In Vitro and In Vivo Anti-Inflammatory Properties of the Hydroethanolic Extract of the Roots of Vernonia guineensis (Asteraceae).

In traditional Cameroonian medicine, to relieve many inflammations, parts of Vernonia guineensis, are very widely used. This study considered the evaluation of acute toxicity and anti-inflammatory properties of the hydroethanolic extract of the roots of Vernonia guineensis. In an acute toxicity study, 250, 2500, and 5000 mg/kg were administered orally to mice in a single dose, and general behavior, adverse effects, and mortality were monitored. In vitro and in vivo anti-inflammatory tests were performed, and then histological, serum, hematological, and oxidative stress parameters have been evaluated. In an acute toxicity, all groups revealed neither mortality nor any significant alteration in behavior; only drowsiness, sedation, and lethargy were observed at 5000 mg/kg. For in vitro tests, the extract inhibited anti-inflammatory activity. In the formalin test, at 250 mg/kg, the extract inhibited edema with a percentage of 56.41% (4th hour) in an acute treatment and 74.44% (10th day). Joint edema was reduced by 67.24% (24th hour) in a single treatment and by 74.25% (7th day) in repeated treatment. The extract caused an increase in red blood cell, hemoglobin, and serum protein levels and reduced the white blood cells as well as the activities of alkaline phosphatase and alanine aminotransferase. The extract modulated oxidative stress parameters in the brain, spinal cord, liver, and kidneys. The extract protected the joint by reducing the bone and cartilage erosion. The present work highlights the anti-inflammatory, antioxidant, and antianemic properties of the hydroethanolic extract of the roots of Vernonia guineensis, which supports its empirical use in traditional medicine for the treatment of inflammatory pathologies.

Aqueous Extract from Cinnamomum zeylanicum (Lauraceae) Stem Bark Ameliorates Gentamicin-Induced Nephrotoxicity in Rats by Modulating Oxidative Stress and Inflammatory Markers.

Nephropathies and especially nephrotoxicity have become one of the serious causes of life-threatening conditions because of intensive exposure to xenobiotic whether by environmental pollution or by drug abuse. The present study was undertaken to assess the protective effects of Cinnamomum zeylanicum stem bark aqueous extract (AECZ) on gentamicin-induced nephrotoxicity. AECZ was prepared by maceration in water and tested orally at the doses of 200 and 400 mg/kg/day to prevent gentamicin-induced nephropathies in male Wistar rats. Gentamicin (100 mg/kg/day) was administered for 14 consecutive days by intraperitoneal route, concomitantly with AECZ or silymarin (50 mg/kg/day) used as reference drug. Animal body weight was monitored during the treatment. After the last treatment on the 14th day, animals were sacrificed. Blood was collected for the evaluation of hematological and renal function biomarkers. The homogenate of one kidney was used to assess oxidative stress markers and proinflammatory cytokines, while the other one was fixed in formaldehyde for histopathological studies. Gentamicin decreased body weight, serum total proteins, and calcium level but increased kidneys' relative weight, serum creatinine, urea, and uric acid. Moreover, the levels of reduced glutathione, catalase, and superoxide dismutase activities were decreased, while an increase in malondialdehyde, proinflammatory cytokines (TNF-α, IL-1ß, and IL-6), and nitrites was observed in the negative control group as compared to normal control. Histological analysis of the kidney revealed the presence of tubular necrosis, glomerular degeneration, and macrophage infiltration in the gentamicin-treated group. All these impairment parameters were prevented by AECZ and silymarin treatments. AECZ has a protective effect against gentamicin-induced nephrotoxicity. The antioxidant and anti-inflammatory potentials of this extract may highly contribute to its nephroprotective activity.

Antihypertensive Effects of the Methanol Extract and the Ethyl Acetate Fraction from Crinum zeylanicum (Amaryllidaceae) Leaves in L-NAME-Treated Rat.

Arterial hypertension (AHT) is a leading cardiovascular disease, with a high negative impact on the quality of life. Crinum zeylanicum (C. zeylanicum) leaves extract is used in the West region of Cameroon to treat AHT and heart problems. This study aimed to investigate the antihypertensive effect of C. zeylanicum extract in N ω -nitro-L-arginine methyl ester- (L-NAME-) induced hypertensive rats. The aqueous extract of C. zeylanicum (LAE) was obtained by lyophilizing the juice of triturated fresh leaves. The methanol extract (LME) prepared by maceration of the dried leaves was further partitioned to chloroform (LCF), ethyl acetate (LEAF), and residual (LRF) fractions. The total polyphenol, flavonoid content, and antiradical potentials of these extracts were determined. The curative antihypertensive and renal function protective effects of LME and LEAF were evaluated in vivo on L-NAME-induced hypertensive rats. Hypertension was induced in rats by oral administration of L-NAME (30 mg/kg/day) for 3 consecutive weeks. Thereafter, plant extracts were administered orally at the doses of 30, 60, and 120 mg/kg/day, concomitantly with L-NAME for three other weeks. Body weight, heart rate, and arterial blood pressure were measured at the end of each week throughout the experimental period. At the end of the treatment, 24-hour urine and plasma were collected to assay nitric oxide (NO), creatinine, and protein. The results revealed that LEAF has the higher content of total polyphenol and flavonoid and exhibited the best antiradical potential. Moreover, treatment of hypertensive rats with LME and LEAF significantly (p < 0.001) reduced AHT and heart rate. LME and LEAF significantly increased rat's body mass, plasmatic NO, and urinary creatinine and reduced urine NO and protein contents as compared to the L-NAME group. LME and its LEAF possess potent antihypertensive effects and further protect the renal function in L-NAME-induced hypertensive rats, thus supporting the use of C. zeylanicum in the management of AHT.

Group B Streptococcus colonisation, prevalence, associated risk factors and antimicrobial susceptibility pattern among pregnant women attending antenatal care at Dschang District Hospital, West Region of Cameroon: A hospital-based cross-sectional study.

BACKGROUND: Group B Streptococcus (GBS), also known as Streptococcus agalactiae, is a Gram-positive bacterium known for its ability to colonise the vaginal and rectal areas of the mother and is a leading cause of neonatal mortality and morbidity. This study aimed at determining the prevalence, associated risk factors and antimicrobial susceptibility of GBS colonisation among pregnant women attending antenatal care (ANC) at Dschang District Hospital. METHODS: This hospital-based cross-sectional study used a multistage sampling method to recruit a total of 621 consented pregnant women who attended ANC in Dchang District Hospital. The 621 Participants at 23.5 ± 6.4 weeks gestation each completed a questionnaire and vaginal swabs were collected for GBS analysis. RESULTS: Among the 621 pregnant women that were included in this study, the colonisation rate of GBS was found to be 8.69%. Induced abortion (odds ratio [CI] = 3.09, 95% [1.56-6.21]), Spontaneous abortions (OR = 2.82, 95% CI 1.14-7.29), Stillbirth (OR [CI] = 7.75, 95% [2.61-21.71]), Fever (OR [CI] = 0.37, 95% [0.19-0.71]) and anaemia (OR [CI] = 0.22, 95% [0.12-0.43]) were found to be factors associated with GBS colonisation. CONCLUSION: Our findings suggest that we found that, induce abortion, spontaneous abortions and stillbirths were highly associated rates of GBS colonisation, while fever and anaemia were associated with lower rates of GBS colonisation. Further longitudinal research is needed to establish the causal relationship and its biological mechanisms.

Antihypertensive Effects of the Vitex cienkowskii (Verbenaceae) Stem-Bark Extract on L-NAME-Induced Hypertensive Rats.

Vitex cienkowskii stem-bark is used in Cameroonian traditional medicine to treat cardiovascular diseases including hypertension. In previous studies, the methanol/methylene chloride stem-bark extract of Vitex cienkowskii (MMVC) showed a preventive activity in L-NAME-induced hypertension and improved blood pressure of spontaneously hypertensive rats. The present study investigated the curative effects in L-NAME-induced hypertensive rats (LNHR). Hypertension was induced in rats by oral administration of L-NAME (40 mg/kg/day) for 28 days. The animals were divided into 2 groups: one group of 5 rats receiving distilled water (10 ml/kg) and another 20 rats receiving L-NAME. At the end of 4 weeks of administration of L-NAME, the animals were divided into 4 groups of 5 rats each: one group of hypertensive rats receiving distilled water, another one receiving captopril (25 mg/kg), and two groups of hypertensive rats receiving MMVC at doses of 200 and 400 mg/kg, respectively. Body weight, food, and water intake were measured weekly. At the end of the treatment, blood pressure and heart rate were recorded by invasive method. Whole heart, left ventricle, kidneys, and liver were weighed. The effects of plant extract on lipid profile and oxidative stress markers, as well as markers of hepatic and renal functions were assessed spectrophotometrically according to well described protocols. Results show that L-NAME significantly increases the mean arterial blood pressure (MABP), atherogenic index, lipid profile, and creatinine and transaminase activities of normotensive rats. MMVC significantly reduced the blood pressure in LNHR. Body weight, food and water intake, left ventricular hypertrophy, antioxidant level, renal and hepatic markers, and lipid profile were improved by the treatment with MMVC. The curative effect of MMVC on L-NAME-induced hypertension is probably related to its antihypertensive, hypolipidemic, and antioxidant properties. These results confirmed the use of Vitex cienkowskii for the treatment of hypertension in traditional medicine.

Antihypernociceptive and Neuroprotective Effects of the Aqueous and Methanol Stem-Bark Extracts of Nauclea pobeguinii (Rubiaceae) on STZ-Induced Diabetic Neuropathic Pain.

The greatest common and devastating complication of diabetes is painful neuropathy that can cause hyperalgesia and allodynia. It can disturb psychosocial functioning by increasing levels of anxiety and depression. This work was designed to evaluate the antihyperalgesic, antidepressant, and anxiolytic-like effects of the aqueous and methanol extracts of Nauclea pobeguinii stem-bark in diabetic neuropathy induced by streptozotocin in mice. Diabetic neuropathy was induced in mice by the intraperitoneal administration of 200 mg/kg streptozotocin (STZ) to provoke hyperglycemia. Nauclea pobeguinii aqueous and methanol extracts at the doses of 150 and 300 mg/kg were administered by oral route, and their effects were evaluated on antihyperalgesic activity (Von Frey filaments, hot plate, acetone, and formalin tests), blood glucose levels, body weight, serum, sciatic nerve proinflammatory cytokines (TNF-α, IL-1ß, and IL-6) and sciatic nerve growth factor (IGF and NGF) rates, depression (open field test, forced swimming test, tail suspension test), and anxiety (elevated plus maze, light-dark box test, social interaction). Oral administration of Nauclea pobeguinii stem-bark aqueous and methanol extracts (150 and 300 mg/kg) produced antihyperalgesic, antidepressant, and anxiolytic-like effects in STZ-induced diabetic neuropathic mice. Extracts also triggered a decrease in glycaemia and increased body weight in treated animals. They also significantly (p <0.001) reduced tumour necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1ß), and IL-6 and significantly (p <0.001) increased nerve growth factor (NGF) and insulin-like growth factor (IGF) in sciatic nerves. The results of this study confirmed that Nauclea pobeguinii aqueous and methanol extracts possess antihyperalgesic, antidepressant, and anxiolytic activities and could be beneficial therapeutic agents.

Methanolic Extract of Distemonanthus benthamianus (Caesalpiniaceae) Stem Bark Suppresses Ethanol/Indomethacin-Induced Chronic Gastric Injury in Rats.

Distemonanthus benthamianus (Caesalpiniaceae) is a plant from the Cameroon pharmacopoeia very widely used in the treatment of many pathologies among which are gastrointestinal disorders. The main purpose of this study was to assess the healing properties of gastric ulcer from the methanolic extract of Distemonanthus benthamianus and its mechanisms of action. The healing properties of gastric ulcers (chronic ulcer model induced by ethanol and indomethacin) were evaluated in vivo in adult male rats, while the mechanisms of action were evaluated in vitro by anti-inflammatory assay (protein denaturation, cyclooxygenase, and lipoxygenase assays) and immunomodulatory assay (ROS production (using technical chemiluminescence), cytokine (TNF-α, IL-1ß, IL-6) production (using ELISA), proliferation of T cells (using liquid scintillation counter), and cytotoxicity (using MTT assay)). The methanolic extract of Distemonanthus benthamianus inhibited protein denaturation (75.63%) and the activities of cyclooxygenase (78.92%) and 5-lipoxygenase (81.54%). The extract also significantly (p < 0.001) inhibited intracellular and extracellular ROS production and T cell proliferation and reduced significantly (p < 0.01, p < 0.001) TNF-α, IL-1ß, IL-6, and PGE2 production. At all doses (125, 250, and 500 mg/kg), the extract significantly reduces the ulceration index and the area of ulceration and significantly increases the mass of gastric mucus. In addition, the extract significantly decreases the level of MDA, significantly increases the activities of catalase and glutathione, and then improves the hematological parameters in sick animals. Histological micrographs show that in the presence of the extract, there is advanced reepithelialization with recovery of the ulcerated epithelium. Thus, the extract of Distemonanthus benthamianus has healing properties against gastric ulcers which are associated with its anti-inflammatory, immunomodulatory, and antioxidant effects.

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.

Effect of Aqueous Extract of Adansonia digitata Stem Bark on the Development of Hypertension in L-NAME-Induced Hypertensive Rat Model.

BACKGROUND: Adansonia digitata is a plant used against cardiovascular disorders in African folk medicine. We assessed the effects of the aqueous extract of its stem bark on the development of hypertension in L-NAME-induced hypertensive rats. METHODS: The animals were administered L-NAME once daily for 3 weeks (25 mg/kg, i.p.), concomitantly with aqueous extract of A. digitata stem bark (100 and 200 mg/kg, p.o.) or captopril (20 mg/kg, p.o.). Then, hemodynamic and electrocardiographic parameters, oxidative stress markers, and the lipid profile were assessed in the blood and heart, aorta, and kidney homogenates, and histopathological analyses were performed. RESULTS: L-NAME-induced hypertensive control animals, but not the animals concomitantly treated with A. digitata extract, displayed increases in the mean arterial blood pressure (21.64% difference, p < 0.001, vs. dose 200 mg/kg), systolic arterial blood pressure (21.33%, p < 0.001), and the diastolic arterial blood pressure (21.84%, p < 0.001). In addition, hypertensive control animals displayed (i) increases in serum triglycerides, total cholesterol, LDL, and creatinine levels, malondialdehyde and transaminase activities, and atherogenic index; (ii) decreases in serum HDL, catalase, reduced glutathione, and nitric oxide; and (iii) aorta wall thickening, inflammatory cell infiltration, and cell loss in the cardiac muscle and renal tissues. As captopril, the extract prevented hypertension-like changes in lipid profile, cardiac, hepatic, and renal affection indicators, and oxidative stress markers. CONCLUSION: Our findings suggest that the extract of A. digitata has antihypertensive and antioxidant effects in L-NAME-induced hypertension rat models. These effects partly justify the traditional medicine use against cardiovascular disorders.

Antihypernociceptive, Anxiolytic, and Antidepressant Properties of Aqueous and Ethanol Extracts of Dissotis thollonii Cogn. (Melastomataceae) in Mice.

Diabetic neuropathy, which affects 7 to 9% of the world's population and that is usually accompanied by anxiety and depression, is chronic pain that results from impaired function of the central or peripheral nervous system. This study aimed at evaluating the antihypernociceptive, antiallodynic, anxiolytic, and antidepressant effects of Dissotis thollonii extracts. Diabetic neuropathy was induced by intraperitoneal injection of streptozotocin (200 mg/kg) in mice. The aqueous and ethanol extracts (250 and 500 mg/kg) were administered orally. Hyperalgesia (thermal and chemical), allodynia (mechanical and thermal), anxiety (high plus labyrinth, light-dark box, and social interaction), and depression (open field test, suspension test tail, and forced swimming test) were evaluated, and then the levels of some cytokines and growth factors were determined. The aqueous and ethanol extracts of Dissotis thollonii demonstrated significant antihypernociceptive (inhibition of hyperalgesia and allodynia), anxiolytic, and antidepressant activities in mice made diabetic by STZ. The extracts also significantly inhibited (p < 0.001) the levels of TNF-α, IL-1ß, and IL-6 in the blood as well as the levels of TNF-α, IL-1ß, IL-6, IGF, and NGF in the sciatic nerve. This study shows that the extracts of Dissotis thollonii have antihypernociceptive and neuroprotective effects which could be linked to the inhibition of proinflammatory cytokines and growth factors in the blood and the sciatic nerve.

Cytoprotective and antisecretory properties of methanolic extract of Distemonanthus benthamianus (Caesalpiniaceae) stem bark on acute gastric ulcer in rats.

OBJECTIVES: In African traditional medicine, Distemonanthus benthamianus (Caesalpiniaceae) is used to treat many diseases including gastric ulcers. We evaluated in this study, the cytoprotective and antisecretory properties of the methanolic extract of the stem bark of this plant using different technics of gastric lesion induction. METHODS: Cytoprotective and antisecretory activity of the methanolic extract of D. benthamianus stem bark was evolved through six methods of gastric lesion induction in experimental Wistar male rats (150-200 g): (1) gastric lesions induced by HCl/ethanol, (2) gastric lesions induced by Indomethacin- HCl/ethanol, (3) gastric lesion induced by Indomethacin, (4) gastric lesions induced by Pylorus ligation, (5) gastric lesions induced by histamine-Pylorus ligation, (6) gastric lesions induced by carbachol-Pylorus ligation. Mucus and gastric mucosal ulceration were evaluated. pH, gastric volume, and acidity were quantified in all pylorus ligation induction technics. Nitric oxide (NO) level was determined in indomethacin induced gastric ulcers. RESULTS: At different doses (125, 250 and 500 mg/kg), extract reduced significantly the ulcer index. In all models used, that is 100.00% with HCl/ethanol; 100.00% with HCl/ethanol/indomethacin; 95.70% with Indomethacin; 74.79% with pylorus ligation, 95.94% histamine-Pylorus ligation, 99.54% carbachol-Pylorus ligation at the highest dose of 500 mg/kg. The lesion formation reduces in all the methods used followed by a significant increase of mucus production. The pylorus ligation technic revealed that the extract has an antisecretory activity. CONCLUSIONS: The methanolic extract of D. benthamianus stem bark has both cytoprotective and antisecretory effects. This extract exerts its antisecretory effect trough cholinergic and histaminergic pathways.

Effects of Aqueous and Methanolic Extracts of Stem Bark of Alstonia boonei De Wild. (Apocynaceae) on Dextran Sodium Sulfate-Induced Ulcerative Colitis in Wistar Rats.

Among the most exploited species in Cameroon, Alstonia boonei is widely used in African medicine for the relief of several pathologies including gastrointestinal disorders. This study was conducted in order to assess the effects of aqueous and methanol stem-bark extracts of Alstonia boonei on DSS- (dextran sodium sulfate-) induced intestinal colitis and to determine its antioxidant potential. The classes of secondary metabolites present in these extracts were determined by chemical screening. The production of TNF-α, IL-6, IL-1ß, and PGE2 was performed by in vitro ELISA analysis. Anticolitis effects were determined using an in vivo model of ulcerative colitis induced by DSS. The colitis was induced with a double dose of DSS (3% and 1%), and the aqueous and methanol extracts were administered orally from the 6th day after commencement of induction. The phytochemical screening revealed the presence of six classes of secondary metabolites in these crude extracts: tannins, saponins, alkaloids, steroids, flavonoids, and phenols. Methanol and aqueous extracts of Alstonia boonei significantly (P < 0.001) inhibited TNF-α, IL-6, IL-1ß, and PGE2 production stimulated by LPS. Both extracts at all doses significantly reduced (P < 0.01, P < 0.001) the signs of DSS-induced colitis in the Wistar rats by decreasing inflammation and chronic colon damage. In addition, the extracts significantly (P < 0.001) reduced malondialdehyde and nitric oxide levels in the colon and significantly (P < 0.01) increased superoxide dismutase and catalase and reduced glutathione (P < 0.05). Both extracts showed greater activity than the reference substance (prednisolone 4 mg/kg) used in this study. This study has demonstrated that aqueous and methanol extracts of Alstonia boonei stem bark have healing properties against colitis experimentally induced by DSS in rats.

Effects of stem bark aqueous extract of Fagara tessmannii Engl (Rutaceae) on cardiovascular risks related to monosodium glutamate-induced obesity in rat: In vivo and in vitro assessments.

ETHNOPHARMACOLOGICAL RELEVANCE: Fagara tessmannii is a shrub of the African rainforests in South-West, Centre, South and East provinces in Cameroon. It is used in traditional medicine for the treatment of tumors, swellings, inflammation, gonorrhoea, schistosomiasis, antifungal, heart diseases and as anti-hypertensive. AIM OF THE STUDY: We investigated the potential effects of F. tessmannii on cardiovascular risk related to monosodium glutamate-induced obesity. MATERIALS AND METHODS: Monosodium glutamate (MSG, 4 mg/g/day) was injected subcutaneously to newborn Wistar rats for the four consecutive first days of their life and on the 6th, 8th and 10th day after birth. After 21 weeks, obese rats were treated orally with F. tessmannii (100 or 200 mg/kg/day), orlistat (10 mg/kg/day) or telmisartan (10 mg/kg/day) for 6 weeks. Body weight, obesity, body mass index (BMI), Lee index, insulin sensitivity and glucose tolerance, blood pressure, lipid profile as a Coronary Risk Index (CRI), and reactivity of isolated thoracic aorta were evaluated. RESULTS: In addition to significantly decrease body weight (17.60% and 20.34%), BMI, Lee's index, retroperitoneal fat, total adiposity, and coronary risk indicators, F. tessmannii has significantly decreased insulin resistance and hyperglycemia and high blood pressure observed in MSG-obese rats. The high contractility to phenylephrine as well as the hypersensitivity to sodium nitroprusside (a nitric oxide-donor), observed in MSG aortic rings were significantly reduced by the F. tessmannii extract. Enhanced serum Na+ and Cl- levels and decreased K+ observed in obese rats were also significantly reversed after F. tessmannii treatment. CONCLUSIONS: F. tessmannii fights against obesity and associated cardiovascular risks by modulating production and vascular responsiveness to vasoactive factors, monitoring premature aging. F. tessmannii promotes the loss of ectopic fat and other fatty tissues, the sensitivity of the peripherical tissues to insulin, the energy expenditure and the renovascular decompression and regulates ions movement which prevents hypertension.

In Vitro Anti-Inflammatory and In Vivo Antiarthritic Activities of Aqueous and Ethanolic Extracts of Dissotis thollonii Cogn. (Melastomataceae) in Rats.

Dissotis thollonii Cogn. (Melastomataceae) is a tropical plant widely used in traditional Cameroonian medicine to relieve and treat many pathologies. It is widespread in the western region where it is used to treat typhoid fever, gastrointestinal disorders, and inflammatory diseases. The purpose of this study is to scientifically demonstrate the anti-inflammatory and antiarthritic properties of the aqueous and ethanolic extracts of the leaves of Dissotis thollonii. The anti-inflammatory properties were evaluated in vitro by inhibition tests for cyclooxygenase, 5-lipoxygenase, protein denaturation, extracellular ROS production, and cell proliferation; while antiarthritic properties were evaluated in vivo in rats using the zymosan A-induced monoarthritis test and the CFA-induced polyarthritis model. This study shows that aqueous and ethanolic extracts at a concentration of 1000 µg/ml inhibit the activity of cyclooxygenase (47.07% and 63.36%) and 5-lipoxygenase (66.79% and 77.7%) and protein denaturation (42.51% and 44.44%). Similarly, both extracts inhibited extracellular ROS production (IC50 = 5.74 µg/ml and 2.96 µg/ml for polymorphonuclear leukocytes, 7.47 µg/ml and 3.28 µg ml for peritoneal macrophages of mouse) and cell proliferation (IC50 = 16.89 µg/ml and 3.29 µg/ml). At a dose of 500 mg/kg, aqueous and ethanolic extracts significantly reduce edema induced by zymosan A (69.30% and 81.80%) and CFA (71.85% and 79.03%). At the same dose, both extracts decreased sensitivity to mechanical hyperalgesia with 69.00% and 70.35% inhibition, respectively. Systemic and histological analyzes show that both extracts maintain the studied parameters very close to normal and greatly restored the normal architecture of the joint in animals. Dissotis thollonii would therefore be a very promising source for the treatment of inflammatory diseases.

Antidiarrheal potential of Distemonanthus benthamianus Baillon. extracts via inhibiting voltage-dependent calcium channels and cholinergic receptors

Objective: To evaluate spasmolytic mechanisms of aqueous and methanolic extracts from Distemonanthus benthamianus trunk-bark. Methods: Spasmolytic activities of extracts were evaluated in vitro on spontaneous and potassium chloride-induced jejunum contractions, or against cholinergic [acetylcholine (0.3μmol/L)] stimulations. High performance liquid chromatography analysis of both extracts was performed in reference to standard compounds. Results: Extracts developed concentration-dependent inhibitory activities. The methanolic extract, which revealed better activity, produced spasmolytic and myorelaxant effects at concentrations of 0.01-0.30 mg/mL with EC50 of 0.06 and 0.09 mg/mL (95％ CI: 0.03-0.3 mg/mL), respectively. Its anticholinergic effect was obtained at the same concentrations with EC50 of 0.11 mg/mL (95％ CI:0.03-0.3 mg/mL). Chromatograms showed the presence of gallic acid in both extracts, rutin being only detected in the aqueous extract. Conclusions: Distemonanthus benthamianus extracts exhibit verapamil and atropine-like activities, thus highlighting calcium channels and muscarinic receptors blocking potentials, which may be conveyed by some phenolic compounds. These results confirm the antidiarrheal activity of Distemonanthus benthamianus extracts.

Anti-inflammatory and anti-arthritic effects of methanol extract of the stem bark of Boswellia dalzielii Hutch (Burseraceae) in rats.

Boswellia dalzielii is a tall tree (more than 13 m high) that produces aromatic white flowers. This plant is commonly used in indigenous medicine across Africa against diarrhea, malaria, vomiting, inflammation and arthritis. The present study focuses on the anti-inflammatory and anti-arthritis potential of methanol extract of Boswellia dalzielii (BDME). Anti-inflammatory activity was evaluated in inflammatory models induced by carrageenan, arachidonic acid, histamine, serotonin, prostaglandin and bradykinin. Anti-arthritis activity was measured using complete Freund's adjuvant model. Intracellular and extracellular ROS production and proliferation of T-cells were evaluated using chemiluminescence and liquid scintillation counter techniques, respectively. TNF-α and IL-1ß production were assessed using ELISA and MTT assay performed for cytotoxicity. BDME revealed a significant anti-inflammatory effect by preventing the development of edema caused by carrageenan, arachidonic acid, histamine, serotonin, prostaglandin and bradykinin. For anti-arthritic properties of BDME, the results showed a significant reduction of the joint diameter and a decrease in pain in the treated animals. The extract also showed a noticeable systemic effect, maintaining the values of the evaluated parameters close to normal in treated rats with an inhibition of joint destruction as shown in histopathological analysis. Furthermore, BDME exhibited significant inhibition of extracellular and intracellular ROS production. Still, the extract displayed significant inhibitory activity on T-cell proliferation as well as a reduced production of TNF-α and IL-1ß. Boswellia dalzielii could be considered as a promising tract in the prevention and/or management of inflammatory diseases.

In vitro chronotropic effects of Erythrina senegalensis DC (Fabaceae) aqueous extract on mouse heart slice and pluripotent stem cell-derived cardiomyocytes.

ETHNOPHARMACOLOGICAL RELEVANCE: Erythrina senegalensis DC (Fabaceae) bark is commonly used in sub-Saharan traditional medicine for the treatment of many diseases including gastrointestinal disorders and cardiovascular diseases. In this study, we investigated the effect of the aqueous extract of the stem bark of Erythrina senegalensis on the contractile properties of mouse ventricular slices and human induced pluripotent stem (hiPS) cell-derived cardiomyocytes. We also investigated the cytotoxic effect of the extract on mouse embryonic stem (ES) cells differentiating into cardiomyocytes (CMs). MATERIALS AND METHODS: We used well-established electrophysiological technologies to assess the effect of Erythrina senegalensis aqueous extract (ESAE) on the beating activity of mouse ventricular slices, mouse ES and hiPS cell-derived CMs. To study the cytotoxic effect of our extract, differentiating mouse ES cells were exposed to different concentrations of ESAE. EB morphology was assessed by microscopy at different stages of differentiation whereas cell viability was measured by flow cytometry, fluorometry and immunocytochemistry. The electrical activity of CMs and heart slices were respectively captured by the patch clamp technique and microelectrode array (MEA) method following ESAE acute exposure. RESULTS: Our findings revealed that ESAE exhibits a biphasic chronotropic activity on mouse ventricular slices with an initial low dose (0.001 and 0.01 µg/mL) decrease in beating activity followed by a corresponding significant increase in chronotropic activity at higher doses above 10 µg/mL. The muscarinic receptor blocker, atropine abolished the negative chronotropic activity of ESAE, while propranolol successfully blocked its positive chronotropic activity. ESAE showed a significant dose-dependent positive chronotropic activity on hiPS cell-derived CMs. Also, though not significantly, ESAE decreased cell viability and increased total caspase-3/7 activity of mouse ES cells in a concentration-dependent manner. CONCLUSION: Erythrina senegalensis aqueous extract exhibits a biphasic chronotropic effect on mouse heart and a positive chronotropic activity on hiPS cell-derived CMs, suggesting a possible mechanism through muscarinic and ß-adrenergic receptor pathways. Also, ESAE is not cytotoxic on mouse ES cells at concentrations up to 100 µg/mL.

In vitro anti-hyperglycemic and antioxidant properties of extracts from the stem bark of Ceiba pentandra.

BACKGROUND: The goal of the study was to determine the antidiabetic mechanisms and the antioxidant effects of aqueous (decoction and maceration) and methanol extracts from the stem bark of Ceiba pentandra. METHODS: These extracts were tested in vitro on glucose uptake by skeletal muscles and liver slices and on glucose release by liver slices. The antioxidant activities of C. pentandra extracts were investigated at concentrations ranging from 1 to 300 µg/mL on 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydrogen peroxide (H2O2)-induced hemolysis, H2O2-induced brain lipid peroxidation, hydroxyl (˙OH) radical as well as their reducing power. RESULTS: The decoction similarly to insulin exhibited a significant glucose lowering activity. In a hyperglycemic milieu, it significantly increased glucose uptake by the liver by 56.57% and in the skeletal muscle by 94.19%. In a hypoglycemic milieu, it significantly reduced glucose release by the liver by 33.94%. The decoction, maceration and methanol extracts exhibited a significant radical scavenging activity on DPPH with respective EC50 of 87.84, 54.77 and 6.15 µg/mL versus 2.24 µg/mL observed with ascorbic acid. All the extracts showed a significant antioxidant effect on hydroxyl radical, against lipid peroxidation and H2O2-induced hemolysis. The decoction showed the greatest antihemolytic effect with a maximum inhibition of 77.57% at the concentration of 100 µg/mL. C. pentandra extracts also showed a concentration-dependent reducing power. CONCLUSIONS: These results suggest that the antidiabetic effect of C. pentandra is due to its ability to increase glucose uptake and to reduce glucose release by target organs. The antioxidant properties of C. pentandra extracts are additional benefit for their antidiabetic effects.

Acute and chronic antihypertensive effects of Cinnamomum zeylanicum stem bark methanol extract in L-NAME-induced hypertensive rats.

BACKGROUND: Previous study showed that the aqueous extract of the stem bark of Cinnamomum zeylanicum possesses antihypertensive and vasodilatory properties. The present work investigates the acute and chronic antihypertensive effects of the methanol extract of Cinnamomum zeylanicum stem bark (MECZ) in L-NAME-induced hypertensive rats. METHODS: The acute antihypertensive effects of MECZ (5, 10 and 20 mg/kg) administered intravenously were evaluated in rats in which acute arterial hypertension has been induced by intravenous administration of L-NAME (20 mg/kg). For chronic antihypertensive effects, animals were treated with L-NAME (40 mg/kg/day) plus the vehicle or L-NAME (40 mg/kg/day) in combination with captopril (20 mg/kg/day) or MECZ (300 mg/kg/day) and compared with control group receiving only distilled water. All drugs were administered per os and at the end of the experiment that lasted for four consecutive weeks, blood pressure was measured by invasive method and blood samples were collected for the determination of the lipid profile. The heart and aorta were collected, weighed and used for both histological analysis and determination of NO tissue content. RESULTS: Acute intravenous administration of C. zeylanicum extract (5, 10 and 20 mg/kg) to L-NAME-induced hypertensive rats provoked a long-lasting decrease in blood pressure. Mean arterial blood pressure decreased by 12.5%, 26.6% and 30.6% at the doses of 5, 10 and 20 mg/kg, respectively. In chronic administration, MECZ and captopril significantly prevented the increase in blood pressure and organs' weights, as well as tissue histological damages and were able to reverse the depletion in NO tissue's concentration. The MECZ also significantly lower the plasma level of triglycerides (38.1%), total cholesterol (32.1%) and LDL-cholesterol (75.3%) while increasing that of HDL-cholesterol (58.4%) with a significant low atherogenic index (1.4 versus 5.3 for L-NAME group). CONCLUSION: MECZ possesses antihypertensive and organ protective effects that may result from its ability to increase the production of the endogenous NO and/or to regulate dyslipidemia.

In vivo antioxidant and vasodilating activities of Gmelina arborea (Verberaceae) leaves hexane extract.

The present study investigated the effects of Gmelina arborea hexane leaves extract on markers of oxidative stress and its vasorelaxant effects on isolated rat aorta, in order to postulate the possible mechanisms involved in the antihypertensive properties of the plant. To evaluate the antioxidant effects of the extract, rats were randomly divided into four groups of five rats each. With the exception to the group receiving Tween (2.5%), the other groups were treated either with NaCl (900mg/kg/day) alone, NaCl (900mg/kg/day) combined with vitamin C (5mg/kg/day) or Gmelina arborea extract (150mg/kg/day). At the end of eight weeks of treatment, animals were sacrificed and some organs as well as blood samples were collected for biochemical analysis. The in vitro vasodilating effects of the extract (0.5-1.5mg/ml) were evaluated using intact and denuded rat thoracic aortic rings or aorta pre-incubated in L-NAME (2µM), indomethacin (2µM) or glibenclamide (2µM) and contracted with phenylephrine (1µM). The in vivo effects of G. arborea hexane extract prevented both left ventricular and vascular hypertrophy, it also modulated lipid metabolism. Moreover, the extract prevented lipid peroxidation, increased superoxide dismutase and catalase activity as well as NO level. On isolated rat aortic rings, the extract induced concentration-dependent vasorelaxant effects. Extract-induced vasodilation was reduced by mechanical denudation of the endothelium as well as pre-treatment with L-NAME, indomethacin or glibenclamide. These results indicate that Gmelina arborea hexane extract possesses bioactive compounds with antioxidant and vasorelaxant properties.