Distribution of cyanotoxins in aquatic environments in the Niger Delta

The presence and types of cyanotoxins in some aquatic environments in the Niger Delta were investigated. Water samples surveyed in the study were surface water of Sombreiro, Nun and New Calabar Rivers. Others were groundwater from Abonnema and Kiama and pond water from Ogboro. Sampling locations of Sombreiro and the New Calabar rivers and the groundwater at Abonnema are all in the Rivers State while other locations were in Bayelsa State all in Nigeria. Cyanotoxins wereextracted using the rotary evaporator procedure. The toxins were intraperitoneally administered to mice. Pathological studies revealed that the extracts contained hepatotoxic peptides (microcystin andnodularin), cytotoxic alkaloids (cylindrospermopsin) and neurotoxic alkaloids (anatoxin-a, anatoxin-a(s) and saxitoxin). Cyanobacterial examination of the water samples revealed that Anabena was the mostpredominant cyanobacterium. Anabena and Microcystis were more predominant in the river and pond water while Anabena and Cylindrospermopsis were more predominant in the ground water. The nutrient load of water bodies influenced biomass (weight) of cyanobacteria. High nutrient load (BOD, COD, nitrates, sulphate, etc) produced high cyanobacterial biomass while low nutrient load producedcorrespondingly low cyanobacterial biomass. Nutrient load of river water were significantly higher than groundwater samples. The pond water produced intermediate values of most physicochemical parameters. The percentage hydrocarbon utilizing fungal counts (6.6 - 10.0%), total coliform (240 MPN/100 ml) and fecal coliform (92 to 160 MPN/100 ml) counts were greater than ground water samples (0%, 7.9 to 24 MPN/100 ml and 0.18 to 0.93 MPN/100 ml) respectively. These results suggested that though the conventional bacterial indicators were high, the presence of cyanobacteria and cyanotoxinsin these aquatic systems may also contribute to rendering these drinking water sources unfit for domestic consumption

Effect of Aloe Vera Gel Extract on Cadmium-Induced High Blood Pressure

This study investigated the anti-hypertensive effect of Aloe vera gel extract in cadmium sulphate-induced hypertensive rats. Forty rats were divided into 8 groups of 5 animals each, to study the protective effects of Aloe vera against cadmium-induced hypertension. The animals were orally pretreated with 300mg/kg and 600mg/kg of Aloe vera gel extract and captopril (positive control) respectively, daily for 14 days before exposure to cadmium sulphate intraperitoneally for another 14 days. Similarly, to evaluate the comparative blood pressure lowering effects of the Aloe vera extract and captopril, the animals were first exposed to cadmium sulphate and later treated orally with Aloe vera gel extract and captopril respectively, daily, for 14 days. The results indicated that unlike the captopril pretreatment, Aloe vera pre-treatment with, 300mg/kg and 600mg/kg of prevented cadmium-induced hypertension. Treatment of cadmium induced hypertensive rats with 300mg/kg and 600mg/kg of Aloe vera gel extract, significantly lowered blood pressure (p< 0.05) when compared with negative control and captopril treated rats. The blood pressure of hypertensive rats treated with 600mg/kg of the extract was restored to normal levels by the 28th day of treatment. Aloe vera gel extract, in the two doses administered caused a significant (pd”0.001) blunting of and reversal of the hypertensive effect of cadmium sulphate. The higher dose of 600mg/kg/day was however more effective in this regard.Keywords: Cadmium, Aloe vera, captopril, hypertensio