Rodrigo A.S. Cruz

Leaves of Spondias mombin L. a traditional anxiolytic and antidepressant: Pharmacological evaluation on zebrafish (Danio rerio)

ETHNOBOTANICAL RELEVANCE Spondias mombin L. is a plant dispersed throughout the tropical regions of South America, Africa, and Asia, being found mainly in the North and Northeast of Brazil, where the leaves are used in preparations for neuropsychiatric disorders. Therefore, it is of great importance to carry out studies in different pharmacological models that can prove the traditional use of this plant species. MATERIALS AND METHODS the hydroethanolic extract from S. mombin leaves (HELSm) was evaluated by oral administration (25 mg/kg) and by immersion (25 mg/l) in scototaxis test in zebrafish (Danio rerio). For this study, caffeine (100 mg/kg) and buspirone (25 mg/kg) were used as standard drugs. The antidepressant action of the HELSm was evaluated assessed in the novel tank diving test (NTDT). In this study, a group with 1% ethanol, one with unpredictable chronic mild stress (UCMS), and another with developmental, social isolation (DSI) were used as induction groups for depression-like behavior and fluoxetine (20 mg/kg) as a drug pattern. RESULTS by the HPLC-UV fingerprint analysis, the HELSm presented several derivatives of polyphenolic compounds and flavonoids and identified ellagic acid and isoquercitrin, and by the gas-chromatographic, the majority of the identified compounds were fatty acids, esters, and alcohols. By immersion, the LC50 was 49.86 mg/l and by oral via the LD50 in 48 h, was 4.515 g/kg in zebrafish. For all spatiotemporal and behavioral variables (time spent, white compartment, latency, toggle, erratic swimming, freezing duration, thigmotaxis, and risk assessment), the treatment with HELSm produced a similar effect to buspirone and was significant when compared to the caffeine and control group (p < 0.01, Tukey-Kramer test). For all spatiotemporal and behavioral variables evaluated (time spent at the top of the apparatus, crossed quadrants, erratic swimming, and duration of freezing), treatment with HELSm produced a change in the depression-like behavior in the groups tested, with a similar effect to fluoxetine, both with a significant difference when compared to the control groups (p < 0.01). CONCLUSIONS Our results suggest that the acute administration of the HELSm in the scototaxis and NTDT tests in a zebrafish model (Danio rerio) produced anxiolytic and antidepressant effects, devoid of hypnotic and sedative actions by immersion, and this action was improved when administered by oral via. Possibly, the presence of isoquercitrin in the leaves of Spondias mombin participates in the anxiolytic and antidepressant effects.

Chemical Constituents of Essential Oils from Leaves of Two Erythroxylum Species

Erythroxylum P. Browne is the most representative genus from the Erythroxylaceae family, being constituted by approximately 97% of its species [1]. They are mainly spread through tropical and subtropical regions such as South America, Africa, and Madagascar [2–4]. Brazil has some species spread through “restinga,” a typical sandy coastal plain originated from quaternary marine deposits [5, 6]. This genus is recognized as a tropane alkaloid producer [7] and also by the presence of terpenoids and flavonoids [8, 9]. However, few studies were performed concerning the volatile constituents of this genus [10]. Erythroxylum ovalifolium Peyr. and Erythroxylum subsessile (Mart.) O. E. Schulz are shrubs that grow spontaneously at Restinga de Jurubatiba National Park (Rio de Janeiro, Brazil). They are commonly known at this location as “quixaba” and used in folk medicine to treat backache [6]. However, to our knowledge, both species remain unexplored regarding their chemical constituents. In this context, the aim of the present study was to describe for the first time the chemical composition of essential oils obtained from leaves of these two Erythroxylum species. Leaves of E. ovalifolium (S22 14.722 , W41 34.916 ) and E. subsessile (S22 16.111 , W41 38.990 ) were collected in January 2009 at Restinga de Jurubatiba National Park, Rio de Janeiro, Brazil. Identification of the plants was carried out by Dr. Marcelo G. Santos. Voucher samples were deposited at the Herbarium of the Rio de Janeiro State University, Sao Goncalo, under the register numbers RFFP 2147 and RFFP 2126, respectively. Fresh leaves (400 g per plant) of E. ovalifolium and E. subsessile were individually ground with distilled water and subjected to hydrodistillation using a Clevenger-type apparatus for 4 h. Essential oils were dried over anhydrous sodium sulfate, and the yields were 0.04% (w/w) and 0.05% (w/w) based on fresh leaves of E. subsessile and E. ovalifolium, respectively. The low yields observed for these essential oils are in accordance with literature data for the genus Erythroxylum [7]. The gas chromatographic (GC) conditions were as follows: injector temperature 260 C, detector temperature 280 C, carrier gas helium, flow rate 1 mL/min, and split injection with split ratio 1:40. Oven temperature was initially 60 C and then raised to 240 C at a rate of 3 C min–1. Each essential oil was dissolved in CH2Cl2 (1:100 mg/ L) for the analysis. Gas-chromatographic analysis revealed a total of 20 constituents in E. ovalifolium essential oil, corresponding to 91.3% total relative composition of this oil, and 22 constituents in E. subsessile essential oil, corresponding to 99.7% of total relative composition of this oil. (2E)-Hexenal (24.1%) and (E)-ocimene (23.2%) were found to be the major compounds of E. ovalifolium essential oil, while (2E)-hexenal (41.0%) and -pinene (20.0%) were found to be the major compounds of E. subsessile essential oil. All identified substances and their relative percentage are presented in Table 1.