Multipurpose effectiveness of Couroupita guianensis-synthesized gold nanoparticles: high antiplasmodial potential, field efficacy against malaria vectors and synergy with Aplocheilus lineatus predators

Mosquito-borne diseases represent a deadly threat for millions of people worldwide. According to recent estimates, about 3.2 billion people, almost half of the world's population, are at risk of malaria. Malaria control is particularly challenging due to a growing number of chloroquine-resistant Plasmodium and pesticide-resistant Anopheles vectors. Newer and safer control tools are required. In this research, gold nanoparticles (AuNPs) were biosynthesized using a cheap flower extract of Couroupita guianensis as reducing and stabilizing agent. The biofabrication of AuNP was confirmed by UV-vis spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), zeta potential, and particle size analysis. AuNP showed different shapes including spheres, ovals, and triangles. AuNPs were crystalline in nature with face-centered cubic geometry; mean size was 29.2-43.8 nm. In laboratory conditions, AuNPs were toxic against Anopheles stephensi larvae, pupae, and adults. LC50 was 17.36 ppm (larva I), 19.79 ppm (larva II), 21.69 ppm (larva III), 24.57 ppm (larva IV), 28.78 ppm (pupa), and 11.23 ppm (adult). In the field, a single treatment with C. guianensis flower extract and AuNP (10 × LC50) led to complete larval mortality after 72 h. In standard laboratory conditions, the predation efficiency of golden wonder killifish, Aplocheilus lineatus, against A. stephensi IV instar larvae was 56.38 %, while in an aquatic environment treated with sub-lethal doses of the flower extract or AuNP, predation efficiency was boosted to 83.98 and 98.04 %, respectively. Lastly, the antiplasmodial activity of C. guianensis flower extract and AuNP was evaluated against CQ-resistant (CQ-r) and CQ-sensitive (CQ-s) strains of Plasmodium falciparum. IC50 of C. guianensis flower extract was 43.21 μg/ml (CQ-s) and 51.16 μg/ml (CQ-r). AuNP IC50 was 69.47 μg/ml (CQ-s) and 76.33 μg/ml (CQ-r). Overall, our results showed the multipurpose effectiveness of C. guianensis-synthesized AuNPs, since they may be proposed as newer and safer tools in the fight against CQ-r strains of P. falciparum and for field control of malaria vectors, in synergy with wonder killifish predators.

A triterpenoid saponin possessing antileishmanial activity from the leaves of Careya arborea

Bioguided-fractionation of the methanol extract of the leaves of Careya arborea led to isolation of a triterpenoid saponin, designated arborenin, and characterized as 3-O-beta-D-glucopyranosyl(1-->2)-beta-D-glucopyranosyl-2 alpha,3beta-dihydroxy-taraxast-20-en-28-oic acid (1), together with desacylescin III (2). The structures were determined on the basis of extensive 2D NMR spectroscopic analysis. The saponin showed in vitro antileishmanial activity against Leishmania donovani (strain AG 83).

Antibacterial compounds from Planchonia careya leaf extracts

AIM OF THE STUDY

The leaves of Planchonia careya (F. Muell.) R. Knuth (Lecythidaceae) have been traditionally implemented in the treatment of wounds by the indigenous people of northern Australia, although the compounds responsible for the medicinal properties have not been identified. In this study, antibacterial compounds from the leaf extracts were isolated and characterized, and the biological activity of each compound was assessed.

MATERIALS AND METHODS

Compounds were isolated from the leaf extracts using HPLC-piloted activity-guided fractionation. The minimum inhibitory concentrations (MICs) were assessed with plate-hole diffusion assays, and the cytotoxicity was determined with MTT assays using monkey kidney epithelial (MA104) cells.

RESULTS

Six known compounds were isolated from the leaf extracts and were identified as 1, (+)-gallocatechin; 2, gallocatechin-(4alpha-->8)-gallocatechin; 3, 9(S)-hydroxy-10E,12Z-octadecadienoic acid (alpha-dimorphecolic acid); 4, 2alpha,3beta,24-trihydroxyolean-12-en-28-oic acid (hyptatic acid-A); 5, 3beta-O-cis-p-coumaroyltormentic acid; and 6, 3beta-O-trans-p-coumaroyltormentic acid. Compounds 5 and 6 were weakly selective for vancomycin-resistant Enterococcus (VRE) compared with eukaryotic cells, with an MIC of 59.4microg/mL and a 50% inhibitory concentration (IC(50)) of 72.0microg/mL for MA104 cells.

CONCLUSIONS

The isolation of six antibacterial compounds from the leaves of Planchonia careya validates the use of this species as a topical wound-healing remedy.

Potentin vitro cytotoxic and antioxidant activity ofCareya arborea bark extracts

Careya arborea is used in traditional medicine for the treatment of tumors and other ailments. The successive chloroform and ethyl acetate extracts and crude 50% methanol extract exhibited potent cytotoxicity against cancerous RD, HEp-2 and HeLa cell lines. They were found to be safe against the normal Vero cell line. The methanol and aqueous extracts possessed strong antioxidant activity against many oxidants in the in vitro antioxidant screening. The total phenol content of these extracts was found to be high. The results suggest strong cytotoxic and antioxidant properties and support the ethnomedical claims for the plant.

Acylated flavonol glycosides from leaves of Planchonia grandis

Three acylated flavonol glycosides have been identified from leaves of Planchonia grandis Ridley. They possess kaempferol as aglycone and two triglycosidic chains substituting hydroxyl groups at the 3- and 7-positions. The first glycosidic unit of each chain is esterified by a cis or trans p-coumaric acid. Structural elucidation was achieved by means of UV, NMR and mass spectrometry.

New triterpene isolated from Eschweilera longipes (Lecythidaceae)

The phytochemical studies of Eschweilera longipes Miers (Lecythidaceae) have led to the identification of a new triterpene 3beta, 24-dihydroxyfriedelane, the known 1beta, 2beta, 3beta, 19beta-tetrahydroxyurs-12-en-28-oic acid (1beta-hydroxyeucaphic acid) besides the saponin sitosterol 3betaO-betaD-glucopyranoside. The structures were established from the IR, NMR and mass spectra data including 2D NMR experiments of natural substances and of the acetyl derivative of the new triterpene.

Acylated triterpenoid saponins from the stem bark of Foetidia africana

Nine new acylated triterpenoid saponins (4-12) were isolated from the stem bark of Foetidia africana. They all possess barringtogenol C as the aglycone, esterified by acetic and/or isovaleric acids. The sugar chain consists of up to three units: D-glucuronic acid (GlcUA) linked to C-3 of the aglycone and substituted by D-galactose (Gal) (at GlcUA C-2) and/or L-rhamnose (Rha) (at GlcUA C-4). The structures were established by acid and alkaline hydrolysis, by NMR experiments including (1)H-(1)H (COSY, HOHAHA, ROESY) and (1)H-(13)C (HSQC, HMBC) spectroscopy, and by mass spectrometry (ESIMS, ESIMS(n)).

Inhibition of proinflammatory mediators by coumaroyl lupendioic acid, a new lupane-type triterpene from Careya arborea, on inflammation-induced animal model

ETHNOPHARMACOLOGICAL RELEVANCE

Careya arborea Roxb. (Lecythidaceae) is a large tree found throughout India in deciduous forests and grasslands. C. arborea is traditionally used in tumors, inflammation, anthelmintic, bronchitis, epileptic fits, astringents, antidote to snake-venom, skin disease, diarrhea, dysentery with bloody stools, dyspepsia, ulcer, tooth ache, and ear pain.

AIM OF THE STUDY

In our previous work, the methanolic extract of Careya arborea stem bark showed significant anti-inflammatory activity. As a continuity of that work, this study aimed at the isolation and evaluation of the anti-inflammatory effect of coumaroyl lupendioic acid, a new lupane-type triterpene from Careya arborea stem bark. Further, to give an insight into the underlying mechanism of action of the compound on the modulation of proinflammatory mediators.

MATERIALS AND METHODS

Methanolic extract of Careya arborea stem bark was suspended in water, and sequentially fractionated with n-hexane and ethyl acetate. Further ethyl acetate fraction was subjected to medium pressure liquid chromatography (MPLC) to isolate the active molecules. The isolated compounds were characterized by the various spectral techniques namely UV, IR, 1H NMR, 13C NMR, DEPT, 1H-1H COSY, HMBC and Mass spectral techniques. In vitro COX-1 and COX-2 enzyme inhibition assays using human whole blood was performed to investigate the inhibitory effect of the isolated compounds. The resulted potent COX-2 inhibitor of the isolated constituents compound 5, designated as coumaroyl lupendioic acid (CLA), was investigated in carrageenan induced inflammation and its effect was also compared with betulinic acid (BA) at the doses of 10 and 20mgkg-1, p.o. using indomethacin and celecoxib (10 and 20mgkg-1, p.o., respectively) as reference drugs. The effect of CLA on the production of NO, MPO, PGE2, TNF-α, IL-1β and IL-6 were assessed. In addition, the histopathology and immunohistochemistry (NF-ҡB, COX-2 and TNF-α protein expression) in paw tissues were also carried out.

RESULTS

The chromatographic fractionation of the methanolic extract resulted in isolation of six new derivatives of lupane type triterpenes for the first time from the stem bark of C. arborea; 3β-hydroxy-lup-5,20 (29),21-trien-28-oic acid (Compound 1), 1, 3, 13, 16-tetrahydroxy-lup-9(11), 20(29)-diene-28-oic acid (Compound 2), 1, 7-di hydroxy betulinic acid (Compound 3), 3β-O-dihydrocinnamyl betulinic acid (Compound 4), 3β-O-trans-coumaryl-lup-6, 9(11), 20(29)-triene-27, 28-dioic acid (Compound 5), 16β-hydroxy-2, 3-seco-lup-5, 20(29)-dien-2, 3, 28-trioic acid (Compound 6). Among the all isolated compounds 3β-O-trans-coumaryl-lup-6, 9(11), 20(29)-triene-27, 28-olioic acid designated as coumaroyl lupendioic acid (CLA) showed higher COX-2 selectivity which is comparable to reference drug (celecoxib). CLA significantly reduced carrageenan induced inflammation whereas CLA revealed greater effect as compared to BA at the similar corresponding doses. Moreover, CLA significantly inhibited pro-inflammatory mediators elevated by carrageenan. CLA also preserved the tissue architecture as evidenced by the histopathology. Furthermore, immunohistochemical studies revealed that CLA significantly down regulated NF-ҡB, COX-2 and TNF-α protein expression.

CONCLUSION

The study gives an insight into the molecular mechanisms of coumaroyl lupendioic acid and suggests that the down-regulations of proinflammatory mediators provide credence to the ethno botanical use of the plant in the management of inflammation.

Effects of Lecythis pisonis Camb. (Lecythidaceae) in a mouse model of pruritus

ETHNOPHARMACOLOGICAL RELEVANCE

Lecythis pisonis Camb. (Lecythidaceae), is popularly known as "Sapucaia". In traditional medicine, leaves are used for the treatment of pruritus.

AIM OF THE STUDY

The present study is aimed to investigate the antipruritic effect of the ethanol extract from leaves of Lecythis pisonis (LPEE), fractions (hexane-LPHF, ether-LPEF and ethyl acetate-LPEAF) and mixture of triterpenes [ursolic and oleanolic acids (MT)] in mice and rats.

MATERIALS AND METHODS

The LPEE, LPHF, LPEF, LPEAF and MT were evaluated on scratching behavior induced by compound 48/80 in mice. In addition, LPEE, LPEF and MT were investigated on rat peritoneal mast cells degranulation induced by compound 48/80 (ex vivo study). The anti-inflammatory activity of LPEE and LPEF was investigated in rats using carrageenan-induced hind paw edema model. In the evaluation of the spontaneous motor activity, the LPEE was studied for its effect on spontaneous motor activity in an open-field test in mice.

RESULTS

The scratching behavior induced by compound 48/80 was significantly inhibited in mice pretreated with LPEE, LPHF, LPEF, LPEAF and MT. The suppressive effect of LPEE, LPEF and MT was only partially antagonized by naloxone. In addition, the compound 48/80-elicited degranulation of rat peritoneal mast cells was also markedly reduced in animals pretreated with LPEE, LPEF and MT. In the anti-inflammatory test, LPEE decreased the paw edema at the third hour after carrageenan (Carr) administration. Moreover, LPEF also was able to inhibit the oedematogenic response evoked by carr at all analysed time points. In the open-field test, LPEE-pretreated mice showed no impairment of spontaneous locomotion. Furthermore, the LPEE demonstrated no overt toxicity up to an oral dose of 2g/kg in an acute toxicity assay.

CONCLUSIONS

These results clearly indicate the antipruritic effects of Lecythis pisonis leaves and suggest that this effect may be related to a stabilizing action on mast cell membrane. Furthermore, these data support the traditional use of this plant against cutaneous pruritus.

Isolation and structure of gustastatin from the Brazilian nut tree Gustavia hexapetala

A bioassay-guided investigation of Gustavia hexapetala led to the isolation of a new cancer cell growth inhibitor designated gustastatin (1) and four previously known cancer cell growth inhibitors that included betulinic acid (2). The structures were assigned on the basis of analyses of HRMS combined with 1D and 2D NMR data. The structure of portentol (5) was confirmed by an X-ray crystal structure determination.

Evaluation of the anti-asthmatic and antitussive potentials of methanol leaf extract of Napoleona vogelii in rodents

Napoleona vogelii is used in ethnomedicine for the treatment of asthma and cough. This study evaluated antiasthmatic and antitussive properties of its methanol leaf extract (NVE) in rodents. Phytochemical screening was conducted using established methods. Acute oral toxicity test was done in mice and guinea pigs. Ovalbumin (OA)-sensitized guinea pigs were orally pretreated with 100, 200 or 400 mg/kg/day of NVE or 0.5 mg/kg/day of salbutamol for 14 days before exposure to 0.2% histamine aerosol. Latency to preconvulsive dyspnea (PCD), tracheal fluid volume (TFV), flow rate (FR), and tracheal morphometry (TM) were evaluated. Tracheal rings from sensitized guinea pigs were tested in organ baths for antispasmodic and spasmolytic effects. Citric acid and ammonium hydroxide cough models were used to evaluate antitussive effects in guinea pigs and mice respectively. Tannins, alkaloids, flavonoids, and phenolic substances were found in NVE. LD₅₀ values in mice and guinea pigs were greater than 5000 mg/kg. NVE caused a significant (P < 0.05) increase in the latency to PCD and a decrease in TFV in the group treated with 200 mg/kg. TM indicated a reduction in airway narrowing in NVE-treated groups. The presence of NVE significantly attenuated responses of tracheal rings to carbachol. Its addition to carbachol precontracted rings resulted in significant relaxation. E_max for calcium concentration-response was significantly (P < 0.01) decreased in the presence of NVE. Cough bouts dose-dependently decreased significantly (P < 0.05) in guinea pigs and mice. We conclude that NVE seems safe and possesses anti-asthmatic effect that involves inhibition of calcium influx. It also has antitussive properties that may be peripherally mediated.

Methanolic extract of Cariniana rubra Gardner ex Miers stem bark negatively regulate the leukocyte migration and TNF-α and up-regulate the annexin-A1 expression

ETHNOPHARMACOLOGICAL RELEVANCE

Cariniana rubra Gardner ex Miers (Lecythidaceae), is a native and endemic tree in Brazil, whose inner stem bark decoction preparation is used in folk medicine to treat various inflammatory disorders. Previous scientific reports confirmed its popular use as an anti-inflammatory, without, however, evaluating its action mechanisms.

AIM

The objective of this study was to determine the cytotoxicity and anti-inflammatory mechanism of action of the methanolic extract of Cariniana rubra (MECr), using experimental models in vivo and in vitro, as well as to identify secondary metabolites present in the extract.

MATERIAL AND METHODS

The MECr was prepared by maceration of inner stem bark powder in methanol (1:10 w/v). The in vitro cytotoxicity effect was evaluated in CHO-k1 cells. The Hippocratic screening test was conducted to evaluate the acute toxicity of MECr in mice. The actions of MECr on leukocyte migration, cytokine levels (IL-1β and TNF-α) and annexin-A1 (AnxA1) expression, were carried out on lambda-type carrageenan air pouch inflammation model in Swiss mice. Additionally, the phytochemical analysis of MECr was carried out by thin-layer chromatography (TLC) and spectrometric mass analysis with electrospray ionization ESI(-)/MS and gas chromatography-mass spectrometry (GC-MS).

RESULTS

Treatment of CHO-k1 cells for 24 h with MECr did not cause cytotoxicity (IC50 > 200 μg/mL), however, the MECr was shown to be cytotoxic after 72 h of cell exposure (IC50 = 19.90 ± 3.51 μg/mL). In the Hippocratic test, oral treatment of mice with 750, 1500, or 3000 mg/kg of MECr did not show any histopathological changes and mortality during the 14 days of observation. In the carrageenan air pouch inflammation model, MECr reduced (p < 0.001) polymorphonuclear migration (57.7% and 57.8%), leukocyte monocyte migration (74.5% and 61.8%) in the air pouch cavity and in the skin tissue, respectively. MECr also inhibited TNF-α concentration in the air cavity wash (3.2%, p < 0.01) and increased expression of the AnxA1 protein (26.9%, p < 0.01) in the skin tissue, particularly in neutrophils. β-sitosterol (1.95%), gallic acid (1.24%), β-amyrin (0.87%) and stigmasterol (0.66%) were identified as the major constituents in methanolic extract.

CONCLUSION

MECr exhibits significant anti-inflammatory action at least by increasing AnxA1 expression and by inhibiting the release of TNF-α pro-inflammatory cytokine and leukocyte migration, which is probably linked to the presence of identified biologically active compounds, especially gallic acid and terpenes. We believe that the results of this study provide a pharmacological basis for the MECr to be considered as a potential therapeutic agent for the treatment of inflammatory diseases.

Phytochemical profile and ethnopharmacological applications of Lecythidaceae: An overview

ETHNOPHARMACOLOGICAL RELEVANCE

The family Lecythidaceae has about 25 genera and 400 identified species, which are distributed especially in the pantropical region, mostly found in the tropics of Central and South America, Southeast Asia and Africa. The third most abundant family in Amazonian forests and the genus Eschweilera, with the large number of species in Lecythidaceae.

AIM OF THE REVIEW

The present review compiles information since the 1934s about of ethnopharmacology, and chemical constituents of species of Lecythidaceae, as well as a summary of the bioactivities shown by the extracts, fractions, and secondary metabolites.

MATERIALS AND METHODS

All relevant information on ethnopharmacology, and chemical constituents of species of Lecythidaceae were gathered from electronic databases including Web of Science, Science Direct, Elsevier, ResearchGate, and Google Scholar. Information was also obtained from local books, PhD. and MSc. Dissertations.

RESULTS

The phytochemical diversity of the family was demonstrated with 180 different metabolites that have been reported from 25 species, most of them being triterpenes or flavonoids. The pharmacological studies carried out with the extracts, fractions and compounds showed promising antibacterial, antifungal, anti-inflammatory, antinociceptive, cytotoxic and antioxidant activities.

CONCLUSION

The present review provides an insight into ethnopharmacology, phytochemistry and pharmacology of species of Lecythidaceae. Based on the pharmacological studies it has been found that different plant species of Lecythidaceae possess a wide range of bioactivities such as anti-arthritic, anti-inflammatory, antileishmanial, antibacterial and antifungal. These activities are due to the presence of bioactive compounds including triterpenoids and their glycosides derivatives, flavonoids, steroids, sesquiterpenoids, alkaloids, and other compounds. However, there are many plants, which have not been assessed pharmacologically and hence warrant further studies.

Stability of a Natural-Based Cream Containing Lecythis pisonis Extract

The outer pericarps of Lecythis pisonis Camb. are by-products with a high content of antioxidant substances. The goal of the present study was to analyze the incorporation of L. pisonis pericarp extract in an all-natural formulation. Physical-chemical and organoleptic characteristics and Challenge tests were evaluated before and after the stability test of the cosmetic formulation. The instability of the formulation increased with the increase of the concentration of the extract. The physical-chemical and organoleptic parameters did not present alterations after the stability test. The extract of the outer pericarp of L. pisonis seems to be compatible with the cream formulation. However, the concentration should be analyzed to not interfere with the stability of the product. The natural formulation developed is under the legal requirements of the National Agency of Sanitary Monitoring of Brazil (Agência Nacional de Vigilância Sanitária), presenting an efficient conservation system.

Analgesic principle from the bark of Careya arborea

Bioactivity guided isolation of the bark of Careya arborea afforded piperine--an alkaloid chemically known as 1-[5-(1,3-benzodioxol-5-yl)-1-oxo-2,4-pentadienyl]piperidine, which was found to possess significant central and peripheral analgesic activity. At oral doses of 10, 20 and 30 mg/kg body weight, piperine exhibited 41 (p < 0.01), 45 (p < 0.01) and 53% (p < 0.001) inhibition of acetic acid induced writhing in mice respectively. At doses of 20 and 30 mg/kg body weight, the compound also showed 31.8 (p < 0.05) and 52.4% (p < 0.01) prolongation of tail flicking time of mice 30 min after the treatments determined by the radiant heat method.