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Combining antibiotics with resistance reversing agents is a key strategy to overcome bacterial resistance. Upon screening antimicrobial activities of plants used in traditional medicine, we found that a leaf dichloromethane extract from the shea butter tree (Vitellaria paradoxa) had antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) with further evidence of synergy when combined with β-lactams. Using HPLC-MS, we identified ursolic (UA) and oleanolic acids (OA) in leaves and twigs of this species, and quantified them by HPLC-UV as the major constituents in leaf extracts (21% and 6% respectively). Both pure triterpenic acids showed antimicrobial activity against reference and clinical strains of MRSA, with MICs ranging from 8-16 mg/L for UA to 32-128 mg/L for OA. They were highly synergistic with β-lactams (ampicillin and oxacillin) at subMIC concentrations. Reversion of MRSA phenotype was attributed to their capacity to delocalize PBP2 from the septal division site, as observed by fluorescence microscopy, and to disturb thereby peptidoglycan synthesis. Moreover, both compounds also inhibited β-lactamases activity of living bacteria (as assessed by inhibition of nitrocefin hydrolysis), but not in bacterial lysates, suggesting an indirect mechanism for this inhibition. In a murine model of subcutaneous MRSA infection, local administration of UA was synergistic with nafcillin to reduce lesion size and inflammatory cytokine (IL-1β) production. Thus, these data highlight the potential interest of triterpenic acids as resistance reversing agents in combination with β-lactams against MRSA. [ABSTRACT FROM AUTHOR]

Lipid-based nutrient supplements (LNS) are used to prevent and treat moderate and severe acute malnutrition, a leading cause of mortality in children-under-five. The physical and chemical changes of two new LNS products were evaluated before and after accelerated shelf life testing (ASLT) according to protocols suggested by the U.S. Agency for International Development (USAID) and Doctors without Borders and compared against USAID's A-20 paste as a control. LNS formulas containing Shea butter from the Shea nut tree (Vitellaria paradoxa), a common fat source in parts of Sub-Saharan Africa, with and without flax-seed oil, as a source of omega-3 fatty acids, were developed. LNS formulas were batched (0.8 kg) in a wet grinder, sealed under nitrogen in three-layer mini-pouches (20 g), and underwent ASLT at 40 ± 2 °C for six months with sampling every eight weeks. At each time point, water activity, moisture, peroxide value, oil separation, vitamin C content, and hardness were evaluated. Results showed comparable stability among all formulas with an increase in Aw (p < 0.05) but no change in vitamin C, oil separation, or peroxide value. Addition of Shea butter improved the LNS's hardness, which remained stable over time. Modifying fat profile in LNS can improve its texture and essential fatty acid content without affecting its storage stability. [ABSTRACT FROM AUTHOR]