In vitro antiplasmodial activity and cytotoxicity of nine plants traditionally used in Gabon

Aim of the study

As part of a project to identify new compounds active on malarial parasites, we tested the in vitro antiplasmodial activity of nine plants traditionally used to treat malaria symptoms in Haut-Ogooué Province, South-East Gabon.

Materials and methods

Dichloromethane and methanolic extracts of each plant were tested for their antiplasmodial activity on two chloroquine-resistant strains of Plasmodium falciparum (FCB and W2), based on lactate dehydrogenase activity. Cytotoxicity was assessed with the MTT test on MRC-5 human diploid embryonic lung cells.

Results

The methanolic extract of Staudtia gabonensis and the dichloromethane extract of Adhatoda latibracteata showed high antiplasmodial activity (IC₅₀ < 1 μg/ml) and low cytotoxicity, with selectivity indexes of about 58.25 and 16.43, respectively. The methanolic extract of Monodora myristica and the dichloromethane extract of Afromomum giganteum also showed promising activity (1 < IC₅₀ < 10 μg/ml) and low cytotoxicity, with selectivity indexes about 15.70 and 12.48, respectively. Dichloromethane extracts of Monodora myristica and Leonotis Africana showed moderate activity (10 < IC₅₀ < 40 μg/ml), with selectivity indexes about 6.07 and 28.89, respectively. Both extracts of Culcasia lancifolia had IC₅₀ values of 10-40 μg/ml but high cytotoxicity (selectivity indexes <2.77). The methanolic extract of Dorstenia klaineana had moderate antiplasmodial activity (IC₅₀ around 17 μg/ml) but strong cytotoxicity (0.43 μg/ml), giving a selectivity index of about 0.03.

Conclusions

Most extracts of nine selected plants traditionally used to treat malaria in Gabon had interesting antiplasmodial activity in vitro. This supports continued investigations of traditional medicines in the search for new antimalarial agents. The compounds responsible for the observed antiplasmodial effects are under investigation.     

Low risk of nevirapine resistance mutations in the prevention of mother-to-child transmission of HIV-1: Agence Nationale de Recherches sur le SIDA Ditrame Plus, Abidjan, Cote d'Ivoire

The frequency of resistance mutations was estimated in the cohort of Agence Nationale de Recherches sur le SIDA Ditrame Plus, a study that evaluated the combination of short-course zidovudine (ZDV) plus lamivudine (3TC) and single-dose nevirapine (SD-NVP) followed by 3 days of postpartum ZDV plus 3TC for the prevention of mother-to-child transmission of human immunodeficiency virus type 1 (HIV-1). The frequency with which resistance mutations were detected in mothers at week 4 postpartum was 1.14% (95% confidence interval [CI], 0.03%-6.17%) for NVP and 8.33% (95% CI, 3.66%-15.76%) for 3TC. In multivariate analysis, 3TC resistance was associated with a longer duration of ZDV plus 3TC prepartum prophylaxis (P=.009). This regimen, which is feasible in resource-limited settings, prevents most peripartum HIV-1 transmission and minimizes the development of NVP resistance.     

Female genital mutilation and noninvasive cervical abnormalities and invasive cervical cancer in Senegal,West Africa: A retrospective study

Female genital mutilation or cutting (FGM/C) is a traditional practice that affects a significant portion of women in sub-Saharan Africa, Egypt, areas of the Middle East and some countries in Asia. While clinical and epidemiological studies have established a close association between inflammation and carcinogenesis, particularly in epithelial cancers, the relationship between FGM/C and cervical cancer is not well known. We performed a secondary analysis using combined data from six research studies conducted in and around Dakar, Senegal from 1994 to 2012. Study subjects included both asymptomatic women who presented to outpatient clinics but were screened for cervical cancer, and women with cancer symptoms who were referred for cervical cancer treatment. We used unconditional logistic regression to estimate adjusted pooled odds ratios (ORs) and 95% confidence intervals (CI) for associations between FGM/C and (1) Invasive cervical cancer (ICC) and (2) noninvasive cervical abnormalities. After adjusting for confounding, women with ICC were 2.50 times more likely to have undergone FGM/C than women without cervical abnormalities (95% CI, 1.28–4.91). Restricting to HPV-positive women increased the strength of the association (OR = 4.23; 95% CI 1.73–10.32). No significant associations between FGM/C and noninvasive cervical abnormalities were observed, except in commercial sex workers with FGM/C (OR = 2.01; 95% CI 1.19–3.40). The potential increased risk for ICC suggested by our study warrants further examination. Study results may impact cancer prevention efforts in populations where FGM/C is practiced and draw awareness to the additional health risks associated with FGM/C.     

Caries of the first permanent molar in Ivory Coast children

The authors study dental decay in the first permanent molar among school children in Dimbokro (C?te d'Ivoire). The study, carried out on 1050 children aged between 7 to 16, revealed a low CAO index but a frequency index greater than 50%.     

Comparison of respiratory triggering and gating techniques for the removal of respiratory artifacts in MR imaging

Respiratory movement degrades magnetic resonance (MR) images of the chest and abdomen by increasing noise through the production of "ghost" artifacts and by decreasing edge sharpness in moving structures. Respiratory gating, which limits data acquisition to end-expiration, is successful in restoring edge sharpness and reducing ghosts but increases imaging time two to three times, which limits its use to sequences with short repetition times (TRs). To overcome this limitation, an alternative technique, respiratory triggering, was developed, which triggers the acquisition of an MR section at a fixed point on the respiratory cycle. This technique restores edge sharpness and reduces ghosts, but unlike gating, it can be used to produce an image at any phase of the respiratory cycle. Triggering requires long TRs since the TR is limited to the respiratory period (TP) or one-half of TP, depending on whether the same section is triggered once or twice during a single respiratory cycle. Gating and triggering were evaluated and compared for single-section and multi-section imaging of both volunteers and patients. The authors conclude that when a chest or abdominal survey is required, triggering takes less time than gating if TRs are required that exceed one-fifth of TP.     

Myéloradiculite à <Emphasis Type="Italic">Schistosoma haematobium</Emphasis> : à propos d’une observation à Dakar (Sénégal)

Nervous localisations of schistosomiasis are rare. We report the case of a 25 year-old Senegalese patient admitted for a progressive myeloradiculitis onset, over a one week period. The diagnosis of Schistosoma haematobium myeloradiculitis was made in front of a positive serum serology for S. haematobium, presence of S. haematobium eggs in urine, hyperproteinorachia, endemicity of S. haematobium in the region where the patient was originating and a past medical history of macroscopic hematuria in a context of river bathing. There was also no arguments for another cause to these neurological manifestations. Our patient was treated with praziquantel, prednisone and physiotherapy. Evolution was marked 6 weeks after the beginning of treatment by a significant improvement of motor deficit, enabling the patient to walk again. There was also a regression of genitosphincter dysfunction. Work-up for patients presenting with paraplegia in tropical countries, should also include search for S. heamatobium infection.