Research Article
Ngugi M Piero, Kimuni NS, N
Abstract
Lantana rhodesiensis Linn is used traditionally in the management of several diseases including diabetes mellitus; however, its efficacy and safety is not scientifically evaluated. The aim of this study was to determine in vivo hypoglycemic activity and safety of aqueous extracts of L. rhodesiensis in white male albino rats. Aqueous extracts were screened for their hypoglycemic activity in alloxan induced diabetic rats using the oral and intraperitoneal routes. The safety of these extracts was studied in rats orally or intraperitoneally administered with 1 g/kg body weight daily for 28 days by recording the changes in body and organ weight, hematological and biochemical parameters and histology. Mineral compositions of the extracts were estimated using total reflection X-Ray Fluorescence System (TRXF) while the types of phytochemicals present were assessed using standard procedures. Aqueous extracts orally and intraperitoneally administered at 50, 100 and 150 mg/kg body weight demonstrated hypoglycemic activity with the intraperitoneal route being more effective than the oral route. Oral and intraperitoneal dose of 1 g/kg body weight of the extracts significantly reduced the body weight gain, increased the testis and spleen, and decreased the lung weight; reduced the hemoglobin levels, red blood cell count, packed cell volume and increased the neutrophil count; decreased the activity of γ-glutamyltransferase and histologically mildly reduced lymphoid follicles. Orally, the same dose decreased the red blood cell count, packed cell volume, mean cell volume, monocyte and platelet count; increased the activity of lactate dehydrogenase, and creatine kinase. The extract contained phenols, tannins, flavonoids, alkaloids, sterols, terpenoids, cardiac glycosides, phylobatannins, resins, and bound anthrax quinones. Potassium, calcium, manganese, iron, lead and zinc levels in the extracts were below the recommended daily allowance. In conclusion, the observed hypoglycemic activity and slight toxicity could be associated with the phytonutrients present in this plant. This study recommends use of this plant as herbal medicine.