Content of Selected Essential and Toxic Metals in Adaptogenic Plants Supporting Post-COVID-19 Recovery

Introduction:
The COVID-19 pandemic, which began in late 2019, has drawn global attention to natural methods of supporting health during recovery. Adaptogens — plant-derived substances enhancing resilience to stress and boosting immunity — may play a vital role in post-infection rehabilitation. This study aimed to determine the content of essential (Mn, Mg, Cu, K, Na, Fe) and toxic (Cr, Cd, Pb, Sr) elements in selected adaptogenic plants used in recovery after SARS-CoV-2 infection.

Methods:
Six plant materials — Withania somnifera (ashwagandha), Centella asiatica (gotu kola), Schisandra chinensis (schisandra), Lycium barbarum (goji berries), Lepidium meyenii (maca), and Glycyrrhiza glabra (licorice root) — were analyzed. Elemental concentrations were determined using atomic absorption spectroscopy (ContrAA 700, Analytik Jena). Results were compared with literature data and international safety limits for heavy metals in herbal products.

Results:
Gotu kola exhibited the highest concentrations of most elements, including Fe (1274.76 mg/kg), Mn (251.95 mg/kg), K (21866.10 mg/kg), Na (2895.86 mg/kg), Cu (12.35 mg/kg), and Cr (29.09 mg/kg). Licorice root showed the highest Sr content (68.90 mg/kg). Cd levels slightly exceeded the permissible limit (1 mg/kg) in gotu kola (1.735 mg/kg) and maca (1.023 mg/kg). Pb concentrations in all plants were below 3.0 mg/kg. The lowest Fe content was found in goji berries (39.61 mg/kg), while schisandra had the lowest Na (25.12 mg/kg) and Sr (2.42 mg/kg) levels.

Conclusions:
The elemental analysis confirmed notable variability among the tested adaptogens, reflecting differences in their origin, cultivation conditions, and possible environmental exposure. Although Cd concentrations in gotu kola and maca slightly exceeded regulatory thresholds, overall heavy metal levels remained within safe limits for human consumption when adhering to recommended dosages. The high mineral content in certain species, particularly gotu kola, indicates their potential contribution to dietary mineral intake during convalescence. These findings highlight the importance of monitoring elemental composition in medicinal plants to ensure both safety and therapeutic effectiveness.