The Effect of Rooibos (Aspalathus linearis), Honeybush (Cyclopia intermedia) and Sutherlandia (Lessertia frutescens) on Testicular Insulin Signalling in Streptozotocin-Induced Diabetes in Wistar Rats

Abstract

Background: Testicular insulin signalling is altered in diabetic (DM) males. While unravelling the mechanism through which DM exert these detrimental effects, studies have shown the importance of insulin regulation in glucose homeostasis, and how a lack in insulin secretion indirectly led to reduced male fertility. The current study aimed to investigate the role of rooibos, honeybush and Sutherlandia on insulin signalling in the testicular tissue of type I diabetic rats. Methods: Animals (n=60) were randomly divided into six groups. The groups include a control group, a vehicle group, and diabetes was induced in the remainder of animals via a single intraperitoneal injection of STZ at 45mg/kg. The remaining four groups included a diabetic control (DC), diabetic + rooibos (DRF), diabetic + honeybush (DHB) and diabetic + Sutherlandia group (DSL). Animals were sacrificed after seven weeks of treatment, and blood and testes were collected. Results: All diabetic groups (DC, DRF, DHB, DSL) presented with a significant increase in blood glucose levels after diabetes induction compared to the control and vehicle (p<0.001). The DC animals presented with decreased testicular protein expression of IRS-1, PkB/Akt and GLUT4 compared to controls. DRF and DHB animals displayed an acute upregulation in IRS-1, while the DSL group showed improvement in IRS-2 compared to DC. Although, DRF animals presented with a decrease in PkB/Akt, DHB and DSL animals displayed upregulation (22.3%, 48%) compared to controls, respectively. Conclusion: The results taken together, it can be suggested that these infusions may enhance insulin signalling through diverse pathways.

Oxidative Stress and Male Infertility: Evidence From a Research Perspective

“…Several other studies have also revealed a significant decrease in semen volume, sperm motility and morphology in the semen of diabetic men ( 148 , 149 ) while some animal studies have equally reported alteration in sperm parameters ( 150 – 152 ). All these effects can partly be explained through the impact of OS, caused by the inequality between ROS production and antioxidant defense mechanisms ( Figure 5 ) ( 19 , 153 ). The process of how OS leads to male subfertility or infertility has been discussed in detail in the earlier section.…”

Pioglitazone Synthetic Analogue Ameliorates Streptozotocin-Induced Diabetes Mellitus through Modulation of ACE 2/Angiotensin 1–7 via PI3K/AKT/mTOR Signaling Pathway

“…After three weeks, the rats subjected to a single intra-peritoneal injection of 45 mg/kg of freshly prepared streptozotocin dissolved in 0.1 M citrate buffer. Besides, to avoid animal death, 20 percent glucose was added to the drinking water for 48 h after induction with the intra-peritoneal streptozotocin injection [ 57 , 58 ]. At 72 h after streptozotocin induction, diabetic rats were defined as those with blood glucose levels greater than 300 mg/dL as determined by a blood sample from the rat’s tail using an (ACCU-CHEK ® , Roche, Hague Road, Indianapolis, IN, USA) instrument [ 59 ].…”

In vitro effects of aqueous extract of unfermented rooibos on human spermatozoa

“…Compared with fermented rooibos, unfermented rooibos possesses a higher level of aspalathin (Canda et al, 2014; Kwak et al, 2015). Aspalathus linearis reduced testosterone production in TM3 Leydig cells (Opuwari & Monsees, 2015) and diabetic male rats (Omolaoye et al, 2021). In other studies, A. linearis improved male reproductive functions in rat models (Awoniyi et al, 2012; Opuwari & Monsees, 2014).…”