Parinari curatellifolia, Biosafety and Pharmacological Efficacy against Biological End Points of Pneumonia

Abstract

Parinari curatellifolia is a widely utilized medicinal plant in Zimbabwe. The major traditional applications include the management of key biological end points of pneumonia, a critical global health concern particularly in the sub-Saharan Africa and south Asia regions where it contributes to over 14% of under-five deaths. Pneumonia is characterized by inflammatory biomarkers such as elevated procalcitonin and C-reactive protein. Given the limitations and challenges associated with current paediatric pneumonia treatments, there is an urgent need for safe, effective, and affordable alternatives capable of modulating the disease’s biological endpoints. This study investigated the phytoconstituent profile, the anti-inflammatory and antibacterial activities of P. curatellifolia. Various wet chemical techniques were employed to screen for the pharmacologically active secondary metabolites; the anti-inflammatory activity was determined through the egg albumin assay using diclofenac as a standard. The antibacterial effectivity was assessed through the agar well diffusion method against S. aureus and K. pneumoniae and the acute oral toxicity evaluation was done using an amended OECD technical guideline 423 (the limit test). The phytochemical screening revealed the presence of diverse biomedically relevant secondary metabolites. Biosafety assessment in Sprague Dawley rats confirmed the absence of acute oral toxicity effects at a fixed dose of 4000 mg/kg body weight. The lyophilised hydroethanolic bark extract also exhibited significant anti-inflammatory activity at 8000mg/kg body weight comparable to diclofenac at 2000mg/kg. The antibacterial tests confirmed antibacterial inhibition with a zone of inhibition diameter of 21mm and 17mm for S. aureus and K. pneumoniae respectively. It was therefore concluded that the numerous bioactive secondary metabolites present in P. curatellifolia bark possess anti-inflammatory, antibacterial, and potentially antioxidant properties and are toxicologically safe. This study validates the use of Parinari curatellifolia as a potential complementary treatment in the management of key biological endpoints of pneumonia in traditional Zimbabwean medicinal practices.