Assessing the Toxicological Effects of Hydrocarbon Pollution within the Safety and Efficacy of Traditional Chinese Medicinal Plants

Total petroleum hydrocarbon (TPH) contamination in soil significantly affects the growth, safety, and medicinal efficacy of traditional Chinese medicinal plants. This study conducted a 3-year environmental risk assessment in a public park in southern Taiwan, where soil pollution from TPH exceeded the regulatory threshold (1,772 mg/kg versus 1,000 mg/kg standard). Four widely used Traditional Chinese Medicinal Herbs—Isatis indigotica (Ban Lan Gen), Lycium barbarum (Goji Berry), Mentha (Mint), and Cinnamomum cassia (Cassia)—were analyzed for changes in medicinal component concentration and toxicity risk. The results revealed that TPH pollution led to a 15% decrease in polysaccharides and flavonoids in Lycium barbarum, reducing its antioxidant and liver-protective functions. Similarly, Mentha exhibited a 10% decline in menthol content, weakening its antibacterial efficacy. Molecular docking analysis indicated strong interactions between aromatic hydrocarbons (C10-12, C12-16) and active plant compounds, with binding energies ranging from ‒7.8 to ‒9.0 kcal/mol, suggesting a high risk of pharmacological alteration. Risk assessment values (R) for Lycium barbarum and Mentha exceeded the safety threshold by 15%–30%, while Isatis indigotica maintained a stable R value within the acceptable range. These findings underscore the need for stringent pollution control measures and remediation strategies to ensure the safe cultivation of medicinal plants in contaminated environments.