Investigation of heavy metals in frequently utilized medicinal plants collected from environmentally diverse locations of north western India

Overview

Kulhari and colleagues measured manganese, chromium, lead, iron, cadmium, nickel, cobalt, zinc, and mercury in stem and leaf samples from ten medicinal plant species collected in Haryana and Rajasthan, India. The study is occurrence evidence for herbal-botanical raw materials, with plant part and collection district visible in the source tables. Values are dry-weight total elemental measurements in ppm; chromium is total chromium (Cr), not hexavalent chromium (Cr-VI), and mercury was below detectable levels in all reported rows.

Key numbers

All values below are from Tables 4 and 5 and are reported as mean ± SE in ppm on a dry-weight basis. BDL means below detectable level in the source table. No unit conversion is applied.

The abstract highlights total Cr 13.19 ± 0.0480 ppm in Bacopa monnieri leaves and 4.93 ± 0.0185 ppm in Withania somnifera stems, both collected from Bahadurgarh. The same abstract highlights lead (Pb) 2.64 ± 0.0260 ppm and cadmium (Cd) 0.04 ± 0.0274 ppm in Bahadurgarh samples; Table 4 identifies the Pb value as Withania somnifera stem, and Table 5 identifies the Cd value as Withania somnifera leaf.

Methods (brief)

The authors collected stem and leaf samples of ten medicinal plants from Jhunjhunu, Churu, Bahadurgarh, Fathebad, and Mahendergarh in northwestern India. Samples were washed with running tap water and deionized autoclaved water, shade-dried, powdered, and stored in airtight bottles. Five-gram powdered portions were charred for 3–4 hours, ashed at 500 °C for 6 hrs, digested in a nitric/perchloric acid mixture at 9:1 for 3 hours in a 70 °C water bath, reconstituted to 20 ml, filtered through 0.45 μ Whatman paper, and analyzed by flame atomic absorption spectrophotometry using a Shimadzu AA 6300. Standards for Fe, Pb, Mn, Cr, Zn, Cd, Co, mercury (Hg), and nickel (Ni) were procured from Merck; all samples were analyzed in triplicate. The source reports total elements; no arsenic speciation, mercury speciation, or Cr-VI data are reported.

Implications

The paper contributes stem- and leaf-specific occurrence data for herbal-botanical raw materials collected across urban, industrial, and less-industrial locations in northwestern India. The data should remain plant-part-specific in downstream evidence work because the reported Cr, Pb, Fe, Cd, Ni, Co, Zn, Mn, and Hg values differ substantially between stem and leaf rows.

Related evidence

• Ingredient class — botanicals/herbs/traditional formulas
• Herbal botanicals
• Dried Herbs
• Manganese
• Chromium
• Lead
• Iron
• Cadmium
• Nickel
• Cobalt
• Zinc
• Mercury

Update history

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