Antidiabetic activity of Solanum torvum fruit extract in streptozotocin-induced diabetic rats

Background

Solanum torvum Swartz, a medicinal plant belonging to the family Solanaceae, is an important medicinal plant widely distributed throughout the world and used as medicine to treat diabetes, hypertension, tooth decay, and reproductive problems in traditional systems of medicine around the world including Malaysia. The objective of this study was to investigate hypoglycemic, antilipidemic, and hepatoprotective activities, histopathology of the pancreas, and specific glucose regulating gene expression of the ethanolic extract of S. torvum fruit in streptozotocin-induced diabetic Sprague–Dawley rats.

Materials and methods

Acute toxicity study was done according to OECD-423 guidelines. Diabetes was induced by intraperitoneal (i.p.) injection of streptozotocin (55 mg/kg) in male Sprague–Dawley rats. Experimental diabetic rats were divided into six different groups; normal, diabetic control, and glibenclamide at 6 mg/kg body weight, and the other three groups of animals were treated with oral administration of ethanolic extract of S. torvum fruit at 120, 160, and 200 mg/kg for 28 days. The effect of ethanolic extract of S. torvum fruit on body weight, blood glucose, lipid profile, liver enzymes, histopathology of pancreas, and gene expression of glucose transporter 2 (slc2a2), and phosphoenolpyruvate carboxykinase (PCK1) was determined by RT-PCR.

Results

Acute toxicity studies showed LD₅₀ of ethanolic extract of S. torvum fruit to be at the dose of 1600 mg/kg body weight. Blood glucose, total cholesterol, triglycerides, low-density lipoproteins, very low-density lipoproteins, serum alanine aminotransferase, and aspartate aminotransferase were significantly reduced, whereas high-density lipoproteins were significantly increased in S. torvum fruit (200 mg/kg)-treated rats. Histopathological study of the pancreas showed an increase in number, size, and regeneration of β-cell of islets of Langerhans. Gene expression studies revealed the lower expression of slc2a2 and PCK1 in treated animals when compared to diabetic control.

Conclusion

Ethanolic extract of S. torvum fruits showed hypoglycemic, hypolipidemic, and hepatoprotective activity in streptozocin-induced diabetic rats. Histopathological studies revealed regeneration of β cells of islets of Langerhans. Gene expression studies indicated lower expression of slc2a2 and PCK1 in treated animals when compared to diabetic control, indicating that the treated animals prefer the gluconeogenesis pathway.

Hypoxic-Mediated Oxidative Stress Condition and Hydroxyapatite-Inducing Osteogenic Differentiation of Human Mesenchymal Stem Cells: A Mathematical Modeling Study

Avascular necrosis (AVN) of the bones remains a major clinical challenge. Fractures in the talus, the scaphoid, and the neck of the femur are especially challenging to heal due to the low blood vessel network and the lack of collateral blood supply. These fractures are associated with high rates of nonunion and increased infections that require repeated operations. Conventional treatments by autografting or allografting bone replacement and synthetic bone implants have limitations, including the invasiveness of operative procedures, tissue supply insufficiency, and the risk of host rejection. The advancement in tissue engineering has revealed the potential of stem cells as restorative agents for bone injuries. The administration of mesenchymal stem cells (MSCs) into the talus, the scaphoid, and the neck of the femur could produce enhanced osteogenesis via the manipulation of MSC culture conditions. In this study, we used hydroxyapatite as the nanomaterial, and hypoxic milieu to enhance MSC differentiation capacity into the osteogenic lineage, allowing for more rapid and efficient bone cell replacement treatment. Our results demonstrate 1% oxygen and 12.5 μg/mL of hydroxyapatite (HAP) as the optimal conditions to incorporate the osteogenic medium for the osteogenic induction of MSCs. We also established a proof of concept that the addition of HAP and hypoxic conditions could augment the osteoinductive capacity of MSCs. We also developed an accurate mathematical model to support future bone cell replacement therapy.

Dental pulp stem cells therapy overcome photoreceptor cell death and protects the retina in a rat model of sodium iodate-induced retinal degeneration

Blindness and vision loss contribute to irreversible retinal degeneration, and cellular therapy for retinal cell replacement has the potential to treat individuals who have lost light sensitive photoreceptors in the retina. Retinal cells are well characterized in function, and are a subject of interest in cellular replacement therapy of photoreceptors and the retinal pigment epithelium. However, retinal cell transplantation is limited by various factors, including the choice of potential stem cell source that can show variability in plasticity as well as host tissue integration. Dental pulp is one such source that contains an abundance of stem cells. In this study we used dental pulp-derived mesenchymal stem cells (DPSCs) to mitigate sodium iodate (NaIO₃) insult in a rat model of retinal degeneration. Sprague-Dawley rats were first given an intravitreal injection of 3 × 10⁵ DPSCs as well as a single systemic administration of NaIO₃ (40 mg/kg). Electroretinography (ERG) was performed for the next two months and was followed-up by histological analysis. The ERG recordings showed protection of DPSC-treated retinas within 4 weeks, which was statistically significant (* P ≤ .05) compared to the control. Retinal thickness of the control was also found to be thinner (*** P ≤ .001). The DPSCs were found integrated in the photoreceptor layer through immunohistochemical staining. Our findings showed that DPSCs have the potential to moderate retinal degeneration. In conclusion, DPSCs are a potential source of stem cells in the field of eye stem cell therapy due to its protective effects against retinal degeneration.