Evaluation of surface water contamination and its impacts on health in the mining districts of Kambélé and Bétaré-Oya (Eastern-Cameroon).

This study aimed to assess water contamination and associated health risks for populations residing in the mining areas of Kambélé and Bétaré-Oya. Key parameters, including pH, EC, TDS, TSS, and concentrations of metallic elements (Cd, Cr, Fe, Pb and Mn), were measured using established water analysis techniques. The analysis included multivariate statistical assessments, calculation of metal pollution and water quality indices, and health risk determinations, including daily intake (DI) and hazard quotient (HQ). Findings indicate a diverse pH range (5.26 < pH < 8.72), low mineralization (33.22 < EC (µS/cm) < 179.64), and elevated TSS content (22.53 < TSS (in mg/l) < 271.51). Metallic elements were observed in the descending order of Fe > Mn > Pb > Cr > Cd. Water quality assessments using the Water Quality Index (WQI) categorized sites as displaying doubtful to very poor quality, notably Woupy (WQI = 719.14) in Kambélé and Mali (WQI = 794.24) in Bétaré-Oya, with Heavy metal Pollution Index (HPI) values exceeding 100. These outcomes highlight consistent chemical degradation of surface water, posing potential risks to local populations' health and well-being. The study emphasizes the critical need for proactive environmental protection measures in mining areas, recommending the adoption of healthy mining practices and effective site reclamation strategies. Furthermore, future studies should consider exposure duration's potential impact on residents' health problems in these areas. Overall, this study contributes significantly to understanding and addressing the intricate interplay between mining activities, water quality, and public health in the Cameroon countryside.

Preventive effects of Aframomum melegueta extracts on the reproductive complications of propylthiouracil-induced hypothyroidism in male rat.

Recent studies have demonstrated that hypothyroidism is associated with infertility. This work was undertaken to evaluate the protective effects of Aframomum melegueta on testicular functions and fertility of hypothyroid male rats. Male rats were orally treated with propylthiouracil (PTU: 10 mg/kg) in combination with plant aqueous or methanol seed extract (20 and 100 mg/kg) for 56 days. Vitamin E and clomiphene citrate served as positive controls. On day 47 of treatment, each male was mated with two adult females for fertilization potential evaluation. At the end of the treatment, genital sex organ weights, sperm characteristics, testicular histology, oxidative status, plasmatic hormones and fertility potential were evaluated. Results indicated that PTU created hypothyroidism characterised by a significant increase in TSH with reduction of T3 and T4. PTU also lowered genital sex organ weights, sperm count, viability and motility, plasmatic levels of luteinising hormone, follicle-stimulating hormone and testosterone, and increased prolactin, cholesterol and testicular oxidative stress. Alteration in sperm morphology, testis and epididymis histology, and fertilization potential was also noticed. Co-administration with A. melegueta extracts successfully reversed PTU-induced infertility without any effect on thyroid hormones. These results provide evidence that A. melegueta has a protective effect on fertility in hypothyroid condition.

Neuroprotective Effects of the Anthocleista Schweinfurthii Gilg. (Loganiaceae) Stem Bark Extract in Postmenopause-Like Model of Ovariectomized Wistar Rats.

Background Estrogen deficiency in postmenopausal period causes severe neuroendocrine changes in brain which influences memory and other nervous functions. Anthocleista schweinfurthii is used traditionally to treat female infertility and menopause related symptoms. This study was performed to investigate the potential neuroprotective effects of aqueous extract of Anthocleista schweinfurthii on brain in a postmenopause-like model of ovariectomized Wistar rats. Methods Thirty animals were sham-operated or ovariectomized (Ovx) 84 days after surgery, six groups of five rats each were daily treated orally during 28 days with: distilled water for groups 1 (sham-operated) and 2 (Ovx), estradiol valerate (group 3) and the three doses of extracts {groups 4, 5 and 6 (Ovx)}. Biochemical and histological evaluations focused on brain. Results Compared to sham-operated control, ovariectomy decreased total protein levels in brain (p<0.01) which was increased by plant extract at the dose of 300 mg/kg (p<0.05), underlying its anabolic properties. Ovariectomy significantly decreased magnesium levels in brain (p<0.001). Anthocleista schweinfurthii increased significantly magnesium levels (p<0.01), showing its capacity to act on synaptic conduction. Ovariectomy induced oxidative stress by increasing malondialdehyde levels (p<0.05) and decreasing reduced glutathione levels (p<0.05) in brain. The plant extract exhibited antioxidative activity by reducing malondialdehyde levels and increasing glutathione levels in brain. Damage in brain structure which was caused by ovariectomy disappeared following the treatment. Conclusions Results suggest that Anthocleista schweinfurthii may have neuroprotective effects in Ovx Wistar rats by increasing total protein, magnesium levels and reducing oxidative stress in brain.

Aqueous extract of Peperomia pellucida (L.) HBK accelerates fracture healing in Wistar rats.

BACKGROUND: Peperomia pellucida (L.) HBK is consumed as vegetable and used in Cameroonian traditional medicine for the management of diseases and for fracture healing. Therefore the aim of this study was to evaluate the effects of the aqueous whole plant extract of Peperomia pellucida on fracture healing in female Wistar rats. METHODS: A drill hole injury was created by inserting a drill bit inthe diaphysis of the femur. The aqueous extract of the whole plant of Peperomia pellucida was administered orally at the doses of 100, 200 and 400 mg/kg to adult female Wistar rats. The vehicle (distilled water) was given to the control. Besides these rats, one group of rats without fracture received the extract (400 mg/kg). After 14 days of treatment, the rats were sacrificed under anesthesia and the effects of the extract were evaluated on body weight, the relative weights of organs (femurs, uteri and ovaries) and on hematology. Bone (calcium, phosphorus, alkaline phosphatase) and serum biochemical parameters (calcium, phosphorus, alkaline phosphatase) were also evaluated. Radiological and histological tests were carried out on the femurs. The mineral content of the plant extract was also investigated. RESULTS: The extract induced an increase in body weight at high dose and in WBCs count at low doses. Aqueous extract from Peperomia pellucida increased bone calcium at lowest dose but maintained this parameter at normal range at high dose in fractured rat. Alkaline phophatase and phosphorus concentrations reduced significantly (p < 0.01) at the dose of 400 mg/kg as compared to fractured rats. Moreover, radiological tests revealed a dose dependent formation of callus at the level of the fracture gap, confirmed by the formation of a highly dense and compact fibrocartilagenous callus. The mineral content of the plant extract revealed the presence of calcium, phosphorus, magnesium, sodium and potassium. CONCLUSION: The aqueous extract of P. pellucida accelerates bone healing due partly to the mineral content of the extract. These results confirm its traditional use in the treatment of bone fractures.

Effects of the aqueous extract of Pittosporum mannii Hook. f. (Pittosporaceae) stem barks on spontaneous and spasmogen-induced contractile activity of isolated rat duodenum.

ETHNOPHARMACOLOGICAL RELEVANCE: Pittosporum mannii Hook. f. (Pittosporaceae) is a plant widely used in traditional medicine in Cameroon for the treatment of many gastrointestinal disorders including diarrhea. To date, no pharmacological study on the antidiarrheal and the antispasmodic properties of this plant has been reported. The aim of the present study was to evaluate in vitro the relaxant activity of the aqueous extract of stem barks of P. mannii (PMAE) on rat duodenum. MATERIALS AND METHODS: Different concentrations of PMAE were tested separately (10-80 µg/mL) or cumulatively (5-80 µg/mL) on spontaneous and spasmogen (carbachol, histamine and KCl)-induced contractions of isolated rat duodenum strips. RESULTS: At concentrations ranging from 10 to 80 µg/mL, PMAE significantly decreased the tonus and the amplitude of spontaneous contractions. However, at high concentration (80 µg/mL), the extract elicited a transient relaxation was followed by a slight increase of tonus, while the amplitude remained lower compared to the normal spontaneous activity. The relaxant effect of the extract was not significantly affected in the presence of atropine (0.713 µg/mL) and promethazine (0.5 µg/mL). In addition, PMAE (20, 40, and 80 µg/mL) partially but significantly inhibited in a concentration related manner the contractions induced by carbachol (10(-9)-10(-4)M) and histamine (10(-9)-10(-4)M) on rat duodenum. PMAE (10-80 µg/mL) also significantly induced a concentration-dependent relaxation on KCl (20mM, 50mM, 10(-3)-6.10(-3)M)-induced contraction of rat duodenum. CONCLUSIONS: These results show that the aqueous extract of P. mannii stem barks possesses antispasmodic and spasmolytic effects at lower concentrations; therefore, supporting the use of the stem barks of this plant in the folk medicine for the treatment of diarrhea. However, caution should be paid while using higher concentrations that instead might produce spasmogenic effect and might worsen the diarrheal condition. The relaxant effect of PMAE appears to be non-specific of muscarinic or histaminic receptors, but may involve at least in part a mechanism of inhibition of the Ca(2+) influx into the smooth muscle cells through voltage-operated Ca(2+) channels.

In vivo estrogenic-like activities of Gouania longipetala Hemsl. (Rhamnaceae) bark extracts in a post-menopause-like model of ovariectomized Wistar rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Gouania longipetala is commonly used in Cameroonian traditional medicine to manage women fertility and menopausal complaints. However, despite this use, the estrogenic properties of G. longipetala have not been studied until now. AIM OF STUDY: The present study was aimed to assess estrogenic activities of the stem bark aqueous (GLA) and ethanolic (GLE) extracts of G. longipetala in post-menopause-like model of ovariectomized (Ovx) Wistar rats. MATERIAL AND METHODS: Animals were either sham-operated or Ovx. 84 days after ovariectomy, animals were divided into seven groups of five animals and were daily treated for 28 days with distilled water (10 mL/kg) for group 1, 2% solution of Tween 80 (10 mL/kg) for group 2, estradiol valerate (1 mg/kg) for group 3, GLA (45 or 180 mg/kg) and GLE (40 or 160 mg/kg) for groups 4 to 7 respectively. Sham-operated animals daily received distilled water (10 mL/kg). During the experimental period, the body weight was registered every week. At the day 29, blood pressure was registered by invasive method while uterine and vagina morphometry as well as body, uterine and abdominal fat weights changes were analyzed. Serum levels of total cholesterol, triglycerides, HDL-cholesterol and LDL-cholesterol were determined. Moreover, oxidative stress markers such as nitrites, reduced glutathione (GSH) and malondialdehyde (MDA) were measured in homogenized liver and aorta. RESULTS: Compared with the sham control, vagina and uterine dystrophy and elevated blood pressure were observed in Ovx rats treated with vehicles. Biochemical parameters showed a significant increase of total cholesterol, triglycerides, LDL-cholesterol and MDA as well as a significant decrease of nitrites and GSH in Ovx animals treated with vehicle as compared to sham group. GLA and GLE displayed estrogen-like effects on vagina and did not affect uterine wet weight and epithelial height compared with vehicle groups. Both extracts displayed anti-atherogenic properties by reducing AI, AIP and LDL-cholesterol level as compared to vehicles groups. GLA and GLE significantly prevented the increase of MDA induced by ovariectomy as compared to rats treated with vehicles. CONCLUSION: This study showed that GLA and GLE exhibited estrogenic effects by providing vaginal lubrication, by modulating blood pressure and improving lipid profile, oxidative status and endothelial function and may not have an undesirable influence on the endometrium in ovariectomized rats.

Antidiabetic and antioxidant effects of Annona muricata (Annonaceae), aqueous extract on streptozotocin-induced diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: The leaves of Annona muricata are used in Cameroon to manage diabetes and its complications. The aim of this study was to evaluate the antidiabetic, antioxidant activities and the potential toxicity of aqueous extract of Annona muricata in streptozotocin-induced diabetic rats. MATERIAL AND METHODS: Oral administration of Annona muricata aqueous extract (100mg/kg or 200mg/kg) was studied in normal and streptozotocin-induced diabetic rats. In long term treatment, 2 weeks after streptozotocin-induced diabetic rats, animals received plant extract during 28 consecutive days. For a protective effect, extract was administered 3 days prior to streptozotocin exposure and animals were observed 2 weeks without treatment. RESULTS: The plant extract was not effective in normal rats. In diabetic rats, single administration of the extract significantly reduced blood glucose levels by 75% and 58.22% respectively at the dose of 100mg/kg and 200mg/kg as compared to the initial value. Treatment of normal rats 3 days prior to diabetes induction showed that, Annona muricata extract has no effect within 72h following STZ injection. However, after 14 days post-treatment, the extract at the dose of 100mg/kg significantly reduced blood glucose levels as compared with initial value and diabetic control rats. Immunohistochemical staining of pancreatic ß-cells of diabetic rats treated with the dose of 100mg/kg expressed strong staining for ß-cell compared to diabetic control. In a long-term study daily administration of Annona muricata aqueous extract for 28 days to diabetic rats, reduced blood glucose levels, serum creatinine, MDA, AST, ALT activity, and nitrite levels LDL-cholesterol. Total cholesterol, triglycerides, SOD, and CAT activity contents were restored. CONCLUSION: These different results show that the antidiabetic activity of Annona muricata aqueous extract can be explained by its hypolipidaemic effect, its antioxidant and protective action on pancreatic ß-cells, which in turn improve glucose metabolism.

In vivo and in vitro anti-natriuretic activity of twigs fraction from Dorstenia picta: a possible mechanism.

The present study examine the in vivo effects of Dorstenia Picta (D. picta) on urinary volume and sodium excretion in streptozotocin-induced diabetic rats, and determine a possible mechanism by which the extract increased sodium transport in A6 cells monolayers. Administration of the plant extract at the dose of 150 mg/kg during two weeks decreased urinary volume and sodium excretion. In vitro study showed that, apical application of the plant extract at the dose of 100 µg/mL does not significantly increase sodium transport, whereas basolateral administration provoked a significant (P<0.05) increase of sodium transport in a concentration-dependent manner. The plant extract increases the sodium transport by 69.93% versus 55.41% for insulin and 78.44% for adenosine after 30 min. Preincubation of A6 cells monolayers with inhibitor of all adenosine receptors completely suppressed adenosine and plant extract stimulated sodium transport. Interesting is that, the A1 inhibitor receptor (DPCPX), at 100 nM completely abolished the effect of plant extract. The plant extract increased sodium transport by increase PI3-kinase activity and this effect is strongly inhibited by LY-294002. These data also suggest that, the twigs methanol fraction from Dorstenia picta increase sodium transport via PI 3-kinase pathway and requires A1 adenosine receptor.