Albert Donatien ATSAMO

PS-BPB03-2: VASORELAXANT-MEDIATED ANTIHYPERTENSIVE EFFECT OF THE SEED AQUEOUS EXTRACT OF AFRAMOMUM PRUINOSUM GAGNEP. (ZINGIBERACEAE)

Elvine Pami Nguelefack Mbuyo, Larissa Orelle Mekontchou, Nidele Lonla Tchinda, Ariane Falone Goumtsa, Albert Donatien Atsamo, Télesphore Benoît Nguelefack

Journal of Hypertension

Objective: Despite the existing therapies, arterial hypertension is still a prevalent and a worldwide major public health concern, prompting the search for new therapeutic alternatives. The present study investigated the antihypertensive and the related mechanisms of action of the seed aqueous extract of Aframomum pruinosum (AEAP), a plant used in Cameroon traditional medicine against cardiovascular ailments. Design and method: Male Wistar rats were rendered hypertensive by chronic oral administration of L-NAME (30 mg/kg/day) for three consecutive weeks, and hypertensive rats were selected and treated with L-NAME alone or in combination with AEAP at doses of 75 or 150 mg/kg/day for an additional 3 consecutive weeks. Captopril (25 mg/kg/day, p.o) was used as reference drug. Blood pressure and heart rate were monitored weekly. At the end of the experiment, the heart was harvested, weighed, and sections of cardiac tissue were stained with hematoxylin and eosin for histological analysis. Cumulative concentrations of the aqueous extract (3, 10, 30, 100, and 300 μg/mL) were tested on intact or endothelium-denuded aorta rings precontracted with norepinephrine (NE; 1 μM) or KCl (90 mM) in absence or presence of L-NAME (a nitric oxide synthase inhibitor, 100 μM), indomethacin (a prostaglandin synthesis inhibitor; 10 μM), methylene blue (a guanylate cyclase inhibitor, 1 μM), tetraethylammonium (TEA; a non-specific potassium channel blocker; 5 μM) or glibenclamide (an ATP-sensitive potassium channel blocker; 10 μM). The contractile response to NE, or CaCl 2 was also assessed in the presence or absence of the plant extract. Results: AEAP completely reversed (p < 0.001) L-NAME-induced elevated systolic and diastolic blood pressure, and increased heart rate. AEAP partially reversed cardiac hypertrophy, leucocyte infiltration, and prevent cardiac necrosis. AEAP induced a concentration-dependent vasorelaxant effect on NE- and KCl-evoked contraction with EC 50 values of 13.46 and 49.37 μg/mL, respectively. Removal of the endothelium and the preincubation of aorta rings with L-NAME significantly (p < 0.05) reduced the vasorelaxant effect of the plant extract, while indomethacin and methylene blue had no effect (p > 0.05). Glibenclamide, similar to TEA, significantly (p < 0.001) inhibited the vasorelaxant response to AEAP. Also, the extract significantly (p < 0.01 and p < 0.001) inhibited NE- and CaCl2-induced contraction. Conclusion: AEAP possesses antihypertensive effects that are at least partially mediated by its vasorelaxant activity. Nitric oxide release, opening of K ATP channels, blockade of alpha-1 receptors, and inhibition of Ca 2+ influx account for this vasorelaxant activity.

• #diverse scientific research studies
• #natural antidiabetic agents studies
• #glibenclamide
• #medicine

Neuroprotective Effects of the Ethanolic Leaf Extract of Crassocephalum crepidioides (Asteracaeae) on Diazepam-Induced Amnesia in Mice

Galba Jean Beppe, Folefack Alice Irène, Albert Donatien Atsamo, Ngatanko Abaïssou Hervé Hervé, Barga Mpoo Bertrand, Allah-Doum Nanou Gael and 4 more

Advances in Pharmacological and Pharmaceutical Sciences

This study aimed to evaluate the neuroprotective effects of the ethanolic leaf extract of Crassocephalum crepidioides (Cc) on diazepam-induced amnesia in mice. Thirty mice distributed into six groups of five mice each were used. The normal control and negative control groups received 2% ethanol per os, the positive control group received piracetam (150 mg/kg, p.o), and three experimental groups were treated with three doses of ethanolic leaf extract of Cc (100, 200, and 400 mg/kg, p.o). All groups except the normal control group were co-treated with diazepam (3 mg/kg, i.p) daily for 14 days. The memory effects were evaluated using the Radial Arm Maze (RAM) and the Novel Object Recognition (NOR) tests, while the anti-depressive effects were evaluated using the tail suspension test. All animals were sacrificed at the end of the study. Hippocampi, isolated from the right hemisphere, were used to prepare a homogenate for the determination of oxidative stress biomarkers. The ethanolic leaf extract of cc significantly ( <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" id="M1"> <a:mi>p</a:mi> <a:mo>&lt;</a:mo> <a:mn>0.001</a:mn> </a:math> ) decreased the number of working and reference memory errors in the RAM test and induced a significant ( <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" id="M2"> <c:mi>p</c:mi> <c:mo>&lt;</c:mo> <c:mn>0.01</c:mn> </c:math> ) increase in the time spent exploring the novel object in the NOR test. The extract also induced a significant ( <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" id="M3"> <e:mi>p</e:mi> <e:mo>&lt;</e:mo> <e:mn>0.001</e:mn> </e:math> ) increase in the mobility time in tail suspension. Moreover, compared to the negative control group, the extract significantly ( <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" id="M4"> <g:mi>p</g:mi> <g:mo>&lt;</g:mo> <g:mn>0.01</g:mn> </g:math> ) increased superoxide dismutase activity and significantly ( <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" id="M5"> <i:mi>p</i:mi> <i:mo>&lt;</i:mo> <i:mn>0.01</i:mn> </i:math> ) decreased malondialdehyde levels. The histopathological analysis of hippocampi showed that the cc extract increased cell density when compared with the negative control. These results suggest that the ethanolic left extract of cc could have neuroprotective properties, which could be attributed to its antioxidant properties.

• #medicinal plants and neuroprotection
• #alkaloids: synthesis and pharmacology
• #medicinal plant extracts effects
• #diazepam

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

Eric Gonzal Tsafack, Marius Mbiantcha, Gilbert Ateufack, Stéphanie Flore Djuichou Nguemnang, William Nana Yousseu, Albert Donatien Atsamo and 3 more

Evidence-based Complementary and Alternative Medicine

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-1β, 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 ( <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" id="M1"> <a:mi>p</a:mi> </a:math> &lt;0.001) reduced tumour necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), and IL-6 and significantly ( <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" id="M2"> <c:mi>p</c:mi> </c:math> &lt;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.

• #alkaloids: synthesis and pharmacology
• #pharmacological effects of natural compounds
• #pain mechanisms and treatments
• #neuropathic pain

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

Magloire Kanyou Ndjenda, Elvine Pami Nguelefack‐Mbuyo, Albert Donatien Atsamo, Christian Kuete Fofié, Chamberlin Fodem, Filomain Nguemo and 1 more

Evidence-based Complementary and Alternative Medicine

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 Nω-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 ( <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" id="M1"><a:mi>p</a:mi><a:mo>&lt;</a:mo><a:mn>0.001</a:mn></a:math> ) 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.

• #chemical synthesis and alkaloids
• #alkaloids: synthesis and pharmacology
• #blood pressure and hypertension studies
• #flavonoid

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

Mireille Flaure Metchi Donfack, Albert Donatien Atsamo, Roméo Joël Temdié Guemmogne, Omer Bébé Ngouateu, Alain Bertrand Dongmo, Théophile Dimo

Evidence-based Complementary and Alternative Medicine

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.

• #phytochemistry and biological activities
• #natural antidiabetic agents studies
• #cholesterol and lipid metabolism
• #blood pressure

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

Albert Donatien Atsamo, Auscar Lontsie Songmene, Mireille Flaure Metchi Donfack, Omer Bébé Ngouateu, Télesphore Benoît Nguelefack, Théophile Dimo

Evidence-based Complementary and Alternative Medicine

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-1β, 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.

• #drug-induced hepatotoxicity and protection
• #antibiotics pharmacokinetics and efficacy
• #drug transport and resistance mechanisms
• #nephrotoxicity

Aqueous extract from Cinnamomum zeylanicum (Lauraceae) stem-bark ameliorates gentamicin-induced nephrotoxicity in rats by modulating oxidative stress and inflammatory markers

Albert Donatien Atsamo, LONTSIE Auscar SONGMENE, Mireille Flaure Metchi Donfack, Omer Bébé Ngouateu, Télesphore Benoît Nguelefack, Théophile Dimo

Research Square

Abstract Nephropathies and especially nephrotoxicity has become one of serious cause of life threatening condition, because of intensive exposure to xenobiotic either by environmental pollution or 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 of the 14 th day, a 24h urine was collected and 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 pro-inflammatory cytokine, while the other one was fixed in formaldehyde for histopathological studies. Gentamicin decreased body weight, serum total proteins and calcemia, 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 (TNFα, IL-1β, IL-6) and nitrites were observed in 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 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.

• #drug-induced hepatotoxicity and protection
• #natural antidiabetic agents studies
• #drug transport and resistance mechanisms
• #cinnamomum zeylanicum

Consumption of Cucurbitaceae Seeds Oils is Better in Risk of Cardiovasular Disease Prevention on Rats Than The Consumption of Refined Palm Oil

Ouattara Howélé, Albert Donatien Atsamo, Bazoumanan Ouattara, Vazoumana Koné, Séraphin Kati-Coulibaly

Research Square

• #coconut research and applications
• #cucurbitaceae
• #palm oil
• #consumption (sociology)

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

Leonard Fonkeng Sama, Michel Noubom, Christelle Kenne, Thibau Flaurant Tchouangueu, Omer Bébé Ngouateu, Albert Donatien Atsamo and 2 more

International Journal of Clinical Practice

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.

• #neonatal and maternal infections
• #preterm birth and chorioamnionitis
• #maternal and neonatal healthcare
• #colonisation

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

Vanessa Mba Matah Marthe, Gilbert Ateufack, Marius Mbiantcha, William Yousseu Nana, Albert Donatien Atsamo, Flore Carine Adjouzem and 4 more

Journal of Complementary and Integrative Medicine

OBJECTIVES: (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: 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: stem bark has both cytoprotective and antisecretory effects. This extract exerts its antisecretory effect trough cholinergic and histaminergic pathways.

• #biological stains and phytochemicals
• #ethnobotanical and medicinal plants studies
• #plant-derived bioactive compounds
• #pylorus

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

Fidèle Ntchapda, Christian Bonabé, Albert Donatien Atsamo, David Romain Kemeta Azambou, Yannick Bekono Fouda, Soudy Imar Djibrine and 2 more

Evidence-based Complementary and Alternative Medicine

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 &lt; 0.001, vs. dose 200 mg/kg), systolic arterial blood pressure (21.33%, p &lt; 0.001), and the diastolic arterial blood pressure (21.84%, p &lt; 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.

• #african botany and ecology studies
• #ethnobotanical and medicinal plants studies
• #ginger and zingiberaceae research
• #adansonia digitata

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

Carine Flore Adjouzem, Gilbert Ateufack, Marius Mbiantcha, William Yousseu Nana, Vanessa Matah Marthe, Stéphanie Flore Djuichou Nguemnang and 2 more

Evidence-based Complementary and Alternative Medicine

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‐1 β , 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 6 th 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 &lt; 0.001) inhibited TNF‐ α , IL‐6, IL‐1 β , and PGE2 production stimulated by LPS. Both extracts at all doses significantly reduced ( P &lt; 0.01, P &lt; 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 &lt; 0.001) reduced malondialdehyde and nitric oxide levels in the colon and significantly ( P &lt; 0.01) increased superoxide dismutase and catalase and reduced glutathione ( P &lt; 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.

• #gastrointestinal motility and disorders
• #pharmacological effects of natural compounds
• #inflammatory bowel disease
• #apocynaceae

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

Yannick Bekono Fouda, Esther Ngo Lemba Tom, Albert Donatien Atsamo, Christian Bonabé, Théophile Dimo

Journal of Ethnopharmacology

• #biochemical analysis and sensing techniques
• #pharmacology and obesity treatment
• #regulation of appetite and obesity
• #medicine

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

Vanessa Mba Matah Marte, Gilbert Ateufack, Marius Mbiantcha, Albert Donatien Atsamo, Carine Flore Adjouzem, Stéphanie Flore Djuichou Nguemnang and 4 more

Gastroenterology Research and Practice

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-1β, 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 ( <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" id="M1"><a:mi>p</a:mi><a:mo>&lt;</a:mo><a:mn>0.001</a:mn></a:math> ) inhibited intracellular and extracellular ROS production and T cell proliferation and reduced significantly ( <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" id="M2"><c:mi>p</c:mi><c:mo>&lt;</c:mo><c:mn>0.01</c:mn></c:math> , <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" id="M3"><e:mi>p</e:mi><e:mo>&lt;</e:mo><e:mn>0.001</e:mn></e:math> ) TNF-α, IL-1β, 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.

• #inflammatory mediators and nsaid effects
• #biological stains and phytochemicals
• #phytochemistry and bioactive compounds
• #cyclooxygenase

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

Gilbert Ateufack, William Yousseu Nana, Marius Mbiantcha, Shamim Khan, Hafiz Majid Rasheed, Albert Donatien Atsamo and 3 more

Asian Pacific Journal of Tropical Biomedicine

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 (0.3 μmol/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.

• #phytochemistry and biological activities
• #essential oils and antimicrobial activity
• #verapamil
• #chemistry

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

Stéphanie Flore Djuichou Nguemnang, Eric Gonzal Tsafack, Marius Mbiantcha, Gilbert Ateufack, Albert Donatien Atsamo, William Yousseu Nana and 2 more

Evidence-based Complementary and Alternative Medicine

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 μ g/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 (IC 50 = 5.74 μ g/ml and 2.96 μ g/ml for polymorphonuclear leukocytes, 7.47 μ g/ml and 3.28 μ g ml for peritoneal macrophages of mouse) and cell proliferation (IC 50 = 16.89 μ g/ml and 3.29 μ g/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.

• #traditional and medicinal uses of annonaceae
• #ethnobotanical and medicinal plants studies
• #natural antidiabetic agents studies
• #in vivo

Cardiovascular and Antioxidant Effects of the Methanol Extract From the Stem Bark of Erythrina Senegalensis DC (Fabaceae)

Albert Donatien Atsamo, Semi Anthelme Nene-Bi, Landre Kouakou, Christian Fofi, Paulin Nyadjeu, Pierre Watcho and 3 more

Journal of Physiology and Pharmacology Advances

The present study was undertaken to investigate the cardiovascular and the in vitro antioxidant activities of the methanol extract of the stem bark of Erythrina senegalensis (EMES), a plant used traditionally in Cameroon against arterial hypertension. The cardiovascular effects of EMES (11-44 mg/kg) were evaluated in vivo on normotensive rat arterial blood pressure and on rabbit’s electrocardiogram (5.5- 55 mg/kg) while the in vitro study (10-10 - 1 mg/ml) on myocardial contractile performance was evaluated on rat isolated heart. The antioxidant activities of EMES (1-1000 µg/ml) were investigated on 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydrogen peroxide (H2O2)-induced haemolysis, nitric oxide (NO) production, as well as its reducing power. The intravenous injection of EMES provoked in anaesthetized normotensive rats, a dose dependent immediate reduction in arterial hypertension. The mean arterial blood pressure dropped by 11.29, 19.84 and 24.42 % at respective doses of 11, 22 and 44 mg/kg. When administered intravenously in rabbit EMES significantly reduced the heart rate, amplitudes of P wave and QRS complex while significantly increasing the duration of the QT interval. EMES exhibited a concentration dependent reducing power, antiradical activity on DPPH (EC50 of 46.9 μg/ml) and a significant (p

• #blood pressure and hypertension studies
• #computational drug discovery methods
• #diverse scientific research studies
• #fabaceae