Screening of Indonesian medicinal plant extracts for antibabesial activity and isolation of new quassinoids from Brucea javanica

The quassinoids bruceines A-M: pharmacology, mechanism of action, synthetic advance, and pharmacokinetics-a review

Bruceines A-L are among the quassinoid representatives found in the medicinal plant Brucea javanica (L.). An overview of their pharmacological activities is still unknown. The given research deals with highlights in their pharmacological result, molecular mechanism of action, synthetic progress, and pharmacokinetics. From previous evidence, bruceine derivatives are potential agents for anticancer treatments, as well as they are appropriate to treat inflammation, diabetes, and parasitic infections, and protect the neurons, kidneys, and lungs. Cytokine inhibitions, oxidative stress responses, and various signaling pathways, such as MAPK (mitogen-activated protein kinase) and NF-κB (nuclear factor-kappa B), have been proposed as the underlying mechanisms of action. Synthetic approaches to synthesize new derivatives with enhancement activities are based on free hydroxyl group modifications. Bruceines seem to be promptly absorbed by both oral and intravenous administrations, but their bioavailability is not high (less than 6%). Pre-clinical and clinical studies to prove their anticancer potential and other activities are urgent. Structural modifications, nano-combinations, and synergistic effects are necessary.

A review of Brucea javanica: metabolites, pharmacology and clinical application

This review examines advances in the metabolites, pharmacological research, and therapeutic applications of the medicinal fruit of Brucea javanica (L.) Merr. Brucea javanica (BJ) is derived from the fruit of the Brucea javanica (L.) Merr. There are nearly 200 metabolites present in BJ, and due to the diversity of its metabolites, BJ has a wide range of pharmacological effects. The traditional pharmacological effects of BJ include anti-dysentery, anti-malaria, etc. The research investigating the contemporary pharmacological impacts of BJ mainly focuses on its anti-tumor properties. In the article, the strong monomeric metabolites among these pharmacological effects were preliminarily screened. Regarding the pharmacological mechanism of action, current research has initially explored BJ's pharmacological agent and molecular signaling pathways. However, a comprehensive system has yet to be established. BJ preparations have been utilized in clinical settings and have demonstrated effectiveness. Nevertheless, clinical research is primarily limited to observational studies, and there is a need for higher-quality research evidence to support its clinical application. There are still many difficulties and obstacles in studying BJ. However, it is indisputable that BJ is a botanical drugs with significant potential for application, and it is expected to have broader global usage.

Quassinoids: Phytochemistry and antitumor prospect

Quassinoids, originating from the oxidative degradation of tetracyclic tirucallane triterpene, are a diverse class of secondary metabolites identifying from nature mostly in Simaroubaceae family. The crucial pharmacological activities and structural complexity of quassinoids have long fascinated scientists due to their medicinal uses, infamous toxicity, and unique biosynthesis. In the past few decades, 482 quassinoids, assigned to 6 skeletons, have been isolated and identified from plants. The names, classes, molecular formula, and plant sources of these secondary metabolites are collated here. This review will be a detailed update of the naturally occurring quassinoids reported from the plant kingdom, providing an in-depth discussion of their diversity, antitumor activities, structure-activity relationship.

Naphthylisoquinoline alkaloids and their synthetic analogs as potent novel inhibitors against Babesia canis in vitro

Babesia canis is the predominant and clinically relevant canine Babesia species in Europe. Transmitted by vector ticks, the parasite enters red blood cells and induces a severe, potentially fatal hemolytic anemia. Here, we report on the antibabesial activities of three extracts of the West African tropical plant species Triphyophyllum peltatum (Dioncophyllaceae) and Ancistrocladus abbreviatus (Ancistrocladaceae) and of 13 genuine naphthylisoquinoline alkaloids isolated thereof. Two of the extracts and eight of the alkaloids were found to display strong activities against Babesia canis in vitro. Among the most potent compounds were the C,C-coupled dioncophyllines A (1a) and C (2) and the N,C-linked alkaloids ancistrocladium A (3) and B (4), with half-maximum inhibition concentration (IC₅₀) values of 0.48 μM for 1a, 0.85 μM for 2, 1.90 μM for 3, and 1.23 μM for 4. Structure-activity relationship (SAR) studies on a small library of related genuine analogs and non-natural synthetic derivatives of 1a and 2 revealed the likewise naturally occurring alkaloid N-methyl-7-epi-dioncophylline A (6b) to be the most potent (IC₅₀, 0.14 μM) among the investigated compounds. Although none of the tested naphthylisoquinolines showed 100 % inhibition of parasite infection - as displayed by imidocarb dipropionate (IC₅₀, 0.07 μM), which was used as a positive control - the antibabesial potential of the dioncophyllines A (1a) and C (2) and related compounds such as 6b, its atropo-diastereomer 6a (IC₅₀, 1.45 μM), and 8-O-(p-nitrobenzyl)dioncophylline A (14) (IC₅₀, 0.82 μM) is to be considered as high. The SAR results showed that N-methylation and axial chirality exert a strong impact on the antibabasial activities of the naphthylisoquinolines presented here, whereas dimerization, as in jozimine A₂ (5) (IC₅₀, 140 μM), leads to a significant decrease of activity against B. canis. Alkaloids displaying good to high activities against B. canis like the dioncophyllines 1a, 2, 6a, and 6b were found to cause only a small degree of hemolysis (< 0.7 %), whereas compounds with moderate to weak antibabesial activities such as 6-O-methyl-4'-O-demethylancistrocladine (15a) (IC₅₀, 14.0 μM) and its atropo-diastereomer 6-O-methyl-4'-O-demethylhamatine (15b) (IC₅₀, 830 μM) caused a high degree of hemolysis (7.3 % for 15a and 11.2 % for 15b). In this respect, the most effective anti-Babesia naphthylisoquinolines are also the safest ones.

Bruceine D induces lung cancer cell apoptosis and autophagy via the ROS/MAPK signaling pathway in vitro and in vivo

Worldwide, lung cancer remains a leading cause of cancer mortality. Bruceine D (BD) has been shown to induce pancreatic cancer cell death via several different mechanisms. In this study, we demonstrated that BD inhibited lung cancer cell proliferation. Apoptosis and autophagy were the most important mechanisms involved in BD-induced lung cancer cell death, and complete autophagic flux was observed in A549 and NCI-H292 cells. In addition, BD significantly improved intracellular reactive oxygen species (ROS) levels. BD-mediated cell apoptosis and autophagy were almost inhibited in cells pretreated with N-acetylcysteine (NAC), an ROS scavenger. Furthermore, MAPK signaling pathway activation contributed to BD-induced cell proliferation inhibition and NAC could eliminate p-ERK and p-JNK upregulation. Finally, an in vivo study indicated that BD inhibited the growth of lung cancer xenografts. Overall, BD is a promising candidate for the treatment of lung cancer owing to its multiple mechanisms and low toxicity.

Quassinoids in Brucea javanica are potent stimulators of lipolysis in adipocytes

Obesity is associated with a number of metabolic disorders. Lipolysis is the initial step in the metabolism of lipids stored in adipocytes and is therefore considered a therapeutic target for obesity. Quassinoids are unique terpenes found in plants of the Simaroubaceae family, which were recently reported to have lipolytic activity and to suppress weight gain. Brucea javanica is a plant employed in traditional medicines in Asia, which is known to contain various quassinoids. Here, we investigated the lipolytic activity of B. javanica extracts, and identified six quassinoids: brucein A, brucein B, brucein C, 3'-hydroxybrucein A, brusatol, and bruceantinol, which represent the bioactive principals. The quassinoids contained in B. javanica demonstrated lipolytic activity at nanomolar concentrations, which were an order of magnitude lower than those of the previously reported quassinoids, suggesting that they may be useful for the treatment of obesity.

Ethanolic extract of Brucea javanica inhibit proliferation of HCT-116 colon cancer cells via caspase activation

Brucea javanica (L.) Merr. is a well-known plant in Chinese System of Medicine. Its fruits and seeds have been reported to possess curative properties against various ailments. The chemical constituents and biological activity of this plant have been an interesting area in plant and chemistry medicine. The aim of this study is to evaluate the antiproliferative effects of the B. javanica extract against a colon cancer cell line and identification of the chemical components derived from the extract. An ethanolic extract from B. javanica fruits was prepared by cold maceration method, subjected to LC-MS profiling to elucidate the composition abbreviated as BJEE. The extract was screened for the cytotoxicity effects on HCT-116 colon cancer cells via MTT and LDH methods. Additionally, AO/PI staining verified apoptosis features in HCT-116 cells through microscopic analysis. ROS, caspase activity, and gene expression has been performed to identify its possible mechanism of actions which contribute to apoptosis. Output data from this study showed BJEE inhibited the cell proliferation of HCT-116 colon cancer cells at IC50 value of 8.9 ± 1.32 (μg mL-1) and significantly increased the levels of caspase-8, 9, and 3/7 in treated cells in comparison to untreated. The changes in expression of caspase genes and some apoptosis genes like Bax and Bcl-2 were confirmed using RT-PCR. Phytochemical analysis by LC-MS identified six major active compounds (bruceine D, isobrucein A, quassimarin, C16 sphinganine, phytosphingosine, and enigmol) in BJEE that may play a key role in cell apoptosis. The current study showed BJEE could be a promising agent for colorectal cancer therapy by significant increase in caspase activity level, and up-regulation of the specific apoptotic genes.

Antimalarial and cytotoxic quassinoids from the roots of Brucea javanica

Two new quassinoids, brujavanol A (1) and brujavanol B (2), along with five known quassinoids (3-7), were isolated from the roots of Brucea javanica. Their structures were elucidated by spectroscopic methods. The antimalarial and cytotoxic activities of the isolated compounds were also assessed. Compounds 1 and 2 exhibited significant in vitro cytotoxicity against human oral cavity cancer (KB) cells with IC₅₀ values of 1.30 and 2.36 μg/ml, respectively, whereas compound 3 showed excellent antiplasmodial activity against the Plasmodium falciparum strains, K1 (IC₅₀ = 0.58 μg/ml).

Antifungal susceptibility and growth inhibitory response of oral Candida species to Brucea javanica Linn. extract

Background

Candida species have been associated with the emergence of resistant strains towards selected antifungal agents. Plant products have been used traditionally as alternative medicine to ease candidal infections. The present study was undertaken to investigate the antifungal susceptibility patterns and growth inhibiting effect of Brucea javanica seeds extract against Candida species.

Methods

A total of seven Candida strains that includes Candida albicans ATCC14053, Candida dubliniensis ATCCMYA-2975, Candida glabrata ATCC90030, Candida krusei ATCC14243, Candida lusitaniae ATCC64125, Candida parapsilosis ATCC22019 and Candida tropicalis ATCC13803 were used in this study. The antifungal activity, minimum inhibitory concentration and minimum fungicidal concentration of B. javanica extract were evaluated. Each strain was cultured in Yeast Peptone Dextrose broth under four different growth environments; (i) in the absence and presence of B. javanica extract at respective concentrations of (ii) 1 mg/ml (iii) 3 mg/ml and (iv) 6 mg/ml. The growth inhibitory responses of the candidal cells were determined based on changes in the specific-growth rates (μ) and doubling time (g). The values in the presence of extract were computed as percentage in the optical density relative to that of the total cells suspension in the absence of extract.

Results

B. javanica seeds extract exhibited antifungal properties. C. tropicalis showed the highest growth rate; 0.319 ± 0.002 h^-1, while others were in the range of 0.141 ± 0.001 to 0.265 ± 0.005 h^-1. In the presence of extract, the lag and log phases were extended and deviated the μ- and g-values. B. javanica extract had significantly reduced the μ-values of C. dubliniensis, C. krusei and C. parapsilosis at more than 80% (ρ < 0.05), while others were reduced within the range of 2.28% to 57.05%. The g-values of most candidal strains were extended and significantly reduced (ρ < 0.05) in relative to the untreated. The candidal population was reduced from an average of 10 x 10⁶ to 6 x 10⁶ CFU/ml.

Conclusions

B. javanica extract exhibited in vitro antifungal activity against seven oral Candida species. The fungistatic and growth inhibiting effects of B. javanica extract have shown that it has potential to be considered as a promising candidate for the development of antifungal agent in oral health products.

Anti-inflammatory activity of ethyl acetate fraction of the seeds of Brucea Javanica

ETHNOPHARMACOLOGICAL RELEVANCE

The seeds of Brucea javanica (L.) Merr. (Yadanzi in Chinese) have been used for the treatment of inflammation, dysentery, malaria, and cancer in Chinese traditional medicine. However, the anti-inflammatory mechanism of Brucea javanica has not been fully elucidated. This study examined the anti-inflammatory activity of ethyl acetate fraction of the seeds of Brucea javanica (EA-BJ) in vitro and in vivo.

MATERIALS AND METHODS

The anti-inflammatory activity of EA-BJ and its ability to modulate the production of NO, PGE2, TNF-α, IL-1β, IL-6 and IL-10 inflammatory mediators in lipopolysaccharide-activated RAW 264.7 macrophage were evaluated. Moreover, the anti-inflammatory activity of EA-BJ was also in vivo assayed by carrageenan induced paw edema in mice.

RESULTS

In vitro assays showed remarkable anti-inflammatory activity of EA-BJ, through the inhibition of production of NO, PGE2, TNF-α, IL-1β and IL-6 inflammatory mediators and induction of production of IL-10 anti-inflammatory cytokine. In vivo assays showed anti-inflammatory activity for decrement of the paw edema in carrageenan induced paw edema test.

CONCLUSION

The results obtained in vitro and in vivo showed that possible anti-inflammatory effects of EA-BJ may be attributed to inhibition pro-inflammatory mediators production, NO, PGE2, TNF-α, IL-1β and IL-6 and to increase production of IL-10 anti-inflammatory cytokine. The seeds of Brucea javanica may thus prove beneficial in the treatment of inflammatory diseases.

Chemical constituents from Brucea javanica

Fourteen apotirucallane-type triterpenoids, named brujavanones A-N, were isolated from the twigs of Brucea javanica, along with four known quassinoids and seven known lignans from the seeds of B. javanica. Their structures were elucidated on the basis of extensive spectroscopic data analysis. The structure of a previously reported triterpenoid, bruceajavanin C, was revised as its C-21 epimer. The cytotoxic activities of triterpenoids and quassinoids against two human tumor cell lines, HL-60 and A-549, were evaluated, but all the compounds were inactive (IC₅₀>10 μM).

Inventory, Constituents and Conservation of Biologically Important Sumatran Plants

An inventory of Sumatran medicinal plants, and reports on their chemistry and conservation carried out in the last three decades are reviewed.

Bioactive quassinoids from the seeds of Brucea javanica

Six new quassinoids (1-6) and eight known compounds of this type (7-14) were isolated from the seeds of Brucea javanica. Their structures were elucidated by analysis of their spectroscopic data and from chemical evidence. Compounds 1-5 were found to be unusual quassinoids with a 2,3-seco A ring. The configurations at C-4 in 4 and 5 were determined by a difference circular dichroism method. In in vitro bioassays, 8 and 10 showed inhibitory activities for nitric oxide production in LPS-activated macrophages, with IC(50) values of 1.9 and 5.0 μM, respectively, while compounds 6, 8-11, 13, and 14 exhibited cytotoxicity against five human tumor cell lines (HCT-8, HepG2, BGC-823, A549, and SKVO3), having IC(50) values in the range 0.12-9.3 μM.

Revealing Indigenous Indonesian Traditional Medicine: Anti-infective Agents

Indonesia is rich in medicinal plants which the population has used traditionally from generation to generation for curing diseases. Our interest in the treatment of infectious diseases has lead to the investigation of traditional Indonesian treatments. In this review, we present a comprehensive review of ethnopharmacologically directed screening in Indonesian medicinal plants to search for new antiviral, antimalarial, antibacterial and antifungal agents. Some potent drug leads have been isolated from Indonesian medicinal plants. Further research is still required for the lead development as well as the search for new bioactive compounds from the enormous medicinal plant resources.

Bruceine a

The title compound, C₂₆H₃₄O₁₁, known as bruceine A, is a natural quassinoid extracted from the dried fruits of Brucea javanica. Its structure consists of five fused rings including an oxygen-containing heterocyclic ring and a lactone ring. Two intra­molecular O—H⋯O links help to establish the mol­ecular conformation. In the crystal, O—H⋯O hydrogen bonds connect the mol­ecules.

Nuphar lutea: in vitro anti-leishmanial activity against Leishmania major promastigotes and amastigotes

Several anti-leishmanial drugs of choice are of plant origin. Many of the available drugs against the disease are toxic and in certain cases parasite drug resistance is developed. The development of new compounds is urgently required.

AIMS OF THE STUDY

To determine the leishmanicidal activity of the Nuphar lutea plant extract against Leishmania major in vitro.

MATERIALS AND METHODS

The leishmanicidal activity of methanolic plant extract against L. major free living promastigotes and intracellular amastigotes was evaluated, using microscopic examinations and the enzymatic XTT assay.

RESULTS

Methanolic extract of N. lutea was highly effective against both Leishmania promastigotes and L. amastigotes (IC(50)=2+/-0.12 microg/ml; ID(50)=0.65+/-0.02 3 microg/ml; LD(50)=2.1+/-0.096 microg/ml, STI=3.23). The extract at 1.25 microg/ml totally eliminated the intracellular parasites within 3 days of treatment. Also, a synergistic anti-leishmanial activity was demonstrated with N. lutea extract combined with the anti-leishmanial drug--paromomycin. The partially purified N. lutea active component was found to be a thermo-stable alkaloid(s) with no electrical charge and is resistant to boiling and to methanol, dichloromethane and xylene treatment.

CONCLUSIONS

The present study suggests that N. lutea might be a potential source of anti-leishmanial compounds.

Hypoglycemic effect of quassinoids from Brucea javanica (L.) Merr (Simaroubaceae) seeds

ETHNOPHARMACOLOGICAL RELEVANCE

The seeds of Brucea javanica (L.) Merr (Simaroubaceae) are recommended by traditional practitioners for the treatment of diabetes mellitus.

AIM OF THE STUDY

To identify the compounds responsible for blood glucose lowering effect and evaluate the acute toxicity of the compounds.

MATERIALS AND METHODS

Extracts, fractions and subfractions were administered to normoglycemic mice and the blood glucose concentration was monitored for 8 h. Bioactive compounds isolated through column chromatography were administered to normoglycemic mice and streptozotocin (STZ) rats with monitoring of blood glucose concentration at 0-8h. The acute toxicity was evaluated in mice.

RESULTS

Bioactivity-guided fractionation led to the isolation of bruceines E (1) and D (2). Normoglycemic mice administered with 1 mg/kg of 1 and 2 exhibited significant blood glucose concentration reduction of 40.07+/-11.45% and 48.82+/-13.34%, respectively. STZ induced diabetic rats administered with 1 and 2 exhibited significant blood glucose concentration reduction of 73.57+/-13.64% and 87.99+/-2.91%, respectively.

CONCLUSION

The reduction of blood glucose concentration by both bruceines was comparable to glibenclamide and they might act as an insulin secretagogue. The presence of a hydroxyl moiety at C(2) in 1 reduced the toxic effect by 9-fold compared to 2.

Constituents from the seeds of Brucea javanica with inhibitory activity of Tobacco mosaic virus

Three new constituents were obtained along with 10 known compounds from the seeds of Brucea javanica. The structures of these compounds were determined based on spectral and chemical evidence. These new compounds included a monoterpenoid glycoside and two sesquiterpenes. Bioactivity screening of these constituents showed that compounds 1, 3, 8, 9, and 13 with obvious activities in inhibiting multiplication of the Tobacco mosaic virus.

Evaluation of efficacy of bruceine A, a natural quassinoid compound extracted from a medicinal plant, Brucea javanica, for canine babesiosis

Bruceine A, a natural quassinoid compound extracted from the dried fruits of Brucea javanica (L.) Merr., was evaluated for its antibabesial activity in vitro and in vivo. Bruceine A inhibited the in vitro growth of Babesia gibsoni in canine erythrocytes at lower concentration compared with the standard antibabesial drug diminazene aceturate and killed the parasites within 24 hr at a concentration of 25 nM. Oral administration of bruceine A at a dosage of 6.4 mg/kg/day for 5 days resulted in no clinical findings in a dog with normal ranges of hematological and biochemical values in the blood. Three dogs were infected with B. gibsoni and two of them were treated with bruceine A at a dosage of 6.4 mg/kg/day for 6 days from day 5 post-infection. An untreated dog developed typical acute babesiosis symptoms including severe anemia, high fever, and complete loss of appetite and movement. However, the two bruceine A-treated dogs maintained their healthy conditions throughout the experimental period of 4 weeks although complete elimination of parasites from the peripheral blood was not achieved and decreases in the packed cell volume and the erythrocyte and platelet counts were observed. Since natural quassinoid compounds have been used as traditional medicines for the treatment of various ailments including cancer and malaria, the present results suggest that bruceine A or other related compounds are potential candidates for the treatment of canine babesiosis.

Bioactivity-guided isolation of cytotoxic constituents of Brucea javanica collected in Vietnam

Five new triterpenoids (1-5), together with two known quassinoids, bruceantin (6) and bruceine A (7), and a known flavonolignan, (-)-hydnocarpin (8), were isolated from the chloroform-soluble subfraction of a methanol extract of the combined twigs, leaves, and inflorescence of Brucea javanica collected in Vietnam. The structures of the new compounds 1-5 were established on the basis of spectroscopic methods. All isolates were evaluated for cytotoxicity against a small panel of human cancer cell lines. Quassinoids 6 and 7 were found to be highly active against these cell lines. (-)-Hydnocarpin (8) showed a potentiating effect when combined with both 6 and 7, during cytotoxicity testing using the MCF-7 human breast cancer cell line.

Anti-babesial Quassinoids from the Fruits of Brucea Javanica

The medicinal plant Brucea javanica (L.) Merr. (Simaroubaceae), grown in China, was examined for anti-babesial properties. The anti-babesial activity of the fruit was found to be attributed to its quassinoid constituents. Ten active compounds were isolated and purified from a chloroform extract. The identities of these compounds were confirmed from NMR spectroscopic and mass spectral data as brusatol (1), bruceantin (2), bruceine A (3), bruceantinol (4), dehydrobruceine B (5), dehydrobrusatol (6), dehydrobruceine A (7), bruceine D (8), bruceoside A (9), and yadanzioside G (10). When tested in vitro against Babesia gibsoni, compounds 1–10 had IC50 values of 0.74, 13.4, 4.0, 12.0, 308.2, 10.5, 835.0, >1000, and >1000 ng/mL, respectively. Compounds 1–4, 6 and 7 had far higher activity than the commercial anti-babesial drug diminazene aceturate, which possesses an IC50 value of 70.5 ng/mL. Except for bruceine A (3), bruceantinol (4) and bruceine D (8), this is the first report of the anti-babesial activity of these isolated quassinoids.