An Overview of Chemistry, Kinetics, Toxicity and Therapeutic Potential of Boldine in Neurological Disorders.

Boldine is an alkaloid obtained from the medicinal herb Peumus boldus (Mol.) (Chilean boldo tree; boldo) and belongs to the family Monimiaceae. It exhibits a wide range of pharmacological effects such as antioxidant, anticancer, hepatoprotective, neuroprotective, and anti-diabetic properties. There is a dearth of information regarding its pharmacokinetics and toxicity in addition to its potential pharmacological activity. Boldine belongs to the aporphine alkaloid class and possesses lipophilic properties which enable its efficient absorption and distribution throughout the body, including the central nervous system. It exhibits potent free radical scavenging activity, thereby reducing oxidative stress and preventing neuronal damage. Through a variety of neuroprotective mechanisms, including suppression of AChE and BuChE activity, blocking of connexin-43 hemichannels, pannexin 1 channel, reduction of NF-κß mediated interleukin release, and glutamate excitotoxicity which successfully reduces neuronal damage. These results point to its probable application in reducing neuroinflammation and oxidative stress in epilepsy, Alzheimer's disease (AD), and Parkinson's disease (PD). Moreover, its effects on serotonergic, dopaminergic, opioid, and cholinergic receptors were further investigated in order to determine its applicability for neurobehavioral dysfunctions. The article investigates the pharmacokinetics of boldine and reveals that it has a low oral bioavailability and a short half-life, requiring regular dosage to maintain therapeutic levels. The review studies boldine's potential therapeutic uses and mode of action while summarizing its neuroprotective benefits.  Given the favorable results for boldine as a potential neurotherapeutic drug in laboratory animals, more research is required. However, in order to optimise its therapeutic potential, it must be more bioavailable with fewer detrimental side effects.

Hepatoprotective effect of boldine against diethylnitrosamine-induced hepatocarcinogenesis in wistar rats.

Discovering the utmost effective and targeted chemotherapy for hepatocellular carcinoma is still a significant challenge. In the present study, diethylnitrosamine was used as a liver carcinogen and boldine a compound of boldo. We anticipated the hypothesis that boldine endow antiproliferative and promote apoptosis on hepatocarcinoma rats. We analyzed that boldine alters the tumor biomarkers and liver markers enzyme levels. Also, we determined boldine modulate the enzymatic and nonenzymatic antioxidant activities, as well as messenger RNA and protein expressions of Bcl2, Bax, and cleaved caspase 3 by reverse transcription polymerase chain reaction and Western blot analysis, respectively. It was also manifested by histopathology studies in liver tissues of HCC rats. Our finding suggested that boldine has antioxidant activity, and moreover, also contributes apoptotic nature by upregulating the protein expression of Bax, and cleaved caspase 3. Our data accomplishes that boldine a candidate drug has dynamic therapeutic activity and suitable for the treatment of HCC.

Exploring the Insecticidal Potential of Boldo (Peumus boldus) Essential Oil: Toxicity to Pests and Vectors and Non-target Impact on the Microcrustacean Daphnia magna.

Every year Chile exports about 2000 tons of boldo folium (Peumus boldus), which is used around the world as a traditional herbal medicinal product (THMP), mostly to relieve gastrointestinal disorders. This biomass may be a resource for the agrochemical industry to manufacture botanical insecticides. In this regard, the insecticidal potential of boldo has been poorly investigated. In the present work, hydrodistillation of a commercial boldo folium gave 1.5% (w/w) of a yellowish essential oil (boldo essential oil, BEO) containing 1,8-cineole (20.7%), p-cymene (18.5%), limonene (9.1%), ascaridole (9.1%) and ß-phellandrene (6.4%) as the main constituents, as determined by gas chromatography-mass spectrometry (GC-MS). NMR analysis allowed us to determine that ascaridole was mainly represented by the cis-isomer. BEO was toxic to larvae of the filariasis vector Culex quinquefasciatus and adults of the housefly Musca domestica, showing LC50/LD50 values of 67.9 mg·L-1 and 98.5 µg·adult-1, respectively. On the other hand, lower insecticidal activity was observed against larvae of the moth pest Spodoptera littoralis (LD50 of 268.9 µg·larva-1). It is worth noting that, when tested at LC90 concentration, BEO was significantly less toxic to aquatic microcrustacean Daphnia magna than the conventional insecticide α-cypermethrin. Finally, in the attempt to explore the BEO mode of action, we tested it for acetylcholinesterase (AChE) inhibitory properties using the Ellman method, obtaining negligible effects (IC50 = 0.45 mg·mL-1). Taken together, these results gave new insights into the potential of BEO as a future ingredient of botanical insecticides.

Telomerase Inhibition by a New Synthetic Derivative of the Aporphine Alkaloid Boldine.

Telomerase, the enzyme responsible for cell immortality, is an important target in anti-cancer drug discovery. Boldine, an abundant aporphine alkaloid of Peumus boldus, is known to inhibit telomerase at non-toxic concentrations. Cytotoxicity of N-benzylsecoboldine hydrochloride (BSB), a synthetic derivative of boldine, was determined using the MTT method in MCF7 and MDA-MB231 cells. Aliquots of cell lysates were incubated with various concentrations of BSB in qTRAP (quantitative telomere repeat amplification protocol)-ligand experiments before substrate elongation by telomerase or amplification by hot-start Taq polymerase. The crystal structure of TERT, the catalytic subunit of telomerase from Tribolium castaneum, was used for docking and molecular dynamics analysis. The qTRAP-ligand data gave an IC50 value of about 0.17 ± 0.1 µM for BSB, roughly 400 times stronger than boldine, while the LD50 in the cytotoxicity assays were 12.5 and 21.88 µM, respectively, in cells treated for 48 h. Although both compounds interacted well with the active site, MD analysis suggests a second binding site with which BSB interacts via two hydrogen bonds, much more strongly than boldine. Theoretical analyses also evaluated the IC50 for BSB as submicromolar. BSB, with greater hydrophobicity and flexibility than boldine, represents a promising structure to inhibit telomerase at non-toxic concentrations.

Boldine Improves Kidney Damage in the Goldblatt 2K1C Model Avoiding the Increase in TGF-ß.

Boldine, a major aporphine alkaloid found in the Chilean boldo tree, is a potent antioxidant. Oxidative stress plays a detrimental role in the pathogenesis of kidney damage in renovascular hypertension (RVH). The activation of the renin-angiotensin system (RAS) is crucial to the development and progression of hypertensive renal damage and TGF-β is closely associated with the activation of RAS. In the present study, we assessed the effect of boldine on the progression of kidney disease using the 2K1C hypertension model and identifying mediators in the RAS, such as TGF-β, that could be modulated by this alkaloid. Toward this hypothesis, rats (n = 5/group) were treated with boldine (50 mg/kg/day, gavage) for six weeks after 2K1C surgery (pressure ≥ 180 mmHg). Kidney function was evaluated by measuring of proteinuria/creatininuria ratio (U prot/U Crea), oxidative stress (OS) by measuring thiobarbituric acid reactive substances (TBARS). The evolution of systolic blood pressure (SBP) was followed weekly. Alpha-smooth muscle actin (α-SMA) and Col III were used as markers of kidney damage; ED-1 and osteopontin (OPN) were used as markers of inflammation. We also explored the effect in RAS mediators, such as ACE-1 and TGF-β. Boldine treatment reduced the UProt/UCrea ratio, plasma TBARS, and slightly reduced SBP in 2K1C hypertensive rats, producing no effect in control animals. In 2K1C rats treated with boldine the levels of α-SMA, Col III, ED-1, and OPN were lower when compared to 2K1C rats. Boldine prevented the increase in ACE-1 and TGF-β in 2K1C rats, suggesting that boldine reduces kidney damage. These results suggest that boldine could potentially be used as a nutraceutic.

Neuroinflammatory response to experimental stroke is inhibited by boldine.

Inflammation plays a pivotal role in the development of ischemic brain damage. Astrocyte activation promotes the production of several proinflammatory mediators, such as TNF-α and iNOS. Eventually, neuronal death occurs, leading to the development of motor and memory deficits in patients. Boldine is the main alkaloid in the leaves and bark of the Peumus boldus Molina, and has anti-inflammatory and antioxidant properties. The aim of this work was to investigate the neuroprotective effect of boldine on neuroinflammation and memory deficits induced by permanent middle cerebral artery occlusion (pMCAO) in mice. Thirty minutes before pMCAO and during the next 5 days, animals received vehicle (0.025 µmol/l HCl) or boldine (8, 16 and 25 mg/kg, intraperitoneally). The extension of the infarct area, neurological scores, and myeloperoxidase activity were evaluated 24 h after pMCAO. Locomotor activity, working, and aversive memory were evaluated 72 h after pMCAO, object recognition memory was tested 96 h after pMCAO, and spatial memory was tested 120 h after pMCAO. Cresyl violet, Fluoro-Jade C staining, and immunohistochemical for GFAP, TNF-α, and iNOS were also carried out. The treatment with boldine significantly decreased the infarct area, improved the neurological scores, and increased cell viability. The vertical exploratory activity and aversive, spatial, object recognition, and working memory deficits induced by pMCAO were prevented by boldine. Moreover, myeloperoxidase activity and GFAP, TNF-α, and iNOS immunoreactivity were decreased significantly by boldine. Although various mechanisms such as its antioxidant activity should be considered, these results suggest that the neuroprotective effect of boldine might be related in part to its anti-inflammatory properties.

Computer-Aided 13C NMR Chemical Profiling of Crude Natural Extracts without Fractionation.

A computer-aided, 13C NMR-based dereplication method is presented for the chemical profiling of natural extracts without any fractionation. An algorithm was developed in order to compare the 13C NMR chemical shifts obtained from a single routine spectrum with a set of predicted NMR data stored in a natural metabolite database. The algorithm evaluates the quality of the matching between experimental and predicted data by calculating a score function and returns the list of metabolites that are most likely to be present in the studied extract. The proof of principle of the method is demonstrated on a crude alkaloid extract obtained from the leaves of Peumus boldus, resulting in the identification of eight alkaloids, including isocorydine, rogersine, boldine, reticuline, coclaurine, laurotetanine, N-methylcoclaurine, and norisocorydine, as well as three monoterpenes, namely, p-cymene, eucalyptol, and α-terpinene. The results were compared to those obtained with other methods, either involving a fractionation step before the chemical profiling process or using mass spectrometry detection in the infusion mode or coupled to gas chromatography.

Antimutagenic evaluation of traditional medicinal plants from South America Peumus boldus and Cryptocarya alba using Drosophila melanogaster.

Peumus boldus Mol. ("Boldo") and Cryptocarya alba Mol. Looser ("Peumo") are medicinal shrubs with wide geographical distribution in South America. Their leaves and fruits are commonly used in traditional medicine because they exhibit natural medicinal properties for treatment of liver disorders and rheumatism. However, there are no apparent data regarding potential protective effects on cellular genetic components. In order to examine potential mutagenic and/or antimutagenic effects of these medicinal plants, the Drosophila melanogaster (D. melanogaster) wing-spot test was employed. This assay detects a wide range of mutational events, including point mutations, deletions, certain types of chromosomal aberrations (nondisjunction), and mitotic recombination. Qualitative and quantitative analyses of phenolic and anthocyanin compounds were carried out using biochemical and high-performance liquid chromatography methodologies. In addition, the antioxidant capacity of P. boldus and C. alba leaf extracts was also analyzed. P. boldus and C. alba extracts did not induce significant mutagenic effects in the D. melanogaster model. However, simultaneous treatment of extracts concurrently with the mutagen ethyl methane sulphonate showed a decrease of mutant spots in somatic cells of D. melanogaster, indicating desmutagenic effects in this in vivo model. Flavonoids and anthocyanins were detected predominantly in the extracts, and these compounds exerted significant antioxidant capacity. The observed antimutagenic effects may be related to the presence of phytochemicals with high antioxidant capacity, such as flavonoids and antohocyanins, in the extracts.

Evaluation of Boldine Activity against Intracellular Amastigotes of Leishmania amazonensis.

Leishmaniasis is a neglected and endemic disease that affects poorest population mainly in developing countries. A lack of adequate and definitive chemotherapeutic agents to fight against this infection has led to the investigation of numerous compounds. The aim of this study was to investigate in vitro activity of boldine against Leishmania amazonensis murine cell infection. Boldine ((S)-2,9-dihydroxy-1,10-dimethoxy-aporphine) is an aporphine alkaloid found abundantly in the leaves/bark of boldo (Peumus boldus Molina), a widely distributed tree native to Chile. The in vitro system consisted of murine macrophage infection with amastigotes of L. amazonensis treated with different concentrations from 50 to 600 µg/ml of boldine for 24 hr. Intracellular parasite destruction was assessed by morphological examination and boldine cytotoxicity to macrophages was tested by the MTT viability assay. When cells were treated with 100 µg/ml of boldine the reduction of parasite infection was 81% compared with untreated cultures cells. Interestingly, boldine-treatment caused a concentration-dependent decrease of macrophage infection that culminated with 96% of reduction when cells were submitted to 600 µg/ml of boldine. Cell cultures exposed to 100 µg/ml of boldine and 300 µg/ml of Glucantime® during 24 hr showed a significant reduction of 50% in parasitized cells compared with cell cultures exposed just to Glucantime®. The study showed that treatment with boldine produces a better effect than treatment with the reference antimonial drug, glucantime, in L. amazonensis infected macrophage. Our results suggest that boldine is a potentially useful agent for the treatment of leishmaniasis.

Peumus boldus (Boldo) Aqueous Extract Present Better Protective Effect than Boldine Against Manganese-Induced Toxicity in D. melanogaster.

The cellular, intracellular and molecular mechanism(s) underlying the toxicity of Mn are still incompletely understood, although several points concerning Mn neurotoxicity have been addressed. Importantly, oxidative changes have been reported to be involved in Mn-induced toxicity. As a consequence, antioxidants are expected to offer protection in Drosophila melanogaster exposed to this metal. So, in this study we evaluated the hypothesis that the aqueous extract of boldo (Peumus boldus), and its alkaloids boldine, could prevent/ameliorate behavioral and oxidative alterations induced by Mn in a D. melanogaster intoxication model. Adult wild-type flies were concomitantly exposed to Mn (3 mM) and boldo aqueous extract (5 mg/mL) or boldine (327.37 µg/mL) in the food during 9 days. Mn-fed flies had a worse performance in the negative geotaxis assay and in the open-field test, as well as a higher incidence of mortality and TBARS levels in head and body, when compared to control group. Boldo aqueous extract was found to reduce the mortality rate of the flies exposed to Mn. In turn, boldine was ineffective against Mn-induced mortality and significantly increases mortality per se. Additionally, Mn-induced locomotors dysfunction were fully ameliorated by boldo crude extract and only partially ameliorated by boldine. Likewise, boldo completely normalize head and body TBARS levels, whereas boldine only partially normalize in body. Finally, we found that flies treated with Mn presented significantly decrease in dopamine levels. Our results suggest that boldo crude extract can exert protective effect against Mn-induced toxicity in D. melanogaster, whereas boldine do not. Moreover, our data confirm the utility of this model to investigate potential therapeutic strategies on movement disorders, such as that caused by Mn.

Larvicidal activity of essential oil of Peumus boldus Molina and its ascaridole-enriched fraction against Culex quinquefasciatus.

Culex quinquefasciatus (Say, 1823), known as the domestic mosquito, is a common and abundant species throughout the world, and a cosmopolitan species. The adults of this mosquito are important in terms of public and animal health since they display adaptability to different hosts. In humans, they are responsible for the transmission of various diseases. One manner of control of this vector is the use of insecticidal or larvicidal products, which may have the drawback of toxicity to mammals and can be harmful to the environment. The present work evaluated the larvicidal potential of the essential oil (EO) and ascaridole-enriched fraction (EF4-5) obtained from the leaves of Peumus boldus Molina (boldo). The EO, obtained by steam distillation, was analyzed by GC/MS and fractionated on silica gel. EO and EF4-5, containing 31.4% and 89.5% ascaridole, respectively, were evaluated against C. quinquefasciatus at concentrations of 100, 50 and 25 µg/ml on the third and fourth instars. They showed lethal concentrations (LC50) of 82.14 and 41.85 µg/ml, respectively. Larvae treated with the EF4-5 showed morphological changes in the midgut, with cells possessing a cytoplasm that contained small vacuole-like structures, as well as a nucleus with decondensed chromatin and a cell apex with a short brush border. The cells of the fat body showed larger protein granules, which were acidophilic relative to the larvae of the control group. Moreover, the enriched fraction at a dose of 50 µg/ml showed a residual larvicidal effect according to exposure time on C. quinquefasciatus. This residual effect deserves consideration, since a long-term larvicidal product may be a useful tool for vector control.

Catechin-based procyanidins from Peumus boldus Mol. aqueous extract inhibit Helicobacter pylori urease and adherence to adenocarcinoma gastric cells.

In this work, the anti-Helicobacter pylori effect of an aqueous extract from dried leaves of Peumus boldus Mol. (Monimiaceae) was evaluated. This extract displayed high inhibitory activity against H. pylori urease. Therefore, in order to clarify the type of substances responsible for such effect, a bioassay-guided fractionation strategy was carried out. The active compounds in the fractions were characterized through different chromatographic methods (RP-HPLC; HILIC-HPLC). The fraction named F5 (mDP = 7.8) from aqueous extract was the most active against H. pylori urease with an IC50 = 15.9 µg gallic acid equivalents (GAE)/mL. HPLC analysis evidenced that F5 was composed mainly by catechin-derived proanthocyanidins (LC-MS and phloroglucinolysis). The anti-adherent effect of boldo was assessed by co-culture of H. pylori and AGS cells. Both the aqueous extract and F5 showed an anti-adherent effect in a concentration-dependent manner. An 89.3% of inhibition was reached at 2.0 mg GAE/mL of boldo extract. In conjunction, our results suggest that boldo extract has a potent anti-urease activity and anti-adherent effect against H. pylori, properties directly linked with the presence of catechin-derived proanthocyanidins.

Simultaneous microwave extraction and separation of volatile and non-volatile organic compounds of boldo leaves. From lab to industrial scale.

Microwave extraction and separation has been used to increase the concentration of the extract compared to the conventional method with the same solid/liquid ratio, reducing extraction time and separate at the same time Volatile Organic Compounds (VOC) from non-Volatile Organic Compounds (NVOC) of boldo leaves. As preliminary study, a response surface method has been used to optimize the extraction of soluble material and the separation of VOC from the plant in laboratory scale. The results from the statistical analysis revealed that the optimized conditions were: microwave power 200 W, extraction time 56 min and solid liquid ratio of 7.5% of plants in water. Lab scale optimized microwave method is compared to conventional distillation, and requires a power/mass ratio of 0.4 W/g of water engaged. This power/mass ratio is kept in order to upscale from lab to pilot plant.

[Behavioural impairments and hallucinations after consumption of boldo leaf infusions]. / Troubles du comportement et hallucinations après consommation d'infusions de feuilles de boldo.

We report a case of behavioural impairments with hallucinations in a twelve-year-old girl, after consumption of boldo leaf infusions. The main alkaloid of boldo, named boldine, is very likely responsible for temporary neuropsychiatric disturbances present in the patient. The emergence of behavioural problems and hallucinations without any obvious cause, should lead to search for consumption of boldo leaf infusion ("tisanes"). This consumption must be avoided in children.

Gall inducer Dasineura sp. alters the polyphenol profile and antioxidant activity of Peumus boldus stems.

Peumus boldus, a tree native to Chile, is extensively used for medicinal purposes due to its richness in alkaloids and antioxidant polyphenols. A species of galling insect, Dasineura sp. induces structural and chemical changes on P. boldus stems while its galls are established and developed. Taking into account the antioxidant properties of P. boldus polyphenols, it would be expected that Dasineura sp. induces changes in the accumulation sites, chemical profile, and antioxidant activity of the P. boldus stem polyphenols, related to different reactive oxygen species (ROS) production levels during gall development. Dasineura sp. induces changes in the accumulation sites of total polyphenols, flavonols, and lignin, redirecting their accumulation toward the sites of greatest production of H2O2 and O2.-. Although changes in total polyphenol content would be expected, this did not vary significantly between non-galled and galled stems. However, the galling insect induced changes in the profile and concentration of soluble polyphenols, leading to the gall extracts' antioxidant capacity decreasing significantly during the maturation and senescence stages. Additionally, during the maturation stage, lignin deposition increases in the more peripheral gall tissues, which also contributes to ROS dissipation. The differences in the different gall developmental stages' antioxidant activity could be related to the identity and concentration of phenolic compounds in each gall extract, rather than to the total phenol content. Regardless of the mechanisms involved, the dissipation of the ROS generated by Dasineura sp. activity occurs, restoring the redox balance in galls and guaranteeing the success of the inducer.

Vascular implications of Dasineura sp. galls' establishment on Peumus boldus stems.

Some chewing larvae are capable of inducing galls in the host vascular cylinder, e.g. Dasineura sp. (Cecidomyiidae) on Peumus boldus stems. Due to the medicinal and economic importance of P. boldus, the anatomical and functional implications of establishment of Dasineura sp. on P. boldus stems were investigated. We asked if establishment of Dasineura sp. in P. boldus stems induces abnormalities at the cellular and organizational level of the vascular system that increase during gall development in favour of the hydric status of the gall. Anatomical alterations induced in the stems during gall development were determined. Cytohistometric analyses in mature galls were compared to non-galled stems, and water potential and leaf area of non-galled stems were compared with galled stems. Dasineura sp. establishes in the vascular cambium, leading to delignification and rupture of xylem cells, inhibiting formation of phloem and perivascular sclerenchyma. Gall diameter increases together with larval feeding activity, producing a large larval chamber and numerous layers of nutritive tissue, vascular parenchyma, and sclerenchyma. These anatomical alterations do not affect the leaf area of galled stems but favour increased water flow towards these stems. The anatomical alterations induced by Dasineura sp. in P. boldus stems guarantee water and nutrient supply to the gall and larva. After the inducer exits stems, some host branches no longer have vascular connections with the plant body.

Role of K+ and Ca2+ Channels in the Vasodilator Effects of Plectranthus barbatus (Brazilian Boldo) in Hypertensive Rats.

Plectranthus barbatus, popularly known as Brazilian boldo, is used in Brazilian folk medicine to treat cardiovascular disorders including hypertension. This study investigated the chemical profile by UFLC-DAD-MS and the relaxant effect by using an isolated organ bath of the hydroethanolic extract of P. barbatus (HEPB) leaves on the aorta of spontaneously hypertensive rats (SHR). A total of nineteen compounds were annotated from HEPB, and the main metabolite classes found were flavonoids, diterpenoids, cinnamic acid derivatives, and organic acids. The HEPB promoted an endothelium-dependent vasodilator effect (~100%; EC50 ~347.10 µg/mL). Incubation of L-NAME (a nonselective nitric oxide synthase inhibitor; EC50 ~417.20 µg/mL), ODQ (a selective inhibitor of the soluble guanylate cyclase enzyme; EC50 ~426.00 µg/mL), propranolol (a nonselective α-adrenergic receptor antagonist; EC50 ~448.90 µg/mL), or indomethacin (a nonselective cyclooxygenase enzyme inhibitor; EC50 ~398.70 µg/mL) could not significantly affect the relaxation evoked by HEPB. However, in the presence of atropine (a nonselective muscarinic receptor antagonist), there was a slight reduction in its vasorelaxant effect (EC50 ~476.40 µg/mL). The addition of tetraethylammonium (a blocker of Ca2+-activated K+ channels; EC50 ~611.60 µg/mL) or 4-aminopyridine (a voltage-dependent K+ channel blocker; EC50 ~380.50 µg/mL) significantly reduced the relaxation effect of the extract without the interference of glibenclamide (an ATP-sensitive K+ channel blocker; EC50 ~344.60 µg/mL) or barium chloride (an influx rectifying K+ channel blocker; EC50 ~360.80 µg/mL). The extract inhibited the contractile response against phenylephrine, CaCl2, KCl, or caffeine, similar to the results obtained with nifedipine (voltage-dependent calcium channel blocker). Together, the HEPB showed a vasorelaxant effect on the thoracic aorta of SHR, exclusively dependent on the endothelium with the participation of muscarinic receptors and K+ and Ca2+ channels.

Biochemical characterization of Peumus boldus fruits: Insights of its antioxidant properties through a theoretical approach.

Peumus boldus is an endemic tree species from Chile whose leaves have been the focus of study for decades given that their infusions are reported to relieve rheumatic symptoms, headache, dyspepsia, urinary tract inflammation, and symptoms of other illnesses. These health properties have been studied mainly using leaves and bark, then it is relevant to know more about these properties in different parts of the plant. Considering the importance of P. boldus fruits in the diet of some rural populations, we analyzed their properties to explore its impact on the Chilean population health. Liquid chromatography and mass spectrometry analysis confirmed the presence of alkaloids such as boldine, although aporphine N-methyl-laurotetanine was the most abundant. In addition, flavonoids catechin, chrysin and quercetin were also found in the extract. Cytotoxicity and anti-inflammatory activities of the fruit extract were invitro tested by using a murine macrophage cell model, observing that a diluted fraction of the extract was not cytotoxic, but showed anti-inflammatory activity, which is likely attributed to antioxidants activities. By means of quantum chemical calculations, we calculated the redox potential of the respective alkaloids and flavonoids found in the extract. Results suggest a synergistic effect between alkaloids and flavonoids, where boldine and N-methyl-laurotetanine showed similar antioxidant properties. Finally, we present a description of the oxidation mechanisms for both groups of molecules which will sustain P. boldus fruit biological properties, in order to give this kind of fruits scientific value focusing on human health.

Herbicidal activity of Peumus boldus and Drimys winterii essential oils from Chile.

The essential oil composition of Peumus boldus and Drimys winterii was analyzed by means of capillary GC-FID and GC-MS. More than 96% of the total oil components (43 and 54 compounds, respectively) were identified, with ascaridole (51.17 ± 9.51), p-cymene (16.31 ± 2.52) and 1,8-cineole (14.45 ± 2.99) as the main compounds in P. boldus and g-eudesmol (21.65 ± 0.41), followed of elemol (12.03 ± 0.34) and terpinen-4-ol (11.56 ± 1.06) in D. winterii. The herbicidal activity was tested against Amaranthus hybridus and Portulaca oleracea. P. boldus essential oil was the most phytotoxic against both weeds, inhibiting seed germination and seedling growth at all concentrations assayed (0.125-1 µL/mL). D. winterii essential oil did not show any effect on A. hybridus germination and only affected P. oleracea germination at the highest concentration. The results suggest the possible use of the essential oil from P. boldus as a natural herbicide.

Evaluation of Chilean Boldo Essential Oil as a Natural Insecticide Against Chrysomya megacephala (Diptera: Calliphoridae).

Chrysomya megacephala (Fabricius, 1794) is a vector of enteric bacteria, protozoa, helminths, and viruses. These Diptera can also be responsible for secondary myiasis in several animal species. Therefore, it is easy to understand the relevance of studies focusing on C. megacephala dissemination control. The employment of essential oils as natural insecticides must be considered as a promising alternative for the replacement of synthetic insecticides. In this context, the essential oil obtained from Chilean boldo leaves should be highlighted. The aim of the present work was to assess the insecticidal activity of Chilean boldo essential oil against C. megacephala blowflies in different life stages (larva, pupa, and adult). The essential oils were extracted from commercial samples of Chilean boldo leaves by hydrodistillation and were mixed to produce a pool that was employed in the study. Gas chromatographic techniques were used to enable the identification and quantification of the pool's components. Larvae, pupae, and adult insects of C. megacephala were exposed (topical application) to different concentrations of this essential oil pool. After that, the larvicidal, pupicidal, and insecticidal actions of the oil were tested. Its toxicity might be associated with compounds such as eucalyptol, linalool, α-pinene, limonene, and ascaridole, either acting alone or by synergic effects. Interestingly, the pupae appeared to be stronger than the larvae and adult insects, needing higher doses of essential oil to be killed. The oil's toxic effects could be useful to control C. megacephala dissemination in all of its development phases.