Arsenic and Mercury Containing Traditional Chinese Medicine (Realgar and Cinnabar) Strongly Inhibit Organic Anion Transporters, Oat1 and Oat3, In Vivo in Mice

Asperulosidic Acid Ameliorates Renal Interstitial Fibrosis via Removing Indoxyl Sulfate by Up-Regulating Organic Anion Transporters in a Unilateral Ureteral Obstruction Mice Model

Asperulosidic acid is a bioactive iridoid isolated from Hedyotis diffusa Willd. with anti-inflammatory and renal protective effects. However, its mechanism on renal interstitial fibrosis has not been elucidated yet. The present study aims to explore whether asperulosidic acid could retard renal fibrosis by reducing the circulating indoxyl sulfate (IS), which is a uremic toxin and accelerates chronic kidney disease progression by inducing renal fibrosis. In this paper, a unilateral ureteral obstruction (UUO) model of Balb/C mice was established. After the mice were orally administered with asperulosidic acid (14 and 28 mg/kg) for two weeks, blood, liver and kidney were collected for biochemical, histological, qPCR and Western blot analyses. Asperulosidic acid administration markedly reduced the serum IS level and significantly alleviated the histological changes in glomerular sclerosis and renal interstitial fibrosis. It is noteworthy that the mRNA and protein levels of the organic anion transporter 1 (OAT1), OAT3 and hepatocyte nuclear factor 1α (HNF1α) in the kidney were significantly increased, while the mRNA expressions of cytochrome P450 2e1 (Cyp2e1) and sulfotransferase 1a1 (Sult1a1) in the liver were not altered after asperulosidic acid administration. These results reveal that asperulosidic acid could accelerate the renal excretion of IS by up-regulating OATs via HNF1α in UUO mice, thereby alleviating renal fibrosis, but did not significantly affect its production in the liver, which might provide important information for the development of asperulosidic acid.

Pharmacology, Toxicology, and Rational Application of Cinnabar, Realgar, and Their Formulations

Ethnopharmacological Relevance. Mineral medicines are widely used traditional Chinese medicines with curative effects. These medicines are used for many refractory diseases. Aim of the Review. In this review, cinnabar (HgS) and realgar (As₂S₂) serve as examples of mineral medicines, and their pharmacology, therapeutic toxicity, use in traditional medicine mixtures, and research perspectives are discussed. Materials and Methods. A search was performed for the literature on cinnabar and realgar in PubMed, the Chinese Pharmacopeia, Google, and other sources. The search included studies using single herbs, traditional formulations, or novel dosage forms. Results. Cinnabar and cinnabar formulas exhibit good efficacy for sedation, sleep improvement, anxiety alleviation, and brain protection. However, previous studies on neurotransmitters have reached different conclusions, and detailed pharmacological mechanisms are lacking. Realgar and its formulas exert promising antitumor activity through regulation of cell cycle arrest, intrinsic and extrinsic apoptosis, induction of differentiation, autophagy, metabolic reprogramming, matrix metalloproteinase-9 (MMP-9) signaling, and reactive oxygen species (ROS) generation. In addition, realgar can be used to treat a variety of refractory diseases by regulating immunity and exerting antibacterial, antiviral, and other effects. However, the existing pharmacological research on the use of realgar for epidemic prevention is insufficient, and animal experiments and research at the cellular level are lacking. Inappropriate applications of cinnabar and realgar can cause toxicity, including neurotoxicity, liver toxicity, kidney toxicity, and genotoxicity. The toxicological mechanism is complex, and molecular-level research is limited. For clinical applications, theory and clinical experience must be combined to guide scientific and rational drug use and to achieve reduced toxicity and increased efficacy through the use of modern preparation methods or combined drugs. Notably, when cinnabar and realgar are used to treat targeted diseases, these agents have a bidirectional effect of “treatment” and “toxicity” on the central nervous system in pathological and normal states. The pharmacological and toxicological mechanisms need to be elucidated in greater detail in the future. Overall, systematic research is needed to provide a basis for better promotion of the rational use of cinnabar and realgar in the clinic. Conclusion. Mineral medicines are multicomponent, multiactivity, and multitargeted substances. The pharmacology and mechanisms of the toxicity and action of realgar and cinnabar are extremely complex. A number of Chinese medicinal preparations of realgar and cinnabar have demonstrated unique efficacy in the treatment of refractory diseases.

Organic anion transporter 1 and 3 contribute to traditional Chinese medicine-induced nephrotoxicity

With the internationally growing popularity of traditional Chinese medicine (TCM), TCM-induced nephropathy has attracted public attention. Minimizing this toxicity is an important issue for future research. Typical nephrotoxic TCM drugs such as Aristolochic acid, Tripterygium wilfordii Hook. f, Rheum officinale Baill, and cinnabar mainly damage renal proximal tubules or cause interstitial nephritis. Transporters in renal proximal tubule are believed to be critical in the disposition of xenobiotics. In this review, we provide information on the alteration of renal transporters by nephrotoxic TCMs, which may be helpful for understanding the nephrotoxic mechanism of TCMs and reducing adverse effects. Studies have proven that when administering nephrotoxic TCMs, the expression or function of renal transporters is altered, especially organic anion transporter 1 and 3. The alteration of these transporters may enhance the accumulation of toxic drugs or the dysfunction of endogenous toxins and subsequently sensitize the kidney to injury. Transporters-related drug combination and clinical biomarkers supervision to avoid the risk of future toxicity are proposed.

New insights and rethinking of cinnabar for chemical and its pharmacological dynamics

Cinnabar is an attractive mineral with many different uses. It is reported that cinnabar is one of the traditional Chinese’s medicines extensively use. The main objective of this critical review is to identify the current overview, concept and chemistry of cinnabar, which includes the process developments, challenges, and diverse options for pharmacology research. It is used as a medicine through probable toxicity, especially when taking overdoes. This review is the first to describe the toxicological effects of cinnabar and its associated compounds. Nuclear magnetic resonance (NMR) dependent metabolomics could be useful for examination of the pharmaceutical consequence. The analysis indicated that the accurate preparation methods, appropriate doses, disease status, ages with drug combinations are significant factors for impacting the cinnabar toxicity. Toxicologically, synthetic mercury sulfide or cinnabar should be notable for mercuric chloride, mercury vapor and methyl mercury for future protection and need several prominent advancements in cinnabar research.

The life-threatening rash of poisoning

Dermatology is frequently viewed by physician and surgical colleagues as a specialty with few emergencies. Although the majority of dermatology practice is in the office setting, cutaneous emergencies do occur through referrals from primary care and as ward consults. Even though cutaneous signs of poisoning would be an uncommon emergency consultation, it is important for dermatologists to be aware of the clinical presentations so as to be able instigate appropriate time critical treatments.

Zuotai and HgS differ from HgCl2 and methyl mercury in Hg accumulation and toxicity in weanling and aged rats

Mercury sulfides are used in Ayurvedic medicines, Tibetan medicines, and Chinese medicines for thousands of years and are still used today. Cinnabar (α-HgS) and metacinnabar (β-HgS) are different from mercury chloride (HgCl₂) and methylmercury (MeHg) in their disposition and toxicity. Whether such scenario applies to weanling and aged animals is not known. To address this question, weanling (21d) and aged (450d) rats were orally given Zuotai (54% β-HgS, 30mg/kg), HgS (α-HgS, 30mg/kg), HgCl₂ (34.6mg/kg), or MeHg (MeHgCl, 3.2mg/kg) for 7days. Accumulation of Hg in kidney and liver, and the toxicity-sensitive gene expressions were examined. Animal body weight gain was decreased by HgCl₂ and to a lesser extent by MeHg, but unaltered after Zuotai and HgS. HgCl₂ and MeHg produced dramatic tissue Hg accumulation, increased kidney (kim-1 and Ngal) and liver (Ho-1) injury-sensitive gene expressions, but such changes are absent or mild after Zuotai and HgS. Aged rats were more susceptible than weanling rats to Hg toxicity. To examine roles of transporters in Hg accumulation, transporter gene expressions were examined. The expression of renal uptake transporters Oat1, Oct2, and Oatp4c1 and hepatic Oatp2 was decreased, while the expression of renal efflux transporter Mrp2, Mrp4 and Mdr1b was increased following HgCl₂ and MeHg, but unaffected by Zuotai and HgS. Thus, Zuotai and HgS differ from HgCl₂ and MeHg in producing tissue Hg accumulation and toxicity, and aged rats are more susceptible than weanling rats. Transporter expression could be adaptive means to reduce tissue Hg burden.

Chemical Speciation of Selenium and Mercury as Determinant of Their Neurotoxicity

The antagonism of mercury toxicity by selenium has been well documented. Mercury is a toxic metal, widespread in the environment. The main target organs (kidneys, lungs, or brain) of mercury vary depending on its chemical forms (inorganic or organic). Selenium is a semimetal essential to mammalian life as part of the amino acid selenocysteine, which is required to the synthesis of the selenoproteins. This chapter has the aim of disclosing the role of selenide or hydrogen selenide (Se^-2 or HSe^-) as central metabolite of selenium and as an important antidote of the electrophilic mercury forms (particularly, Hg²⁺ and MeHg). Emphasis will be centered on the neurotoxicity of electrophile forms of mercury and selenium. The controversial participation of electrophile mercury and selenium forms in the development of some neurodegenerative disease will be briefly presented. The potential pharmacological use of organoseleno compounds (Ebselen and diphenyl diselenide) in the treatment of mercury poisoning will be considered. The central role of thiol (-SH) and selenol (-SeH) groups as the generic targets of electrophile mercury forms and the need of new in silico tools to guide the future biological researches will be commented.

Mercury sulfides are much less nephrotoxic than mercury chloride and methylmercury in mice

Mercury sulfides (α-HgS, β-HgS) are frequently included in traditional medicines. Mercury is known for nephrotoxicity, their safety is of concern. To address this question, mice were orally administrated with Zuotai (54% β-HgS, 30mg/kg), α-HgS (HgS, 30mg/kg), HgCl₂ (33.6mg/kg), or MeHgCl (3.1mg/kg) for 7days, and nephrotoxicity was examined. Animal body weights were decreased by HgCl₂ and to a lesser extent by MeHg, but unaltered after Zuotai and HgS. HgCl₂ and MeHg produced renal tubular vacuolation, interstitial inflammation and cell degeneration with protein cysts in the tubular lumen, while these pathological lesions were mild in Zuotai and HgS-treated mice. Electron microscopy showed that HgCl₂ and MeHg produced spotted swelling endothelium reticulum, while these lesions were mild or absent in Zuotai and HgS-treated mice. Renal Hg contents reached 250-300ng/mg kidney in HgCl₂ and MeHg groups as compared to 2-3ng/mg in Zuotai and HgS groups. The expression of kidney injury biomarkers, kidney injury molecule-1 (Kim-1) and neutrophil gelatinase-associated lipocalin (Ngal), were increased after HgCl₂ and MeHg, but unaltered after Zuotai and HgS. The expression of renal influx transporters Oat3 and Oatp4c1 was decreased, while the expression of renal efflux transporter such as Mrp2, Mrp4, and Mate2 was increased following HgCl₂ and MeHg. These gene expressions were unchanged after Zuotai and HgS. In summary, both α-HgS and β-HgS are less nephrotoxic than HgCl₂ and MeHg, indicating that chemical forms of mercury are a major determinant of mercury disposition and toxicity.