Therapeutic properties of aqueous extracts of leaves and stems bark of Prosopis africana (Guill. & Perr.) Taub. (Fabaceae) used in the management of dental caries

Prosopis africana  (Guill. & Perr.) Taub. (Fabaceae) is used in the herbal medicine of Burkina Faso to treat dental caries. This study aims to contribute to the valorization of the said plant by investigating the antioxidant, anti-inflammatory and antibacterial properties of aqueous leaves and stems extracts. The inhibitory activity on lipoxygenase was used to evaluate the anti-inflammatory effect of the extracts. The antioxidant activity of bots extracts of the plant was assessed using DPPH radical scavenging, ABTS+ radical cation decolorization. The anti-biofilm effect of the extracts was evaluated on Streptococcus mutans ATCC 25175, Staphylococcus aureus ATCC 43300, Pseudomonas aeruginosa PAOI and the anti-Quorum sensing effect on Chromobacterium CV026. Aqueous extracts of Prosopis africana stems show the highest content of phenolic compounds (30,04± 0,59 mgAGE/100 mg extract) while those of the leaves show the highest content of total flavonoids (3.29 ± 0.53 mgQE/100mg extract). The aqueous extract of stem bark show the strongest antioxidant activity ( IC50 = 4.58±0.07µg/ml for the ABTS) , a best Inhibitory action on activity of lipoxygenase (IC50 = 13.42 ± 1.26 μg/mL ), a highest anti-biofilm activity ( 63.6%;  at the concentration of 100µg/ml) without affecting the bacterial growth. In addition, this extract has the strongest anti-quorum sensing activity with an percentage of inhibition 53,5%. These findings suggested that the aqueous extracts of stem bark and leaves of Prosopis africana contain promoted phytomolecules to combat dental caries infections. Keywords : Anti-biofilm, Anti-quorum sensing, Lipoxygenase, Prosopis african

Enhanced effect of seasonal malaria chemoprevention when coupled with nutrients supplementation for preventing malaria in children under 5 years old in Burkina Faso: a randomized open label trial

Background In rural African settings, most of the children under the coverage of Seasonal Malaria Chemoprevention (SMC) are also undernourished at the time of SMC delivery, justifying the need for packaging malarial and nutritional interventions. This study aimed at assessing the impact of SMC by coupling the intervention with nutrients supplementation for preventing malaria in children less than 5 years old in Burkina Faso.Methods A randomized trial was carried out between July 2020 and June 2021 in the health district of Nanoro, Burkina Faso. Children (n = 1059) under SMC coverage were randomly assigned to one of the three study arms SMC + Vitamin A (SMC-A, n = 353) or SMC + Vitamin A + Zinc (SMC-AZc, n = 353) or SMC + Vitamin A + PlumpyDoz(tm) (SMC-APd, n = 353)-a medium quantity—lipid-based nutrient supplement (MQ-LNS). Children were followed up for one year that included an active follow-up period of 6 months with scheduled monthly home visits followed by 6 months passive follow-up. At each visit, capillary blood sample was collected for malaria diagnosis by rapid diagnosis test (RDT).Results Adding nutritional supplements to SMC had an effect on the incidence of malaria. A reduction of 23% (adjusted IRR = 0.77 (95%CI 0.61–0.97) in the odds of having uncomplicated malaria in SMC-APd arm but not with SMC-AZc arm adjusted IRR = 0.82 (95%CI 0.65–1.04) compare to control arm was observed. A reduction of 52%, adjusted IRR = 0.48 (95%CI 0.23–0.98) in the odds of having severe malaria was observed in SMC-APd arm compared to control arm. Besides the effect on malaria, this combined strategy had an effect on all-cause morbidity. More specifically, a reduction of morbidity odds of 24%, adjusted IRR = 0.76 (95%CI 0.60–0.94) in SMC-APd arm compared to control arm was observed. Unlike clinical episodes, no effect of nutrient supplementation on cross sectional asymptomatic infections was observed.Conclusion Adding nutritional supplements to SMC significantly increases the impact of this intervention for preventing children from malaria and other childhood infections. Trial registration : NCT04238845