Effects and contributory factors of sulfur-fumigation on the efficacy and safety of medicinal herbs evaluated by meta-analysis

A triphenylamine-benzofuran-derived fluorescent probe for monitoring sulfite in Chinese medicinal materials and bioimaging

In this work, a triphenylamine-benzofuran-derived fluorescent probe TBSF was developed for monitoring the sulfite level in Chinese medicinal materials and imaging in living cells. In the testing system, under 445 nm excitation, TBSF responded to sulfite steadily with a 540 nm fluorescence reporting signal. The testing system showed advantages including high sensitivity, rapid response, and high selectivity. In particular, TBSF achieved the sulfite detection in the water decoction of Chinese medicinal materials from both addition and excessive fumigation. It also realized the intracellular imaging of both exogenous and endogenous sulfite in living HepG2 cells. The imaging in water decoction-treated cells inferred the potential for the interdisciplinary detection.

Metals/bisulfite system involved generation of 24-sulfonic-25-ene ginsenoside Rg1, a potential quality control marker for sulfur-fumigated ginseng

Ginseng is a most popular health-promoting food with ginsenosides as its main bioactive ingredients. Illegal sulfur-fumigation causes ginsenosides convert to toxic sulfur-containing derivatives, and reduced the efficacy/safety of ginseng. 24-sulfo-25-ene ginsenoside Rg1 (25-ene SRg1), one of the sulfur-containing derivatives, is a potential quality control marker of fumigated ginseng, but with low accessibility owing to its unknown generation mechanism. In this study, metals/bisulfite system involved generation mechanism was investigated and verified. The generation of 25-ene SRg1 in sulfur-fumigated ginseng is that SO2, formed during sulfur-fumigation, reacted with water and ionized into HSO3-. On the one hand, under the metals/bisulfite system, HSO3- generates HSO5- and free radicals which converted ginsenoside Rg1 to 24,25-epoxide Rg1; on the other hand, as a nucleophilic group, HSO3- reacted with 24,25-epoxide Rg1 and further dehydrated to 25-ene SRg1. This study provided a technical support for the promotion of 25-ene SRg1 as the characteristic quality control marker of sulfur-fumigated ginseng.

Fe(III)/peroxymonosulfate oxidation system for the degradation of rhein, a toxic component abundance in rhubarb residue

Rhubarb is widely used in health care, but causing a great amount of rhein-containing herbal residue. Rhein with several toxicities might pollute environment, damage ecology and even hazard human health if left untreated. In this study, the degradation effects of bisulfite- (BS) and peroxymonosulfate- (PMS) based oxidation systems on rhein in rhubarb residue were compared and investigated. The effects of BS and PMS with two valence states of ferric ion (Fe) on the degradation of rhein in rhubarb residue were optimized for the selection of optimal oxidation system. The influences of reaction temperature, reaction time and initial pH on the removal of rhein under the optimal oxidation system were evaluated. The chemical profiles of rhubarb residue with and without oxidation process were compared by UPLC-QTOF-MS/MS, and the degradation effects were investigated by PLS-DA and S plot/OPLS-DA analysis. The results manifested that PMS showed relative higher efficiency than BS on the degradation of rhein. Moreover, Fe(III) promoted the degradation effect of PMS, demonstrated that Fe(III)/PMS is the optimal oxidation system to degrade rhein in rhubarb residue. Further studies indicated that the degradation of rhein by the Fe(III)/PMS oxidation system was accelerated with the prolong of reaction time and the elevation of reaction temperature, and also affected by the initial pH. More importantly, Fe(III)/PMS oxidation system could degrade rhein in rhubarb residue completely under the optimal conditions. In conclusion, Fe(III)/PMS oxidation system is a feasible method to treat rhein in rhubarb residue.

Unveiling the Chemical Composition of Sulfur-Fumigated Herbs: A Triple Synthesis Approach Using UHPLC-LTQ-Orbitrap MS-A Case Study on Steroidal Saponins in Ophiopogonis Radix

Ophiopogonis Radix (OR) is a traditional Chinese medicine. In recent years, in order to achieve the purpose of drying, bleaching, sterilizing and being antiseptic, improving appearance, and easy storage, people often use sulfur fumigation for its processing. However, changes in the chemical composition of medicinal herbs caused by sulfur fumigation can lead to the transformation and loss of potent substances. Therefore, the development of methods to rapidly reveal the chemical transformation of medicinal herbs induced by sulfur fumigation can guarantee the safe clinical use of medicines. In this study, a combined full scan-parent ions list-dynamic exclusion acquisition-diagnostic product ions analysis strategy based on UHPLC-LTQ-Orbitrap MS was proposed for the analysis of steroidal saponins and their transformed components in sulfur-fumigated Ophiopogonis Radix (SF-OR). Based on precise mass measurements, chromatographic behavior, neutral loss ions, and diagnostic product ions, 286 constituents were screened and identified from SF-OR, including 191 steroidal saponins and 95 sulfur-containing derivatives (sulfates or sulfites). The results indicated that the established strategy was a valuable and effective analytical tool for comprehensively characterizing the material basis of SF-OR, and also provided a basis for potential chemical changes in other sulfur-fumigated herbs.

A rationally designed fluorescent probe for sulfur dioxide and its derivatives: applications in food analysis and bioimaging

Exogenous sulfur dioxide (SO2) and its derivatives (SO32-/HSO3-) have been extensively utilized in food preservation and endogenous SO2 is recognized as a significant gaseous signaling molecule that can mediate various physiological processes. Overproduction and/or extensive intake of these species can trigger allergic reactions and even tissue damage. Therefore, it is highly desirable to monitor SO2 and its derivatives effectively and quantitatively both in vitro and in vivo. Herein, a new mitochondria-targeted fluorescent probe (PIB) had been constructed, which could ratiometrically recognize SO2 and its derivatives with excellent sensitivity (DL = 15.9 nM) and a fast response time (200 s). The obtained high selectivity and good adaptability of this SO2-specific probe in a wide pH range (6.5-10.0) allowed for quantitatively tracking of SO2 and its derivatives in real food samples (granulated sugar, crystal sugar, and white wine). In addition, PIB could locate at mitochondrion and was capable of imaging exogenous/endogenous SO2 in the cells and zebrafish. In particular, our findings represented one of the rare examples that have demonstrated endogenous SO2 is closely related with the apoptosis of cells. Importantly, probe PIB was successfully employed for in situ metabolic localization in mouse organs, implying the potential applications of our probe in further exploration on SO2-releated pathological and physiological processes.

Exploring the nephrotoxicity of sulfur-containing derivatives in sulfur-fumigated Panacis Quinquefolii Radix based on chemical profiling and untargeted metabolomics

ETHNOPHARMACOLOGICAL RELEVANCE

Panacis Quinquefolii Radix (PQR) is often illegally sulfur fumigated to extend shelf life and improve appearance, but existing regulations of detecting SO₂ residues do not accurately identify desulfurized sulfur-fumigated PQR (SF-PQR). Although sulfur-containing derivatives (SCDs) have been reported in some sulfur-fumigated herbs, there is a lack of research on the generation mechanisms and toxicity of SCDs. Our previous study reported the nephrotoxicity of SF-PQR, and there is an urgent necessity to illuminate the mechanism of toxicity as well as its association with SCDs.

AIM OF THE STUDY

To investigate the transformation pattern of chemical components and SCDs in SF-PQR, and to disclose the linkage between SCDs and SF-PQR nephrotoxicity.

MATERIALS AND METHODS

The extracts of PQR (before and after SF) were detected by the UPLC-LTQ-Orbitrap-MS method, and SCDs were screened as quality markers (Q-markers). The composition of sulfur combustion products was examined by ion chromatography to exploit the conversion mechanism of SCDs. After administration of PQR extracts to mice for two weeks, serum was collected for GC-MS-based untargeted metabolomics study to mine for differential metabolites. The upstream genes were traced by network analysis to probe toxicity targets. Molecular docking was used to uncover the interactions between SCDs and the targets.

RESULTS

Thirty-three compounds were identified and 11 SCDs of saponins were screened, including four SO₃ sulfonation products and five H₂SO₃ sulfonation products. Metabolomics study showed significant alterations in serum biochemistry of SF-PQR group, with substantial increases in fumarate and 2-heptanone content, and induced disturbances in glycerolipid metabolism and phenylalanine, tyrosine, and tryptophan biosynthesis in mice. Network analysis revealed that the key toxicity targets were DECR1, PLA2G1B, and CAT. Molecular docking indicated that SCDs had stable interaction forces with the above three toxicity targets.

CONCLUSION

SF-PQR caused kidney damage by affecting glycerolipid metabolism and phenylalanine, tyrosine, and tryptophan biosynthesis. Eleven SCDs were potential nephrotoxic substances and Q-markers for identifying SF-PQR. This study is the first to systematically elucidate the mechanism of SF-PQR-related nephrotoxicity, providing a robust basis for the construction of new quality control standards and a global prohibition of sulfur fumigation.

Composition of Three Common Chinese Herbal Medicines and the Influence of Preparation Types on the Bioaccessibility of Trace Elements

The high concentration of trace elements in Chinese herbal medicine (CHM) is an important research topic for quality control. This study investigated the total concentration of trace elements in three herbs used as both medicine and supplementary food, including Astragalus membranaceus, Glycyrrhiza, and Isatidis. Further, the effects of different preparation ways, such as decoct, granule, and oral liquid, on the bioaccessibility of trace elements in CHM were disclosed. Results indicated that the total concentrations of trace elements in these three herbs were lower than the medical standards, but the concentrations of As and Pb in CHMs were higher than the standards for supplementary food. Different preparations ways affect bioaccessibility. Powder and oral liquid show a high bioaccessibility possibly because of the grinding process and the repeated extraction with ethanol. Among the three different CHMs, Isatidis showed higher bioaccessibility of As, which may be related to the sulfur fumigation process of this CHM. The three investigated CHMs were found to be safe as medicine but presented risks as supplementary food. The apparent influence of preparation procedures on the bioaccessibility of trace elements indicated that it is necessary to appropriately regulate preparation processes for CHMs.

Effects of sulfur-fumigated ginseng on the global quality of Si-Jun-Zi decoction, a traditional ginseng-containing multi-herb prescription, evaluated by metabolomics and glycomics strategies

Si-Jun-Zi decoction (SJZD) with ginseng as the principal medicinal herb is a traditional Chinese Medicine multi-herb prescription that commonly employed to treat colorectal cancer etc. Previous studies showed that nearly half of the commercial ginseng was sulfur-fumigated, one of the postharvest processing methods that commonly causes sulfur-dioxide (SO₂) residue and chemical composition transformation in medical herbs. In this study, the effect of sulfur-fumigated ginseng on global quality of SJZD was evaluated by UPLC-QTOF-MS/MS based metabolomics and multiple chromatographic techniques based glycomics strategies. For non-saccharides components, sulfur-fumigated ginseng led to the emergence of sulfur-containing derivatives and alteration of saponins and flavonoids in SJZD. For saccharide components, sulfur-fumigated ginseng decreased the total contents and molecular weights of polysaccharides, changed the monosaccharide composition of polysaccharides, and increased the contents of oligosaccharides and free monosaccharides of SJZD. The alterations of SJZD were aggravated with the sulfur-fumigated content of ginseng. Those phenomena might be attributed to 1) sulfur-fumigation caused the generation of sulfur-containing derivatives in ginseng, which further transferred to SJZD, and 2) sulfur-fumigation caused the residue of SO₂ in ginseng, which reduced the pH value and further changed the dissolution of saponins and flavonoids and accelerated the degradation of the polysaccharides to oligosaccharides and/or monosaccharides in SJZD. Furthermore, although storage reduced the SO₂ residue in sulfur-fumigated ginseng, it couldn't recover the alterations of chemical profiles in SJZD. In conclusion, sulfur-fumigated ginseng altered the global quality of SJZD, which promoted that extra attention must be paid during the application of herbal formulas that containing sulfur-fumigated herbs.