Analgesic and Anti-Inflammatory Properties of Extracts from the Bulbils of Dioscorea bulbifera L. var sativa (Dioscoreaceae) in Mice and Rats

The aqueous and methanol extracts from the dry bulbils of Dioscorea bulbifera L. var sativa (Dioscoreaceae)—evaluated orally at the doses of 300 and 600 mg/kg against pain induced by acetic acid, formalin, pressure and against inflammation induced by carrageenan, histamine, serotonin and formalin in mice and rats, showed a dose dependant inhibition of pain and inflammation with a maximum effect of 56.38%, 73.06% and 42.79% produced by the aqueous extract, respectively on pain induced by acetic acid, formalin and pressure while the methanol extract at the same dose respectively inhibited these models of pain by 62.70%, 84.54% and 47.70%. The oral administration of aqueous and methanol extracts caused significant anti-inflammatory activity on paw oedema induced by histamine, serotonin and formalin. The present results show that the bulbils of Dioscorea bulbifera var sativa possess potent analgesic and anti-inflammatory activities. These activities may results from the inhibition of inflammatory mediators such as histamine, serotonin and prostaglandins. Thus, the analgesic activity of the bulbils of Dioscorea bulbifera may be at least partially linked to its anti-inflammatory activity

Antiinflammatory activity of leaf extracts of Kalanchoe crenata Andr.

Objective: To evaluate the acute and chronic antiinflammatory properties of leaf extracts of Kalanchoe crenata in rats. Material and methods: The methylene chloride/methanol extract of K. crenata was extracted by using hexane, methylene chloride, ethyl acetate, and n-butanol. The antiinflammatory profile of these extracts was investigated on the basis of paw edema induced by carrageenan. The n-butanol fraction (most potent) was further assessed through acute inflammatory models induced by histamine, serotonin, and formalin. The chronic antiinflammatory and the ulcerogenic activities of the n-butanol fraction were also examined. Results: The oral administration of n-butanol fraction (600 mg/kg) caused a maximum inhibition of about 45% in paw edema induced by carrageenan. The n-butanol fraction also exhibited acute antiinflammatory activity on paw edema induced by histamine (47.51%), serotonin (54.71%), and formalin-(40.00%) . In the chronic inflammation model, this extract showed maximum inhibition of 61.26% on the ninth day of treatment. The ulcerogenic assessment showed that ulcer indices after oral treatment with n-butanol fraction were zero and 0.40±.2, for the 300 and 600 mg/kg doses, respectively. Conclusion: On the basis of these findings, it may be inferred that K. crenata is an antiinflammatory and antiarthritic agent that blocks histamine and serotonin pathways. The results are in agreement with the traditional use of the plant in inflammatory conditions

Polyhydroxyoleanane-type triterpenoids from Combretum molle and their anti-inflammatory activity

A new oleanane-type triterpene saponin, b-D-glucopyranosyl 2a,3b,6b-trihydroxy-23-galloylolean-12-en-28-oate (1), together with four known oleanane-type pentacyclic triterpenoids, combregenin (2), arjungenin (3), arjunglucoside I (4), and combreglucoside (5) were isolated from the stem bark of Combretum molle. Their structures were established mainly on the basis of 1D and 2D NMR spectral data. Compounds 1–3 exhibited more significant activity against carrageenan-induced paw edema in rat compared to compounds 4 and

Phytochemical composition and in vitro effects of the ethyl acetate bark extract of Distemonanthus benthamianus Baillon (Caesalpiniaceae) on Staphylococcus aureus and Streptococcus agalactiae

Distemonanthus benthamianus is a tree used in traditional African medicine to treat bacterial, fungal and viral infections. The pasty phase and the granular phase obtained from the ethyl acetate bark extract of D. benthamianus were tested for antimicrobial purposes on Staphylococcus aureus and on Streptococcus agalactiae alone and in combination with erythromycin. Only the pasty phase of the extract was active against the above bacteria (MIC = 1024 µg/mL ; MBC = 4096 µg/mL). The MIC of erythromycin against S. aureus and S. agalactiae was 8 µg/mL and 4 µg/mL, respectively. The MBC of erythromycin was 32 µg/mL against S. aureus and 8 µg/mL against S. agalactiae. The combination of that active phase (256 µg/mL) with erythromycin (1 µg/mL) was synergistic and the ratio MBC / MIC was 4 suggesting that the plant extract may be a bactericidal agent. Phytochemical analysis revealed the presence of flavonoids and phenolic compounds in the pasty phase of the plant extract and the absence of sterols, triterpenes and alkaloids in the same phase. In contrast, the granular phase contained all the above compounds except flavonoids. This result suggests that the active principle may belong to the class of flavonoids. Keywords: Distemonanthus benthamianus, MBC, MIC, Staphylococcus aureus, Streptococcus agalactiae. RESUME Distemonanthus benthamianus est un arbre utilisé en médecine traditionnelle africaine pour traiter les infections bactériennes et virales, ainsi que les mycoses. Les effets antibactériens des phases pâteuse et granulaire obtenues à partir de l'extrait à l'acétate d'éthyle de l'écorce de D. benthamianus ont été testés sur Staphylococcus aureus et sur Streptococcus agalactiae seule ou en association avec l'érythromycine. Seule la phase pâteuse a été active sur les bactéries évoquées (CMI = 1024 µg/mL ; CMB = 4096 µg/mL). La CMI de l'érythromycine vis à vis de S. aureus et de S. agalactiae a été de 8 µg/mL et de 4 µg/mL, respectivement. La CMB de l'érythromycine a été de 32 µg/mL sur S. aureus et de 8 µg/mL sur S. agalactiae. L'association de la phase pâteuse (256 µg/mL) avec l'érythromycine a été synergique et le rapport CMB / CMI a été de 4. Ceci montre que cet extrait de plante pourrait être un agent bactéricide. L'analyse phytochimique a révélé la présence des flavonoïdes et des composés phénoliques dans la phase pâteuse de l'extrait et l'absence des stérols, des triterpènes et des alcaloïdes dans cette même phase. Par contre, tous les composés sus-cités à l'exception des flavonoïdes ont été notés dans la phase granulaire. Ce résultat suggère que le principe actif appartiendrait à la classe des flavonoïdes. Mots clés: Distemonanthus benthamianus, CMB, CMI, Staphylococcus aureus, Streptococcus agalactiae Cameroon Journal of Experimental Biology Vol. 1(1) 2005: 50-5

Effects of Mondia whitei extracts on the contractile responses of isolated rat vas deferens to potassium chloride and adrenaline

Objective: To investigate the effects of the methylene chloride:methanol (CH2Cl2:MeOH, 1:1) extract of the dried roots of Mondia whitei Linn and its hexane and methanol fractions on potassium chloride (KCl) and adrenaline (Adr)-induced contractions of rat vas deferens. Materials and Methods: Isolated strips of normal adult rat vas deferens were mounted in a Ugo Basile single-organ bath containing Krebs solution. Cumulative concentration-response curves of KCl (1-7 x 10-2 M ) and adrenaline (1.21-8.45 x 10-7 M ) were established in the absence and presence of M. whitei (50-400 μg/ml). In separate experiments, after obtaining a stable plateau of contractions with KCl (60 m M ), M. whitei samples (50-400 μg/ml) were added cumulatively to relax the preparation. In KCl (60 m M ), containing depolarizing medium, cumulative concentration-contraction curve to CaCl2 (2-14 x 10-2 M ) was elicited in the absence and presence of the hexane fraction of M. whitei (50-400 μg/ml). Results: All the M. whitei samples produced rightward shift of the concentration-response curves to KCl and Adr. At high concentration of the plant extracts (400 μg/ml), a decrease of the maximal response to the contractile agents was observed compared with that obtained with the control. All the three extracts produced concentration-dependent relaxation of the plateau of contraction induced by KCl and the hexane fraction appeared to be the more potent. In calcium-free physiological salt solution, the hexane fraction of M. whitei produced rightward shift to the concentration-response curve to CaCl2 and completely abolished the contractile effect of calcium at high concentration (400 μg/ml). Conclusion: It is concluded that M. whitei extracts antagonized the contractile responses to KCl and Adr in isolated rat vas deferens, which could be due to the blockade of voltage-operated calcium channels

In Vitro

Sclerocarya birrea is a medicinal plant used for the treatment of inflammatory- and bacterial-related diseases. The present study investigated in vitro and in vivo the effects of the stem bark methanol extract of S. birrea. Nitrite, TNF, IL-1beta, IL-6 and IL-12p40 production by bone marrow-derived macrophages (BMDM) pre-incubated with or without S. birrea, and stimulated with Lipopolysaccharide (LPS) or infected with live Mycobacterium bovis Bacillus Calmette Guerin (BCG) was evaluated. S. birrea extract inhibited, in a concentration-dependent manner, nitrite, TNF, IL-1beta, IL-6 and IL-12p40 production by BMDM stimulated with LPS or infected with live BCG. The iNOS expression was reduced by S. birrea after stimulation of BMDM with LPS. In addition, S. birrea inhibited the nuclear factor kB (NF-kB) activation by both LPS and BCG. The effects of the plant extract were also evaluated in an in vivo model of liver injury induced by D-galactosamine/LPS (D-GalN/LPS) administration in mice. S. birrea limited D-GalN/LPS-liver injury as assessed by a reduction in transaminases and TNF, IL-1beta, IL-6 serum levels, and translocation of NF-kB to the nucleus. Taken together, our data indicate that stem bark methanol extract of S. birrea possesses anti-inflammatory properties by inhibiting NF-kB activation and cytokine release induced by inflammatory or infectious stimuli

Protective Effects of Extracts, Isolated Compounds from Desmodium uncinatum and Semi-Synthetic Isovitexin Derivatives against Lipid Peroxidation of Hepatocyte’s Membranes

Lipid peroxidation plays a pivotal role in the pathogenicity and maintenance of hepatitis. Thus, substances protecting hepatocyte membranes from lipid peroxidation are of great importance in the management of hepatotoxicity and hepatitis. The present work deals with the in vitro hepatoprotective activity of the methanol extract of Desmodium uncinatum, its sub-fractions, the major isolated compounds and some of their semi-synthetic derivatives in order to study structure activity relationships. Using hydrogen peroxide (H2O2)-induced lipid peroxidation of hepatocyte membranes as a model, the hepatoprotective-guided phytochemical survey of the methanol extract of aerial parts of D. uncinatum was carried out by successive column chromatography. One of the most active compounds (Isovitexin) was chemically transformed to yield new semi-synthetic. The identification of isolated and semi-synthetic compounds was performed using NMR techniques, mass spectrometry and by comparison of their data with those reported in the literature. The n-butanol fraction was the most effective (IC50: 22.9 μg/mL) compared to the crude methanol extract (IC50: 43.6 μg/mL) and other fractions. The n-butanol sub-fractions FA (containing non-phenolic compounds) and FB (mainly containing phenolic compounds) exhibited respective IC50 of 14.36 and 128.2 μg/ml. Purification of FA yielded 3-O-β-D-glucopyranosyl-β-sitosterol (1), 3-O-β-D- 2-acetyl-amino-2-deoxyglucopyranoxyloleanoic acid (2), (2S, 3S, 4R, 7R, 8Z)-1-O-β-D-glucopyranosyl-2-[(R)-2'-hydroxyarachidoylamino]-docosan-8-ene-3,4,7-triol (4), spiraeamide (5), mannitol (6), while FB afforded essentially three C-glycosylflavonoids namely isovitexin (7), vitexin (8) and vicenin-3 (9). Chemical transformations (methylation, allylation and prenylation) of isovitexin afforded five new semi-synthetic derivatives: 4',5,7-Otrimethylisovitexin (10), 4'-O-allylisovitexin (11), 4',7-O-diallylisovitexin (12), 4'-O-prenylisovitexin (13) and 8-C-prenyl-4',7-O-diprenylisovitexin (14). The screening of these derivatives revealed that allylation did not significantly affect the hepatoprotective activity while methylation, prenylation, number and position of sugar moieties on the A ring of flavonoids significantly reduced it. Results demonstrated that the n-butanol fraction obtained from the methanol extract of Desmdium uncinatum may possess hepatoprotective activity due to its content in C-glycosylflavonoids and cerebrosides. Hydroxyl groups in C-glycosylflavonoids are important for their lipid peroxidation inhibitory activity