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Quillay (Quillaja saponaria Molina) and peumo (Cryptocarya alba [Molina] Looser) are two tree species endemic to Chile that grow in Mediterranean climate zones, characterized by a summer season with high temperatures, high solar radiation, and low soil water availability. A study was conducted with 2-year-old Q. saponaria and C. alba plants and two substrate water conditions: well-watered and controlled water restriction. At the end of the study, anatomical leaf modifications were analyzed. The tissues were anatomically described in transverse sections of juvenile and adult leaves, measuring leaf thickness, cuticle thickness, and cell density of the mesophyll parenchymal tissues. In the young leaves of Q. saponaria plants undergoing water restriction treatment, an increase in cuticle and leaf thickness and a decrease in the density of the palisade and spongy parenchyma were observed. In contrast, a significant reduction in leaf thickness was observed in adult leaves of both species with water restriction treatment. The anatomical changes in the leaves of Q. saponaria and C. alba suggest an adaptation to adverse environmental conditions, such as water restriction. [ABSTRACT FROM AUTHOR]

Abstract Background Methotrexate (MTX) is an antineoplastic/immunosuppressive drug, whose clinical use is impeded owing to its serious adverse effects; one of which is acute kidney injury (AKI). Most of MTX complications emerged from the provoked pro-oxidant-, pro-inflammatory- and pro-apoptotic effects. Quillaja saponaria bark saponin (QBS) is a bioactive triterpene that has been traditionally used as an antitussive, anti-inflammatory supplement, and to boost the immune system due to its potent antioxidant- and anti-inflammatory activities. However, the protective/therapeutic potential of QBS against AKI has not been previously evaluated. This study aimed to assess the modulatory effect of QBS on MTX-induced reno-toxicity. Methods Thirty-two male rats were divided into 4-groups. Control rats received oral saline (group-I). In group-II, rats administered QBS orally for 10-days. In group-III, rats were injected with single i.p. MTX (20 mg/kg) on day-5. Rats in group-IV received QBS and MTX. Serum BUN/creatinine levels were measured, as kidney-damage-indicating biomarkers. Renal malondialdehyde (MDA), reduced-glutathione (GSH) and nitric-oxide (NOx) were determined, as oxidative-stress indices. Renal expression of TNF-α protein and Nrf-2/Keap-1 mRNAs were evaluated as regulators of inflammation. Renal Bcl-2/cleaved caspase-3 immunoreactivities were evaluated as apoptosis indicators. Results Exaggerated kidney injury upon MTX treatment was evidenced histologically and biochemically. QBS attenuated MTX-mediated renal degeneration, oxidant-burden enhancement, excessive inflammation, and proapoptotic induction. Histopathological analysis further confirmed the reno-protective microenvironment rendered by QBS. Conclusions In conclusion, our results suggest the prophylactic and/or therapeutic effects of QBS in treating MTX-induced AKI. Such reno-protection is most-likely mediated via Nrf-2 induction that interferes with oxidant load, inflammatory pathways, and proapoptotic signaling. Graphical Abstract

Background: Methotrexate (MTX) is an antineoplastic/immunosuppressive drug, whose clinical use is impeded owing to its serious adverse effects; one of which is acute kidney injury (AKI). Most of MTX complications emerged from the provoked pro-oxidant-, pro-inflammatory- and pro-apoptotic effects. Quillaja saponaria bark saponin (QBS) is a bioactive triterpene that has been traditionally used as an antitussive, anti-inflammatory supplement, and to boost the immune system due to its potent antioxidant- and anti-inflammatory activities. However, the protective/therapeutic potential of QBS against AKI has not been previously evaluated. This study aimed to assess the modulatory effect of QBS on MTX-induced reno-toxicity. Methods: Thirty-two male rats were divided into 4-groups. Control rats received oral saline (group-I). In group-II, rats administered QBS orally for 10-days. In group-III, rats were injected with single i.p. MTX (20 mg/kg) on day-5. Rats in group-IV received QBS and MTX. Serum BUN/creatinine levels were measured, as kidney-damage-indicating biomarkers. Renal malondialdehyde (MDA), reduced-glutathione (GSH) and nitric-oxide (NOx) were determined, as oxidative-stress indices. Renal expression of TNF-α protein and Nrf-2/Keap-1 mRNAs were evaluated as regulators of inflammation. Renal Bcl-2/cleaved caspase-3 immunoreactivities were evaluated as apoptosis indicators. Results: Exaggerated kidney injury upon MTX treatment was evidenced histologically and biochemically. QBS attenuated MTX-mediated renal degeneration, oxidant-burden enhancement, excessive inflammation, and proapoptotic induction. Histopathological analysis further confirmed the reno-protective microenvironment rendered by QBS. Conclusions: In conclusion, our results suggest the prophylactic and/or therapeutic effects of QBS in treating MTX-induced AKI. Such reno-protection is most-likely mediated via Nrf-2 induction that interferes with oxidant load, inflammatory pathways, and proapoptotic signaling. [ABSTRACT FROM AUTHOR]

Teline monspessulana and Ulex europaeus (Fabaceae) are highly invasive species distributed worldwide. In Chile, both species share a similar distribution area with the native species Quillaja saponaria and Peumus boldus. This research focused on determining the effects caused by the aqueous extracts of the aerial organs of both invaders on the initial growth and photosynthetic performance of the two native tree species. Experiments were established under controlled conditions simulating natural conditions where both invasive and native species coexist. Morphometric variables defining root and aerial development were evaluated. Photosynthetic performance was also evaluated by measuring chlorophyll fluorescence, pigment content, and non-structural carbohydrates. In Q. saponaria seedlings, the growth of aerial and root organs was affected, but the production of photoassimilates increased under allelochemical stress. No damage to the photosynthetic machinery was observed in P. boldus, but its initial growth was notably reduced, possibly compromising its survival when interacting with both invasive species. The results indicated that allelochemicals synthesized by the two invasive species differentially affected the morphophysiological performance of the two native species. In terms of carbon administration, our results indicate that Q. saponaria seedlings probably use the assimilated carbon for biomass and defensive compound production. In contrast, P. boldus seedling growth is more sensitive to allelochemical stress and is seriously compromised, maybe because its metabolism is mainly invested in defensive compounds to deal with invasive species. [ABSTRACT FROM AUTHOR]

Quillay (Quillaja saponaria Molina) and peumo (Cryptocarya alba [Molina] Looser) are two tree species endemic to Chile that grow in Mediterranean climate zones, characterized by a summer season with high temperatures, high solar radiation, and low soil water availability. A study was conducted with 2-year-old Q. saponaria and C. alba plants and two substrate water conditions: well-watered and controlled water restriction. At the end of the study, anatomical leaf modifications were analyzed. The tissues were anatomically described in transverse sections of juvenile and adult leaves, measuring leaf thickness, cuticle thickness, and cell density of the mesophyll parenchymal tissues. In the young leaves of Q. saponaria plants undergoing water restriction treatment, an increase in cuticle and leaf thickness and a decrease in the density of the palisade and spongy parenchyma were observed. In contrast, a significant reduction in leaf thickness was observed in adult leaves of both species with water restriction treatment. The anatomical changes in the leaves of Q. saponaria and C. alba suggest an adaptation to adverse environmental conditions, such as water restriction.

Aqueous extracts of Quillaja saponaria Molina are US FDA approved as food additives in beverages with known antiviral activity. Due to lack of commercially available vaccines against human noroviruses (HNoVs), alternate methods to prevent their spread and the subsequent emergence of variant strains are being researched. Furthermore, HNoVs are not yet culturable at high enough titers to determine inactivation, therefore surrogates continue to be used. This research analyzed the effect of aqueous Quillaja saponaria extracts (QE) against HNoV surrogates, Tulane virus (TV), murine norovirus (MNV-1), and feline calicivirus (FCV-F9) at room temperature (RT) and 37 °C. Viruses (~ 5 log PFU/mL) were individually treated with 1:1 or 1:5 (v/v) diluted QE (pH ~ 3.75), malic acid control (pH 3.0) or phosphate-buffered saline (pH 7.2, as control) at 37 °C or RT for up to 6 h. Individual treatments were replicated three times using duplicate plaque assays for each treatment. FCV-F9 at ~ 5 log PFU/mL was not detectable after 15 min by 1:1 QE at 37 °C and RT. At RT, 1:5 QE lowered FCV-F9 titers by 2.05, 2.14 and 2.74 log PFU/mL after 0.5 h, 1 h and 2 h, respectively. MNV-1 showed marginal reduction of < 1 log PFU/mL after 15 min with 1:1 or 1:5 QE at 37 °C without any significant reduction at RT, while TV titers decreased by 2.2 log PFU/mL after 30 min and were undetectable after 3 h at 37 °C. Longer incubation with higher QE concentrations may be required for improved antiviral activity against MNV-1 and TV. [ABSTRACT FROM AUTHOR]

Simple Summary: Antibiotics are banned in animal feed, and substances used to replace antibiotics are being found continuously. Yucca schidigera, Quillaja saponaria, and Yucca saponin are natural plants and their components, which have many beneficial health functions for animals, are suitable as animal feed additives to replace antibiotics. By comparing the impacts of three substances on the growth, immunity, and intestinal health of broilers, this study found that Yucca schidigera, Quillaja saponaria, and Yucca saponin all promote the healthy growth of broilers, and Yucca saponin has better effects than the other two substances. The purpose of this study is to investigate the effects of Yucca saponin (YSa), Yucca schidigera (YS), and Quillaja Saponaria (QS) on growth performance, nitrogen metabolism, immune ability, antioxidant capability, and intestinal flora of yellow-feather broilers. This study randomly divided a total of 480 1-day yellow-feather broilers into 4 treatment groups. Factors in the 4 groups included CON group (basic diet), YSa group (basic diet mixed with 500 mg/kg YSa), YS group (basic diet mixed with 500 mg/kg YS), and QS group (basic diet mixed with 500 mg/kg QS). Throughout the 56-day study period, YSa, YS, and QS groups had higher average daily gain in broilers than the CON group (p < 0.01). The YS group had a lower feed gain ratio (F: G) in broilers than the CON group (p < 0.05). YSa, YS, and QS showed increased serum immunoglobin A (IgA), immunoglobin Y (IgY), immunoglobin M (IgM), and total antioxidant capacity (T-AOC) levels; enhanced acetic acid, butyric acid, and valeric acid levels of cecal content; and reduced contents of ammonia nitrogen, urea nitrogen, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and malondialdehyde (MDA) in serum in broilers (p < 0.05). The relative abundance of Lachnoclostridium in the QS group was decreased compared with that in the CON group (p < 0.05). Higher IgA and IgY sera contents were observed in the YS group compared to the YSa and QS groups (p < 0.05). In contrast with the QS group, the serum IL-6 concentration of the YS group was reduced (p < 0.05). In conclusion, YSa, YS, and QS promoted growth performance, nitrogen metabolism, immunity, antioxidant capability, and intestinal flora in broilers. Through the comparison of YSa, YS, and QS, it was found that YS is more suitable as a feed additive to ameliorate the healthy growth of broilers. [ABSTRACT FROM AUTHOR]

Honey adulteration is a common practice that affects food quality and sale prices, and certifying the origin of the honey using non-destructive methods is critical. Guindo Santo and Quillay are fundamental for the honey production of Biobío and the Ñuble region in Chile. Furthermore, Guindo Santo only exists in this area of the world. Therefore, certifying honey of this species is crucial for beekeeper communities—mostly natives—to give them advantages and competitiveness in the global market. To solve this necessity, we present a system for detecting adulterated endemic honey that combines different artificial intelligence networks with a confocal optical microscope and a tunable optical filter for hyperspectral data acquisition. Honey samples artificially adulterated with syrups at concentrations undetectable to the naked eye were used for validating different artificial intelligence models. Comparing Linear discriminant analysis (LDA), Support vector machine (SVM), and Neural Network (NN), we reach the best average accuracy value with SVM of 93% for all classes in both kinds of honey. We hope these results will be the starting point of a method for honey certification in Chile in an automated way and with high precision. [ABSTRACT FROM AUTHOR]

Saponins from Quillaja saponaria and Chenopodium quinoa were evaluated as natural emulsifiers in the formation of astaxanthin enriched canola oil emulsions. The aim of this study was to define the processing conditions for developing emulsions and to evaluate their physical stability against environmental conditions: pH (2–10), temperature (20–50 °C), ionic strength (0–500 mM NaCl), and storage (35 days at 25 °C), as well as their performance in an in vitro digestion model. The emulsions were characterized, evaluating their mean particle size, polydispersity index (PDI), and zeta potential. Oil-in-water (O/W) emulsions were effectively produced using 1% oil phase and 1% emulsifier (saponins). Emulsions were stable over a wide range of pH values (4–10), but exhibited particle aggregation at lower pH, salt conditions, and high temperatures. The emulsion stability index (ESI) remained above 80% after 35 days of storage. The results of our study suggest that saponins can be an effective alternative to synthetic emulsifiers. [ABSTRACT FROM AUTHOR]

The primary aim of this research study is to assess the effect of diesel vehicles' high gases and particulate matter emissions on Quillaja saponaria Mol.'s (Quillay) photosystem II (Fv/FmPD) maximum quantum performance at pre-dawn. Q. saponaria is the most common native tree species in Santiago's (Chile) urban area. Young Q. saponaria individuals are assessed in a growth chamber under two different irrigation conditions. The results show that plants with restricted irrigation (-30 bars on average) resist coarse particulate matter better and have significantly higher Fv/FmPD values than plants without restricted irrigation (-8 bars on average). Carbon monoxide, fine particulate matter, and ozone emissions reduced Fv/FmPD significantly in irrigated plants, including plants with restricted irrigation. It is concluded that Fv/FmPD is more affected by pollutants in plants without restricted irrigation than in plants with restricted irrigation. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the effects of Yucca saponin (YSa), Yucca schidigera (YS), and Quillaja Saponaria (QS) on growth performance, nitrogen metabolism, immune ability, antioxidant capability, and intestinal flora of yellow-feather broilers. This study randomly divided a total of 480 1-day yellow-feather broilers into 4 treatment groups. Factors in the 4 groups included CON group (basic diet), YSa group (basic diet mixed with 500 mg/kg YSa), YS group (basic diet mixed with 500 mg/kg YS), and QS group (basic diet mixed with 500 mg/kg QS). Throughout the 56-day study period, YSa, YS, and QS groups had higher average daily gain in broilers than the CON group (p < 0.01). The YS group had a lower feed gain ratio (F: G) in broilers than the CON group (p < 0.05). YSa, YS, and QS showed increased serum immunoglobin A (IgA), immunoglobin Y (IgY), immunoglobin M (IgM), and total antioxidant capacity (T-AOC) levels; enhanced acetic acid, butyric acid, and valeric acid levels of cecal content; and reduced contents of ammonia nitrogen, urea nitrogen, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and malondialdehyde (MDA) in serum in broilers (p < 0.05). The relative abundance of Lachnoclostridium in the QS group was decreased compared with that in the CON group (p < 0.05). Higher IgA and IgY sera contents were observed in the YS group compared to the YSa and QS groups (p < 0.05). In contrast with the QS group, the serum IL-6 concentration of the YS group was reduced (p < 0.05). In conclusion, YSa, YS, and QS promoted growth performance, nitrogen metabolism, immunity, antioxidant capability, and intestinal flora in broilers. Through the comparison of YSa, YS, and QS, it was found that YS is more suitable as a feed additive to ameliorate the healthy growth of broilers.

The effect of shelter tubes on plant performance has been widely studied. Although, the role of shelter tubes in alleviating the effects of drought and high-irradiance stresses during seedling establishment has been less studied than its effect on survival. The present study compares the effects of shelter tubes with different light transmissivities (Lt) on survival and morpho-physiological responses of two coexisting tree species (drought-tolerant Quillaja saponaria and relatively more drought-sensitive Maytenus boaria) of the Chilean matorral during an exceptionally dry and warm growing season (2014–2015). Two-year-old seedlings were randomly assigned to shelter tubes differing in Lt (20, 40, 60, 80%) or to a control (no shelter, Lt 100%) at field conditions. Survival was measured monthly, while shoot and root biomass, root length, pre-dawn xylem water potential, and non-structural carbohydrate concentration (NSC) were measured 8 months after transplanting. Shelter tubes increased the seedling survival of Q. saponaria by 80–100% relative to the control conditions, where full mortality was observed by the end of the experiment. By contrast, M. boaria exhibited high mortality regardless of the presence of shelters, suggesting that tubes were ineffective to alleviate the summer-related stresses in this species. Xylem water potential of Q. saponaria seedlings was significantly lower at 80% Lt than at 40% Lt, where maximum values were observed. Also, at 40% Lt, plant height and root length were highest and shoot/root ratio the lowest. By contrast, no differences in NSC, stomatal conductance, and photochemical efficiency were observed among Lt treatments. We conclude that shelter tubes may alleviate summer stresses in drought-tolerant species such as Q. saponaria; hence, they appear to be effective reforestation ecotechnology under severe water limitations and high-irradiance stress imposed by the current drought and heatwaves conditions in central Chile. [ABSTRACT FROM AUTHOR]

This study was aimed to evaluate the synergistic effect of Quillaja Saponaria (QS) and linseed oil (LO) on water quality, growth performance, welfare profile, blood health and immune‐oxidative status of Nile tilapia, Oreochromis niloticus fingerlings. Fish (n = 120, 10.28 ± 0.521 g) were randomly distributed in 12 aquaria in triplicate. Fish were divided into four groups: (1) fish received only basal diet (control group, CG), (2) basal diet supplemented with 300 mg kg−1Quillaja Saponaria (QS), (3) basal diet supplemented with 2% linseed oil (LO) and (4) basal diet supplemented with 300 mg kg−1Quillaja Saponaria and 2% linseed oil (QS/LO). Results revealed a significant (p < 0.05) improvement in fish productivity (final weight, weight gain, specific growth rate and feed conversion ratio), water quality (low total ammonia nitrogen and unionized ammonia) and welfare indices (low detached scales and fin damage) in fish received QS and/or LO with the best findings being detected in QS/LO. Dietary inclusion of QS and/or LO increased the serum total protein and globulin and reduced the cholesterol and triglycerides compared with CG (p < 0.05) with the best findings in QS/LO. Antioxidant enzymes (increased catalase, superoxide dismutase and reduced malonaldehyde), digestive enzymes (lipase and amylase) and relative gene expression (insulin growth factor I, superoxide dismutase, tumour necrosis factor‐alpha) were improved when fish received QS and/or LO with the best results in QS/LO. In conclusion, dietary supplementation of QS and/or LO improved growth performance, water quality, welfare profile and immune‐oxidative status of Nile tilapia fingerlings. The best findings being reported in fish received QS/LO. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the synergistic effects of Quillaja saponaria (QS) and Yucca schidigera (YS) on water quality, growth performance and health status of Nile tilapia. Fish (n = 120, 11.97 ± 0.497 g) were randomly distributed into four experimental groups in triplicates. (1) Control group (CG), fish received basal diet; (2) Yucca schidigera group (YS); fish received basal diet and 0.11 ml/m³ per week YS extract in water; (3) Quillaja saponaria group (QS), fish received basal diet supplemented with 300 mg/ kg QS extract; (4) Mixed group (QS/YS), fish received basal diet supplemented with 300 mg/kg QS and 0.11 ml/m³ per week YS extract in water. Results revealed an improvement of water quality parameters in QS/YS, YS and QS compared with CG (p ≤ 0.05). Fish received QS and/or YS showed higher growth performance and lower feed conversion ratio than CG (p ≤ 0.05), with the best findings being reported in QS/YS. Using QS and/or YS improved gill health, increased intestinal villi length and goblet cell number compared with CG (p ≤ 0.05). Lymphocytes, total protein, globulin and lysozyme activity were increased, while cholesterol, triglycerides, glucose and creatinine were decreased in fish received QS and/or YS compared with CG (p ≤ 0.05), with the best results being observed in QS/YS. QS and/or YS supplementation increased lipase, amylase, superoxide dismutase, catalase while reduced malonaldehyde activity compared with CG, with the highest activity being recorded in QS/YS. Conclusively, Nile tilapia received QS and YS prompted synergistic effects that improved water quality, growth performance, immune- oxidative status, digestive enzymes, gills and intestine histomorphology. [ABSTRACT FROM AUTHOR]

The effect of two different commercial products of Quillaja saponaria saponin extract on mortality of the free‐living copepodite stage sea‐lice Caligus rogercresseyi were assessed in vitro. Parasites were exposed for 24 hr to different concentrations of Quillaja extracts and then observed until 30 hr in non‐Quillaja media. The EC50 and EC90 were evaluated at 30 hr. High mortalities of copepodites were obtained at higher doses (500 ppm) for both extracts. Higher mortalities were obtained using the product with higher saponin content at 24 hr (23.3% vs. 86.6%) and 30 hr (63.3% vs. 93.3%) compared with the product containing less saponins. In addition, mortalities increased even after removing the extracts suggesting a residual and prolonged effect on the survival of the parasite. Our results indicated that the free‐living stage of the parasite is sensitive to saponins from Q. saponaria extracts and may be used to control or prevent the infestation of C. rogercresseyi in salmonids in Chile. [ABSTRACT FROM AUTHOR]

Honey adulteration is a common practice that affects food quality and sale prices, and certifying the origin of the honey using non-destructive methods is critical. Guindo Santo and Quillay are fundamental for the honey production of Biobío and the Ñuble region in Chile. Furthermore, Guindo Santo only exists in this area of the world. Therefore, certifying honey of this species is crucial for beekeeper communities—mostly natives—to give them advantages and competitiveness in the global market. To solve this necessity, we present a system for detecting adulterated endemic honey that combines different artificial intelligence networks with a confocal optical microscope and a tunable optical filter for hyperspectral data acquisition. Honey samples artificially adulterated with syrups at concentrations undetectable to the naked eye were used for validating different artificial intelligence models. Comparing Linear discriminant analysis (LDA), Support vector machine (SVM), and Neural Network (NN), we reach the best average accuracy value with SVM of 93% for all classes in both kinds of honey. We hope these results will be the starting point of a method for honey certification in Chile in an automated way and with high precision.

The abundance of saponin-rich plants across different ecosystems indicates their great potential as a replacement for harmful synthetic surfactants in modern commercial products. These organic saponins have remarkable biological and surface-active properties and align with sustainable and eco-friendly practices. This article examines and discusses the structure and properties of plant saponins with high yield of saponin concentrations and their exploitable applications. This highlights the potential of saponins as ethical substitutes for traditional synthetic surfactants and pharmacological agents, with favorable effects on the economy and environment. For this purpose, studies on the relevant capabilities, structure, and yield of selected plants were thoroughly examined. Studies on the possible uses of the selected saponins have also been conducted. This in-depth analysis highlights the potential of saponins as workable and ethical replacements for traditional synthetic medications and surfactants, thus emphasizing their favorable effects on human health and the environment. [Display omitted] • An exploration into the multifaceted nature of plant saponins unveiling their versatile potential was attempted. • The sources, structure, physiochemical and biological properties of saponins were discussed. • Examines structural attributes and properties of high-concentration plant saponins for potential applications. • The structure and concentrations of selected plant saponins were recorded. • Sustainable plant saponin extraction offers health and industrial benefits, like anti cancer and anti-diabetic properties. [ABSTRACT FROM AUTHOR]

Saponins from Quillaja saponaria and Chenopodium quinoa were evaluated as natural emulsifiers in the formation of astaxanthin enriched canola oil emulsions. The aim of this study was to define the processing conditions for developing emulsions and to evaluate their physical stability against environmental conditions: pH (2–10), temperature (20–50 °C), ionic strength (0–500 mM NaCl), and storage (35 days at 25 °C), as well as their performance in an in vitro digestion model. The emulsions were characterized, evaluating their mean particle size, polydispersity index (PDI), and zeta potential. Oil-in-water (O/W) emulsions were effectively produced using 1% oil phase and 1% emulsifier (saponins). Emulsions were stable over a wide range of pH values (4–10), but exhibited particle aggregation at lower pH, salt conditions, and high temperatures. The emulsion stability index (ESI) remained above 80% after 35 days of storage. The results of our study suggest that saponins can be an effective alternative to synthetic emulsifiers.

• The Time of Emergence of forest is a useful tool to manage climate change impacts. • Detecting when and where Mediterranean forest will present changes in distribution. • Time of Emergence tool can be adapted to evaluate climate change in other forests. Climate change has intensified in recent decades, leading to increasingly severe droughts. This trend will continue due to the emissions and increasing concentration of greenhouse gas (GHG). One of the main direct climate change consequences is the modification and alteration of the dynamics and function of forest ecosystems, having effects ranging from physiological alterations in plants to definitive changes in their geographical distribution. Mediterranean ecosystems are particularly threatened, where the sclerophyllous forest of central Chile that is considered a biodiversity hotspot, is no exception. Despite that sclerophyllous species present drought adaptation mechanisms, there is no certainty of the climatic minimum thresholds in which it develops, or when climate changes will exceed these thresholds, causing definitive changes in its distribution. To evaluate these changes on the Andean Mediterranean Sclerophyllous Forest vegetation belt of Quillaja saponaria and Lithraea caustica , the forest was divided into six quadrants with similar climates. In each quadrant, a critical threshold ​​of a simplified water balance (SWB) was defined where the forest has historically developed. The SWB is considered to be a limiting factor in the forest development. Then, the Time of Emergence (ToE) of the forest is estimated, as the time when climate change projections exceed the critical thresholds, by using CMIP6 General Circulation Models (GCM), under SSP2-4.5 (moderate) and SSP5-8.5 (pessimistic) scenarios. Results indicate that the forest would begin to be displaced between 2060 and 2080 under the SSP5-8.5 scenario, particularly in the Talagante, Isla de Maipo, Paine, and Doñihue area, while no distribution changes are presented under SSP2-4.5 scenario. [ABSTRACT FROM AUTHOR]