ABSTRACT
OBJECTIVE: To evaluate the effects of aqueous and methanolic extracts of Bersama engleriana (B. engleriana) leaves on the expulsion phase of fictive ejaculation in nicotinamide/streptozotocin-induced type 2 diabetic male rats. METHODS: The electromyographic activity of the bulbospongiosus muscles was recorded in urethane anaesthetized, spinal cord transected rats receiving dopamine (0.1 µmol/L/kg) intravenously, in the absence or presence of aqueous and methanolic extracts of B. engleriana (2.5, 10, 50, 60, 75 mg/kg). In another experiment, the pro-ejaculatory effect of dopamine (0.1 µmol/L/kg, i.v.) was monitored in rats orally pre-treated with the aqueous and methanolic extracts (60 mg/kg) of B. engleriana for 1 or 4 weeks. RESULTS: Results of the study showed that the intravenous administration of B. engleriana did not provoke any contraction of the ejaculatory muscles whilst rhythmic and rapid contractions of the bulbospongiosus muscles accompanied sometimes by penis movement and expulsion of the urethral contents were recorded after dopamine application. The sequential treatment of animals with B. engleriana extracts (2.5-75.0 mg/kg) followed by dopamine (0.1 µmol/L/kg) resulted in a dose-dependent abolishment of the pro-ejaculatory response due to dopamine. However, in animals orally submitted to a daily gavage with B. engleriana extracts (60 mg/kg) for 1 or 4 weeks, the ejaculation stimulating effect of dopamine (0.1 µmol/L/kg) was significantly delayed (P<0.01) but not completely suppressed. CONCLUSIONS: Present findings suggest the involvement of dopaminergic system in the activity of B. engleriana and further support its aphrodisiac potentials due to sterols and saponins revealed in this plant.
ABSTRACT
Objective: To evaluate the effects of aqueous and methanolic extracts of Bersama engleriana (B. engleriana) leaves on the expulsion phase of fictive ejaculation in nicotinamide/streptozotocin-induced type 2 diabetic male rats. Methods: The electromyographic activity of the bulbospongiosus muscles was recorded in urethane anaesthetized, spinal cord transected rats receiving dopamine (0.1 μmol/L/kg) intravenously, in the absence or presence of aqueous and methanolic extracts of B. engleriana (2.5, 10, 50, 60, 75 mg/kg). In another experiment, the pro-ejaculatory effect of dopamine (0.1 μmol/L/kg, i.v.) was monitored in rats orally pre-treated with the aqueous and methanolic extracts (60 mg/kg) of B. engleriana for 1 or 4 weeks. Results: Results of the study showed that the intravenous administration of B. engleriana did not provoke any contraction of the ejaculatory muscles whilst rhythmic and rapid contractions of the bulbospongiosus muscles accompanied sometimes by penis movement and expulsion of the urethral contents were recorded after dopamine application. The sequential treatment of animals with B. engleriana extracts (2.5-75.0 mg/kg) followed by dopamine (0.1 μmol/L/kg) resulted in a dose-dependent abolishment of the pro-ejaculatory response due to dopamine. However, in animals orally submitted to a daily gavage with B. engleriana extracts (60 mg/kg) for 1 or 4 weeks, the ejaculation stimulating effect of dopamine (0.1 μmol/L/kg) was significantly delayed (P<0.01) but not completely suppressed. Conclusions: Present findings suggest the involvement of dopaminergic system in the activity of B. engleriana and further support its aphrodisiac potentials due to sterols and saponins revealed in this plant.
ABSTRACT
OBJECTIVE@#To evaluate the effects of aqueous and methanolic extracts of Bersama engleriana (B. engleriana) leaves on the expulsion phase of fictive ejaculation in nicotinamide/streptozotocin-induced type 2 diabetic male rats.@*METHODS@#The electromyographic activity of the bulbospongiosus muscles was recorded in urethane anaesthetized, spinal cord transected rats receiving dopamine (0.1 μmol/L/kg) intravenously, in the absence or presence of aqueous and methanolic extracts of B. engleriana (2.5, 10, 50, 60, 75 mg/kg). In another experiment, the pro-ejaculatory effect of dopamine (0.1 μmol/L/kg, i.v.) was monitored in rats orally pre-treated with the aqueous and methanolic extracts (60 mg/kg) of B. engleriana for 1 or 4 weeks.@*RESULTS@#Results of the study showed that the intravenous administration of B. engleriana did not provoke any contraction of the ejaculatory muscles whilst rhythmic and rapid contractions of the bulbospongiosus muscles accompanied sometimes by penis movement and expulsion of the urethral contents were recorded after dopamine application. The sequential treatment of animals with B. engleriana extracts (2.5-75.0 mg/kg) followed by dopamine (0.1 μmol/L/kg) resulted in a dose-dependent abolishment of the pro-ejaculatory response due to dopamine. However, in animals orally submitted to a daily gavage with B. engleriana extracts (60 mg/kg) for 1 or 4 weeks, the ejaculation stimulating effect of dopamine (0.1 μmol/L/kg) was significantly delayed (P<0.01) but not completely suppressed.@*CONCLUSIONS@#Present findings suggest the involvement of dopaminergic system in the activity of B. engleriana and further support its aphrodisiac potentials due to sterols and saponins revealed in this plant.
ABSTRACT
BACKGROUND: The genus Bersama belongs to the Melianthaceae family and comprises of four species (B. swinnyi, B. yangambiensis, B. abyssinica, and B. engleriana) all of which are very high trees; the latter two detected species are found in Cameroon. Previous phytochemical investigation on B. yangambiensis, B. swinnyi, and B. abyssinica led to the isolation of triterpenes, saponins, flavonoids, and xanthones. METHOD: The stem bark of B. engleriana were collected in the village, Baham near Bafoussam city, Cameroon in August 2003 and identifi ed by Dr. Onana National Herbaruim, Yaoundι, Cameroon. The air dried and powdered stem bark of B. engleriana (1 kg) was extracted at room temperature with CH2Cl2-MeOH (1:1) 5 L for 48 hours. The mixture of the solvent was removed by evaporation to yield 200 g of crude extract. The latter was then dissolved in CH2Cl2 to give the CH2Cl2 soluble fraction of 5 g and a remaining gum of 195 g. Part of the remaining gum (22 g) was dissolved in water and extracted four times with butanol to give 12 g of red oil; which was then separated by paper chromatography, with butanol-acetic acid-water (4:1:5), to give 3 g of orange gum; purification was carried out on HPLC with MeOH (100%) to yield 2 g of mangiferin (1) as red oil. The CH2Cl2 soluble extract was eluted on silica gel n-hexane-CH2Cl2 gradient ratio and Sephadex LH-20 (n-hexane -CH2Cl2 -MeOH, (7:4:0.5) to afford compounds swinniol (2), Δ4-stigmaster-3ß-ol (3), 4-methylstigmaster-5,23-dien-3ß-ol(4). RESULTS: Herein, we carried out a phytochemical study of the stem bark of B. engleriana, and we report herein the isolation and structural elucidation of mangiferin, in addition to three triterpenes, previously reported from other species of the genus.[35] The assignment of the signals of mangiferin was determined using 1H, 13C-NMR, and 2D-NMR spectral data (HMQC, COSY, HMBC). The terpenoids were identifi ed by comparison of their 1H and 13C-NMR spectra with the literature data. Fractionation of the CH2Cl2-MeOH (1:1) extract of the stem bark of B. engleriana Guike gave mangiferin (1), in addition to three previously reported triterpenes, swinniol (2), Δ4-stigmaster-3ß-ol (3), and 4-methylstigmaster-5,23-dien-3-ß-ol (4). CONCLUSIONS: A chemical investigation of the CH2Cl2-MeOH extract of the stem bark of Bersama engleriana afforded a xanthone C-glucoside (mangiferin) and fi rst isolation of three terpenoids from this species: swinniol (2), Δ4-stigmaster-3ß-ol (3), and 4-methylstigmaster-5,23-dien-3-ß-ol (4). The complete 1H and 13C chemical shift assignments of mangiferin were determined using 1D and 2D NMR spectroscopic data (COSY, HMQC, HMBC, DEPT). The structures of the terpenoids were determined from their 1H and 13C NMR data and compared with the literature data.
