Anti-inflammatory, anti-oxidant and anti-ulcer activities of aqueous lyophilizate of Markhamia lutea (Bignoniaceae).

OBJECTIVES: This work was carried out with a view to determining the antioxidant, anti-inflammatory and anti-ulcer properties of the aqueous lyophilized extract of Markhamia lutea. METHODS: In vitro proteinases inhibition, albumin denaturation, hemolysis of red blood cells by heat, inhibition of the proton pump H+/K+ATPase, FRAP (Ferric reducing antioxidant power) and DPPH (1,1-diphenyl-2-picrylhydrazyl) assays were performed. In vivo, cold water immersion-induced ulceration and methylene blue-induced ulceration was used to determine the anti-ulcer properties of the lyophilizate (100, 200 and 300 mg/kg). RESULTS: In vitro, the lyophilizate (400 µg/mL) significantly inhibited protein denaturation (66.65 %), hemolysis of red blood cells (56.54 %), proteinase activity (69.22 %); then the IC50 was 26.31 µg/mL on proton pump activity. It has also developed a strong ferric reducing antioxidant power (EC50=52.96 mmol FeSO4/g) as well as free radicals scavenging activity (EC50=22.38 µg/mL). In vivo, the aqueous lyophilizate (200 and 300 mg/kg) protected the gastric mucosa (70.68 and 79.00 % protection respectively) and reduced (p<0.05) acetylcholine, calcium and corticosterone concentrations. A decrease in malondialdehyde level, an increased glutathione level and an increased in catalase and SOD activities were recorded. In the methylene blue test, it significantly increased gastric fluid pH, while reducing gastric volume and improving hematological parameters in ulcer animals. In addition, the histological sections show that the aqueous lyophilizate of M. lutea protected the gastric mucosa from the deleterious effects of stress. CONCLUSIONS: The aqueous lyophilizate of M. lutea has anti-ulcer properties thanks to its anti-inflammatory, antioxidant and anti-secretory properties.

Anti-arthritic effect of Distemonanthus benthamianus extracts against rheumatoid arthritis in rats

Objective: To evaluate the anti-arthritic effect of aqueous and methanolic extracts of Distemonanthus benthamianus. Methods: Monoarthritis was induced by an injection of 0.3 mL zymosan A (0.9% NaCl, v/v) in the right posterior knee joints of rats. Then, joint diameter and pain threshold were determined. Polyarthritis was induced by an intracaudal injection of complete Freund’s adjuvant and rats were treated from day 14 post 1st complete Freund’s adjuvant injection until 28 day. The clinical, hematological, biochemical and oxidative stress parameters were evaluated. In addition, histological analysis of the knee joint was perfomed in both tests. Results: The aqueous and methanolic extracts of Distemonanthus benthamianus at a dose of 500 mg/kg ameliorated zymosan A-induced monoarthritis, as evidenced by reduced joint diameter, increased pain threshold, as well as improved joint architecture. In addition, both extracts of Distemonanthus benthamianus markedly increased body weight and pain threshold, while reducing paw edema in polyarthritic rats. They also led to a marked decrease in platelets and white blood cells (P<0.05), as well as a significant increase in red blood cells, hemoglobin and hematocrit (P<0.05). The aqueous and methanolic extracts of Distemonanthus benthamianus significantly reduced alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase activities, while increasing serum protein levels (P<0.05) with no significant variation in creatinine level. Moreover, both extracts increased catalase and glutathione activities (P<0.05), and inhibited malondialdehyde and nitric oxide production (P<0.01 and P<0.001) in the liver and kidneys. Histological analysis of the joints showed that both extracts triggered tissue reparation. Conclusions: Distemonanthus benthamianus could be used as a potential candidate in the treatment of rheumatoid arthritis.

In Vitro Antioxidant, Anti-inflammatory, and In Vivo Anticolitis Effects of Combretin A and Combretin B on Dextran Sodium Sulfate-Induced Ulcerative Colitis in Mice.

Combretum fragrans (Combretaceae) is a Cameroonian medicinal plant containing various secondary metabolites and traditionally used for the treatment of several pathologies. Two cycloartane-type triterpenes, Combretin A and Combretin B, were isolated from this plant. This study was aimed at evaluating the anti-inflammatory, antioxidant, and anticolitis effects of these compounds. In vitro anti-inflammatory properties were evaluated by inhibition of cyclooxygenase, 5-lipoxygenase, and denaturation of the protein; antioxidant properties were assessed by using 1,1-diphenyl-2-picrylhydrazyl (DPPH), (2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)) ABTS•+, capacity tests ferric reducing antioxidant (FRAP), and trapping nitric oxide. For in vivo analysis, we used the model of ulcerative colitis induced by Dextran Sulfate Sodium (DSS). Studies of the anti-inflammatory activity showed that Combretin A and Combretin B had maximal inhibitory activity on cyclooxygenase (71.92% and 89.59%), 5-lipoxygenase (76.68% and 91.21%), and protein denaturation (63.93% and 87.78%). Antioxidant activity on DPPH, ABTS•+, ferric reducing antioxidant capacity (FRAP), and nitric oxide scavenging showed that Combretin A and Combretin B showed good antioxidant activities. These compounds significantly reduced the signs of DSS-induced colitis in the treated animals by preventing the weight loss of the animals, by significantly reducing the disease activity index, improving the condition of the stool, preventing the reduction of the length of the colon, and preventing the degradation of the colon. This study revealed that Combretin A and Combretin B have anti-inflammatory, antioxidant, and curative properties against colitis experimentally induced by DSS in rats.

In vitro anti-inflammatory, anti-oxidant and in vivo anti-arthritic properties of stem bark extracts from Nauclea pobeguinii (Rubiaceae) in rats

Objective: To explore the immunomodulatory, anti-inflammatory, anti-oxidant and anti-arthritic activity of aqueous and methanolic extracts of Nauclea pobeguinii stem bark.Methods: For in vitro assays, the production of reactive oxygen species (chemiluminescence technique), the proliferation of T cells (liquid scintillation counter method), as well as the inhibition of cyclooxygenase, lipoxygenase, protein denaturation, and free radicals [DPPH, ABTS and nitric oxide (NO) inhibition methods] were evaluated. For in vivo assays, a polyarthritis model was induced by complete Freund's adjuvant in rats. The aqueous and methanolic extracts of Nauclea pobeguinii stem bark were administered orally at 150 and 300 mg/kg. After 28 days of treatment, the total blood was taken to quantify the hematological parameters and the serum was used to evaluate the biochemical parameters (alanine aminotransferase, aspartate transaminase, phenylalnine ammonialyase, and proteins) and oxidative stress parameters (malondialdehyde, catalase, superoxide dismutase, glutathione and NO), and then the knee joint was removed for histological analysis. Results: The extracts of Nauclea pobeguinii significantly reduced the production of intra- and extracellular reactive oxygen species and decreased T cell proliferation. They had an inhibitory effect on cyclooxygenase, lipoxygenase, and protein denaturation, and both extracts had antioxidant capacity on DPPH, ABTS and NO. Both extracts alleviated joint inflammation and pain sensitivity after complete Freund's adjuvant injection, reduced alanine aminotransferase, aspartate transaminase, alkaline phosphatase, NO and malondialdehyde levels, increased protein concentration, superoxide dismutase, catalase and glutathione activity, and restored the cytoarchitecture of the joint after complete Freund's adjuvant injection. Conclusions: The aqueous and methanolic extracts of Nauclea pobeguinii have immunomodulatory, anti-inflammatory, anti-oxidant and anti-arthritic properties.

Curative effects of Distemonanthus benthamianus Baillon. Trunk-bark extracts on enteropathogenic Escherichia coli 31-induced diarrhea in rats.

Background Distemonanthus benthamianus is used in the Western part of Cameroon to treat diarrheal episodes and infections. This study assessed its trunk-bark extracts activity against enteropathogenic Escherichia coli 31 (EPEC 31)-induced diarrhea in rats. Methods Aqueous and methanolic extracts were analyzed through high-performance liquid chromatography (HPLC). In vitro minimum inhibitory and bactericidal concentrations (MICs/MBCs) were evaluated on Enterococcus faecalis (ATCC 10,541), E. coli (ATCC 6539), Klebsiella pneumoniae (ATCC 13,883), Salmonella typhi (ATCC 6539) strains and on Proteus mirabilis, Pseudomonas aeruginosa (PA 01) and Shigella flexneri isolates using the microdilution method. Diarrhea was induced by inoculating rats with EPEC 31 (1.5 × 108 CFU/mL; p.o). Serum transaminases level assay and enzyme-linked immunosorbent assay (ELISA) for cytokines determination were performed. Hematoxylin-eosin (H-E) staining was used for intestinal tissue analysis. Results HPLC fingerprints of extracts showed presence of gallic acid and other unidentified compounds. The lowest MIC of 256 µg/mL was obtained with methanolic extract. At 100 mg/kg, both extracts significantly (p<0.001) inhibited diarrhea, with the methanolic extract being the most active. In addition, the methanolic extract significantly (p<0.001) increased the relative mass of the liver compared to negative control (Tween-DMSO 8%). The aqueous extract (100 mg/kg) significantly (p<0.01) increased alanine aminotransferase (ALT) serum concentration; while the methanolic extract (100 mg/kg) exhibited similar effect over aspartate aminotransferase (AST). At 50 and 100 mg/kg, the methanolic extract significantly (p<0.05 and p<0.01) decreased the Interleukin-1ß (IL-1ß) serum level, compared to negative control (Tween-DMSO 8%). Serum level of tumor necrosis factor alpha (TNF-α) significantly (p<0.001) decreased with 100 mg/kg of aqueous extract and all doses of methanolic extract. Inhibition of inflammatory cells tissue infiltration and epithelial regeneration was highly noticed in the ileum and colon of extracts-treated rats than in ciprofloxacin-treated animals. Conclusion These findings suggest that D. benthamianus trunk-bark extracts displayed therapeutic effects against infectious diarrhea in rats.

Analgesic, anti-inflammatory and anti-arthritic properties of aqueous and methanolic stem bark extracts from Nauclea pobeguinii (Rubiacee) in rats.

Background Nauclea pobeguinii is a plant species found in the centre region of Cameroon. The stem bark of this plant is traditionally used to ease pain and cure inflammation. Method This study was undertaken to evaluate the effects of doses 150 and 300 mg/kg of the aqueous and methanolic stem bark extracts from Nauclea pobeguinii on acute pain, acute and chronic inflammation induced by formalin and arthritis induced by zymosan A in rats. Oxidative stress parameters such as catalase, malondialdehyde and nitric oxide were measured in rats subjected to chronic inflammation. The standard used was diclofenac at 5 mg/kg. Results Aqueous extract as well as methanolic extract of Nauclea pobeguinii led to a significant reduction in the second phase of formalin induced pain with 54.22 and 48.02% of inhibition percentage, respectively. The formalin-induced inflammatory oedema was reduced by both extracts, and this effect remains significant until the tenth day of treatment. Equally, extracts significantly increased the catalase activity and inhibited the production of malondialdehyde (MDA) in serum, brain and spinal cord and NO reduction only in serum. Both extracts significantly reduced the articular oedema induced by zymosan A for 6 h and for 5 days. Furthermore, the histological study of the articulations shows a non-altered synovial membrane and a small cartilage in all treated animals versus negative control group. Conclusions From these results, it can be concluded that pain, inflammation and arthritic healing activities of both stem bark extracts were expressed in rats and could conciliate the use of this vegetable by traditional African healers.

NO-cGMP-K channel-dependent anti-nociceptive activities of methanol stem bark extract of Piptadeniastrum africanum (Mimosaceae) on rats

Objective:To explore anti-hyperalgesic properties of methanol extract of Piptadeniastrum africanum stem bark (PAME) and it possible action mechanism.Methods:PAME was tested on carrageenan induced hyperalgesia using plantar test (thermal) and analgesymeter (mechanical) in rats,on prostaglandin E2 (PGE2) induced mechanical hyperalgesia and vincristine induced neuropathic pain in rat,both with analgesymeter.Modulators of NO/cGMP/K+ channel pathway and endogenous opioids receptor antagonists and/or agonists were used to determine the possible action mechanism of PAME.Results:PAME significantly decreased carrageenan induced thermal and mechanical hyperalgesia,as well as PGE2 induced mechanical hyperalgesia.PAME significantly protected the animals against the installation of neuropathic pain.Anti-nociception activity produced by PAME was significantly blocked in animals pre treated with all the antagonists (naloxone,NW-nitro-L-arginine methyl ester (L-NAME),methylene blue and glibenclamide).Conclusions:Results of this study reveal that,PAME administrate orally,can induce anti-hyperalgesic action against installation of inflammatory pain as well as neuropathic pain.The mechanism underlying PAME antihyperalgesic effect could probably be associated with an activation of opioid receptors and NO/cGMP/K+ channel pathway.