Khan et al. 2013 - metals in Pakistan medicinal plants

Khan and colleagues measured lead, nickel, cadmium, and chromium in eight medicinal plant species collected near Kallar Kahar Lake in Punjab, Pakistan. The paper is occurrence evidence for herbal-botanical raw materials used in traditional medicine, with paired soil concentrations as collection-site context. Values are reported as total elemental metals in mg/kg; chromium is total Cr, not Cr-VI.

Key numbers

All values below are from Table 5 and are reported as mean concentrations in mg/kg in medicinal plants. The source describes plant sampling as three replicates of each plant at each location. No unit conversion or wet/dry conversion is applied.

The plant table maxima are Pb 6.696 mg/kg in Dodonaea viscosa at Site II, Ni 3.641 mg/kg in Dodonaea viscosa at Site I, Cd 0.086 mg/kg in Paganum hermala at Site II, and total Cr 4.651 mg/kg in Cannabis sativa at Site I.

Paired soil values are collection-site context and should not be pooled as medicinal-plant occurrence.

The abstract and results text summarize plant concentration ranges as Site I Pb 5.78 to 6.27, Ni 3.25 to 3.64, Cd 0.025 to 0.040, and Cr 3.40 to 4.65 mg/kg; and Site II Pb 6.28 to 6.69, Ni 3.20 to 3.62, Cd 0.066 to 0.086, and Cr 3.87 to 4.27 mg/kg.

Methods (brief)

The study area was a sub-urban area of Kallar Kahar, Chakwal District, Punjab, Pakistan. The authors collected Dodonaea viscosa, Withania somnifera, Solanum nigrum, Calotropis gigantea, Mentha spicata, Paganum hermala, Cannabis sativa, and Adhatoda vasica from two locations around Kallar Kahar Lake in September 2012, with three plant replicates per species per location. Plant samples were stored in plastic food-grade containers, dried at 70 °C for 48 hours, washed with distilled water and diluted HCl, digested with HNO3/HClO4 in a 9:1 ratio, diluted to 25 ml, and analyzed for Pb, Ni, Cd, and Cr using a Shimadzu AAS 6300 atomic absorption spectrophotometer. The source reports total metals; no arsenic, mercury, or chromium speciation is reported.

Implications

The paper contributes Pakistan occurrence data for medicinal-plant raw materials, with a compact two-site table for Pb, Ni, Cd, and total Cr. The paired soil rows can support collection-context and soil-to-plant notes, but the product occurrence evidence is the Table 5 medicinal-plant concentration table.

Wiki pages this source may touch

• supplements-botanicals-herbs
• herbal-botanicals
• dried-herbs
• lead
• nickel
• cadmium
• chromium

Verification notes

• Identity checks on 2026-06-09 found no existing source page for DOI 10.5897/AJPP2012.1894, raw handle MFK_khan2013, or cite key khan2013-medicinal-plants-metals-pakistan.
• All Key numbers values were re-checked against Tables 4 and 5 in /tmp/hmi-june9-101.txt extracted with pdftotext -layout. The plant and soil values are copied exactly, including trailing zeros where printed.
• Units are preserved as mg/kg, the unit printed in the abstract and table titles. No conversion to ppb or dry-weight normalization was performed.
• Speciation check: chromium is total Cr by AAS; the paper does not report Cr-VI. Arsenic and mercury are not measured.
• Soil values are included only as paired collection-site context and should not be pooled as plant/product occurrence.
• Brand firewall check: no commercial brands or producers are reported.
• Closed vocabulary check: products, ingredients, metals, and wiki-page links use slugs present in docs/gpt-collaboration/taxonomy-snapshot.md. Exact species names such as Dodonaea viscosa, Withania somnifera, Solanum nigrum, Calotropis gigantea, Mentha spicata, Paganum hermala, Cannabis sativa, and Adhatoda vasica do not all have closed ingredient slugs, so they remain in table text and matrix descriptions only.

Page history

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