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.

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.

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.

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.

Effects of Astragalus membranaceus, Peumus boldus and Curcuma longa extracts in diabetic rats / Efeitos de extratos de Astragalus membranaceus, Peumus boldus e Curcuma longa em ratos com diabetes induzida

Objectives: the aim of this study was to evaluate the effects of the association of dry extracts of Astragalus membranaceus, Peumus boldus and Curcuma longa in rats with induced diabetes. Methods: After the induction of type 2 diabetes by intraperitoneal streptozotocin, male Wistar rats were randomly assigned to groups (n=6) and treated for 20 days. The extracts were suspended in water and administered through orogastric gavage once daily as described: Group I: healthy control (saline); group II: received Astragalus membranaceus, Peumus boldus and Curcuma longa (400 mg/kg/day of each dry extract); group III: received Astragalus membranaceus, Peumus boldus, Curcuma longa (400 mg/kg/day of each dry extract) and glibenclamide (15 mg/kg/day). Fasting glucose, glucose tolerance, alanine aminotransferase, aspartate aminotransferase and fructosamine were evaluated. Results: Fasting blood glucose and glucose tolerance for groups II and III were influenced by treatments (p<0.05). The extracts did not significantly influence the efficacy of glibenclamide. Conclusion: The results found in this study allow us to consider that it is not possible to conclude that the compounds evaluated are not effective in DM in rats, due to variables such as total treatment period, doses, size of pancreatic injury caused by streptozotocin, and diet profile may have influenced the results. The studied compounds have potential for application in diabetes and further studies should be carried out to adjust the treatment.

Objetivos: avaliar os efeitos da associação de extratos secos de Astragalus membranaceus, Peumus boldus e Curcuma longa em ratos com diabetes induzida. Métodos: Após a indução de diabetes tipo 2 (DM) por estreptozotocina intraperitoneal, ratos Wistar machos foram distribuídos aleatoriamente em grupos (n=6) e tratados por 20 dias. Os extratos foram suspensos em água e administrados por gavagem orogástrica uma vez ao dia conforme descrito: Grupo I: controle saudável (solução salina); grupo II: recebeu Astragalus membranaceus, Peumus boldus e Curcuma longa (400 mg/kg/dia de cada extrato seco); grupo III: receberam Astragalus membranaceus, Peumus boldus, Curcuma longa (400 mg/kg/dia de cada extrato seco) e glibenclamida (15 mg/kg/dia). A glicemia de jejum, tolerância à glicose, alanina aminotransferase, aspartato aminotransferase e frutosamina foram avaliados. Resultados: A glicemia de jejum e a tolerância à glicose para os grupos II e III foram influenciadas pelos tratamentos (p<0,05). Os extratos não influenciaram significativamente na eficácia da glibenclamida. Conclusão: Os resultados encontrados neste estudo permitem considerar que não é possível concluir que os compostos avaliados não são eficazes no DM em ratos, devido às variáveis como tempo total de tratamento, doses e tamanho da lesão pancreática causada por estreptozotocina, além do perfil da dieta, que podem ter influenciado os resultados. Os compostos estudados têm potencial para aplicação em diabetes e mais estudos devem ser realizados para adequar o tratamento.

Conhecimento etnobotânico sobre plantas medicinais utilizadas por moradores de um município ribeirinho no interior do estado do Amazonas, Brasil / Ethnobotanical knowledge of medicinal plants used by residents of a riverside city in the Amazonas state, Brazil

Mesmo com a evolução do conhecimento científico, a utilização de plantas medicinais é uma das práticas mais antigas ainda realizadas pelo homem, especialmente pelos habitantes de comunidades e municípios do interior do Brasil, principalmente em regiões com baixos índices de desenvolvimento humano. O objetivo deste trabalho foi realizar um estudo etnobotânico sobre as plantas medicinais utilizadas pelos moradores de um bairro localizado em um município ribeirinho do interior do estado do Amazonas. Participaram do estudo cem indivíduos, e os dados obtidos pela pesquisa foram compilados por meio de um formulário, contendo 14 questões (objetivas e discursivas). Os resultados demonstraram que 95% dos moradores faziam uso de plantas medicinais. Foram citadas 89 espécies, pertencentes a 48 famílias botânicas, com destaque para a Lamiaceae. As plantas mais citadas foram: Plectranthus barbatus (boldo) ­ 6,1%, Citrus sinensis (laranjeira) ­ 5,8% e Allium sativum (alho) ­ 4,7%. No entanto, quando analisado o índice de concordância (porcentagem de uso principal = CUP), a Citrus sinensis (laranjeira) apresentou um CUP de 80,9%, seguida por Plectranthus barbatus (boldo) e Disphania ambrosioides (mastruz), com 68,1% e 61,5%, respectivamente. Com relação ao modo de preparo, 61,1% citaram infusão, e as principais enfermidades tratadas foram as dores de estômago, com 13,1%. É importante enfatizar a necessidade de mais estudos acerca dos reais benefícios dessas ervas, a fim de que a divulgação de tais informações possa complementar o conhecimento empírico já difundido entre a população local. Dessa forma, será possível ampliar o conhecimento etnobotânico como um todo e, consequentemente, promover saúde e bem-estar.

Despite the evolution of scientific knowledge, the use of medicinal plants is one of the oldest practices still used by men and, especially by the inhabitants of communities and municipalities of the interior of Brazil, mainly in regions with low human development rates. The purpose of this work was to perform an ethnobotanical study on medicinal plants used by residents of a neighborhood located in a riverside city in the interior of the state of Amazonas. A total of 100 individuals participated in the study, with data being obtained through the use of a form containing 14 open and closed-ended questions. The results showed that 95% of the residents used medicinal plants. A total of 89 species, belonging to 48 botanical families were mentioned, with emphasis to Lamiaceae. The plants that were most frequently mentioned were Plectranthus barbatus (locally known as boldo) ­ 6.1%; Citrus sinensis (orange tree) ­ 5.8%; and Allium sativum (garlic) ­ 4.7%. However, when analyzing the agreement index (percentage of main use = CUP), Citrus sinensis (orange tree) presented a CUP of 80.9%, followed by Plectranthus barbatus (boldo) and Disphania ambrosioides (Mexican tea), with 68.1 and 61.5%, respectively. In relation to the method of preparation, 61.1% cited infusion, with the main disorder treated being stomachache, with 13.1%. It is important to emphasize the need for further studies on the actual benefits of these herbs so that the dissemination of the information can complement the already widespread empirical knowledge among the local population. Thus, it will be possible to expand the ethnobotanical knowledge as a whole and, consequently, promote health and well-being.

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.

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.

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.

Evaluation of the volatile composition, toxicological and antioxidant potentials of the essential oils and teas of commercial Chilean boldo samples.

Chilean boldo (Peumus boldus Molina) is the boldo species most consumed around the world. Digestive and hepatobiliary disorders represent the main targets of its action. This work aims to characterize the volatile chemical composition, toxicological, and antioxidant potentials of the essential oils and teas of commercial samples of Chilean boldo packed on sachets [Group 1 (G1): five samples] or in plastic bags [Group 2 (G2): five samples]. Fifty-three compounds have been identified in the essential oils of commercial samples of Chilean boldo from Brazil, while only twelve compounds have been found in the volatile fraction of their infusions. Terpineol, 1,8-cineole, and p-cymene are the major compounds of essential oils. Terpineol is also the major compound of the volatile fraction of teas, followed by limonene dioxide. The presence in all samples of the chemical markers p-cymene, 1,8-cineole, ascaridole, and boldine suggests that they are genuine. The teas offer a better antioxidant capacity than essential oils, thereby indicating that antioxidant activity is concentrated in the non-volatile fraction of these herbs. All LD50 values estimated for the essential oils are below 200 ppm, thus indicating that the oils are highly cytotoxic. G1 and G2 appear to be very similar with respect to all the parameters analyzed. This similarity may indicate a single source for these products.

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.

Immobilization of Aspergillus ficuum tannase in calcium alginate beads and its application in the treatment of boldo (Peumus boldus) tea.

Tannase (tannin acyl hydrolase, E.C. 3.1.1.20) is an enzyme that catalyzes the hydrolysis of ester and depside linkages in hydrolysable tannins such as tannic acid, releasing gallic acid and glucose. It has several commercial applications in food industry, among which are gallic acid production, reduction of tannin content in fruit juices, and preparation of instantaneous tea. In this study we immobilized Aspergillus ficuum tannase in calcium alginate beads and then used it to treat boldo (Peumus boldus) tea. Such a technique allowed entrapping tannase with a 75% efficiency and appreciably increasing its thermal and pH stability compared with the free enzyme. Storage stability and reuse of the immobilized enzyme were very promising, in that about 60% of starting enzyme activity was retained after bead storage for 90 days at 4 °C or after six cycles of use. Boldo tea treatment with immobilized tannase for 120 min at 40 °C led to 31 and 60% removals of tannins and epigallocatechin gallate, an increase of about two orders of magnitude in gallic acid content, 56 and 109% increases in total flavonoids and epigallocatechin contents, a 42.8% increase in antioxidant activity and significant enhancements of tea color, clarity and pH.

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.

Herbal sun protection agents: Human studies.

Topical sunscreens are the mainstay for protection from ultraviolet (UV) radiation. With skin cancer rates on the rise and great interest in reversing or preventing the effects of photoaging, new molecules with potential to defend against UV damage have received a great deal of attention. Specifically, there is a growing interest in herbal substances that offer protection against the damaging effects of UV rays. Herbal substances may work as adsorbents of the UV rays and antioxidants and potentially have few side effects. Many of them have shown the potential to protect from UV rays in in vitro studies and animal models; however, only a limited number of human studies were conducted which we discuss in the current review. Among the most studied herbal substances that have proven photoprotective activity are green tea extract, carotenoids, and Polypodium leucotomos extract (PLE). They have been shown to increase minimal erythema dose and improve signs of photodamage. PLE has been shown to be helpful in holistic treatment of several conditions, including polymorphous light eruption, solar urticaria, and melasma; it also may be used as an adjuvant to the UVB treatment of vitiligo and photodynamic therapy of actinic keratosis.

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.

Variation of the alkaloid content of Peumus boldus (boldo).

Eighteen alkaloids were detected in the bark, leaves, wood and roots of Peumus boldus, including traces of secoboldine, N-methylsecoboldine (boldine methine), glaucine and norreticuline, not reported previously as constituents of this species. Using appropriate standards, we quantified thirteen of them by UHPLC-MS/MS. Boldine was dominant in the bark, and laurolitsine in wood and roots. The alkaloid composition of the leaves, determined for 130 individually identified trees, classified by age and sex, was highly variable, where N-methyllaurotetanine, laurotetanine, coclaurine and in some cases isocorydine predominated, but not boldine.

Evaluation on the effects of 0.1% Peumus boldus leaf and Spiraea ulmaria plant extract combination on bacterial colonization in canine atopic dermatitis: A preliminary randomized, placebo controlled, double-blinded study.

Defective skin barrier characterize canine atopic dermatitis (AD). Pyoderma is the most common complication. Herbal compounds have been suggested as alternatives to control bacterial colonization for their effect on natural antimicrobial peptides (AMPs). This study evaluated the effects of 0.1% Peumus boldus leaf and Spiraea ulmaria plant extract combination on clinical signs, bacterial colonization and AMPs secretion in atopic dogs compared to placebo. Twenty privately-owned atopic dogs were randomly divided in 2 groups (treatment: n = 10; placebo: n = 10) and their abdomen was sprayed every 24 h for 4 weeks. Total and inguinal clinical scores (CADESI-03), manual bacterial count, and skin washes for AMPs (cBD3-like and cCath) were performed on days 0, 14 and 28. AMPs were detected using in-house, previously-validated, canine-specific ELISAs. Data were statistically analyzed and a p < 0.05 was considered significant. Clinical scores and AMPs secretion did not differ significantly between the two groups at any time point. A significant reduction of the clinical scores was seen in the placebo group at 14 and 28 days (p < 0.04). On days 14 and 28, a reduction in the bacterial count was seen in the treated group compared with placebo (p < 0.009 and p = 0.04, respectively). Compared to baseline, a reduction in Staphylococcus spp. was seen in the treated group after 14 days of treatment (p < 0.03). These results show the efficacy of this plant extract combination against bacterial colonization, suggesting its potential usefulness in preventing bacterial infection in atopic dogs. The influence of this compound on AMPs secretion or other mechanisms should be further evaluated.

Peumus boldus attenuates copper-induced toxicity in Drosophila melanogaster.

Peumus boldus (P. boldus) is a medicinal plant popularly used in the treatment of gastrointestinal disorders. P. boldus aqueous extract is rich in phenolic compounds and alkaloids that possess antiinflammatory and antioxidant effects. In the present study, the potential protective effect of P. boldus against Cu2+-induced toxicity was investigated. Adult Drosophila melanogaster were exposed to Cu2+ (1mM and 3mM) and/or P. boldus aqueous extract (5mg/mL) in the food during 4days. Cu2+-fed flies had impairment in the negative geotaxis performance (i.e. motor climbing capability) as well as a higher incidence of mortality when compared to the control group. P. boldus co-treatment afforded protection against the Cu2+-induced toxicity. Acetylcholinesterase (AChE) and glutathione S-transferase (GST) activity decreased significantly in D. melanogaster after Cu2+ exposure. P. boldus co-exposure for 4days restored enzyme activities to control levels. In addition, Cu2+ exposure caused a significant increase in the mRNA levels of antioxidant enzymes, superoxide dismutase (Sod1), catalase (Cat), thioredoxin reductase (TrxR1) and nuclear factor erythroid 2-related factor 2 (Nrf2), as well as increased the mRNA levels of acetylcholinesterase (Ace). The expression of P-type ATPase (Atp7A) and copper uptake protein 1 (Ctr1A) mRNAs were up-regulated in D. melanogaster exposed to Cu2+. The co-treatment with P. boldus blunted Cu2+-induced up-regulation of Atp7A and down-regulated Ctr1A mRNA expression. These findings suggest that P. boldus extracts reduce Cu2+-induced toxicity but not Cu2+ absorption in D. melanogaster. Consequently, P. boldus can be a potential therapeutical alternative for modulating Cu2+-associated toxicity.