Zul Izhar Mohd Ismail

Effect of Honey on Testicular Functions in Rats Exposed to Cigarette Smoke

Summary Honey is traditionally consumed by the local Malaysian population as a nutrient, as well as for the enhancement of fertility. The decline in male reproductive health and fertility in the last 30 years has been linked to environmental toxicants including cigarette smoke (CS). In human and experimental studies, CS exposure has been associated with decreased plasma testosterone level, lower sperm count and increased percentage of abnormal sperm. The aim of this study, therefore, was to determine the possible protective role of honey against the toxic effects of CS on testicular functions in rats. Thirty-two adult Sprague-Dawley rats were randomly divided into 4 groups (8 rats per group) i.e. control group, honey-treated group (H), cigarette smoke-exposed group (CS) and honey-treated plus CS-exposed group (H+CS). Rats in control and CS groups received oral administration of distilled water daily while rats in H and H+CS groups received honey (1.2 g/kg body weight) orally by gavage daily. Rats in CS and H+CS groups were also exposed to CS for 8 min (3 times/day). After 13 weeks of treatment, each rat was sacrificed for reproductive parameters analysis. Rats in CS group had significantly lower sperm count, daily sperm production, percentage of motile sperm and testosterone level as well as a higher percentage of abnormal sperm compared to control and H groups. However, supplementation of honey significantly improved all these parameters in H+CS group. Administration of honey significantly attenuated the toxic effects of CS on spermatogenesis and testosterone level in rats. This study suggests that honey might have a protective effect against CS-induced impaired testicular functions in rats.

Tualang honey supplement improves memory performance and hippocampal morphology in stressed ovariectomized rats

Recently, our research team has reported that Tualang honey was able to improve immediate memory in postmenopausal women comparable with that of estrogen progestin therapy. Therefore the aim of the present study was to examine the effects of Tualang honey supplement on hippocampal morphology and memory performance in ovariectomized (OVX) rats exposed to social instability stress. Female Sprague-Dawley rats were divided into six groups: (i) sham-operated controls, (ii) stressed sham-operated controls, (iii) OVX rats, (iv) stressed OVX rats, (v) stressed OVX rats treated with 17β-estradiol (E2), and (vi) stressed OVX rats treated with Tualang honey. These rats were subjected to social instability stress procedure followed by novel object recognition (NOR) test. Right brain hemispheres were subjected to Nissl staining. The number and arrangement of pyramidal neurons in regions of CA1, CA2, CA3 and the dentate gyrus (DG) were recorded. Two-way ANOVA analyses showed significant interactions between stress and OVX in both STM and LTM test as well as number of Nissl-positive cells in all hippocampal regions. Both E2 and Tualang honey treatments improved both short-term and long-term memory and enhanced the neuronal proliferation of hippocampal CA2, CA3 and DG regions compared to that of untreated stressed OVX rats.

Rats exposed to cocaine during late gestation and early postnatal life show deficits in hippocampal pyramidal and granule cells in later life

In humans, the offspring of maternal cocaine misusers are known to have subtle cognitive and motor impairments in later life. It was therefore hypothesized that such exposure in animals would also affect the morphological structure of the brain. This possibility was investigated by exposing rats to cocaine between embryonic day 15 and postnatal day 6. Samples of the cocaine‐exposed and control rats were killed for examination at 22 and 150 postnatal days of age. Stereological procedures (the Cavalieri principle together with the physical disector method) were utilized to estimate the total number of pyramidal and granule cells in defined regions of the hippocampal formation. At 22 days of age, the control offspring had about 373 000 pyramidal cells whereas the cocaine‐treated animals only had about 310 000 cells in the CA1 + CA2 + CA3 region. By 150 days of age the values were about 396 000 and 348 000, respectively. The differences between age‐matched groups were statistically significant. There were about 626 000 and 687 000 dentate gyrus granule cells in the 22‐day‐old control and cocaine‐treated groups, respectively. By postnatal day 150 the control rats had about 832 000 granule cells whilst the cocaine‐treated rats had about 693 000. There was a significant main effect of age as well as group–age interaction in this measure. These results show that even moderate exposure to cocaine during the late gestation and early postnatal period in rats is a potent teratogen and can markedly influence the development of neurons in the hippocampal formation.

The Effects of Progesterone on Hypoxic Ischemic Injuries in the Cornu Ammonis (CA) Region of the Hippocampus of Neonatal Rats

Hypoxia-ischemia (HI) is a major cause of brain damage in the newborn. Several studies elicited the neuroprotective effects of progesterone in adult rats but there is very little literature available on neonatal rats. Therefore the present study is undertaken to see the effect of progesterone in hypoxic ischemic brain injury in neonatal rats, using an established neonatal HI rat pup model. Sevenday- old rat pups were subjected to right common carotid artery ligation and then 60 minutes hypoxia. The first dose of progesterone to treatment group was administered by peritoneal injection (4 mg/kg), after 10 minutes of exposure and subsequent doses were given by subcutaneous injection at 6 h, 24 h and 48 h intervals. Control group was also exposed to HI and was given only the vehicle (peanut oil) through the same route and intervals as that of treatment group. After 96 h, the pups were perfused with 10% formalin and brains were sampled and stained with toluidine blue. Cells density and number of pyramidal cells of the hippocampal Cornu Ammonis (CA) regions were examined by stereological methods. The histomorphometric assessment of the effects of progesterone showed minimal but no significant protective value in the volume, cells density and total number of pyramidal cells of hippocampal CA region of the treatment and control groups (p>0.05) after HI. Our results concluded that 4 mg/kg of PROG had no significant neuroprotective effect in HI model of the neonatal rat’s hippocampus.

Empowering students’ minds through a cognitive load theory-based lecture model: A metacognitive approach

ABSTRACT Lecturing is widely considered to be a passive, teacher-centred teaching method that fails to foster learning, yet it remains the most feasible method of teaching among higher institutions. Some modern lectures, aligned with recommendations from published guidelines on effective lecturing, are less didactic and more interactive than others, but little is known about converting the classical knowledge-transfer process of lecturing to actual learning. We introduce a cognitive load theory-based lecture guideline that adopts various types of empirically proven strategies to manage learners’ mental loads during lectures. We conducted a randomised controlled trial to evaluate its effectiveness by determining the between-group difference in cognitive load level, self-perceived learning, knowledge acquisition and knowledge retention. This study discusses the practical application of the guideline and several examples of the principles.

Normal values of foot arch parameters in adult Hausa population of Nigeria

Background: Deformities of foot arches have been implicated in various lower extremity injuries. Normal values of foot arch parameters have been studied in various populations. However, studies in Nigerian population are very limited and therefore require attention. Objective: The objectives of this study were to establish the normal values of foot arch parameters in adult Hausa population of Nigeria, to find the effect of gender on these parameters and to make comparison with previous studies in other populations. Materials and Methods: A total of 59 consented subjects (44 males, 15 females) that have no history of lower extremity deformity were recruited. Lateral radiograph of the right foot of each participant was taken in a bilateral standing position. For the medial longitudinal arch, navicular height (NH), first cuneiform height (FCH), calcaneal inclination angle (CIA), and calcaneal- first metatarsal angle (C1MA) were measured. Cuboid height (CH) and calcaneal-fifth metatarsal angle (C5MA) were measured for the lateral longitudinal arch. Measurements for angles and heights were performed using a universal plastic goniometer and a plastic ruler, respectively. Results: The mean (standard deviation [SD]) value of the NH was found to be 2.89 (0.54) cm, FCH 2.08 (0.44) cm, CIA 16.57° (3.30°), and C1MA 140.05° (5.63°). The mean (SD) of CH and C5MA was found to be 1.19 (0.31) cm and 160.96° (4.69°), respectively. There was no significant mean difference in those parameters between males and females. Conclusion: The mean values of foot arch parameters in adult Hausa population of Nigeria is comparable to previous studies on other populations, but generally lower than those of Caucasians. Similarly, our findings showed that gender has no significant effect on foot arch parameters.