Dalbergiella welwitschia (Baker) Baker f. alkaloid-rich extracts attenuate liver damage in streptozotocin-induced diabetic rats.

This experiment was conducted to evaluate the Dalbergiella welwitschia alkaloid-rich extracts on liver damage in streptozotocin-induced diabetic rats. Hence, to induce diabetes, 45 mg/kg body weight of streptozotocin was intraperitoneally injected into the Wistar rats. Subsequently, 5 % (w/v) of glucose water was given to the induced animals for 24 h. Thus, the animals (48) were grouped into five groups (n = 8), containing normal control (NC), diabetic control (DC), diabetic rats placed on low (50 mg/kg body weight) and high (100 mg/kg body weight) doses of D. welwitschi alkaloid-rich leaf extracts (i.e. DWL and DWH respectively), and diabetic rats administered 200 mg/kg body weight of metformin (MET). The animals were sacrificed on the 21st day of the experiment, blood and liver were harvested, and different liver damage biomarkers were evaluated. The results obtained demonstrated that diabetic rats administered DWL, DWH and MET significantly (p < 0.05) increased hepatic AST, ALT, albumin, SOD, CAT, GSH, and GPX levels when compared to DC with no significant (p > 0.05) different when compared with NC. Also, diabetic rats administered DWL, DWH and MET revealed a significant (p < 0.05) decrease in GGT and MDA levels, as well as, fragmented DNA and protein carbonyl levels when compared to DC with no significant (p > 0.05) different when compared with NC. In addition, histological examination revealed that diabetic rats placed on DWL, DWH and MET normalized the hepatocytes. Consequently, it can be inferred that alkaloid-rich extracts from D. welwitschi leaf could be helpful in improving liver damage associated with diabetes mellitus rats.

Age-related emotionality is associated with cortical delta-opioid receptor dysfunction-dependent astrogliosis.

Multiple changes occur in the aging brain, leading to age-related emotional disorders. A growing body of recent evidence suggests that the cortical delta-opioid receptor system plays a critical role in anxiety- and depressive-like behaviors in the rodent. In this study, we show that aging mice promoted anxiety-like behaviors as characterized by both the light-dark and elevated plus-maze tests, and they exhibit an increase in astrocytes in the cingulate cortex due to the dysfunction of cortical delta-opioid receptor systems. As well as aging mice, mice with a dysfunction of the delta-opioid receptor system induced by chronic treatment with the selective delta-opioid receptor antagonist naltrindole, revealed astrogliosis in the cingulate cortex, which was associated with anxiety. We also found that the microinjection of cultured astrocytes into the cingulate cortex of young mice enhanced the expression of anxiety-like behavior. Our results indicate that the aging process promotes astrogliosis in the cingulate cortex through the dysfunction of cortical delta-opioid receptors. This phenomenon may lead to emotional disorders including aggravated anxiety during normal aging.