Heavy metals contamination in geothermal medicinal plant extract (Chromolaena odorata Linn).

BACKGROUND AND OBJECTIVES: Medicinal plants growing in geothermal areas have been reported to possess relatively high abundance of bioactive secondary metabolites concomittant to the adaptive heat stress response. Nonetheless, the exploitation of their medicinal benefits is limited by the possible healththreatening concentrations of heavy metal contamination. Chromolaena odorata Linn, or also called as seurapoh, is a well-known medicinal plant but could absorb and accumulate heavy metal from the soil. Herein, this present study aimed to investigate the contents of Hg, Pb, Cd, and As in ethanolic extract of Chromolaena odorata Linn leaves collected from a geothermal area in Aceh of Indonesia. METHODS: Three hot springs (Ie-Suum, Ie-Jue, and Ie-Brouk) located in the same geothermal area Seulawah Agam was selected as the sampling points, where three samples of Chromolaena odorata were collected in each sampling point. Extraction was carried out by means of maceration employing ethanol solvent. The contents of heavy metals in each extract were determined by priorly validated atomic absoption spectrometry and graphite furnace atomic absorption. FINDINGS: The results revealed that arsenic (0.0482 ± 0.004 - 0.0639 ± 0.007 miligram per kilogram) and lead (0.0219 ± 0.004 - 0.0672 ± 0.006 miligram per kilogram) were found in trace levels and did not exceed Indonesian maximum safety thresholds (=5 and =10 miligram per kilogram, respectively). The presence of mercury in all samples was not observable (limit of detection= 0.018 miligram per liter). Cadmium was observed in almost all samples with a concentration range of 0.0219 ± 0.005 - 1.1472 ± 0.006 miligram per kilogram exceeding the maximum threshold (0.3 miligram per liter). CONCLUSION: Contamination of heavy metals in the ethanolic extract of geothermal Chromolaena odorata leaves is thought to be originated from volcanic activities. Among the heavy metals of concern, cadmium was the only one with concentration exceeding the safety limit. The presence of cadmium in the extract with high concentration could act cause its translocation to human body which eventually lead to multiple organ damages. Therefore, the extract of geothermal C. odorata leaves collected from a geothermal area should be consumed with caution for possible cadmium intoxication. [ABSTRACT FROM AUTHOR]