The antioxidant and neuroprotective effects of the Psychotria camptopus Verd. Hook. (Rubiaceae) stem bark methanol extract contributes to its antiepileptogenic activity against pentylenetetrazol kindling in male Wistar rats.

A substantial number of epileptic patients are resistant to the current medication thus necessitating the search for alternative therapies for intractable forms of the disease. Previous studies demonstrated the acute anticonvulsant properties of the methanol extract of the stem bark of Psychotria camptopus (MEPC) in rats. This study investigated the effects of MEPC on pentylenetetrazole-kindled Wistar rats. Kindling was induced by intraperitoneal injection of pentylenetetrazole (37.5 mg/kg) on every alternate day, 1 h after each daily oral pretreatment of rats (8 ≤ n ≤ 10) with MEPC (40, 80 and 120 mg/kg), vehicle or diazepam (3 mg/kg) for 43 days. The kindling development was monitored based on seizure episodes and severity. Rats' brains were collected on day 43 for the determination of oxidative stress parameters. The histomorphological features and neuronal cell viability of the prefrontal cortex (PFC) and hippocampus were also assessed using H&E and Cresyl violet stains. Chronic administration of pentylenetetrazole time-dependently decreased the latency to myoclonic and generalized seizures, and increased seizure scores and the number of kindled rats. MEPC and diazepam significantly increased the latencies to myoclonic jerks and generalized tonic-clonic seizures. These substances also reduced seizure score and the number of rats with PTZ-kindling. MEPC improved glutathione status and decreased lipid peroxidation in the brains of kindled rats. MEPC also exhibited neuroprotection against pentylenetetrazole-induced hippocampal and PFC neuronal damages. These results suggest that P. camptopus has antiepileptogenic activity, which might be related to the augmentation of antioxidant and neuroprotective defense mechanisms, and further confirm its usefulness in the management of epilepsy.

Anticonvulsant effects of the aqueous and methanol extracts from the stem bark of Psychotria camptopus Verdc. (Rubiacaea) in rats.

ETHNOPHARMACOLOGY RELEVANCE: The decoction from the stem bark of Psychotria camptopus (Rubiaceae) is used in the Cameroonian pharmacopoeia to treat neurological pathologies including epilepsy. AIM: The present work was undertaken to study the anticonvulsant properties of the aqueous (AE) and methanol (ME) extracts from the stem bark of P. camptopus in acute models of epileptic seizures in Wistar rats. METHOD: AE and ME were obtained by decoction and maceration of the stem bark powder in water and methanol, respectively. They were tested orally at the doses of 40, 80 and 120 mg/kg, on the latency of onset and duration of epileptic seizures induced by pentylene tetrazole (PTZ, 70 mg/kg, i.p.). The kinetic effect of both extracts at 120 mg/kg was evaluated. Their effects on diazepam (50 mg/kg) induced sleep and strychnine (STR, 2.5 mg/kg, i.p.) induced seizures were determined. ME was further tested on picrotoxin (PIC, 7.5 mg/kg, i.p.) and thiosemicarbazide (TSC, 50 mg/kg, i.p.) induced seizure models. The phytochemical composition of ME was assessed using LC-MS method, as well as its acute toxicity. RESULTS: AE and ME significantly (p < 0.001) reduced the duration of seizures in both PTZ and STR models. Their maximal effect was observed at 1 h after administration, though their effect at 120 mg/kg was maintained (p < 0.05) up to 24 h post-treatment. Both extracts significantly (p < 0.01) reduced sleep duration. ME significantly (p < 0.001) increased the latency of rat death on PIC-induced convulsions. In TSC rats, ME significantly (p < 0.001) delayed the latency to the first convulsion, and decreased the duration and frequency of convulsions. ME showed no acute toxicity while its phytochemical screening revealed the presence of two flavonoids (Rutin and Butin), two triterpenoid saponins (Psycotrianoside B and Bauerenone) and four alkaloids (10-Hydroxy-antirhine, 10-hydroxy-iso-deppeaninol, Emetine and Hodkinsine). In conclusion, AE and ME from the stem bark of P. camptopus have comparable anticonvulsant properties. The effect of ME is likely due to the presence of flavonoids and alkaloid and the activation of GABA pathway. These results further justify and support the use of P. camptopus in traditional medicine for the treatment of epilepsy.

Anti-hyperalgesic activity of the aqueous and methanol extracts of the leaves of Pittosporum mannii Hook on CFA-induced persistent inflammatory pain.

BACKGROUND: Previous study showed that aqueous (AEPM) and methanol (MEPM) extracts from the leaves of Pittosporum mannii have analgesic effects in acute pain models. The present study evaluates the acute and chronic anti-hypernociceptive and anti-inflammatory effects of AEPM and MEPM in a model of persistent inflammatory pain. METHODS: The third day after induction of inflammatory pain by subplantar injection of 100 µL of CFA in Wistar rats, AEPM and MEPM were administered orally (75, 150 and 300 mg/kg/day) and their anti-hyperalgesic and anti-inflammatory effects were follow in acute (1-24 h) and chronic (for 14 days) treatments. At the end of the chronic treatment, oxidative stress and liver parameters were assessed. Effects of plant extracts were also evaluated on nociception induced by Phorbol 12-Myristate 13-Acetate (PMA) and 8-bromo 3',5'-cAMP (8-Br-cAMP) in mice. RESULTS: AEPM and MEPM significantly reversed the mechanical hyperalgesia caused by CFA in acute and chronic treatment. Moreover, AEPM and MEPM also significantly reduced the nociception caused by PMA (60%) and 8-Br-cAMP (87%). Nevertheless, AEPM and MEPM failed to inhibit the paw edema caused by CFA. Plant extracts significantly reduced the nitric oxide content in the spinal cord and the plasmatic concentration of alanine aminotransferase. MEPM also significantly increased the glutathione content in the spinal cord. CONCLUSION: AEPM and MEPM given orally are effective in inhibiting mechanical hyperalgesia in persistent inflammatory pain caused by CFA. Their mechanisms of action seem to involve an interaction with PKC, PKA and nitric oxide pathways. These extracts might be devoid of hepatotoxic effects.

Androgenic effects of aqueous and methanolic extracts of Ficus asperifolia in male Wistar rats.

BACKGROUND: Androgen deficiency is a clinical syndrome resulting from the inability of the testes to produce physiological levels of testosterone due to a disturbance occurring at one or more levels of the hypothalamic-pituitary-testicular axis. The present study was undertaken to evaluate the androgenic properties of aqueous and methanolic extracts of Ficus asperifolia on normal and castrated immature rats. METHODS: Normal rats were treated either per os with aqueous or methanolic extract of Ficus asperifolia (100 mg/kg or 500 mg/kg b.w.), distilled water (10 ml/kg b.w.), 5% Tween 80 (10 ml/kg b.w.) or subcutaneously with testosterone propionate (0.5 mg/kg b.w.). Castrated rats were treated with plant extracts (100 mg/kg b.w. or 500 mg/kg b.w.) alone or with the co-administration of plant extracts and testosterone propionate (s.c., 0.5 mg/kg b.w.) or bicalutamide (2 mg/kg b.w. per os). Animals were treated once a day during four weeks. Body weight growth and relative sexual organ weights were recorded at the end of each treatment. Some biomedical parameters were measured in the plasma (proteins, cholesterol), testes (cholesterol) and epididymis (proteins). RESULTS: In normal rats, Ficus asperifolia significantly (p < 0.05) increased the relative weights of the testes and all sexual-dependent organs whereas total testicular cholesterol concentration was significantly (p < 0.05) decreased. In castrated groups, treatment with Ficus asperifolia was followed by an increase in the sexual organ weights, epididymal protein and prostatic acid phosphatase concentrations. The co-administration of testosterone and plant extracts significantly (p < 0.05) increased the weight of accessory sexual organs and epididymal protein contents. In the presence of bicalutamide (an anti-androgen), the sexual stimulating activity of Ficus asperifolia was diminished with remarkable effects on vas deferens weight (p < 0.05), plasma (p < 0.01) and epididymal (p < 0.05) protein contents. CONCLUSION: Ficus asperifolia possesses androgen-like activity through possible stimulation of cytoplasmic and/or nuclear receptors by the bioactive compounds found in its extracts.

Antinociceptive effects of the aqueous and methanol extracts of the leaves of Pittosporum mannii Hook. F. (Pittosporaceae) in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Pittosporum mannii (Pittosporaceae) is used in Africa traditional medicine to treat various ailments including pain and inflammation. AIM OF THE STUDY: The present work was undertaken to evaluate the antinociceptive effects of the aqueous (AEPM) and methanol (MEPM) extracts from the leaves of Pittosporum mannii. METHODS: High performance liquid chromatography coupled with mass spectrometry (LCMS) was used for the phytochemical analysis of AEPM prepared as decoction and MEPM prepared as cold maceration. The in vitro cytotoxicity of AEPM and MEPM were evaluated on Artemia salina larvae. AEPM and MEPM antinociceptive effects were evaluated at the doses of 35, 75, 150 and 300mg/kg given orally, against pain induced by acetic acid, formalin, hot plate, capsaicin and glutamate. The rota rod test was also performed at the same doses. To determine the mechanism of action of these extracts, their antinociceptive effects were tested in animals pretreated with yohimbine (α2-adrenergic antagonist), atropine (muscarinic antagonist) or naloxone (an opioids antagonist). RESULT: The LCMS analysis showed that both extracts contain pittovidoside and 1-O-rhamnopyranosyl-23-acetoxyimberbic acid 29-methyl ester, the aqueous extract being more concentrated. Oral administration of both extracts significantly reduced pain symptoms induced by acetic acid, formalin, capsaicin, glutamate and hot plate. The antinociceptive effect of AEPM was significantly inhibited by yohimbine, atropine and naloxone while these inhibitors tend to potentiate the activity of MEPM. Both extracts have no effect on Rota rod test. AEPM and MEPM showed respective LC50 of 2.44 and 0.70mg/ml on Artemia larvae and were therefore, considered non-toxic. CONCLUSION: These results indicate that AEPM and MEPM possesses analgesic effects with different mechanism of action. Although effects of both extracts may involve TRPV1 receptors and glutamatergic pathway, AEPM may in addition, interact with alpha-adrenergic, muscarinic and opioidergic pathways that are not involve in the effects of MEPM.

Endiandric Acid Derivatives and Other Constituents of Plants from the Genera Beilschmiedia and Endiandra (Lauraceae).

Plants of the Lauraceae family are widely used in traditional medicine and are sources of various classes of secondary metabolites. Two genera of this family, Beilschmiedia and Endiandra, have been the subject of numerous investigations over the past decades because of their application in traditional medicine. They are the only source of bioactive endiandric acid derivatives. Noteworthy is that their biosynthesis contains two consecutive non-enzymatic electrocyclic reactions. Several interesting biological activities for this specific class of secondary metabolites and other constituents of the two genera have been reported, including antimicrobial, enzymes inhibitory and cytotoxic properties. This review compiles information on the structures of the compounds described between January 1960 and March 2015, their biological activities and information on endiandric acid biosynthesis, with 104 references being cited.

High fat diet-induced estrus cycle disruption: effects of Ficus asperifolia.

BACKGROUND: Ficus asperifolia (L) Hook. Ex Miq (Moraceae) fruits are used in Cameroonian traditional medicine to cure some cases of infertility in women. This study determines the mechanism of alleviating effect of the plant extracts on rat infertility induced by a high fat diet (HFD). METHODS: Obesity was reached by feeding female rats with a HFD for 10 weeks. Vaginal smear was observed daily for 3 weeks after animals were obese. Then, 70 animals with abnormal estrus cyclicity were selected and partitioned into two sets of 35 animals. Each set was further divided into seven groups of five rats. These obese rats with disrupted estrus cyclicity were orally administered the aqueous and methanolic extracts (100 and 500 mg/kg), distilled water (10 mL/kg), 5% Tween 80 (10 mL/kg) or lutenyl (0.8 µg/kg) once a day for 1 week (set I) or 4 weeks (set II). Estrus cyclicity, body weight gain, hematocrit, lipid profile, ovarian, uterine and hepatic growth indices were determined at the end of each treatment. RESULTS: HFD increased the body weight of the animals by 27% and disrupted the estrus cyclicity by 98.44%. Aqueous extract (100 mg/kg) of F. asperifolia given for 1 week corrected 40% of the irregular estrus cycle and this percentage increased to 80% as the treatment progressed to 4 weeks. F. asperifolia-treated obese rats (mostly with the aqueous extract at 100 mg/kg) showed a significant decrease (p<0.001) in the total plasma cholesterol and low density lipoprotein (LDL) cholesterol level and a significant increase (p<0.001) in high density lipoprotein (HDL) cholesterol. F. asperifolia has bioactive agents that may maintain conducive conditions for reproduction in obese female rats. CONCLUSIONS: Our data support the anecdotal claims of F. asperifolia in folk medicine to cure some cases of infertility in women.

Tetra-acetylajugasterone a new constituent of Vitex cienkowskii with vasorelaxant activity.

Tetra-acetylajugasterone C (TAAC) was found to be one of the naturally occurring compounds of the Cameroonian medicinal plant Vitex cienkowskii which is responsible for a vasorelaxant activity of an extract of this plant. The evaluation of the underlying mechanisms for the relaxing effect of TAAC was determined using aortic rings of rats and mice. TAAC produced a concentration-dependent relaxation in rat artery rings pre-contracted with 1µM noradrenaline (IC50: 8.40µM) or 60mM KCl (IC50: 36.30µM). The nitric oxide synthase inhibitor l-NAME (100µM) and the soluble guanylate cyclase inhibitor ODQ (10µM) significantly attenuated the vasodilatory effect of TAAC. TAAC also exerted a relaxing effect in aorta of wild-type mice (cGKI(+/+); IC50=13.04µM) but a weaker effect in aorta of mice lacking cGMP-dependent protein kinase I (cGKI(-/-); IC50=36.12µM). The involvement of calcium channels was studied in rings pre-incubated in calcium-free buffer and primed with 1µM noradrenaline prior to addition of calcium to elicit contraction. TAAC (100µM) completely inhibited the resulting calcium-induced vasoconstriction. The same concentration of TAAC showed a stronger effect on the tonic than on the phasic component of noradrenaline-induced contraction. This study shows that TAAC, a newly detected constituent of Vitex cienkowskii contributes to the relaxing effect of an extract of the plant. The effect is partially mediated by the involvement of the NO/cGMP pathway of the smooth muscle but additionally inhibition of calcium influx into the cell may play a role.

Pentacyclic triterpenoids and ceramide mediate the vasorelaxant activity of Vitex cienkowskii via involvement of NO/cGMP pathway in isolated rat aortic rings.

ETHNOPHARMACOLOGICAL RELEVANCE: Vitex cienkowskii Kotschy & Peyritsch is a deciduous tree, prescribed by Cameroonian traditional healers as one of the most popular plant widely used in many disorders including cardiovascular diseases. The preliminary pharmacological studies carried out on Vitex cienkowskii showed its vasorelaxant activities on guinea-pig aortic rings. AIM OF THE STUDY: The present work evaluated the vasorelaxant activity of extract and isolated compounds from Vitex cienkowskii. MATERIALS AND METHODS: Rat aortic rings were used to evaluate the in vitro vascular effect of the extract. The antioxidant activity was determined by measuring the reduction of the free radical 1,1-diphenyl-1-picryl-hydrazyl (DPPH). RESULTS: Vitex cienkowskii induced significant relaxation in a concentration- and endothelium-dependent manner (EC(50)=12.12 µg/ml, CH(2)Cl(2)-MeOH, 1:1) and did not produce a vasorelaxant effect on contraction evoked by KCl (60 mM). In order to determine its mode of action, Vitex cienkowskii-induced relaxant effect was evaluated in the presence of indomethacin (10 µM), L-NAME (100 µM), ODQ (1 µM) and SQ22356 (100 µM). Relaxation was significantly blocked by L-NAME and ODQ. These results indicate that Vitex cienkowskii-mediated relaxation is endothelium dependent, probably due to NO release, and the consequent activation of vascular smooth muscle soluble guanylate cyclase (sGC), a signal transduction enzyme that forms the second messenger cGMP. Bio-guided study of Vitex cienkowskii allowed the isolation of the known pentacyclic triterpenoids and a ceramide. It is the first report of salvin A, maslinic acid and a ceramide from Vitex cienkowskii. The activity induced by these compounds indicated that they may be partly responsible for the vasorelaxant effect of the plant extract. A dose of 40 mg/kg of CH(2)Cl(2)-MeOH (1:1) extract administered intravenously induced a decrease of mean arterial pressure but did not affect the heart rate. Moreover the plant extracts were found to be highly active in the DPPH radical scavenging assay. CONCLUSION: Vitex cienkowskii extract possesses antioxidant property, vasorelaxing, and hypotensive effect linked to the endothelium related factors, where nitric oxide is involved.

Obscurine: a new cyclostachine acid derivative from Beilschmiedia obscura.

From the methylene chloride extract of the stem bark of Beilschmiedia obscura, a new cyclostachine derivative, obscurine (1), has been isolated, together with six known compounds. The structure of compound 1 was established by spectroscopic methods, including 1- and 2-dimensional NMR techniques.

Antibacterial endiandric acid derivatives from Beilschmiedia anacardioides.

Three endiandric acid derivatives, beilschmiedic acids A, B and C were isolated from the stem bark of Beilschmiedia anacardioides together with the known beta-sitosterol. Their structures were established by means of modern spectroscopic techniques. The relative configuration of compound 1 was determined by single crystal X-ray analysis. The antibacterial activities of compounds A,B,C were evaluated in vitro against five strains of microbes. Compound C showed strong activity against Bacillus subtilis, Micrococcus luteus and Streptococcus faecalis (MICs below 23 microM). This Compound was more active than the reference antibiotic ampicillin against B. subtilis and M. luteus.