Protium Heptaphyllum Resin Research Articles

Acute toxicity study of the isomeric mixture of alpha and beta amyrin from Protium heptaphyllum (Aubl.) Marchand

The isomeric mixture of alpha and beta amyrin (AMY), present in the resin of Protium heptaphyllum, is popularly used as anti-inflammatory and anti-ulcer. The literature has been demonstrating pharmacological activities of these triterpenes in the central and peripheral nervous systems, and in the gastrointestinal and immunological systems. This study traces a toxicological profile of amyrin, aiming to provide information that may clarify its safety. Nine female Wistar rats (170 to 200 g) were divided into three groups of three animals each (control, amyrin 300 and amyrin 2000 mg kg-1, p.o.), which were evaluated by protocols preconized by the Organization for Economic Co-operation and Development (OECD). Open field Test and Malone Hippocratic Screening Scale were performed. AMY, mostly at 2000 mg kg-1, reduced the number of crossings by 57% vs. saline (22.67 ± 2.40) and the number of rearing by 53% vs. saline (42.67 ± 2.96), but increased the number of grooming by 26% vs. saline (1.66 ± 0.33). AMY (2000 mg kg-1) increased the serum glucose by 77% vs. saline (126.70 ± 4.33 mg dL-1), triglycerides by 50% vs. saline (78.67 ± 2.18 mg dL-1) and uric acid by 65% vs. saline (0.73 ± 0.03 mg dL-1). AMY induced vascular congestion and hemorrhage in the liver, spleen and cerebral cortex. Renal changes (cellular damage, inflammatory infiltrate, tubular protein deposition and glomeruli atrophy) were also seen. In conclusion, AMY decreased rat locomotor activity, caused minor biochemical changes, and altered the morphology of the kidney. The present study may contribute to deepen the knowledge about the safety of AMY, aiming the development of a novel pharmacological product.

Spectroscopic, physicochemical, and pharmacokinetic analysis of α,β-amyrin mixture obtained from Protium heptaphyllum (Aubl.) Marchand resin

In the present study, the α,β-amyrin mixture was obtained from Protium heptaphyllum resin, and its molecular structure was determined by one- and two-dimensional Nuclear Magnetic Resonance (NMR) techniques and Mass spectroscopy. This natural compound was also characterized by Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR), Fourier Transform Raman (FT-Raman), and Ultraviolet-Visible (UV–Vis) spectroscopy. Vibrational wavenumber and wavevector have been predicted using the Density Functional Theory (DFT) calculations, and the comparison with experimental data allowed us to assign the most of the normal modes of this isomeric binary mixture. The absorption wavelengths and oscillator strengths for the three singlet states of this binary mixture were calculated using time-dependent density functional theory (TD-DFT). The electrochemical behavior was also evaluated. The physical-chemical parameters for ionization constant (pKa), partition coefficient (log P), distribution coefficient (log D), solubility coefficient (log S), and Polar Surface Area (PSA) were predicted. The cardiotoxic effect was also evaluated using the Pred-hERG computational tool. Furthermore, the pharmacokinetic behavior of the α-amyrin and β-amyrin molecules was evaluated by studies of absorption, distribution, metabolism and excretion, and toxicity (ADMET). From the study of the physical-chemical properties, it was possible to infer that the α-amyrin and β-amyrin compounds do not possess ionizable groups in physiological environment. They are essentially lipophilic and remain constant between pH 2–14. From the study of the pharmacokinetic properties of AMDE, it was observed that the α-amyrin and β-amyrin had values that suggest low intestinal absorption and do not reach the central nervous system. It was also verified that they present a lower risk of hepatic toxicity by metabolic activation and do not present cardiotoxic risk.

Biocidal Activity of a Nanoemulsion Containing Essential Oil from Protium heptaphyllum Resin against Aedes aegypti (Diptera: Culicidae).

This work aimed to prepare a nanoemulsion containing the essential oil of the Protium heptaphyllum resin and evaluate its biocidal activities against the different stages of development of the Aedes aegypti mosquito. Ovicide, pupicide, adulticide and repellency assays were performed. The main constituents were p-cymene (27.70%) and α-pinene (22.31%). The developed nanoemulsion showed kinetic stability and monomodal distribution at a hydrophilic–lipophilic balance of 14 with a droplet size of 115.56 ± 1.68 nn and a zeta potential of −29.63 ± 3.46 mV. The nanoemulsion showed insecticidal action with LC50 0.404 µg·mL−1 for the ovicidal effect. In the pupicidal test, at the concentration of 160 µg·mL−1, 100% mortality was reached after 24 h. For adulticidal activity, a diagnostic concentration of 200 µg·mL−1 (120 min) was determined. In the repellency test, a concentration of 200 µg·mL−1 during the 180 min of the test showed a protection index of 77.67%. In conclusion, the nanobiotechnological product derived from the essential oil of P. heptaphyllum resin can be considered as a promising colloid that can be used to control infectious disease vectors through a wide range of possible modes of applications, probably as this bioactive delivery system may allow the optimal effect of the P. heptaphyllum terpenes in aqueous media and may also induce satisfactory delivery to air interfaces.

Quali–Quantitative Characterization of Volatile and Non-Volatile Compounds in Protium heptaphyllum (Aubl.) Marchand Resin by GC–MS Validated Method, GC–FID and HPLC–HRMS2

Protium heptaphyllum (Aubl.) Marchand (PH) trees are endemic to the tropical region of South America, mostly Brazil. Antibacterial, antinociceptive, anti-inflammatory, anxiolytic, antidepressant and anti-hyperlipidemic/anti-hypercholesterolemic effects were reported for its resinous exudate Protium heptaphyllum resin (PHR). This work aims to provide a qualitative and quantitative consistent chemical profiling of the major constituents of this resin and two extracts enriched in acid (acidic triterpene concentrated extract, ATCE) and neutral triterpenes (α and β-amyrin concentrated extract, AMCE). GC–MS/GC–FID was used for volatile terpene fraction, a validated GC–MS method was developed for quantification of neutral α and β-amyrin and HPLC–APCI HRMS2 was used for acidic triterpenes analysis. The chemical investigation reported 29 molecules, including 14 volatile terpenes, 6 neutral triterpenes and 11 acid triterpenes. The most abundant compounds were α-amyrin (251.28 g kg−1, 123.98 g kg−1 and 556.82 g kg−1 in PHR, ATCE and AMCE, respectively), β-amyrin (172.66 g kg−1, 95.39 g kg−1 and 385.58 g kg−1 in PHR, ATCE and AMCE, respectively), 3-oxo-tirucalla-7,24-dien-21-oic acid (80.64 g kg−1, 157.10 g kg−1 and 15.31 g kg−1 in PHR, ATCE and AMCE, respectively) and 3α-hydroxy-tirucalla-8,24-dien-21-oic acid (77.71 g kg−1, 130.40 g kg−1 and 11.64 g kg−1 in PHR, ATCE and AMCE, respectively). Results showed specific enrichment of acidic and neutral triterpenoids in the two respective extracts.

Development of a bio-based adhesive from Protium heptaphyllum resin

In this work, a bio-based adhesive is prepared from Protium heptaphyllum resin. The resin is first characterized by 1H and 13C nuclear magnetic resonance spectroscopy and the bioadhesive is then prepared using a simple mixture of the resin with linseed oil, catalyzed by cobalt octanoate, to induce crosslinking. The precursors and bioadhesive obtained are characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The NMR analysis shows the presence of groups of triterpenes, such as α- and β-amyrins, and diols, such as brein and maniladiol. Thermogravimetric analysis reveals that the resin has less thermal stability than the bioadhesive. Mechanical tests indicate that the bioadhesive has greater adhesion strength compared to the commercial adhesive, reaching an average stress at break of 7.66 and 0.113 MPa for the wood and carbon steel substrates, respectively. In conclusion, the bioadhesive can be used for the production of composites.

Larvicide Activity on Aedes aegypti of Essential Oil Nanoemulsion from the Protium heptaphyllum Resin.

The aim of this work was to prepare a nanoemulsion containing the essential oil of Protium heptaphyllum resin and to evaluate the larvicidal activity and the residual larvicidal effect against Aedes aegypti. The essential oil was identified by gas chromatography coupled to a mass spectrometer, and the nanoemulsions were prepared using a low-energy method and characterized by photon correlation spectroscopy. The results indicated the major constituents as p-cimene (27.70%) and α-Pinene (22.31%). Nanoemulsions had kinetic stability and a monomodal distribution in a hydrophilic-lipophilic balance of 14 with particle diameters of 115.56 ± 1.68 nn and zeta potential of −29.63 ± 3.46 mV. The nanoemulsion showed larvicidal action with LC50 = 2.91 µg∙mL−1 and residual larvicidal effect for 72 h after application to A. aegypti larvae. Consequently, the nanobiotechnological product derived from the essential oil of P. heptaphyllum resin could be used against infectious disease vectors.

Evaluation of supercritical fluid extraction of tacamahaco (Protium heptaphyllum) resin

An experimental design 23 was developed to investigate the effect of operating pressure (80–100 bar), operating temperature (40–60 °C) and static extraction time (30–35 min) on extraction yield and on its quality during supercritical carbon dioxide extraction from the resin of Protium heptaphyllum (Aubl.) March. The response variables were extraction yield and the quality of the extract measured as the concentration of p-cymen-8-ol. The statistical analysis showed which individual factors had significant effects. The central composite design performed produced a surface response for optimal extraction measured for the percentage of p-cymene-8-ol at 43 °C, a pressure of 106.8 bar and a static time of 36.63 min. A perfume was formulated according to international guidelines with the extract obtained by supercritical fluid extraction and a market survey with a sample of sixty-seven subjects was carried out to find its level of acceptance from the public.

Essential Oil from the Resin of Protium heptaphyllum: Chemical Composition, Cytotoxicity, Antimicrobial Activity, and Antimutagenicity.

Background:Protium heptaphyllum (Aubl.) March is popularly used as an analgesic and anti-inflammatory agent.Objective:This study aimed to evaluate the chemical composition of P. heptaphyllum essential oil, its cytotoxicity in a breast cancer cell line (MCF-7), antimicrobial activity, and its antimutagenicity in vivo.Materials and Methods:The chemical composition of the essential oil collected in three 3 years was determined by gas chromatography-mass spectrometry. The cytotoxicity was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Annexin V conjugated with fluorescein isothiocyanate, caspase-3, and tumor necrosis factor-alpha (TNF-α) assays were performed to evaluate apoptosis and inflammatory events. The antimutagenic activity at doses of 25, 50, and 100 mg/kg was determined using a micronucleus test in murine bone marrow.Results:The essential oil showed a predominance of monoterpene compounds, being the terpinolene, p-cymene-8-ol, and p-cymene, present in the essential oil extracted in the 3 years. The essential oil showed a protection against cyclophosphamide-induced genotoxicity, and the cytotoxicity index polychromatic erythrocytes/normochromatic erythrocytes ratio in animals treated with oil at all doses (1.34 ± 0.33; 1.15 ± 0.1; 1.11 ± 0.13) did not differ from the negative control animal (1.31 ± 0.33), but from the cyclophosphamide group (0.61 ± 0.12). Cytotoxicity, at a concentration of 40.0 μg/mL, and antimicrobial activity were not observed for the essential oil (minimum inhibitory concentration ≥0.5 mg/mL). The essential oil did not change the levels of caspase-3 in the TNF-α level.Conclusion:The essential oil showed antimutagenic activity due to its chemical composition.SUMMARY Terpinolene, p-cymene-8-ol, and p-cymene are the main constituents of the essential oil of P. heptaphyllum collected within 3-yearsThe essential oil of P. heptaphyllum did not show antimicrobial activity (MIC >0.5 mg/mL) against E. coli, S. aureus, E. faecalis, and C. albicansThe essential oil of P. heptaphyllum has activity against S. mutans (MIC = 0.5 mg/mL)The essential oil showed a protection against cyclophosphamide-induced genotoxicity in the micronuclei assay. Abbreviations used: GC–MS: Gas Chromatography–Mass Spectrometry, MTT: 3-(4,5dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, Annexin V-FITC: Annexin V conjugated with fluorescein isothiocyanate, TNF-α: Tumor necrosis factor alpha, MIC: Minimum Inhibitory Concentration

Antifungal activity of plant extracts with potential to control plant pathogens in pineapple

ObjectiveTo evaluate the in vitro antifungal activity of extracts, resins, oils and mother tinctures from plants against the filamentous fungi Fusarium guttiforme (F. guttiforme) and Chalara paradoxa, and to evaluate the control of the pineapple fusariosis in situ using mother tinctures. MethodsThe screening of the antifungal potential of 131 extract forms from 63 plant species was performed in vitro by using plate-hole method. To control pineapple fusariosis in situ, preventive and post-infection treatments were performed on detached pineapple leaves of cv. Pérola (susceptible). ResultsThe quantitative study indicated that among the 49 mother tincture samples analyzed, 46% were effective against F. guttiforme and 29% for the Chalara paradoxa. The natural plant extracts, mother tincture of Glycyrrhiza glabra (MTGG1), mother tincture of Myroxylon balsamum (MTBT2), mother tincture of Aloe vera (MTAV3), mother tincture of Allium sativum (MTAS4), resin of Protium heptaphyllum (RESAM5) and crude extracts of Rhizophora mangle (CEMV6), exhibited an antifungal activity against F. guttiforme. In the preventive treatment against pineapple fusariosis, MTAV3, MTAS4 and MTGG1 were statistically similar to the treatment with tebuconazol fungicide. The curative treatments with MTAV3, MTAS4, MTGG1 and MTBT2 presented similar activity to fungicide (P < 0.05). ConclusionsThe findings of the present study concluded that mother tinctures can effectively control phytopathogens. The mother tincture extract of Myroxylon balsamum showed antifungal activity and was used here for the first time for inhibition of phytopathogenic fungi. This study paves the way for the development of bioactive natural products with phytosanitary applications, with the added benefits of an environmentally safe and economically viable product.

The Alpha, Beta-Amyrin from Protium Heptaphyllum Exerts Antiobese-Related Effects in Mice Fed on High Fat Diet

Recent studies have shown that pentacyclic triterpene group of natural compounds possess antiobese properties. This study evaluated the alpha, beta-amyrin, a pentacyclic triterpene from Protium heptaphyllum resin for its anti-obesity effects in mice fed a high-fat diet (HFD) for 15 weeks. Adult male Swiss mice treated or not with alpha, beta-amyrin (AMY, 10 and 20 mg/kg) were fed a HFD during 15 weeks. Sibutramine (SIB) treated group (10 mg/kg) was included for comparison. Mice treated with AMY and fed a HFD showed significantly decreased body weights, visceral adiposity, levels of blood glucose, plasma lipids, amylase and lipase activities relative to their respective controls fed no AMY. Additionally AMY significantly decreased the level of ghrelin, leptin, MCP-1, TNF-α, and IL-6. Sibutramine-treated group also manifested similar effects like AMY except for TNF-α level that was not different from HFD control. These findings suggest that AMY has an antiobese potential through modulation of carbohydrate and fat metabolism, and by regulating inflammatory cytokines.

Antihyperglycemic and hypolipidemic effects of α, β-amyrin, a triterpenoid mixture from Protium heptaphyllum in mice

BackgroundPentacyclic triterpenes in general exert beneficial effects in metabolic disorders. This study investigated the effects of α, β-amyrin, a pentacyclic triterpene mixture from the resin of Protium heptaphyllum on blood sugar level and lipid profile in normal and streptozotocin (STZ)-induced diabetic mice, and in mice fed on a high-fat diet (HFD).FindingsMice treated with α, β-amyrin (10, 30 and 100 mg/kg, p.o.) or glibenclamide (10 mg/kg, p.o.) had significantly reduced STZ-induced increases in blood glucose (BG), total cholesterol (TC) and serum triglycerides (TGs). Unlike glibenclamide that showed significant reductions in BG, TC and TGs in normoglycemic mice, α, β-amyrin did not lower normal blood sugar levels but at 100 mg/kg, manifested a hypolipidemic effect. Also, α, β-amyrin effectively reduced the elevated plasma glucose levels during the oral glucose tolerance test. Moreover, the plasma insulin level and histopathological analysis of pancreas revealed the beneficial effect of α, β-amyrin in the preservation of beta cell integrity. In mice treated orally with α, β-amyrin (10, 30 and 100 mg/kg) or fenofibrate (200 mg/kg), the HFD-associated rise in serum TC and TGs were significantly less. The hypocholesterolemic effect of α, β-amyrin appeared more prominent at 100 mg/kg with significant decreases in VLDL and LDL cholesterol and an elevation of HDL cholesterol. Besides, the atherogenic index was significantly reduced by α, β-amyrin.ConclusionsThese findings reflect the potential antihyperglycemic and hypolipidemic effects of α, β-amyrin mixture and suggest that it could be a lead compound for drug development effective in diabetes and atherosclerosis.

Chemical composition of the essential oils from two subspecies of Protium heptaphyllum

Qualitative and quantitative analyses of the volatile constituents from resin of Protium heptaphyllum (Aubl.) Marchand subsp. ulei (Swat) Daly (PHU), and Protium heptaphyllum (Aubl.) Marchand subsp. heptaphyllum (PHH), Burseraceae were performed using GC-MS and GC-FID. The resins were collected around the city of Cruzeiro do Sul, state of Acre, Brazil. Essential oils from the two subspecies were extracted by hydrodistillation with a yield of 8.6% (PHU) and 11.3% (PHH); the main components were terpinolene (42.31%) and p-cymene (39.93%) for subspecies ulei (PHU) and heptaphyllum (PHH), respectively.

Composition and Antinociceptive Activity of the Essential Oil from Protium Heptaphyllum Resin

The chemical composition of the essential oil from Protium heptaphyllum resin was analyzed by GC/MS and the oil examined for antinociceptive activity in chemical and thermal tests. Fourteen compounds were characterized, representing 95.8% of the total essential oil, with the monoterpenes α-phellandrene (10.4%), α-terpinene (13.7%) and 1,8-cineole (58.7%) as major components. Oral administration of the essential oil (50 and 100 mg/kg) significantly inhibited chemical nociception induced by capsaicin and formalin in mice. In rats, the oil also effectively enhanced the radiant heat-induced tail-flick latency response at a dose of 100 mg/kg. However, the essential oil, at either dose, was ineffective against thermal pain in the hot-plate test.

Obtenção de derivados da mistura triterpenoídica alfa- e beta-amirina

Using classic reactions such as esterification and oxidation, a series of derivatives was obtained from the a- and b-amyrin mixture, major compounds of the Protium heptaphyllum resin. The obtained compounds were characterized by spectroscopic data such as: IR, 1 H and 13C NMR and comparison with literature.

A possible mechanism for anxiolytic and antidepressant effects of alpha- and beta-amyrin from Protium heptaphyllum (Aubl.) March

In the present study, we examined the anxiolytic and antidepressant effects of the mixture of alpha- and beta-amyrin (AMY), pentacyclic triterpenes isolated from the stem bark resin of Protium heptaphyllum. These effects of AMY were demonstrated by the open-field, elevated-plus-maze, rota rod, forced swimming, and pentobarbital-induced sleeping time tests, in mice. In the open-field test, AMY at the doses of 10, 25 and 50 mg/kg, after intraperitoneal or oral administrations, significantly decreased the number of crossings, grooming, and rearing. All these effects were reversed by the pre-treatment with flumazenil (2.5 mg/kg, i.p.), similarly to those observed with diazepam used as a positive standard. In the elevated-plus-maze test, AMY increased the time of permanence and the number of entrances in the open arms. On the contrary, the time of permanence and the number of entrances in the closed arms were decreased. All these effects were also completely reversed by flumazenil, an antagonist of benzodiazepine receptors. In the pentobarbital-induced sleeping time test, AMY at the same doses significantly increased the animals sleeping time duration. In the rota rod test, AMY did not alter motor coordination and, thus, was devoid of effects, as related to controls. Since AMY, at the doses of 10 and 25 mg/kg, showed a sedative effect in the open field test, lower doses (2.5 and 5.0 mg/kg) were used in the forced swimming test, producing a decrease in the immobility time, similarly to that of imipramine, the positive control. The effect of AMI was greater when it was administered 15 min after imipramine (10 mg/kg). However, the antidepressant AMY effects were not altered by the previous administration of paroxetine, a selective blocker of serotonin uptake. In addition, AMY effects in the forced swimming test were totally blocked by reserpine pretreatment, a drug known to induce depletion of biogenic amines. In conclusion, the present work evidenced sedative and anxiolytic effects of AMY that might involve an action on benzodiazepine-type receptors, and also an antidepressant effect where noradrenergic mechanisms will probably play a role.

Antimicrobial and Antioxidant Activities of the Essential Oil of Resin of Protium heptaphyllum

The essential oil obtained by hydrodistillation from the fresh resin of Protium heptaphyllum was analyzed by GC/MS. The main constituents were: α-pinene (10.5%), α-phellandrene (16.7%), limonene (16.9%), and terpinolene (28.5%). The essential oil was tested in vitro for antimicrobial and antioxidant activities. The results showed a moderate antimicrobial, but significant antioxidant activity. These results suggested that this essential oil is beneficial to human health, having the potential to be used for medical purposes and to be utilized as anti-bacterial additives to skin cosmetics.

Attenuation of Visceral Nociception by α- and β-Amyrin, a Triterpenoid Mixture Isolated from the Resin ofProtium heptaphyllum, in Mice

In the search for novel natural compounds effective against visceral nociception, the triterpenoid mixture alpha- and beta-amyrin, isolated from Protium heptaphyllum resin, was assessed in two established mouse models of visceral nociception. Mice were pretreated orally with alpha- and beta-amyrin (3, 10, 30, and 100 mg/kg) or vehicle, and the pain-related behavioral responses to intraperitoneal cyclophosphamide or to intracolonic mustard oil were analyzed. The triterpenoid mixture showed a dose-related significant antinociception against the cyclophosphamide-induced bladder pain, and at 100 mg/kg, the nociceptive behavioral expression was almost completely suppressed. Intracolonic mustard oil-induced nociceptive behaviors were maximally inhibited by 10 mg/kg alpha- and beta-amyrin mixture in a naloxone-reversible manner. While pretreatment with ruthenium red (3 mg/kg, s. c.), a non-specific transient receptor potential cation channel V1 (TRPV1) antagonist, also caused significant inhibition, the alpha (2)-adrenoceptor antagonist, yohimbine (2 mg/kg, s. c.), showed no significant effect. The triterpene mixture (10 mg/kg, p. o.) neither altered significantly the pentobarbital sleeping time, nor impaired the ambulation or motor coordination in open-field and rotarod tests, respectively, indicating the absence of sedative or motor abnormalities that could account for its antinociception. These results indicate that the antinociceptive potential of alpha- and beta-amyrin possibly involves the opioid and vanilloid (TRPV1) receptor mechanisms and further suggests that it could be useful to treat visceral pain of intestinal and pelvic origins.

Attenuation of capsaicin-induced acute and visceral nociceptive pain by α- and β-amyrin, a triterpene mixture isolated from Protium heptaphyllum resin in mice

The triterpene mixture, α- and β-amyrin, isolated from Protium heptaphyllum resin was evaluated on capsaicin-evoked nociception in mice. Orally administered α- and β-amyrin (3 to 100 mg/kg) significantly suppressed the nociceptive behaviors—evoked by either subplantar (1.6 μg) or intracolonic (149 μg) application of capsaicin. The antinociception produced by α- and β-amyrin against subplantar capsaicin-induced paw-licking behavior was neither potentiated nor attenuated by ruthenium red (1.5 mg/kg, s.c.), a non-specific antagonist of vanilloid receptor (TRPV1), but was greatly abolished in animals pretreated with naloxone (2 mg/kg, s.c.), suggesting an opioid mechanism. However, participation of α 2-adrenoceptor involvement was unlikely since yohimbine (2 mg/kg, i.p.) pretreatment failed to block the antinociceptive effect of α- and β-amyrin in the experimental model of visceral nociception evoked by intracolonic capsaicin. The triterpene mixture (3 to 30 mg/kg, p.o.) neither altered significantly the pentobarbital sleeping time, nor impaired the ambulation or motor coordination in open-field and rota-rod tests, respectively, indicating the absence of sedative or motor abnormality that could account for its antinociception. Nevertheless, α- and β-amyrin could significantly block the capsaicin (10 mg/kg, s.c.)-induced hyperthermic response but not the initial hypothermia. These results suggest that the triterpene mixture, α- and β-amyrin has an analgesia inducing effect, possibly involving vanilloid receptor (TRPV1) and an opioid mechanism.

Protective effect of α- and β-amyrin, a triterpene mixture from Protium heptaphyllum (Aubl.) March. trunk wood resin, against acetaminophen-induced liver injury in mice

In the search of hepatoprotective agents from natural sources, α- and β-amyrin, a triterpene mixture isolated from the trunk wood resin of folk medicinal plant, Protium heptaphyllum was tested against acetaminophen-induced liver injury in mice. Liver injury was analysed by quantifying the serum enzyme activities and by histopathological observations. In mice, acetaminophen (500 mg/kg, p.o.) caused fulminant liver damage characterized by centrilobular necrosis with inflammatory cell infiltration, an increase in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, a decrease in hepatic glutathione (GSH) and 50% mortality. Pretreatment with α- and β-amyrin (50 and 100 mg/kg, i.p. at 48, 24, and 2 h before acetaminophen) attenuated the acetaminophen-induced acute increase in serum ALT and AST activities, replenished the depleted hepatic GSH, and considerably reduced the histopathological alterations in a manner similar to N-acetylcysteine, a sulfhydryls donor. Also, the acetaminophen-associated mortality was completely suppressed by terpenoid pretreatment. Further, α- and β-amyrin could potentiate the pentobarbital (50 mg/kg, i.p.) sleeping time, suggesting the possible suppression of liver cytochrome-P450. These findings indicate the hepatoprotective potential of α- and β-amyrin against toxic liver injury and suggest that the diminution in oxidative stress and toxic metabolite formation as likely mechanisms involved in its hepatoprotection. In conclusion, this study supports the traditional use of Protium heptaphyllum resin as a medicinal agent and suggests the feasibility of developing herbal drugs for treatment of liver disorders.

Triterpenes from the resin of Protium heptaphyllum

From the neutral fraction of the resin of Protium heptaphyllum, a mixture of α- and β-amyrin, a mixture of maniladiol and brein have been isolated as main components, and the novel 3β,24-dihydroxy-urs-12-ene (1), 3-oxo-20 S-hydroxytaraxastane (2) and 3β,20 S-dihydroxytaraxastane (3) as minor components. NMR data of the last three compounds are provided.