Use of WhatsApp®, for distance teaching during COVID-19 pandemic: Experience and perception from a sub-Saharan African setting.

BACKGROUND: In the midst of the COVID-19 pandemic, to palliate to the lockdown and cover academic programs, the faculty of medicine and pharmaceutical sciences (FMPS) of the university of Dschang (UDs) in Cameroon has implemented e-learning using WhatsApp®. AIM: Describe the opinion of students and lecturers after its implementation of e-learning at the FMPS of UDs. METHODS: We designed a uniform teaching scheme using WhatsApp® during the university lockdown. Students and members of the teaching staff of the FMPS of UDs were enrolled after receiving clear information on the study implementation. At the end of the online-teaching period of two and a half months, we surveyed our students and teaching staff. Sociodemographic characteristics and opinions about e-learning were collected using a standard questionnaire. RESULTS: We enrolled 229 students and 40 lecturers of the FMPS. Students reported a decremented quality of internet connection (p < 0.001, p-homogeneity < 0.001) despite an increased expenditure related to internet use. Electronic devices were broadly used before the implementation of mobile learning. The use of course materials was significantly more challenging among students because of the size/format of lecture notes and internet connection/cost (all p < 0.05). Perception of discipline compared to classroom-based lessons was not significantly different among students compared to lecturers (all p > 0.05). While lecturers were mainly more comfortable conveying the contents of their lectures, students tended to be less prone to actively participate. The motivation and satisfaction of the latter group toward e-learning were modest compared to classroom-based lectures while their feedback about the organization was positive. CONCLUSIONS: E-learning using WhatsApp® could be an effective alternative to conventional classroom-based lessons in the context of COVID-19 pandemic. The use of a blended-learning program including classroom-based sessions could help improve its limitations.

Anti-androgenic, anti-oxidant and anti-apoptotic effects of the aqueous and methanol extracts of Pterorhachis zenkeri (Meliaceae): Evidence from in vivo and in vitro studies.

The aim of this study was to evaluate the effects of Pterorhachis zenkeri (Meliaceae) on sex organ growth in immature male rats and, oxidative stress and apoptosis markers in CCL-97 (R2C) Leydig cells. For the in vivo studies, 70 immature male Wistar rats (n = 10/group) were treated for 2 or 4 weeks with: distilled water (10 ml/kg, per os) plus soya oil (1 ml/kg, sc), bicalutamide (10 mg/kg, per os), aqueous or methanol extract of P. zenkeri (10 mg/kg or 62 mg/kg, per os) or testosterone propionate (3 mg/kg, sc). After each treatment period, body and sexual organ weights, plasmatic testosterone, total proteins and total cholesterol levels were measured. In the in vitro test, the effects of the methanol extract of P. zenkeri on cell viability, apoptosis, reactive oxygen species (ROS) production, intracellular calcium release and caspases 3/9 were assessed using CCL-97 Leydig cells. Pterorhachis zenkeri extracts decreased sex organ weights, plasmatic testosterone and protein levels in rats. In the in vitro studies, P. zenkeri inhibited apoptosis, ROS production, calcium release and caspase 3/9 activities. These results suggest that P. zenkeri has anti-androgenic, anti-oxidant and anti-apoptotic activities with methanol extract being the most active and could be an effective alternative for the management of androgen-related diseases.

The methanolic extract of Guibourtia tessmannii (caesalpiniaceae) and selenium modulate cytosolic calcium accumulation, apoptosis and oxidative stress in R2C tumour Leydig cells: Involvement of TRPV1 channels.

This study evaluated the effects of the methanolic extract of Guibourtia tessmannii (GT) and selenium (Se) on cell viability, intracellular calcium concentration ([Ca2+ ]i ), apoptosis and oxidative stress through transient receptor potential vanilloid 1 (TRPV1) channel activity in CCL-97 (R2C) tumour Leydig cells. The cells were divided into nine groups and treated as follows: (a)-Control, (b)-Capsazepine (CPZ, 0.1 mM, a TRPV1 channel blocker), (c)-Capsaicin (CAP, 0.01 mM, a TRPV1 channel activator), (d)-GT (500 µg/ml), (e)-GT+CPZ, (f)-GT+CAP, (g)-Se (200 nM), (h)-Se+CPZ and (i)-Se+CAP. After treatments, cell viability, [Ca2+ ]i , apoptosis, caspase 3/9, reactive oxygen species (ROS) and mitochondrial membrane depolarisation (MMD) were evaluated. The [Ca2+ ]i , apoptosis, caspase 3/9, MMD and ROS levels were significantly (p < 0.001) increased in CAP group, but lowered in CPZ group. Interestingly, these parameters were significantly (p < 0.001) improved by GT and Se, compared to the CAP group. Moreover, the co-administration of GT+CAP or Se+CAP inhibited the cytotoxicity of CAP. Thus, the modulatory properties of GT and Se on Ca2+ influx, apoptosis and oxidative stress require the integrity of TRPV1 channel in CCL-97 Leydig cells. These results suggest that GT and Se might be used in the management of cytotoxicity in the testes, involving TRPV1 channel activity.

Aqueous and ethanol extracts of Dracaena arborea (Wild) Link (Dracaenaceae) alleviate reproductive complications of diabetes mellitus in rats.

Reproductive dysfunction is one of the most prevalent diabetes complications. Draceana arborea is known to enhance sexual function in diabetic rats, but the underlying mechanisms have not been thoroughly elucidated. This study examined the effects of D. arborea on some reproductive complications of diabetes in rats. Aqueous and ethanol (500 and 100 mg/kg respectively) extracts of D. arborea, Sildenafil citrate (1.44 mg/kg), trimethylamine-N-oxide (TMAO, 20 mg/kg) and distilled water (10 ml/kg) were orally administered for 28 days to streptozotocin-induced diabetic rats. Glycaemia, body and reproductive organ masses, fertility parameters, total proteins, antioxidant enzymes activities, serum and testicular testosterone and the histology of the testes and epididymis were determined. Results revealed significant decreases in body and absolute and relative masses of testes, epididymis, seminal vesicles, prostate and vas deferens, fertility parameters, epididymal and testicular total proteins, serum and testicular testosterone levels as well as antioxidant enzymes activities. Interestingly, while having minor anti-hyperglycaemic effects, these abnormalities associated with testicular and epididymal alterations were alleviated by D. arborea especially the aqueous extract (500 mg/kg). These outcomes provided evidence of the androgenic properties of D. arborea in diabetic rats, which could be useful for a better management of sexual dysfunctions in diabetic patients.

Androgenic effects of aqueous and methanolic extracts of Ficus asperifolia in male Wistar rats.

BACKGROUND: Androgen deficiency is a clinical syndrome resulting from the inability of the testes to produce physiological levels of testosterone due to a disturbance occurring at one or more levels of the hypothalamic-pituitary-testicular axis. The present study was undertaken to evaluate the androgenic properties of aqueous and methanolic extracts of Ficus asperifolia on normal and castrated immature rats. METHODS: Normal rats were treated either per os with aqueous or methanolic extract of Ficus asperifolia (100 mg/kg or 500 mg/kg b.w.), distilled water (10 ml/kg b.w.), 5% Tween 80 (10 ml/kg b.w.) or subcutaneously with testosterone propionate (0.5 mg/kg b.w.). Castrated rats were treated with plant extracts (100 mg/kg b.w. or 500 mg/kg b.w.) alone or with the co-administration of plant extracts and testosterone propionate (s.c., 0.5 mg/kg b.w.) or bicalutamide (2 mg/kg b.w. per os). Animals were treated once a day during four weeks. Body weight growth and relative sexual organ weights were recorded at the end of each treatment. Some biomedical parameters were measured in the plasma (proteins, cholesterol), testes (cholesterol) and epididymis (proteins). RESULTS: In normal rats, Ficus asperifolia significantly (p < 0.05) increased the relative weights of the testes and all sexual-dependent organs whereas total testicular cholesterol concentration was significantly (p < 0.05) decreased. In castrated groups, treatment with Ficus asperifolia was followed by an increase in the sexual organ weights, epididymal protein and prostatic acid phosphatase concentrations. The co-administration of testosterone and plant extracts significantly (p < 0.05) increased the weight of accessory sexual organs and epididymal protein contents. In the presence of bicalutamide (an anti-androgen), the sexual stimulating activity of Ficus asperifolia was diminished with remarkable effects on vas deferens weight (p < 0.05), plasma (p < 0.01) and epididymal (p < 0.05) protein contents. CONCLUSION: Ficus asperifolia possesses androgen-like activity through possible stimulation of cytoplasmic and/or nuclear receptors by the bioactive compounds found in its extracts.

Guibourtia tessmannii-induced fictive ejaculation in spinal male rat: involvement of D1, D2-like receptors.

CONTEXT: Guibourtia tessmannii (Caesalpiniaceae) is a plant traditionally used as aphrodisiac. We previously reported the pro-ejaculatory effects of the aqueous and methanol extracts of G. tesmannii in spinal male rat. However, the mechanism underlying such effects has not been elucidated. OBJECTIVE: This study characterizes the dopaminergic sub-type receptors involved in G. tesmannii-induced ejaculation in male Wistar rat. MATERIALS AND METHODS: Urethane-anesthetized spinal male rats were intravenously treated with saline solution (1 mL/kg, control); dopamine (0.1 µmol/kg, reference); aqueous or methanol extracts of G. tesmannii (20 mg/kg) in the absence or presence of haloperidol (0.26 µmol/kg), a nonspecific dopaminergic receptor antagonist, Sch23390 (0.26 µmol/kg), a specific D1-like receptor antagonist or, sulpiride (0.26 µmol/kg), a specific D2-like receptor antagonist. Electromyography of the bulbospongiosus muscles and intraseminal pressure were recorded after urethral, penile and drug stimulations. RESULTS: Urethral and penile stimulations, intravenous injection of dopamine or, aqueous and methanol extracts of G. tesmannii always triggered the expression of rhythmic contraction of the bulbospongiosus muscles with an average mean of 3.33 ± 0.43; 7.83 ± 0.85; 9.80 ± 0.86; 0.83 ± 0.54 and 2.67 ± 0.95 contractions, respectively. The intraseminal pressure was more expressed after urethral and penile stimulations (15.66 ± 1.58 and 13.60 ± 2.40 mmHg, respectively). In rats pretreated with haloperidol, Sch23390 or sulpiride, no ejaculation was recorded after intravenous injection of G. tesmannii extracts or dopamine. DISCUSSION AND CONCLUSION: Guibourtia tesmannii-induced ejaculation requires the integrity of D1 and D2-like receptors. These findings further justify the ethno-medicinal claims of G. tesmannii as an aphrodisiac.

The expanded program on immunization service delivery in the Dschang health district, west region of Cameroon: a cross sectional survey.

BACKGROUND: Vaccination is the most effective intervention strategy, and the provision of vaccination at fixed posts and outreach posts is a backbone of a sustainable vaccination system in developing countries. Access to immunization services is still limited in Cameroon. Several health districts in the west region have recorded new epidemic outbreaks, including the occurrence of a wild polio virus epidemic outbreak in 2013. The aim of this study was to assess immunization service delivery in one of the largest health districts in the west region of Cameroon; the Dschang Health district. METHODS: It was a cross sectional study conducted in 2013, in 42 health facilities covering 18 health areas in the Dschang Health District. Data were collected with questionnaires administered to health personnel face to face and an observation grid was used to assess resources and tools. Data were entered and analyzed in Epi Info. RESULTS: A total of 42 health facilities were assessed and 77 health personnel were interviewed. Overall, 29 (69.0 %) health facilities organized one vaccination session monthly, 2 (4.8 %) organized an outreach within the last 3 months prior to the study, 15 (35.7 %) did not have a vaccination micro plan, 24 (32.9 %) health personnel had not been supervised for at least the last 6 months prior to the study, 7 (16.7 %) health facilities did not have a functional refrigerator, 1 (2.4 %) did not have a vaccine carrier, 23 (54.8 %) did not have a means of transport (vehicle or motorcycle) and 12 (28.6 %) did not have an EPI guideline. The knowledge of health personnel on vaccine and cold chain management, and on diseases of the EPI under epidemiological surveillance was found to be limited. CONCLUSION: The frequency and strategic provision of immunization services in the Dschang Health district is inadequate. Resource availability for an adequate provision of immunization services is insufficient. The knowledge of health personnel on vaccine management, cold chain management and on diseases under surveillance by the EPI is limited.

Cycloartanes from Oxyanthus pallidus and derivatives with analgesic activities.

BACKGROUND: The leaves of Oxyanthus pallidus Hiern (Rubiaceae) are extensively used in the west region of Cameroon as analgesic. These leaves are rich in cycloartanes, a subclass of triterpenes known to possess analgesic and anti-inflammatory properties. The present study aimed at evaluating the analgesic properties of three cycloartanes isolated from Oxyanthus pallidus leaves as well as their aglycones and acetylated derivatives. METHODS: Three cycloartanes OP3, OP5 and OP6 obtained by successive chromatography of the crude methanol extract of the leaves were hydrolysed to yield respective aglycone AOP1, AOP2, AOP3 and acetylated to HOP1, HOP2 and HOP3 respectively. Formalin-induced pain model was used to evaluate the acute anti-nociceptive properties of these cycloartanes (5 mg/kg, p.o) in mice and to determine the structure-activity relationship. Acute (24 h) and chronic (10 days) anti-hyperalgesic and anti-inflammatory activities of OP5 were evaluated at the doses of 2.5 and 5 mg/kg/day administered orally. OP6 was also evaluated in acute experiments. The antioxidant and hepato-protective activities of OP5 were evaluated at the end of the chronic treatment. RESULTS: The mixture and the individual isolated cycloartanes significantly inhibited both phases of formalin-induced pain with percentage inhibition ranging from 13 to 78%. Acid hydrolysis did not significantly affect their antinociceptive activities while acetylation significantly reduced the effects of these compounds during the second phase of pain. OP5 and OP6 induced acute anti-hyperalgesic activity in formalin-induced mechanical hyperalgesia but not an anti-inflammatory effect. Repeated administration of OP5 for 10 days did not induce any anti-hyperalgesic effect. The evaluation of in vivo antioxidant properties showed that OP5 significantly reduced malondialdehyde and increased superoxide dismutase levels in liver without significantly affecting other oxidative stress and hepatotoxic parameters. Chronic administration of OP5 did not cause gastric ulceration. CONCLUSION: Cycloartanes isolated from Oxyanthus pallidus possess analgesic effects but lack anti-inflammatory activities. This analgesic effect especially on inflammatory pain may be due to the presence of hydroxyl group in front of the plane. OP5 is devoid of ulcerogenic effect and possess antioxidant properties that might be of benefit to its analgesic properties.

Assessing the detection, reporting and investigation of adverse events in clinical trial protocols implemented in Cameroon: a documentary review of clinical trial protocols.

BACKGROUND: International guidelines recommend ethical and scientific quality standards for managing and reporting adverse events occurring during clinical trials to competent research ethics committees and regulatory authorities. The purpose of this study was to determine whether clinical trial protocols in Cameroon are developed in line with national requirements and international guidelines as far as detecting, reporting and investigating of adverse events is concerned. METHODS: It was a documentary review of all approved clinical trial protocols that were submitted at the Cameroon National Ethics Committee for evaluation from 1997 through 2012. Data were extracted using a preconceived and validated grid. Protocol review process targeted the title, abstract, objectives, methodology, resources, and the chapter on safety. RESULTS: In total, 106 (4.9 %) clinical trial protocols were identified from 2173 protocols seen in the archive and 104 (4.8 %) included for review. Seventy six (73.1 %) trials did not include the surveillance of adverse events as part of their objective. A total of 91 (87.5 %) protocols did not budget for adverse event surveillance, 76 (73.1 %) did not have a data safety management board (DSMB), 11(10.6 %) included insurance for participants, 47 (45.2 %) did not include a case definition for serious adverse events, 33 (31.7 %) described procedures to detect adverse events, 33 (31.7 %) described procedure for reporting and 22 (21.2 %) described procedure for investigating adverse events. DISCUSSIONS: Most clinical trial protocols in Cameroon are developed to focus on benefits and pay little attention to harms. The development of national guidelines can improve the surveillance of adverse events in clinical trial research conducted in Cameroon. Adverse events surveillance tools and a budget are critical for an adequate planning for adverse event surveillance when developing trial protocols. CONCLUSION: Clinical trial protocols submitted in the Cameroon National Ethics Committee do not adequately plan to assess adverse events in clinical trial protocols. In order to improve on the safety of participants and marketed drug, there is a need to develop national guidelines for clinical trials by the government, and to improve evaluation procedures and monitoring of ongoing trials by the ethics committee.

Ethnomedicinal, phytochemical, pharmacological and toxicological profile of Mondia whitei: A review.

Mondia whitei is an aromatic plant native to sub-Saharan Africa. This spice is commonly used in the treatment of various diseases, such as hypertension, diabetes, erectile dysfunction, and premature ejaculation. This review was undertaken to provide updated information on the botanical, phytochemical, pharmacological, and toxicological knowledge of this plant of high relevance to African populations. Moreover, its mechanism of action was described based on previous experimental studies. Data were compiled from various online databases such as PubMed, Google Scholar, Scopus, Science Direct, Web of Science, Springer link, Taylor and Francis, and SciFinder. Additionally, books, book chapters and proceedings were used as secondary sources. The chemical structures of phytocompounds were drawn using PubChem Sketcher program. M. whitei contains various phytocompounds, including reducing sugars, triterpenes, steroids, alkaloids, saponins, tannins, phenolics, hydrogen cyanide, carotenoid, oxalate and phytate. Moreover, para-pentylphenyl-benzoate, (-)-Loliolide, 5-chloropropacin, propacin, 2-hydroxy-4-methoxybenzaldehyde, isovanillin, 9-hexacosene, 2-hexen-1-ol, and heptacosane were isolated from this spice. M. whitei has several pharmacological benefits, including aphrodisiac, pro-fertile, pro-erectile, androgenic, antioxidant, antiparasitic, antimalarial, antibacterial, antiviral, antifungal, antiepileptic, anti-inflammatory, analgesic, antidepressant, antidiarrheal, hepatoprotective, antisickling, and anticancer activities. Toxicological studies showed an LD50 of above 5000 mg/Kg and no signs of toxicity after one week of oral treatment. The aphrodisiac effect of this spice is one of its main activities, supported by numerous experimental studies. Because M. whitei delays contractions of the bulbospongiosus muscles, its aphrodisiac effect could be mediated through the modulation of the spinal generator of ejaculation. This can justify its folkloric use in the treatment of premature ejaculation.

Ethanolic extract of Persea americana Mill. (Lauraceae) seeds induced antiestrogenic effects in young female Wistar rats.

OBJECTIVES: The ethanol extract of Persea americana seeds was found to inhibit the development of estrogen-dependent conditions in female Wistar rats, suggesting the ability of its secondary metabolites to interact with estrogen receptors (ERs), either as partial agonists or as antagonists. To test this hypothesis, the abovementioned extract was assessed for its ability to mimic and/or antagonize estradiol effects. METHODS: Two experiments were conducted in ovariectomized (OVX) rats: (1) animals were treated with estradiol valerate (E2V; 1 mg/kg) or P. americana at doses of 25 and 50 mg/kg; (2) animals were treated with E2V alone (0.75 mg/kg) or in combination with P. americana at the abovementioned doses. Treatments were given orally for 3 days and animals were sacrificed for biochemical and histological analyses of the uterus and vagina. RESULTS: When administered alone, P. americana did not change the histomorphology of both organs (uterus and vagina). In combination with E2V, P. americana decreased uterine weight [30 % decrease (p<0.001) at 25 mg/kg and 24 % (p<0.01) at 50 mg/kg] and epithelium height (37 % decrease). This was associated with decreased estradiol levels (at least 86 % decrease, p<0.001) in the uterus. Similarly, vagina epithelium height decreased by at least 34 % (p<0.05) when E2V was co-administered with P. americana. CONCLUSIONS: The seed extract of P. americana contains ER antagonist secondary metabolites accounting for its ability to inhibit the development of estrogen-dependent conditions in female rats.

Aphrodisiac and androgenic effects of the aqueous extract of the roots of Vepris afzelii on cyproterone acetate-induced hypogonadism in rat.

This work aimed to evaluate the effects of the aqueous extract of Vepris afzelii roots on a rat model of hypogonadism. Phytochemical screening and acute toxicity of the extract were performed using different procedures. Hypogonadism was induced orally in adult Wistar rats using cyproterone acetate (30 mg/kg) for ten days. Besides six normal rats (10 ml/kg of distilled water, normal control), 30 hypogonadal rats were subdivided into five groups of six animals each, receiving for 14 days: distilled water (10 ml/kg, hypogonadal control), testosterone (4 mg/kg/3days) and the extract of V. afzelii (100, 200 and 400 mg/kg). Sexual behavior, sperm parameters, testes function and structure were assessed. Compared to the normal controls, significant (p = 0.0000) increases in mount (24 ± 0.94 seconds vs. 1200 ± 00 seconds) and intromission (49.16 ± 10.85 seconds vs. 1200 ± 00 seconds) latencies, and post-ejaculatory interval (381.72 ± 37.55 seconds vs. 1200 ± 00 seconds) were observed in all groups receiving cyproterone acetate on day 0. Total inhibitions of mounts (63.50 ± 8.91 vs. 00 ± 00), intromissions (36.66 ± 3.51 vs. 00 ± 00) (p = 0.0000), ejaculations (2.83 ± 00 vs. 00 ± 00, p = 0.0002) frequencies and mean copulatory interval (627.30 ± 81.80 vs. 00 ± 00, p = 0.0000) were also observed in these groups. Moreover, decreases in daily sperm production (2.65 ± 0.19 vs. 1.17 ± 0.08, p = 0.0498), percentage of sperm mobility (78.64 ± 8.41 vs. 10.12 ± 2.32), serum testosterone level (8.39 ± 0.63 ng/dl vs. 1.68 ± 0.19 ng/dl), diameter of seminiferous tubules (111.97 ± 0.51 µm vs. 94.51 ± 0.57 µm) and height of germinal epithelium (46.58 ± 0.34 µm vs. 33.74 ± 0.66 µm) (p = 0.0000) associated with increases in sperm transit (3.13 ± 0.45 vs. 11.07 ± 1.45, p = 0.0000) were also observed in these groups. Interestingly, compared to hypogonadal control and day 0, the administration of V. afzelii extract induced significant (p = 0.0000) improvements in all these altered parameters with 400 mg/kg being the most active dose. These results, attributed to saponins, flavonoids, polyphenols and triterpenes detected in this plant's extract confirm its traditional usage and could be useful for the management of patients suffering from hypogonadism.

Na+/H+ exchanger 1 inhibition reverses manifestation of peripheral diabetic neuropathy in type 1 diabetic rats.

Evidence for an important role for Na(+)/H(+) exchangers in diabetic complications is emerging. The aim of this study was to evaluate whether Na(+)/H(+) exchanger 1 inhibition reverses experimental peripheral diabetic neuropathy. Control and streptozotocin-diabetic rats were treated with the specific Na(+)/H(+) exchanger 1 inhibitor cariporide for 4 wk after 12 wk without treatment. Neuropathy end points included sciatic motor and sensory nerve conduction velocities, endoneurial nutritive blood flow, vascular reactivity of epineurial arterioles, thermal nociception, tactile allodynia, and intraepidermal nerve fiber density. Advanced glycation end product and markers of oxidative stress, including nitrated protein levels in sciatic nerve, were evaluated by Western blot. Rats with 12-wk duration of diabetes developed motor and sensory nerve conduction deficits, thermal hypoalgesia, tactile allodynia, and intraepidermal nerve fiber loss. All these changes, including impairment of nerve blood flow and vascular reactivity of epineurial arterioles, were partially reversed by 4 wk of cariporide treatment. Na(+)/H(+) exchanger 1 inhibition was also associated with reduction of diabetes-induced accumulation of advanced glycation endproduct, oxidative stress, and nitrated proteins in sciatic nerve. In conclusion, these findings support an important role for Na(+)/H(+) exchanger 1 in functional, structural, and biochemical manifestations of peripheral diabetic neuropathy and provide the rationale for development of Na(+)/H(+) exchanger 1 inhibitors for treatment of diabetic vascular and neural complications.

Dracaena arborea alleviates ultra-structural spermatogenic alterations in streptozotocin-induced diabetic rats.

BACKGROUND: Infertility is a common complication in diabetic men and experimental animals, mainly due to loss of germ cells by apoptotic cell death. The aim of this study was to evaluate the effects of aqueous and ethanol extracts of Dracaena arborea in streptozotocin-induced ultra-structural spermatogenic alterations in Wistar rats. METHODS: Diabetic animals were orally treated with Millipore water (10 ml/kg), sildenafil citrate (1.44 mg/kg) or Dracaena arborea aqueous (500 mg/kg) and ethanol (100 mg/kg) extracts for three weeks. A group of non diabetic rats received Millipore water (10 ml/kg) and served as healthy control group. Blood glucose was monitored at the beginning and the end of the study. One day after the last treatment, animals were sacrificed and the testes immediately removed were morphologically observed and prepared for electron microscopy analysis of spermatogenesis. RESULTS: Our results showed that Dracaena arborea was devoid of any anti-hyperglycemic activity. In the untreated diabetic rats, hyperglycemia severely damaged the testes morphology as well as the spermatogenic process as evidenced by the: thickness of basement membrane of the seminiferous tubule; mitochondria alteration; abnormal spermatocyte cells displaying polymorphous nuclei, cytoplasmic vacuolization and necrosis; and disorganization and degeneration of sperm germ cells. Administration of sildenafil citrate and Dracaena arborea extracts to the diabetic rats improved testes morphology and reversed, although not completely, the impairment of spermatogenesis; this alleviating effect was more pronounced in animals treated with the aqueous extract (500 mg/kg) of Dracaena arborea. CONCLUSION: Dracaena arborea improves testes morphology and restores spermatogenesis in type 1 diabetic rats, without having major anti-hyperglycemic properties. These effects could be attributed to saponins, flavonoids, phenols and sterols revealed in this plant, which could be a useful component in the treatment of diabetes-induced testicular dysfunction.

Mondia whitei (Periplocaceae) prevents and Guibourtia tessmannii (Caesalpiniaceae) facilitates fictive ejaculation in spinal male rats.

BACKGROUND: Mondia whitei and Guibourtia tessmannii are used in Cameroon traditional medicine as aphrodisiacs. The present study was undertaken to evaluate the pro-ejaculatory effects of the aqueous and organic solvent extracts of these plants in spinal male rats. METHODS: In spinal cord transected and urethane-anesthetized rats, two electrodes where inserted into the bulbospongiosus muscles and the ejaculatory motor pattern was recorded on a polygraph after urethral and penile stimulations, intravenous injection of saline (0.1 ml/100 g), dopamine (0.1 µM/kg), aqueous and organic solvent plant extracts (20 mg/kg). RESULTS: In all spinal rats, urethral and penile stimulations always induced the ejaculatory motor pattern. Aqueous or hexane extract of Mondia whitei (20 mg/kg) prevented the expression of the ejaculatory motor pattern. The pro-ejaculatory effects of dopamine (0.1 µM/kg) were not abolished in spinal rats pre-treated with Mondia whitei extracts. Aqueous and methanolic stem bark extracts of Guibourtia tessmannii (20 mg/kg) induced fictive ejaculation characterized by rhythmic contractions of the bulbospongiosus muscles followed sometimes with expulsion of seminal plugs. In rats pre-treated with haloperidol (0.26 µM/kg), no ejaculatory motor pattern was recorded after intravenous injection of Guibourtia tessmannii extracts (20 mg/kg). CONCLUSION: These results show that Mondia whitei possesses preventive effects on the expression of fictive ejaculation in spinal male rats, which is not mediated through dopaminergic pathway; on the contrary, the pro-ejaculatory activities of Guibourtia tessmannii require the integrity of dopaminergic system to exert its effects. The present findings further justify the ethno-medicinal claims of Mondia whitei and Guibourtia tessmannii.

Ejaculatory activities of Allanblackia floribunda stem bark in spinal male rats.

CONTEXT: Medicinal plants have become a great source of relief for more 70% of the population in developing countries where access to modern medicine is very limited. Some of these plants are used as aphrodisiac agents. The stem bark of Allanblackia floribunda Oliver (Clusiacea) has been used in Cameroon as an aphrodisiac. OBJECTIVE: This study was designed to assess the effects of Allanblackia floribunda aqueous and ethanol extracts and their potential mechanism on fictive ejaculation in spinal male rats. MATERIALS AND METHODS: Electromyographic activities of the bulbospongiosus muscles were recorded in 24 groups of spinal rats after intravenous administration of aqueous and ethanol extracts (2.5, 10, 20, 40 or 60 mg/kg) from the stem bark of A. floribunda in the presence or absence of dopamine (60 mg/kg). Furthermore, electromyographic activities of the bulbospongiosus muscles were recorded in five groups of spinal rats pre-treated orally during 8 d with extracts (150 and 300 mg/kg) in the presence of dopamine. RESULTS: Sequential treatments of rats with extracts significantly decreased the occurrence of ejaculation induced by dopamine up to 88.94% inhibition. The oral pre-treatment with both extracts significantly decreased the ejaculation induced by dopamine with the highest inhibition of 89.79%. DISCUSSION AND CONCLUSION: Two extracts of A. floribunda used in this study had inhibitory activities on ejaculation. The inhibitory effect of A. floribunda extracts on fictive ejaculation in rat may be directly mediated through dopaminergic pathways. Inhibition of ejaculation caused by these extracts could support its use in patients suffering from rapid ejaculation.

Factors Associated with COVID-19 Vaccine Refusal: A Community-Based Study in the Menoua Division in Cameroon.

COVID-19, which was named in March 2020 as a global pandemic by the WHO, remains a serious public health threat worldwide. Despite the adoption of vaccines as an effective strategy to counter this pandemic, the vaccination rate in Cameroon is far lower than that planned by the Cameroonian government and its partners. The main objective of this study was to determine the factors limiting COVID-19 vaccine acceptance in the Menoua Division in the West Region of Cameroon. A community-based cross-sectional and analytical study was conducted between March and April 2022 in the Menoua Division. A pre-tested questionnaire was filled out by willing participants of more than 18 years old, and data were further expressed in order to estimate the knowledge of participants on COVID-19, vaccine status, and the factors associated with vaccine refusal. A Pearson test was performed in order to identify the associated factors, with a p-value < 0.05 considered as significant. A total of 520 participants with a mean age of 33.27 ± 12.78 were included. Most had a secondary education level (56.15%), and trade and informal sectors (34.04%) were the main occupations. Knowledge on COVID-19 was average, and it was significantly associated (p < 0.05) with gender and education level. The vaccination rate was 10%, which was six times less than the national target. A lack of information, confidence, and medicinal plant use were all factors significantly associated with vaccine refusal. This pioneer community-based study in Cameroon identified a lack of knowledge, confidence, and medicinal plant use as the leading factors limiting COVID-19 vaccine acceptance in Cameroon. Health authorities should therefore strengthen sensitization in order to tackle the lack of information and the misinformation among the target groups.

The edible plant Amaranthus hybridus (Amaranthaceae) prevents the biochemical, histopathological and fertility impairments in colibri®-treated female rats.

Colibri® a commercial formulation of Imidacloprid severely impairs the reproductive function. This study aimed at evaluating the preventive effects of Amaranthus hybridus on the reproductive toxicity of colibri® in female rats. Eighty rats (n = 10/group) were orally treated with colibri® (22.5 mg/kg) and co-administered with either aqueous or methanolic extracts of A. hybridus (55 or 110 mg/kg) within four weeks. Control animals received either distilled water (10 ml/kg), clomiphene citrate or vitamin E. Starting from day 18 of treatment till the end, half of animals in each group (n = 5) was used for the fertility test whereas the remaining rats were kept under treatment until sacrifice. Blood, ovaries, uterus and vagina were collected after sacrifice for measurement of sexual hormones, oxidative stress markers and histological assessment. Exposure of female rats to colibri® was followed by a significant reduction (p < 0.05) in the ovarian and uterine weights, LH, FSH, estradiol and progesterone levels as well as ovarian superoxide dismutase, catalase and peroxidase activities. Moreover, alteration of ovaries, uteri and vagina histology, increase in MDA concentration, decrease in fertility and parturition indices and, pup's viability were recorded. Co-administration of colibri® and plant extracts significantly (p < 0.05-0.001) prevented the above-mentioned damages through biochemical parameter regulations. These results suggest that A. hybridus exerts a preventive effect against colibri®-induced female reproductive toxicity.

Amaranthus hybridus (Amaranthaceae) prevents the detrimental effects of cyclophosphamide on ovarian function in Wistar rats: An experimental study.

Background: Cyclophosphamide (CP) is an anticancer agent, but its chronic administration induces ovarian toxicity. Objective: We evaluated the effects of aqueous extract (AE) and methanol extract (ME) of Amaranthus hybridus (A. hybridus) on CP-induced ovarian toxicity in rats. Materials and Methods: 40 female Wistar rats (10 wk, 170-200 gr) were distributed into 8 groups (n = 5/each) as follows: 1) healthy control; 2) CP+distilled water (10 ml/kg/d); 3) CP+3%-tween 80 (10 mL/kg/d); 4) CP+clomiphene citrate (2 mg/kg/d); 5, 6) CP+AE of A. hybridus (55 and 110 mg/kg/d); and 7, 8) CP+ME of A. hybridus (55 and 110 mg/kg/d). After 28 days of treatment, estrus cyclicity, ovarian and uterine weights as well as estradiol levels and ovarian histology were determined. Results: CP induced ovarian toxicity after 28 days of exposure. More specifically, CP disturbed the estrus cycle, decreased ovary and uterus weights (p = 0.04), and the 17-ß estradiol level (p = 0.04), and induced severe ovarian damages. Remarkably, A. hybridus significantly increased (p = 0.03) the ovarian weight (AE and ME at all doses) and uterus weight (ME at 110 mg/kg/d), compared with the CP-treated rats. Moreover, the 17-ß estradiol level was significantly elevated (p = 0.02) in rats given clomiphene citrate and A. hybridus (AE 110 mg/kg/d; ME 55 mg/kg/d). Finally, the ovaries of rats given plant extracts had many corpus luteum and normal follicles, and no cystic follicles. Conclusion: prevented the detrimental effects of CP on ovarian function, which could support its traditional use as a fertility enhancer.

Poly(ADP-ribose) polymerase-1 (PARP-1) gene deficiency alleviates diabetic kidney disease.

Poly(ADP-ribose)polymerase (PARP) inhibitors prevent or alleviate diabetic nephropathy. This study evaluated the role for PARP-1 in diabetic kidney disease using the PARP-1-deficient mouse. PARP-1-/- and the wild-type (129S1/SvImJ) mice were made diabetic with streptozotocin, and were maintained for 12 weeks. Final blood glucose concentrations were increased ∼ 3.7-fold in both diabetic groups. PARP-1 protein expression (Western blot analysis) in the renal cortex was similar in non-diabetic and diabetic wild-type mice (100% and 107%) whereas all knockouts were PARP-1-negative. PARP-1 gene deficiency reduced urinary albumin (ELISA) and protein excretion prevented diabetes-induced kidney hypertrophy, and decreased mesangial expansion and collagen deposition (both assessed by histochemistry) as well as fibronectin expression. Renal podocyte loss (immunohistochemistry) and nitrotyrosine and transforming growth factor-ß1 accumulations (both by ELISA) were slightly lower in diabetic PARP-1-/- mice, but the differences with diabetic wild-type group did not achieve statistical significance. In conclusion, PARP-1-/- gene deficiency alleviates although does not completely prevent diabetic kidney disease.