Geopolitics of bitterness: Deciphering the history and cultural biogeography of Quassia amara L

ETHNOPHARMACOLOGICAL RELEVANCE

Quassia amara L. recently came into the spotlight in French Guiana, when it became the object of a biopiracy claim. Due to the numerous use records throughout the Guiana shield, at least since the 18th century, a thorough investigation of its origin seemed relevant and timely. In the light of the Convention on Biological Diversity (CBD) and the Nagoya protocol, questions about the origin of local knowledge are important to debate.

AIM OF THE STUDY

Defining cultural biogeography as the dynamics through space and time of biocultural complexes, we used this theoretical framework to shed light on the complex biogeographical and cultural history of Q. amara. We explored in particular the possible transfer of medicinal knowledge on an Old World species to a botanically related New World one by enslaved Africans in Suriname.

MATERIALS AND METHODS

Historical and contemporary literature research was performed by means of digitized manuscripts, archives and databases from the 17th to the 21st century. We retrieved data from digitized herbarium vouchers in herbaria of the Botanic Garden Meise (Belgium); Naturalis Biodiversity Center (the Netherlands); Missouri Botanical Garden, the Smithsonian National Museum of Natural History, the Field Museum (USA); Royal Botanic Gardens Kew (UK); the IRD Herbarium, French Guiana and the Museum National d'Histoire Naturelle (France). Vernacular names were retrieved from literature and herbarium specimens and compared to verify the origin of Quassia amara and its uses.

RESULTS

Our exploration of digitized herbarium vouchers resulted in 1287 records, of which 661 were Q. amara and 636 were Q. africana. We observed that the destiny of this species, over at least 300 years, interweaves politics, economy, culture and medicine in a very complex way. Quassia amara's uses are difficult to attribute to specific cultural groups: the species is widely distributed in Central and South America, where it is popular among many ethnic groups. The species spread from Central to South America during the early 18th century due to political and economic reasons. This migration possibly resulted from simultaneous migration by religious orders (Jesuits) from Central America to northern South America and by Carib-speaking Amerindians (from northern South America to Suriname). Subsequently, through colonial trade networks, Q. amara spread to the rest of the world. The absence of African-derived local names in the Guiana shield suggests that Q. africana was not sufficiently familiar to enslaved Africans in the region that they preserved its names and transferred the associated medicinal knowledge to Q. amara.

CONCLUSIONS

Cultural biogeography has proven an interesting concept to reconstruct the dynamics of biocultural interactions through space and time, while herbarium databases have shown to be useful to decipher evolution of local plant knowledge. Tracing the origin of a knowledge is nevertheless a complex adventure that deserves time and interdisciplinary studies.

Phytochemical Analysis of a Cytotoxic Fraction of Quassia silvestris using LC-HR-ESI-MSn

INTRODUCTION

The genus Quassia is a promising source of secondary metabolites with biological potential including antimalarial and cytotoxic activities. Limited data are available on the phytochemistry and pharmacology of Quassia silvestris Cheek & Jongkind, a Cameroonian medicinal plant used to treat various ailments.

OBJECTIVES

To carry out the bioassay-guided fractionation and LC-HR-ESI-MS analyses of the leaves extract from Q. silvestris; to purify the active fractions and isolate the major compounds using different chromatographic and spectroscopic methods. The obtained compounds will be evaluated for their biological activity.

MATERIAL AND METHODS

Following the cytotoxic screening and LC-HR-ESI-MS profiling of fractions obtained from partition of the methanolic extract of Q. silvestris leaves, the CH₂ Cl₂ -soluble fraction which exhibited the highest cytotoxicity was retained for further investigations.

RESULTS

Sixteen squalene-derived metabolites were identified with oxasqualenoid derivatives being the most predominant. Among the isolates, structure elucidation of two new oxasqualenoids quassiols E (1) and F (2), were achieved by NMR (one-dimensional (1D) and two-dimensional (2D)) and MS methods. The newly characterised compounds 1 and 2, together with the known tetraol (3) and 3-oxo-oleanoic acid (16) displayed moderate cytotoxicity.

CONCLUSION

The identification and structural characterisation of highly oxidised squalene derived metabolites from this plant may provide important insight data for further pharmacological investigations. The LC-HR-ESI-MSⁿ method reported here could be developed as a rapid and efficient tool for the analyses of structurally related compounds in the genera Quassia, Simarouba, and Eurycoma of the subfamily Simarouboideae. Copyright © 2016 John Wiley & Sons, Ltd.

Development and validation of liquid chromatography combined with tandem mass spectrometry methods for the quantitation of simalikalactone E in extracts of Quassia amara L. and in mouse blood

INTRODUCTION

Simalikalactone E (SkE) from Quassia amara, has been proved to be a valuable anti-malarial and anti-cancer compound. As SkE is very scarce, methods of quantitation are needed in order to optimise its isolation process and to determine pharmacokinetic data.

OBJECTIVE

To validate methods using liquid chromatography coupled to mass spectrometry for the quantitation of SkE in plant extracts and in biological fluids.

METHODS

High- and ultrahigh-performance liquid chromatography (UHPLC) coupled to ion trap mass spectrometry (MS) with single ion monitoring detection and to triple quadrupole-linear ion trap tandem mass spectrometry with multiple reaction monitoring detection methods were developed. Validation procedure was realised according to the International Conference on Harmonisation guideline. Methanol extracts of dried Quassia amara leaves, and mouse-blood samples obtained after various routes of administration, were analysed for SkE.

RESULTS

Methods were validated and gave similar results regarding the content of SkE expressed per kilogram of dry leaves in the traditional decoction (160 ± 12 mg/kg) and in the methanol extract (93 ± 2 mg/kg). The recovery of the analyte from mouse blood ranged from 80.7 to 119.8%. Simalikalactone E was only detected using UHPLC-MS/MS (0.2 ± 0.03 mg/L) in mouse blood after intravenous injection: none was detected following intraperitoneal or oral gavage administration of SkE.

CONCLUSION

The LC-MS methods were used for the quantitation of SkE in plant extracts and in mouse blood. These methods open the way for further protocol optimisation of SkE extraction and the determination of its pharmacokinetic data.

Larvicidal properties of simalikalactone D from Quassia africana (Simaroubaceae) Baill and Baill, on the malaria vector Anopheles gambiae

BACKGROUND

Botanical and microbial insecticides have been increasingly used for the control of mosquito given their efficacy and documented nontoxic effects on non-target organisms. The discovery of new insecticides is imperative because of the development of resistance by the mosquitoes to the readily available insecticides. The aim of this study was therefore to isolate and characterize compounds from a local medicinal plant, Quassia africana Baill and Baill (Simaroubaceae) that were toxic to Anopheles gambiae.

MATERIAL AND METHODS

The methanol extracts of the leaves, stem and roots of Quassia africana were tested against fourth instar larvae of An. gambiae. The root extract was partitioned into hexane, chloroform and ethyl acetate and the resulting extracts screened for larvicidal properties. The extracts and the fraction with the highest bioactivity were subjected to repeated column chromatography and isolated compounds evaluated for potential toxicity to An. gambiae larvae. The structure of the active compound was elucidated using spectroscopic techniques. The root extract showed the strongest activity profile (LC50 = 17.58 µg/mL). The chloroform soluble fraction obtained after partitioning the crude extract into solvents based on polarities was the most toxic. Further bio-activity-guided chromatographic separation of the chloroform fraction of the root extract led to the identification and isolation of a simalikalactone D as the larvicidal compound in Q. africana (LC50 = 1.25 µg/mL).

RESULTS

Results suggest that Q. africana may serve as a source for vector control agent for malaria.

CONCLUSION

Simalikalactone D was identified as the larvicidal compound in Q. africana (LC50 = 1.25 µg/mL).

Efficacy of topical 4% Quassia amara gel in facial seborrheic dermatitis:a randomized, double-blind, comparative study

BACKGROUND

Seborrheic dermatitis (SD) is a chronic mild skin disorder with high prevalence. Various treatment options are available, including topical antifungals and anti-inflammatories. Antifungal and anti-inflammatory properties of Quassia amara have been reported.

AIM

To check the efficacy and safety of a topical gel with 4% Quassia amara extract and compare it with topical 2% ketoconazole and 1% topical ciclopiroxolamine in the treatment of facial SD.

METHODS

A group of 60 patients displaying facial SD were randomly distributed in 3 groups and given either a topical gel with 4% Quassia amara extract, a topical gel with 2% ketoconazole, or a topical gel with 1% ciclopirox olamine for 4 weeks. Disease severity was assessed at the start and weekly along treatment, as well as 4 weeks after the end of treatment. In each selected area, severity of erythema, scaling, pruritus, and papules were scored from 0 to 3, the sum of these values representing the score of SD on the face. This evaluation was conducted at each visit. The decrease in SD score with all 3 products was compared at each visit. At each stage, overall improvement, safety, and tolerability were also assessed.

RESULTS

Of the 60 patients, 54 (90%) completed the study. The 3 therapeutic options resulted to be very effective, with a significant advantage in efficacy for 4% Quassia extract. For the other 2 drugs, the results were in line with those previously published in the literature.

CONCLUSION

Topical gel with 4% Quassia extract represents a new, safe, and effective treatment for facial SD.

Antiulcerogenic effects and possible mechanism of action of Quassia amara (L. Simaroubaceae) extract and its bioactive principles in rats

The effects of Quassia amara extract (Q. amara) and its bioactive principles-quassin and 2-methoxycanthin-6-one on gastric ulceration were studied in albino rats. Q. amara (200-800 mg/kg p.o.; 5-20 mg/kg i.p) and 2-methoxycanthin-6-one (12.5, 25.0 and 50.0 mg/kg p.o; 1, 2 and 4 mg/kg i.p) but not quassin (12.5, 25.0 and 50 mg/kg p.o; 1, 2 and 4 mg/kg i.p) significantly inhibited gastric ulceration induced by indomethacin (40mg/kg). Administration of Q. amara (800 mg/kg p.o and 20 mg/kg i.p) and 2-methoxycanthin-6-one (12.5 mg/kg p.o; 4 mg/kg i.p) caused between 77%-85% cytoprotection against indomethacin (40 mg/kg, i.p) - induced gastric ulceration. Quassin did not cause any significant change in indomethacin-induced gastric ulceration. The inhibition of gastric ulceration produced by Q. amara and 2-methoxycanthin-6 one was accompanied by significant dose-dependent decreases (P< 0.01) in total gastric acidity. To investigate the probable mechanism of action, the individual effects of the extract and its principles alone and in combination with histamine (1 mg/kg) or cimetidine (0.12 mg/kg) on gastric acid secretion in situ were studied. Q. amara (20 mg/kg) and 2-methoxycanthin-6-one (4 mg/kg) but not quassin significantly (P< 0.01) inhibited the basal and histamine-induced gastric acid secretion. Inhibition of gastric acid secretion by Q. amara and 2-methoxycanthin-6-one was accentuated by cimetidine. The results suggest that Q. amara and its bioactive principle, 2-methoxycanthin-6-one possess antiulcer activity probably acting via histamine H2 receptor. This could be a potential source of potent and effective antiulcer agents.

Anti-ulcerogenic properties of Quassia amara L. (Simaroubaceae) standardized extracts in rodent models

AIM OF THE STUDY

Quassia amara L. is commonly used in Costarican folk medicine. It has been used for the treatment of a broad range of gastrointestinal symptoms such as dyspepsia, gastritis and constipation. In this study, the gastroprotective activity of two standardized extracts of Quassia amara L., Lipro(®) and Ligas(®), was evaluated.

MATERIALS AND METHODS

Anti-ulcerogenic properties were evaluated in female rats under acute ulcer-induction models (ethanol, indomethacin and hypotermic restraint). To get a deeper insight in the anti-ulcerogenic properties of the extracts, Ligas(®) was evaluated in the Shay rat model. Five parameters were estimated with this model: gastric mucus barrier, non-protein sulfhydril groups (NPSG) in the gastric mucosa, and pH, total acidity and peptic activity of the gastric juice.

RESULTS

Induction of ulcers by 95% ethanol (0.5 mL per os), indomethacin (100 mg/kgs.c.) and stress (2h in hypothermic restraint) was inhibited significantly with administration of Lipro(®) (p<0.05), in a dosage range from 4.9 mg/kg/d to 48.9 mg/kg/d. Treatment was given for one week. The extract Ligas(®) showed a significant augmentation of NPSG (p<0.05) in a dosage range from 4.0 to 39.7 mg/kg. Ligas(®) did not produce a significant change (p>0.05) in the other indicators.

CONCLUSIONS

Quassia amara L. standardized extracts, Lipro(®) and Ligas(®), showed an important anti-ulcerogenic effect in acute ulcer induction models. Their effect was related to an increase in gastric barrier mucus and non-protein sulfhydril groups.

Quassinoid constituents of Quassia amara L. leaf herbal tea. Impact on its antimalarial activity and cytotoxicity

AIM OF THE STUDY

Our objective was to assess whether it could be contemplated to recommend Quassia amara young leaf tea for treatment against malaria, and if yes, set up a standard protocol for preparing the herbal tea.

MATERIALS AND METHODS

The leaf tea was extracted with methylene chloride and the organic extract was fractionated with HPLC. Pure compounds were characterized and their in vitro cytotoxicity and antiplasmodial activity was determined.

RESULTS AND DISCUSSION

We discovered that antimalarial Quassia amara young leaf tea contains several quassinoids: simalikalactone D (SkD, 1), picrasin B (2), picrasin H (3), neoquassin (4), quassin (5), picrasin I (6) and picrasin J (7). These last two compounds are new. In addition, our experiments demonstrate that both biological activity and cytotoxicity of the remedy may be attributed solely to the presence of SkD.

CONCLUSION

In conclusion, this preparation should not be recommended for treatment of malaria until a clinical study in humans is performed with SkD.

Antifeedant activity of botanical crude extracts and their fractions on Bemisia tabaci (Homoptera: Aleyrodidae) adults: III. Quassia amara (Simaroubaceae)

Bemisia tabaci is a key virus vector on several crops worldwide. Then, a preventive approach to deal with viral epidemics may be the deployment of repellents or phagodeterrents at earlier stages of plant development (critical period). Thus, the crude extract and four fractions thereof (water, water: methanol, methanol, and diethyl ether) of bitterwood (Quassia amara, Simaroubaceae) were tested for phagodeterrence to B. tabaci adults under greenhouse conditions, on tomato plants, in Costa Rica. Both restricted-choice and unrestricted-choice experiments showed that the crude extract and some fractions exerted such effect on the insect. In the former case (in sleeve cages), all fractions caused deterrence at doses as low as 0.1% (methanol), 0.5% (water: methanol and diethyl ether), and 1% (water). In the latter case (plants exposed in a greenhouse) the methanol fraction stood out, followed by the diethyl ether fraction. Nonetheless, none of the fractions performed better than the deterrent control (mineral oil).

Quassia amara L. (Simaroubaceae) leaf tea: effect of the growing stage and desiccation status on the antimalarial activity of a traditional preparation

In French Guiana, Quassia amara L. (Simaroubaceae) leaf tea is a well-known widely used traditional antimalarial remedy. Impact of the vegetal sampling condition on in vivo and in vitro antimalarial activity was assessed. Traditional infusions were prepared with juvenile or mature leaves, both either fresh or dried. Results showed that growing stage and freshness of vegetal material exert a striking effect on antimalarial activity, both in vitro and in vivo. By far, leaf tea made from fresh juvenile (FJ) Quassia amara leaves was the most active. In vitro, active component (simalikalactone D) concentration correlates biological activities, although unexplained subtle variations were observed. In vivo, tea made with dried juvenile (DJ) leaves displays a peculiar behavior, meaning that some components may help simalikalactone D delivery or may be active in vivo only, therefore enhancing the expected curative effect of the traditional preparation.

Promoting potential of a Jamaica quassia extract in a rat medium-term hepatocarcinogenesis bioassay

Jamaica quassia extract (JQE), a natural bittering agent, was investigated for hepatocarcinogenesis-promoting potential using a medium-term liver bioassay system. F344 male rats were given a single intraperitoneal injection of diethylnitrosamine (200mg/kg body weight) and then starting 2 weeks later, received JQE in the diet at concentrations of 500, 5000 or 30,000 ppm for 6 weeks. Animals for tumor promotion (+) and (-) controls were fed 500 ppm sodium phenobarbital (PB) and basal diet, respectively during the promotion phase in this model. All animals were subjected to two-thirds partial hepatectomy at week 3 and killed at week 8. As with the PB-promoted case, both numbers and areas of glutathione S-transferase placental form-positive liver cell foci were significantly increased by JQE at 30,000 ppm, with non-significant increases evident at 5000 ppm. The results thus indicate that JQE at high dose has promoting potential for rat hepatocarcinogenesis.

Simalikalactone D is responsible for the antimalarial properties of an Amazonian traditional remedy made with Quassia amara L. (Simaroubaceae)

French Guiana (North-East Amazonia) records high malaria incidence rates. The traditional antimalarial remedy most widespread there is a simple tea made out from Quassia amara L. leaves (Simaroubaceae). This herbal tea displays an excellent antimalarial activity both in vitro and in vivo. A known quassinoid, simalikalactone D (SkD), was identified as the active compound, with an IC(50) value of 10nM against FcB1 Plasmodium falciparum chloroquine resistant strain in vitro. Lastly, it inhibits 50% of Plasmodium yoelii yoelii rodent malaria parasite at 3.7 mg/kg/day in vivo by oral route. These findings confirm the traditional use of this herbal tea.

[Analysis of constituents in Jamaica quassia extract, a natural bittering agent]

Jamaica quassia extract, a natural bittering agent, is described as "a substance extracted from bark of Jamaica quassia (Quassia excelsa Sw.)" in the List of Existing Food Additives in Japan. The constituents in Jamaica quassia extract product were investigated as a part of an ongoing study to evaluate its quality and safety as a food additive. The main constituents of the extract were identified as quassin and two isomers of neoquassin by using LC/MS. The main constituent, quassin, was isolated and the structure was determined by spectral means. The quantification of their main constituents was performed by HPLC using quassin as a standard, and the concentrations of quassin and total of neoquassin isomers were 21.4% and 55.5%. In addition, it was confirmed that Jamaica quassia extract was different from quassia extract, which is extracted from bark of Picrasma quassioides Benn. belonging to the same family as Q. excelsa, by comparing their HPLC profiles.

A comprehensive evaluation of the reproductive toxicity of Quassia amara in male rats

Chloroform extracts of the bark of Quassia amara in different dilutions was used to assess its impact on the male reproductive system of albino rats. Single daily intramuscular injections of the extract for 15 days resulted in a significant reduction in the weight of testis and epididymis but not that of the seminal vesicles and prostate (all lobes). A marked decrease in the sperm count, motility, viability was also observed in sperm collected from the cauda epididymis of treated animals. A number of abnormalities like double heads, double tails, detached heads and fragile tails were frequently seen. Epididymal alpha-glucosidase activity was drastically reduced. However, prostatic acid phosphatase activity and citric acid levels and seminal vesicle fructose concentrations remained unchanged following treatment. Thus, it appears that the prime site of action is at the level of both the testis and the epididymis. Examination of the blood showed that cell counts and hemoglobin levels were in the normal range. Bilirubin, SGPT, SGOT, protein and urea were also not altered by the herbal extract. From the selective action on the male reproductive tract we suggest that the chloroform extract of the bark of Quassia amara has potential for use as an antifertility agent.