Cao et al. 2014 - arsenic speciation in Sargassum pallidum decoction

Cao and colleagues developed an HPLC-HG-AFS method for arsenic species in rat plasma and applied it after oral administration of a water decoction of Sargassum pallidum. The occurrence-relevant part is a single dried Chinese medicinal seaweed material and its aqueous extract, not a market survey. The source reports total arsenic in the dried seaweed and separately reports DMA and As(V) in the decoction, with As(III) and MMA not detected.

Key numbers

All product-material concentrations below are copied in the source’s units. The paper states that concentrations of arsenic compounds were expressed as concentrations of As unless otherwise indicated.

Preparation context:

• S. pallidum (1 kg) was refluxed with water two times at 1:10 and 1:8 w/v.
• Each reflux step lasted 2 h.
• The combined solution was condensed to 1 g mL−1 (crude drugs/decoction).

Rat pharmacokinetic context, not product occurrence:

The rat experiment used three treatment groups with n = 6 rats each. Oral doses were 5 g kg−1 body weight (0.25 g mL−1), 10 g kg−1 body weight (0.5 g mL−1), and 20 g kg−1 body weight (1 g mL−1). Blood was collected at 0.083, 0.33, 0.66, 1.0, 1.33, 1.66, 2.0, 2.5, 3.0, 5.0, 8.0, 12, and 24 h after dosing.

Methods (brief)

The S. pallidum material was collected from Yantai City, Shandong Province, China, dried at room temperature (25 °C), identified by the corresponding author, and deposited at the Herbarium in Nanjing University of Chinese Medicine as voucher No. 100701. Total arsenic in the seaweed material was measured by ICP-OES after microwave digestion with nitric acid and hydrogen peroxide.

Arsenic species were separated by HPLC on a Hamilton PRP-X 100 anion-exchange column and detected by hydride-generation atomic fluorescence spectrometry. The method targeted As(III), DMA, MMA, and As(V). Plasma calibration ranges and LLOQs were 0.80-100.0 ng mL−1 and 0.80 ng mL−1 for As(III), 1.00-100.0 ng mL−1 and 1.00 ng mL−1 for DMA, 1.25-50.0 ng mL−1 and 1.25 ng mL−1 for MMA, and 2.00-200.0 ng mL−1 and 2.00 ng mL−1 for As(V).

Implications

This source is useful as medicinal seaweed arsenic-speciation context for Sargassum pallidum: the single dried material had high total arsenic, and the water decoction retained a large share of that arsenic as DMA plus As(V). Because the occurrence data come from one collected material and one extract preparation, the page should not be treated as a market prevalence estimate. The rat plasma results show that As(V) and DMA from the decoction were absorbed and eliminated in the study animals, but those plasma concentrations are exposure-context values rather than product concentrations.

Wiki pages this source may touch

• seaweed-kelp-foods
• supplements-algae-seaweed-based
• dietary-supplements
• seaweed
• herbal-botanicals
• arsenic-total
• arsenic-inorganic

Verification notes

• Identity checks before writing found no existing source page for DOI 10.1016/j.jpba.2014.03.045, raw handle MFK_cao2014, title text, or cite key cao2014-sargassum-pallidum-arsenic-speciation.
• All Key numbers were rechecked against /tmp/hmi-seaweed-028.txt, extracted with pdftotext -layout. The occurrence values 114.3 mg kg−1, 4.059 mg kg−1, 91.61 mg kg−1, and 83.70% are stated in the extraction text, and Table 4 supports the plasma Cmax/AUC values copied here.
• Units are preserved as mg kg−1, g mL−1, g kg−1 body weight, ng mL−1, ng h mL−1, and h; no unit conversion was performed.
• Speciation check: raw material total arsenic is recorded as tAs. The aqueous extract reports As(V), an inorganic arsenic species, separately from DMA; As(III) and MMA are recorded only as not detected. No total-As value is promoted to iAs.
• Brand firewall: the source does not provide consumer brands, and the page does not attach a contamination value to any named commercial product.
• Scope caution: the paper’s rat plasma pharmacokinetic values are kept as exposure context and not used as product occurrence concentrations.

Page history

The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.