a potential to promote tumor cell death, however due to the low stability of these compounds, encapsulation becomes an alternative for their preservation. The objective was to encapsulate the broccoli extract by electrospraying and to evaluate its cytotoxicity in the primary cell culture of astrocytes and gliomas. The capsules were produced and characterized by encapsulation efficiency, functional groups, thermal stability and morphology, the capsule that presented the best parameters was used for the evaluation of cell cytotoxicity and antitumor activity. Capsules with equal or less than 50 % extract showed high encapsulation efficiency, high thermal stability and uniform morphology due to non-saturation of the active zein sites, which allowed a complete encapsulation of the added extract, as well as a greater protection of the compounds. The capsule with 50 % of the extract showed good results of the efficiency, morphology and thermal stability and was used to evaluate the antitumor activity, since the addition of extract in proportions greater than 60 % promoted saturation of the active sites and lower encapsulation efficiency, and directly affects the morphology and thermal stability. The encapsulated and unencapsulated extracts showed strong selective antitumor effect against glial tumor cells without toxicity to non-tumor cells.

Simultaneous Analysis of Glucosinolates and Isothiocyanates by Reversed-Phase Ultra-High-Performance Liquid Chromatography-Electron Spray Ionization-Tandem Mass Spectrometry

A new method to simultaneously analyze various glucosinolates (GSLs) and isothiocyanates (ITCs) by reversed-phase ultra-high-performance liquid chromatography-electron spray ionization-tandem mass spectrometry has been developed and validated for 14 GSLs and 15 ITCs. It involved derivatization of ITCs with N-acetyl-l-cysteine (NAC). The limits of detection were 0.4-1.6 μM for GSLs and 0.9-2.6 μM for NAC-ITCs. The analysis of Sinapis alba, Brassica napus, and Brassica juncea extracts spiked with 14 GSLs and 15 ITCs indicated that the method generally had good intraday (≤10% RSD) and interday precisions (≤16% RSD). Recovery of the method was unaffected by the extracts and within 71-110% for GSLs and 66-122% for NAC-ITCs. The method was able to monitor the enzymatic hydrolysis of standard GSLs to ITCs in mixtures. Furthermore, GSLs and ITCs were simultaneously determined in Brassicaceae plant extracts before and after myrosinase treatment. This method can be applied to further investigate the enzymatic conversion of GSLs to ITCs in complex mixtures.

Intensifying sulforaphane formation in broccoli sprouts by using other cruciferous sprouts additions

Sulforaphane is a significant chemopreventive compound which is the predominant glucosinolate in broccoli sprouts. However, the existence of the epithiospecifier protein could direct the hydrolysis of glucosinolates toward sulforaphane nitrile formation instead of sulforaphane. Therefore, the study aimed on improving the yielding of sulforaphane in broccoli sprouts with a new method of the united hydrolysis of cruciferous sprouts. According to the results, the addition of radish, rocket and rape sprouts to broccoli sprouts could promote the hydrolysis of the glucoraphanin to anticancer effective sulforaphane to 2.03, 2.32 and 1.95-fold, respectively, compared to single broccoli sprouts. Meanwhile, the formation of non-bioactive sulforaphane nitrile in these three groups decreased greatly. However, the addition of mustard sprouts had no positive effect. These observations could make a contribution to the potential chemoprotective effects of broccoli sprouts.

Degradation of Biofumigant Isothiocyanates and Allyl Glucosinolate in Soil and Their Effects on the Microbial Community Composition

Brassicales species rich in glucosinolates are used for biofumigation, a process based on releasing enzymatically toxic isothiocyanates into the soil. These hydrolysis products are volatile and often reactive compounds. Moreover, glucosinolates can be degraded also without the presence of the hydrolytic enzyme myrosinase which might contribute to bioactive effects. Thus, in the present study the stability of Brassicaceae plant-derived and pure glucosinolates hydrolysis products was studied using three different soils (model biofumigation). In addition, the degradation of pure 2-propenyl glucosinolate was investigated with special regard to the formation of volatile breakdown products. Finally, the influence of pure glucosinolate degradation on the bacterial community composition was evaluated using denaturing gradient gel electrophoresis of 16S rRNA gene amplified from total community DNA. The model biofumigation study revealed that the structure of the hydrolysis products had a significant impact on their stability in the soil but not the soil type. Following the degradation of pure 2-propenyl glucosinolate in the soils, the nitrile as well as the isothiocyanate can be the main degradation products, depending on the soil type. Furthermore, the degradation was shown to be both chemically as well as biologically mediated as autoclaving reduced degradation. The nitrile was the major product of the chemical degradation and its formation increased with iron content of the soil. Additionally, the bacterial community composition was significantly affected by adding pure 2-propenyl glucosinolate, the effect being more pronounced than in treatments with myrosinase added to the glucosinolate. Therefore, glucosinolates can have a greater effect on soil bacterial community composition than their hydrolysis products.

Reactivity and stability of glucosinolates and their breakdown products in foods

The chemistry of glucosinolates and their behavior during food processing is very complex. Their instability leads to the formation of a bunch of breakdown and reaction products that are very often reactive themselves. Although excessive consumption of cabbage varieties has been thought for long time to have adverse, especially goitrogenic effects, nowadays, epidemiologic studies provide data that there might be beneficial health effects as well. Especially Brassica vegetables, such as broccoli, radish, or cabbage, are rich in these interesting plant metabolites. However, information on the bioactivity of glucosinolates is only valuable when one knows which compounds are formed during processing and subsequent consumption. This review provides a comprehensive, in-depth overview on the chemical reactivity of different glucosinolates and breakdown products thereof during food preparation.

Inhibitory effect of Raphanobrassica on Helicobacter pylori-induced gastritis in Mongolian gerbils

Helicobacter pylori (H. pylori) infection is well known to be associated with chronic gastritis and also development of gastric cancer. Raphanobrassica (RB) is an intergeneric hybrid of the genera Raphanus (radish) and Brassica (cabbages) containing appreciable amounts of glucoraphanin (GR) and glucoraphenin (GRe), which are actively hydrolyzed by the enzyme myrosinase to sulforaphane and sulforaphene, respectively. Both of these metabolites exert antimicrobial and anti-inflammatory activity. The purpose of the present study was to investigate the effect of two freeze-dried products of RB (RB1 and RB2) on H. pylori-induced gastritis in Mongolian gerbils. Six-week-old male Mongolian gerbils were inoculated orally with H. pylori (ATCC 43504), and 2weeks later were fed diets containing no additives or diets supplemented with 2% RB1 (containing both GR and GRe) or 2% RB2 (containing GR only) for 10weeks. In the RB1, but not the RB2 group, mononuclear cell infiltration, mRNA expression of IL-6, and cell proliferation in the gastric mucosa were significantly suppressed. These results indicate that RB1 containing both GR and GRe exerted significant inhibitory effects on H. pylori-induced gastritis in Mongolian gerbils apparently mediated via suppression of IL-6 expression and chronic inflammation.