[Safety evaluation of niuhuang jiedu tablet].

Realgar-containing Niuhuang Jiedu tablet (NHJD) has been applied in clinic for more than 800 years. However, because realgar contains arsenic (As), it has aroused wide concerns and controversies both at home and abroad. Currently, there are two misunderstandings about realgar-containing Chinese patent medicines. First, some people exaggerated realgar's toxicity as that of arsenic. Second, they recommended to remove realgar from traditional Chinese medicine compounds. In this paper, the authors summarized the advance in studies on NHJD, and proposed different opinions: (1) It is inappropriate to take total As as the index in safety evaluation of NHJD. (2) The toxicity of NHJD is dependent on the dose and duration of administration. (3) Realgar is an active ingredient of NHJD, and shall be deeply studied. Classic realgar-containing traditional Chinese medicine prescriptions, such as Niuhuang Jiedu tablet, shall be evaluated with rigorous modern scientific basis, with the aim to guide rational and safe application.

Evaluation of hepatotoxicity potential of cinnabar-containing An-Gong-Niu-Huang Wan, a patent traditional Chinese medicine.

An-Gong-Niu-Huang Wan (AGNH) is a patent traditional Chinese medicine for brain disorders. It contains 10% cinnabar (HgS). Hg is known to produce toxicity to the kidney, brain and liver. Is AGNH safe? Liver is a major organ for drug metabolism, whether the long-term use of AGNH would affect hepatic P450 enzymes is unknown. To address these concerns, mice were given orally cinnabar (300mg/kg), cinnabar-containing AGNH daily for 44days, and liver toxicity was examined and compared with that of methylmercury (MeHg, 2.6mg/kg) and mercuric chloride (HgCl(2), 32mg/kg). Serum aminotransferases were increased by MeHg and HgCl(2) only. Histopathology showed more severe liver damage in MeHg- and HgCl(2)-treated mice than in the cinnabar and AGNH groups. Accumulation of Hg in MeHg- and HgCl(2)-treated mice was 96- and 71-fold higher than controls, respectively, but was only 2-fold after cinnabar and AGNH administration. Expressions of metallothionein-1 and heme oxygenase-1, biomarkers for Hg toxicity, were increased by MeHg and HgCl(2,) but were not altered in cinnabar- and AGNH-treated mice. Expression of hepatic cytochrome P450 genes, such as Cyp1a1, Cyp1b1 and Cyp4a10 was increased only after MeHg and HgCl(2), and the expressions of Cyp3a11and Cyp3a25 were increased by all treatments, indicating the potential Hg-drug interactions after long-term use of cinnabar-containing traditional medicines. Taken together, the results demonstrate that AGNH is much less hepatotoxic than common mercurials, and that the use of total Hg content to evaluate the toxicity of cinnabar-containing traditional Chinese medicines appears to be inappropriate.

Toxicology evaluation of realgar-containing niu-huang-jie-du pian as compared to arsenicals in cell cultures and in mice.

Niu-Huang-Jie-Du Pian (NHJD) is a widely used traditional Chinese medicine containing realgar (As4S4). Realgar has been included in many traditional medicines, but is often taken as arsenite for risk assessment. To evaluate true risk of realgar and realgar-containing NHJD, their toxicity was compared with common arsenicals. In cultured cells, the LC50 for NHJD (1200 µM) and realgar (2000 µM) was much higher than arsenite(35 µM), arsenic trioxide (280 µM), and arsenate (400 µM). Acute toxicity in mice showed more severe liver and kidney injury after arsenite or arsenate, but was mild after realgar and NHJD, corresponding to cellular and tissue arsenic accumulation. The expressions of arsenic-sensitive stress gene metallothionein-1 were increased 3-7-folds after arsenite or arsenate, but were unaltered after NHJD and realgar. Thus, realgar and NHJD are much less toxic than arsenite and arsenate. The use of total arsenic to evaluate the safety of realgar and realgar-containing NHJD is inappropriate.

Realgar and realgar-containing Liu-Shen-Wan are less acutely toxic than arsenite and arsenate.

ETHNOPHARMACOLOGICAL RELEVANCE: Liu-Shen-Wan (LSW) is a widely-used traditional Chinese medicine containing realgar (As(4)S(4)). AIM OF THE STUDY: Realgar has been included in many traditional medicines, and is often taken as arsenite for risk assessment in realgar-containing traditional remedies. Is realgar toxicologically similar to arsenite? MATERIALS AND METHOD: Mice were orally given LSW (60 and 200mg/kg; 200mg LSW contains 27 mg realgar), realgar (30 mg/kg, equivalent to 21 mg As/kg), and the equivalent As dose as sodium arsenite (NaAsO(2)), or as arsenate (Na(2)HAsO(4)). Acute toxicity and tissue As accumulation were determined 8h later. RESULTS: Arsenite and arsenate increased serum alanine aminotransferase (ALT) levels, indicative of liver injury; blood urea nitrogen (BUN) was also increased by arsenite and arsenate, indicative of nephrotoxicity. No elevations of ALT and BUN were observed in LSW and realgar groups. Histopathology showed more damage in arsenite- and arsenate-treated liver and kidneys, while in realgar- and LSW- treated animals, only mild alterations were seen. Hepatic and renal As contents were dramatically increased to 6200 and 3350ng/g, respectively, after arsenite, but only increased to 260 and 180 ng/g after LSW. The expressions of arsenic-sensitive stress genes, namely metallothionein-1 and heme oxygenase-1, were increased after arsenite or arsenate by 3-10-folds, but were unaltered after LWS and realgar. CONCLUSIONS: Realgar and LSW are much less toxic than arsenite and arenate. The use of total As content to evaluate the safety of realgar-containing traditional medicines is not scientifically sound.