An Eluate of the Medicinal Plant Garcinia kola Displays Strong Antidiabetic and Neuroprotective Properties in Streptozotocin-Induced Diabetic Mice.

Materials and Methods: G. kola methanolic extract was fractionated using increasingly polar solvents. Fractions were administered to streptozotocin (STZ)-induced diabetic mice until marked motor signs developed in diabetic controls. Fine motor skills indicators were measured in the horizontal grid test (HGT) to confirm the prevention of motor disorders in treated animals. Column chromatography was used to separate the most active fraction, and subfractions were tested in turn in the HGT. Gas chromatography-mass spectrometry (GC-MS) technique was used to assess the components of the most active subfraction. Results: Treatment with ethyl acetate fraction and its fifth eluate (F5) preserved fine motor skills and improved the body weight and blood glucose level. At dose 1.71 mg/kg, F5 kept most parameters comparable to the nondiabetic vehicle group values. GC-MS chromatographic analysis of F5 revealed 36 compounds, the most abundantly expressed (41.8%) being the ß-lactam molecules N-ethyl-2-carbethoxyazetidine (17.8%), N,N-dimethylethanolamine (15%), and isoniacinamide (9%). Conclusions: Our results suggest that subfraction F5 of G. kola extract prevented the development of motor signs and improved disease profile in an STZ-induced mouse model of diabetic encephalopathy. Antidiabetic activity of ß-lactam molecules accounted at least partly for these effects.

Garcinia kola seeds may prevent cognitive and motor dysfunctions in a type 1 diabetes mellitus rat model partly by mitigating neuroinflammation.

Background We reported recently that extracts of seeds of Garcinia kola, a plant with established hypoglycemic properties, prevented the loss of inflammation-sensible neuronal populations like Purkinje cells in a rat model of type 1 diabetes mellitus (T1DM). Here, we assessed G. kola extract ability to prevent the early cognitive and motor dysfunctions observed in this model. Methods Rats made diabetic by single injection of streptozotocin were treated daily with either vehicle solution (diabetic control group), insulin, or G. kola extract from the first to the 6th week post-injection. Then, cognitive and motor functions were assessed using holeboard and vertical pole behavioral tests, and animals were sacrificed. Brains were dissected out, cut, and processed for Nissl staining and immunohistochemistry. Results Hyperglycemia (209.26 %), body weight loss (-12.37 %), and T1DM-like cognitive and motor dysfunctions revealed behavioral tests in diabetic control animals were not observed in insulin and extract-treated animals. Similar, expressions of inflammation markers tumor necrosis factor (TNF), iba1 (CD68), and Glial fibrillary acidic protein (GFAP), as well as decreases of neuronal density in regions involved in cognitive and motor functions (-49.56 % motor cortex, -33.24 % medial septal nucleus, -41.8 % /-37.34 % cerebellar Purkinje /granular cell layers) were observed in diabetic controls but not in animals treated with insulin or G. kola. Conclusions Our results indicate that T1DM-like functional alterations are mediated, at least partly, by neuroinflammation and neuronal loss in this model. The prevention of the development of such alterations by early treatment with G. kola confirms the neuroprotective properties of the plant and warrant further mechanistic studies, considering the potential for human disease.

Garcinia kola aqueous suspension prevents cerebellar neurodegeneration in long-term diabetic rat - a type 1 diabetes mellitus model.

ETHNOPHARMACOLOGICAL RELEVANCE: The development of compounds able to improve metabolic syndrome and mitigate complications caused by inappropriate glycemic control in type 1 diabetes mellitus is challenging. The medicinal plant with established hypoglycemic properties Garcinia kola Heckel might have the potential to mitigate diabetes mellitus metabolic syndrome and complications. AIM OF THE STUDY: We have investigated the neuroprotective properties of a suspension of G. kola seeds in long-term type 1 diabetes mellitus rat model. MATERIALS AND METHODS: Wistar rats, made diabetic by single injection of streptozotocin were monitored for 8 months. Then, they were administered with distilled water or G. kola oral aqueous suspension daily for 30 days. Body weight and glycemia were determined before and after treatment. After sacrifice, cerebella were dissected out and processed for stereological quantification of Purkinje cells. Histopathological and immunohistochemical analyses of markers of neuroinflammation and neurodegeneration were performed. RESULTS: Purkinje cell counts were significantly increased, and histopathological signs of apoptosis and neuroinflammation decreased, in diabetic animals treated with G. kola compared to diabetic rats given distilled water. Glycemia was also markedly improved and body weight restored to non-diabetic control values, following G. kola treatment. CONCLUSIONS: These results suggest that G. kola treatment improved the general condition of long-term diabetic rats and protected Purkinje cells partly by improving the systemic glycemia and mitigating neuroinflammation.