METHODS: A total of 32 female Sprague Dawley rats were taken and randomly divided into four groups (n = 8). Throughout the experimental period of 6 weeks, negative control-NC (vehicle deionized water), positive control-CD (Cd at 5 mg/kg), Tualang honey followed by Cd exposure-TH (Tualang honey at 200 mg/kg and Cd at 5 mg/kg) and Tualang honey control-THC (Tualang honey at 200 mg/kg) groups, were administered orally on a daily basis.
RESULTS: Rats exposed to Cd were significantly higher in ovarian weight, number of antral and atretic follicles as compared to the NC group. The disruptive effects of Cd on ovarian follicles were associated with a disruption in gonadotropin hormones and decreases in follicular stimulating hormone (FSH) and luteinizing hormone (LH). Moreover, a significant formation of oxidative stress in ovarian Cd-exposed rats has been proven by increasing the level of lipid peroxidation products (malondialdehyde) and decreasing the levels of enzymatic antioxidant (catalase). Interestingly, a daily supplementation of high antioxidant agents such as Tualang honey in these animals, caused significant improvements in the histological changes. Additionally, less atretic follicles were observed, restoring the normal level of LH and FSH (P
Objectives: The present study investigates the applicability of water hyacinth (Eichhornia crassipes), a tropical aquatic plant with reported heavy metal hyper-accumulation in microcosm floating wetland treatment systems designed to remediate AMD with copper (Cu) and cadmium (Cd) concentrations exceeding threshold limits.
Methods: Twelve water hyacinth samples were prepared with varying concentrations of Cu (1 mg/L, 2 mg/L, 4 mg/L) and Cd (0.005 mg/L, 0.01 mg/L, 0.02 mg/L). Water samples of 5 ml each were collected from each sample at 24-hour intervals for analysis with an atomic absorption spectrometer.
Results: Plant growth varied according to Cu and Cd concentrations and no plants survived for more than 14 days. There was a significant discrepancy in the rate at which the Cd concentrations abated. The rate of reduction was rapid for higher concentrations and after 24 hours a substantial reduction was achieved. There was a reduction in Cu concentration after the first 24-hour period, and after the next 24-hour period the concentrations were again elevated in the samples at initial concentrations of 2 mg/L and A4 mg/L. 4 mg/L Cu concentration was shown to be toxic to the plants, as they had low accumulations and rapid dying was evident.
Conclusions: Water hyacinth has the capability to reduce both Cu and Cd concentrations, except at an initial concentration of 4 mg/L of Cu, which was toxic to the plants.
Competing Interests: The authors declare no competing financial interests.