The development of large-scale mining activity along the Central Andes of Argentina (CAA) has generated significant amounts of waste materials containing heavy metals. Phytoremediation is a promising eco-friendly, low-cost, and effective technology for the removal of heavy metals. The present study aimed to identify two native dominant species from the CCA, Adesmia subterranea and A. pinifolia, as metal-tolerant plant species for the first time, by evaluating the germination and early seedling growth at different concentrations (ppm) of Cd (3, 4.5 and 6), Ni (150, 225 and 300), As (20, 30 and 40), and Hg (0.8, 1.2 and 1.6) Early seedling growth was found to be more sensitive to heavy metals than germination. Ni and As exhibited the greatest inhibitory effect on both species’ germination percentages. In contrast, with Cd and Hg, no inhibitory effect was recorded. Root length, metal tolerance index, and fresh and dry weight were stimulated with Hg. However, the phytotoxic effect was greater as the concentration of Ni, As, and Cd increased. As an overall conclusion, the order of toxicity for these species can be classified as Ni > As > Cd > Hg. Therefore, Adesmia species could be considered as candidates for phytoremediation of soils contaminated with Hg and low concentrations of Cd.

In Argentina and globally, pistachio (Pistacia vera) production has significantly grown, driven by its high nutritional value and food industry demand. Its harvesting and processing generate about 40% of pistachio waste (PW), including leaves, twigs, seed coats, green, and empty kernels. Underutilized PW has led to environmental problems, including soil and water contamination by landfill accumulation. However, it could be a potential source of undiscovered bioactive compounds. This study aimed to characterize the chemical profile and to evaluate the bioactive properties of PW. The dried pistachio waste (dPW) was used to prepare the pistachio waste decoction (PWD) (10% w/v). The total phenolic content (TPC) and flavonoid content (FC) were quantified, and the chemical profile was analyzed using UPLC-DAD-ESI-MS/MS. Nematicidal activity against Meloidogyne incognita (J2), acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibition, antioxidant capacity (ABTS, DPPH, FRAP), and phytotoxicity on Allium cepa, Lactuca sativa, and Raphanus sativus were evaluated. The UPLC-DAD-ESI-MS/MS analysis identified 26 compounds, including phenolics, flavonoids, and unsaturated fatty acids. The main compounds were gallic acid, anacardic acid, and quercetin derivatives. The TPC and FC were 212.65 mg GAE/g dPW and 0.022 mg QE/g dPW, respectively, displaying strong antioxidant activity across the assays DPPH, ABTS, and FRAP. PWD exhibited nematicidal activity against M. incognita (J2) (LC₅₀ = 0.12% at 24 h). Alterations in the cuticle were observed, including structural disorganization and detachment from internal tissues. Additionally, a remarkable cholinesterase inhibitory effect was detected at 2.0% PWD (42.65% for AChE and 58.90% for BuChE). PWD showed low phytotoxic effects across the tested species, and the germination percentage (GP) and the mean germination time (MGT) were not significantly affected (GP > 79%). These findings highlight the potential of PW as a sustainable alternative for M. incognita control, the remarkable nematicidal, anticholinesterase, and antioxidant properties, and the low phytotoxicity, supporting its use in sustainable agricultural practices.

This study highlights Adesmia pinifolia, a native high-Andean species, as a potential candidate for the phytoremediation of soils contaminated with Cd and Hg. In this work, a semi-hydronic assay with different doses of Cd (3, 4.5, and 6 mg L⁻¹) and Hg (0.8, 1.2, and 1.6 mg L⁻¹) was analysed to evaluate the establishment of plants, antioxidant defence systems, oxidative stress, and the ability to accumulate heavy metals. The results indicate high survival rates (>80%); however, Cd significantly reduced shoot and root biomass, while Hg increased root biomass with the 1.6 mg L⁻¹ treatment. Cd and Hg tend to accumulate more in roots (2534.24 µg/g and 596.4 µg g⁻¹, respectively) compared to shoots (398.53 µg g⁻¹ and 140.8 µg g⁻¹, respectively). A significant decrease in the bioconcentration factor of Cd and Hg in roots was observed as metal levels increased, reaching the maximum value at 3 mg L⁻¹ (805.59 ± 54.38) and 0.8 mg L⁻¹ (804.54 ± 38.09). The translocation factor, <1 for both metals, suggests that translocation from roots to shoots is limited. An overproduction of reactive oxygen species (ROS) was observed, causing lipid peroxidation and oxidative damage to plant membranes. Tolerance strategies against subsequent toxicity indicate that enhanced glutathione reductase (GR) activity and glutathione (GSH) accumulation modulate Cd and Hg accumulation, toxicity, and tolerance.

Hieronymiella bedelarii is a Bolivian endemic species known from a single locality in Torotoro National Park and currently assessed as Critically Endangered on the IUCN Red List. Its alkaloid composition and cholinesterase-inhibitory activity have not previously been investigated. The GC–MS analysis identified eighteen alkaloids representing six structural types, with lycorine-, pretazettine- and homolycorine-type alkaloids being the most abundant groups. Bulbs of H. bedelarii yielded an alkaloid-enriched extract (0.80% w/w). Eight of the identified alkaloids are reported here for the first time in Hieronymiella, including candimine. Complementary UPLC–MS/MS analysis detected pretazettine and the artifact tazettine in the alkaloid-enriched extract. This extract showed stronger inhibition of acetylcholinesterase than butyrylcholinesterase, with IC₅₀ values of 10.18 and 193.19 µg·mL⁻¹, respectively. In a preliminary cultivation trial, 11 of 20 bulbils (55%) established and developed roots and leaves after 12 months under nursery conditions.

Heavy metal (HM) pollution is a major threat to terrestrial ecosystems. Addressing it requires identifying native plant species that tolerate HMs while maintaining physiological function. This study evaluated the physiological responses, antioxidant defense mechanisms, and phytoremediation potential of the high-Andean species Adesmia subterranea Clos under cadmium (Cd 3, 4.5, and 6 mg L⁻¹) and mercury (Hg 0.8, 1.2, and 1.6 mg L⁻¹) in a semi-hydroponic system. Survival, growth performance, metal accumulation, bioconcentration factor (BCF), translocation factor (TF), oxidative stress biomarkers such as hydrogen peroxide (H₂O₂), and antioxidant responses including catalase (CAT), ascorbate peroxidase (APX), and glutathione (GSH) were assessed. Exposure to Cd reduced survival and decreased biomass in a concentration-dependent manner, whereas Hg did not affect survival and reduced biomass only at 0.8 mg L⁻¹. Both metals were efficiently taken up (BCF > 1); Cd was consistently retained in roots (TF < 1), while Hg translocation increased with dose (TF up to 0.79 at 1.6 mg L⁻¹). Cd and Hg exposure induced oxidative stress, evidenced by increased H₂O₂ accumulation and lipid peroxidation, which was accompanied by activation of antioxidant defenses. The APX activity and GSH levels increased significantly, while CAT showed a metal-specific response. These results indicate coordinated regulation of enzymatic and non-enzymatic antioxidant pathways to maintain redox homeostasis under HM stress. Overall, these results provide a preliminary indication of the potential of A. subterranea for phytostabilization in metal-contaminated Andean ecosystems.