Antihypertensive potential of the stem bark of Canarium schweinfurthii Engl. (Burseraceae) in wistar rats: UPLC-ESI-QToF-MS/MS-based prediction of antihypertensive phytochemicals.

Ethnopharmacological relevance: Canarium schweinfurthii, also called ''Elemierd'Afrique'', is used in Cameroonian folk medicine (bark decoction) to treat patients suffering from hypertension.Aim of the study: This study aimed at evaluating the antihypertensive activities of the stem bark of Canarium schweinfurthii and identifying potential compounds present in its extract that may support or oppose its ethnomedicinial use. Materials and methods: Stem bark extract of Canarium schweinfurthii was prepared by maceration using 70 % ethanol followed by redissolution in methanol and hyphenated. Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS) analysis for the detection and characterisation of secondary metabolites. Antihypertensive effects were assessed in Wistar rats after induction of hypertension with sodium chloride (NaCl) 18 % at a dose of 0.01mL/gbody weight once a day for four weeks.Hemodynamic parameters were measured weekly by anon-invasive method using the CODA system. Results: The ethanolic bark extract of C. schweinfurthii significantly inhibited the increase of blood pressure with a maximum of 23.18 % (systolic pressure, p < 0.0001), 24.77 % (diastolic pressure, p < 0.001) and 22.95 % (mean pressure, p < 0.0001) at a dose of 200 mg/kgbody weight at the 4th week, compared to agroup of Wistar rats that received only NaCl (negative control). Similarly, the extract significantly inhibited the increase in heart rate by 18.84 % (p < 0.001) at 200 mg/kgbody weight at week four. Hematological parameters did not differ significantly between the extract-treated and control groups. The UPLC-MS/MS spectrometric analysis provided evidence for the presence of several C30 terpenoids containing three or five oxygen atoms and exhibiting pentacyclic triterpenoid structures, as well as C29 terpenoids and related compounds containing nitrogen in addition to oxygen, using spectral matching, and in silico molecular formula and structure prediction. Additionally, two features were annotated with high-confidence as lignans, structurally closely related to hinokinin and dehydrocubebin through MS/MS-based in silico structure prediction using CSI: Finger ID in SIRIUS5. The lignans have been previously reported from stem bark of plants belonging to the Burseraceae family. Conclusion: The ethanolic stem bark extract of C. schweinfurthii demonstrated antihypertensive properties on the tested Wistar rats. These results support the ethnopharmacological use of C. schweinfurthii concoctions for the treatment of hypertension and suggest a protective effect against salt damage, hypothetically by the up regulation of antioxidative enzymes and/or lipids, mitigatings membrane peroxidation.

Antihypertensive Effects of Aqueous Extract of Ricinodendron heudelotii (Baill.) Pierre (Euphorbiaceae) in Wistar Rat.

Ricinodendron heudelotii stem bark is commonly used in Cameroonian traditional medicine to treat cardiovascular diseases such as hypertension. The present study was designed to investigate the antihypertensive and antioxidant properties of the aqueous extract of Ricinodendron heudelotii in salt-induced hypertensive rats. Analysis by HPLC-ESI-Q-TOF-MS was used to identify various chemical components of the extract. A total of thirty rats were used for each test. High-salt hypertension was induced in rats by oral administration of NaCl for 12 weeks. Mean blood pressure (MBP) and heart rate (HR) were monitored by noninvasive methods. Oral administration of Ricinodendron heudelotii significantly (p < 0.01) reduced the increase of mean blood pressure (23.12%, 26.14%, and 24.34%) and heart rate (31.19%, 31.09%, and 26.98%), respectively, at the doses of 40, 20, and 6 mg/kg, compared to the hypertensive group. All the doses tested significantly reduced or/and ameliorated biochemical and oxidative stress parameters. Histological analysis showed that Ricinodendron heudelotii restored renal disorders induced by the administration of salt. The aqueous extract of Ricinodendron heudelotii exerts a cardioprotective effect, and the antihypertensive activity seems associated with an improvement in antioxidant status. Overall, the results justify and support the traditional use of Ricinodendron heudelotii.

Acute and sub-acute toxicity assessment of aqueous leaves extract of Crassocephalum crepidioides (Asteraceae) in Wistar rats.

OBJECTIVES: Several studies establish the therapeutic properties of various plants which are sometimes a source of minerals, vitamins and phytochemical compounds. However, many studies evoked potential toxic of some. In Cameroon, Crassocephalum crepidioides (C.c) is used in folk medicine to treat several diseases, but there are not much informations about its toxicity. This study evaluate its acute and sub-acute toxicity. METHODS: Our study was undertaken to evaluate acute and sub-acute toxicity of aqueous leaves extract of C.c. The study was conducted using the OECD guidelines about oral toxicity's study. For acute toxicity, rats were administrated single oral dose of 5,000 mg/kg body weight (b.w) and monitored for death and weight impairment during seven days. In sub-acute toxicity, experimental rats received daily doses of 250,500 and 1,000 mg/kg b.w during 28 consecutive days. The toxics effects of the extract were assessed using anthropometric, haematological, biochemical parameters as well as histology of vital body's organs (liver, kidneys, lungs and spleen). RESULTS: lethal dose 50 (LD50) was find to be greater than 5,000 mg/kg b.w in rats. In sub-acute toxicity, we observed significant increase of body weight, food and water consumption with the maximums of 15.14, 24.52 and 28.86% respectively at 1,000 mg/kg b.w. There was no significant change in haematological parameters. However, we observed significant change in biochemical parameters. Furthermore, structural disorders were noticed in liver and kidneys of animals treated with C.c. CONCLUSION: Data obtained suggesting that C.c extract could be safe in single administration, but with toxic effects in repeated treatment.

Eco-friendly synthesis, characterization, in vitro and in vivo anti-inflammatory activity of silver nanoparticle-mediated Selaginella myosurus aqueous extract.

INTRODUCTION: There is emerging interest in medicinal plants in the biomedical field, due to their multitude of chemicals which show anti-inflammatory, antimicrobial, antiviral, or antitumoral potential. Research on medicinal plants has shown that nanotechnology could offer new solutions in the quality control, delivery aspects, or in sustaining herbal biological activities. This work reports on the preparation and characterization of silver nanoparticle-mediated Selaginella myosurus plant extract. METHODS: Ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, powder X-ray diffraction, energy dispersive X-ray spectroscopy, high-resolution scanning electron microscopy, high-resolution transmission electron microscopy, and selected area electron diffraction have been used to characterize the prepared silver nanoparticles. The synthetic stability was studied by varying concentrations and pH of reactants. Egg albumin denaturation and carrageenan-induced rat paw edema model were used to ascertain the anti-inflammation. RESULTS: Ultraviolet-visible spectroscopy gave plasmon resonance ranging between 420 and 480 nm while Fourier transform infrared spectroscopy proved nano interface functionalized with organics. The powder X-ray diffraction pattern is in agreement with silver and silver chloride nanoparticles of crystallite size 33.7 nm and 44.2 nm for silver and silver chloride, respectively. Energy dispersive X-ray spectroscopy enables elemental characterization of the particles consisting of silver and silver chloride among main elements. Spherical silver grain of 58.81 nm average size has been depicted with high-resolution scanning electron microscopy and high-resolution transmission electron microscopy. Inhibitions of 99% and 60% were obtained in vitro and in vivo, respectively. CONCLUSION: The albumin denaturation and carrageenan-induced rat hind paw edema model to assess the anti-inflammatory potential of generated nanoparticles suggests that the silver nanoparticles may act as reducing/inhibiting agents on the release of acute inflammatory mediators. Hence, this work clearly demonstrated that silver nanoparticles mediated-Selaginella myosurus could be considered as a potential source for anti-inflammatory drugs.

Biological activities of plant extracts from Ficus elastica and Selaginella vogelli: An antimalarial, antitrypanosomal and cytotoxity evaluation.

The cytotoxic, antiplasmodial, and antitrypanosomal activities of two medicinal plants traditionally used in Cameroon were evaluated. Wood of Ficus elastica Roxb. ex Hornem. aerial roots (Moraceae) and Selaginella vogelii Spring (Selaginellaceae) leaves were collected from two different sites in Cameroon. In vitro cell-growth inhibition activities were assessed on methanol extract of plant materials against Plasmodium falciparum strain 3D7 and Trypanosoma brucei brucei, as well as against HeLa human cervical carcinoma cells. Criteria for activity were an IC50 value < 10 µg/mL. The extract of S. vogelii did not significantly reduce the viability of P. falciparum at a concentration of 25 µg/mL but dramatically affected the trypanosome growth with an IC50 of 2.4 µg/mL. In contrast, at the same concentration, the extract of F. elastica exhibited plasmodiacidal activity (IC50 value of 9.5 µg/mL) and trypanocidal (IC50 value of 0.9 µg/mL) activity. Both extracts presented low cytotoxic effects on HeLa cancer cell line. These results indicate that the selected medicinal plants could be further investigated for identifying compounds that may be responsible for the observed activities and that may represent new leads in parasitical drug discovery.

Antiplasmodial activity of some phenolic compounds from Cameroonians Allanblackia.

BACKGROUND: Plasmodium falciparum, one of the causative agents of malaria, has high adaptability through mutation and is resistant to many types of anti-malarial drugs. This study presents an in vitro assessment of the antiplasmodial activity of some phenolic compounds isolated from plants of the genus Allanblackia. METHODS: Tests were performed on well plates filled with a fixed parasitized erythrocytes volume. Compounds to be tested were then added in wells. After incubation, tritiated hypoxanthine is added and the plates were returned to the incubator. After thawing, the nucleic acids are collected. Inhibitory Concentration 50 (IC50) was determined by linear interpolation. RESULTS: From Allanblackia floribunda, have been isolated and characterized 1,7-dihydroxyxanthone 1, macluraxanthone 4, morelloflavone 9, Volkensiflavone 10 and morelloflavone 7-O-glucoside 11; from Allanblackia monticola, α-mangosine 2, rubraxanthone 3, allaxanthone C 5, norcowanine 6, tovophiline A 7, allaxanthone B 8 and from Allanblackia gabonensis, 1,7-dihydroxyxanthone 1. Six of them were evaluated for their antimalarial properties. The most active compound, macluraxanthone, presented a very interesting activity, with an IC50 of 0.36 and 0.27 µg/mL with the F32 and FcM29 strains respectively. CONCLUSION: This work confirms that species of Allanblackia genus are medicinally important plants containing many biologically active compounds that can be used effectively as antiplasmodial.

Xanthones from the seeds of Allanblackia monticola and their apoptotic and antiproliferative activities.

Phytochemical investigations of the seeds of ALLANBLACKIA MONTICOLA have led to the isolation and characterization of one new xanthone derivative, named allanxanthone E ( 1), together with seven known compounds, including five xanthones, 1,7-dihydroxy-3-methoxy-2-(3-methylbut-2-enyl)xanthone ( 2), alpha-mangostin ( 3) , garciniafuran ( 4) , allanxanthone C ( 5), and 1,6-dihydroxy-2,4-diprenylxanthone ( 6), and two pentacyclic triterpenes, friedelin and lupeol. The structures of these compounds were established on the basis of one- and two-dimensional NMR homo- and heteronuclear correlation evidence. Some of these compounds were evaluated for their apoptotic and antiproliferative activities against human leukemic B lymphocytes, such as the hairy cell leukemia-derived ESKOL cell line and cells from B-CLL (B-cell chronic lymphocytic leukemia) patients.

Anti-inflammatory and anti-nociceptive activities of the stem bark extracts from Allanblackia monticola STANER L.C. (Guttiferae).

THE AIM OF THIS STUDY: was to assess the anti-inflammatory and mechanism of action of Allanblackia monticola (Guttiferae). The anti-inflammatory activity "in vivo" of the methylene chloride/methanol extract, methanol and methylene chloride fractions of stem barks of Allanblackia monticola, administered orally at doses of 37.5; 75; 150 and 300 mg/kg, was evaluated on carrageenan-induced oedema in rats to determine the most active fraction. Indomethacin, inhibitor of cyclo-oxygenase was used as reference drug. The effects of the most active fraction were then examined on the rat paw oedema caused by histamine, serotonin, arachidonic acid and dextran followed by its ulcerogenic effect. The results showed that the methylene chloride fraction of Allanblackia monticola was more effective on the oedema caused by the carrageenan. The anti-nociceptive activity of the methylene chloride fraction was assessed using the acetic acid-induced abdominal constriction model, formalin test and hot plate test. At 150 mg/kg, Allanblackia monticola caused maximum inhibitions of inflammation induced by carrageenan (83.33%), by histamine (42.10%), by dextran (40.29%) and by arachidonic acid (64.28%). Allanblackia monticola (75-300 mg/kg) did not cause significant modification of the oedema induced by serotonin. Concerning the anti-nociceptive properties of the plant, the methylene chloride fraction (75-300 mg/kg) caused a dose-dependent inhibition on abdominal contractions induced by acetic acid (32.34-77.37%) and significantly inhibited the inflammatory pain caused by formalin (40.71-64.78%). Allanblackia monticola did not increase the latency time in the hot plate test. Like indomethacin (10mg/kg), the fraction at the dose of 150 mg/kg caused ulceration of the gastric mucous membrane in treated rats. These results show that Allanblackia monticola has an anti-inflammatory and analgesic activities with gastric ulcerative side effects.

Prenylated xanthone derivatives with antiplasmodial activity from Allanblackia monticola STANER L.C.

Further study of the methanol extract of the stem bark of Allanblackia monticola STANER L.C. resulted in the isolation of a new prenylated xanthenedione, designated allanxanthone C, together with the five known xanthones, garciniafuran, tovophyllin A, rubraxanthone, norcowanin and mangostin and one saponin, stigmasterol-3-O-beta-D-glucopyranoside. The structure of the new compound was established by detailed spectroscopic analysis to be 1,2-dihydro-3,6,8-trihydroxy-1,1,7-tri(3-methylbut-2-enyl)xanthen-2,9-dione (3-hydroxyapetalinone C). The methanol extract and pure compounds were tested on two strains of Plasmodium falciparum, F32 (chloroquine sensitive) and FcM29 (chloroquine resistant). The IC50 values obtained ranged from 0.6 to 8.9 microg/ml. Their cytotoxicity was estimated on human melanoma cells (A375) and the cytotoxicity/antiplasmodial ratio was found to be between 15.45 and 30.46. The antimicrobial activities against a range of microorganisms of the crude extract and some of these compounds are also reported.