CA was supported by the Nigerian government (Tertiary Education Trust (TET) Fund). The authors have no conflicts of interest.

Human sperm show a variety of different behaviours (types of motility) that have different functional roles. Previous reports suggest that sperm may reversibly switch between these behaviours. We have recorded and analysed the behaviour of individual human sperm (180 cells in total), each cell monitored continuously for 3–3.5 min either under control conditions or in the presence of Ca2+-mobilising stimuli. Switching between different behaviours was assessed visually (1 s bins using four behaviour categories), and was verified by fractal dimension analysis of sperm head tracks. In the absence of stimuli, ~90% of cells showed at least one behavioural transition (mean rate under control conditions = 6.4 ± 0.8 transitions.min−1). Type 1 behaviour (progressive, activated-like motility) was most common, but the majority of cells (>70%) displayed at least three behaviour types. Treatment of sperm with Ca2+-mobilising agonists had negligible effects on the rate of switching but increased the time spent in type 2 and type 3 (hyperactivation-like) behaviours (P < 2*10−8; chi-square). Treatment with 4-aminopyridine under alkaline conditions (pHo = 8.5), a highly-potent Ca2+-mobilising stimulus, was the most effective in increasing the proportion of type 3 behaviour, biasing switching away from type 1 (P < 0.005) and dramatically extending the duration of type 3 events (P < 10−16). Other stimuli, including 300 nM progesterone and 1% human follicular fluid, had qualitatively similar effects but were less potent. We conclude that human sperm observed in vitro constitutively display a range of behaviours and regulation of motility by [Ca2+]i, at the level of the single cell, is achieved not by causing cells to adopt a ‘new’ behaviour but by changing the relative contributions of those behaviours.

The aim of this study was to compare the minerals, heavy metals and amino acids compositions of the seeds and juice of Cucumis metuliferus. The minerals and heavy metals content were evaluated using FS240AA agilent atomic absorption spectrometer according to the method of American Public Health Association while the amino acids content was evaluated using High Performance Liquid Chromatography (HPLC). From the mineral analysis, concentrations of calcium (23.416 ppm), aluminum (0.094 ppm), manganese (0.242 ppm) and iron (1.243 ppm) were higher in the juice than in the seeds with respective values of 20.084 ppm, 0.079 ppm, 0.221 ppm and 0.934 ppm while the concentrations of magnesium (29.749 ppm), zinc (4.184 ppm), copper (0.125 ppm), sodium (8.927 ppm) and potassium (7.594 ppm) were higher in the seeds than in the juice with respective values of 20.592 ppm, 1.271 ppm, 0.030 ppm, 8.594 ppm and 6.833 ppm. The juice had higher concentrations of heavy metals such as arsenic (20.082 ppm), lead (4.135 ppm), cobalt (0.178 ppm), silver (0.074 ppm), selenium (7.246 ppm) and mercury (4.609 ppm) as against the seed with respective values of 0.578 ppm, 1.455 ppm while cobalt, silver, selenium and mercury were not detected. However, the concentrations of cadmium (0.389 ppm), chromium (0.545 ppm) and nickel (0.288 ppm) were higher in the seeds than in the juice with respective values of 0.082 ppm, 0.252 ppm and 0.016 ppm. From the result of amino acid analysis, 18 amino acids were found in both the seeds and juice which include 9 essential and 9 non-essential amino acids respectively. The qualitative composition of amino acids in both the seeds and the juice was same, but the quantitative contents differed although non-significantly from each other with prevalence of amino acids in the seeds. Aspartate was the most abundant of the amino acids found while cysteine was the least.  These results suggest that the seeds and juice of Cucumis metuliferus contain adequate essential minerals which are beneficial to human health. The contaminant levels of heavy metals highlights the necessity on the quality and safety concerns about their use and handling. The amino acids analysis showed that both the seeds and juice of Cucumis metuliferus are good sources of amino acid and could be used as food supplement. The amino acid content may also provide useful information for determination of the protein quality of Cucumis metuliferus.

The study was aimed at determining the effect of Crude oil and its product on bilirubin of a Catfish Fishes w th an average weight of 21.08 ± 0.12g were subjected to the toxic and recovery phases o d f erent concentrat ons (0.2 ml/L, 0.4 ml/L, 2.0 ml/L. and 4 ml/L) of Crude oil, d esel, kerosene and petrol for 4 days and 26 days respectively. The bilirubin level of fishes subjected to different concentrations of toxicants was higher than that of the control. The biochemical parameters investigated showed sign icant (P < O 05) difference when compared to the control. The bilirubin level increased w th increasing concentrations of toxicants. Increased bilirubin level suggests l ver cell damage or a metabolic disturbance in the liver involving defective conjugation and / or excretion of bilirubin.

Cucumis metuliferus commonly called Kiwano is a well-known plant in the middle belt area of Nigeria. It is consumed for nutritional and medicinal purposes. This study evaluated the bioactive compound content, In-vitro antioxidant and anti-inflammatory properties of ethanol extract of the seed of Cucumis metuliferus fruit. The antioxidant properties were evaluated using DPPH (2, 2 diphenyl-1-picrylhydrazyl) radical, iron reducing power and inhibition of lipid peroxidation tests. Ascorbic acid served as standard. The anti-inflammatory activity at concentration of 200-1000 µg/ml was measured In-vitro using anti-proteinase activity, membrane stabilization and inhibition of albumin denaturation assay systems. Aspirin and diclofenac were used as reference drugs. The bioactive compounds evaluated were phenol, flavonoid, beta carotene, lycopene and ascorbic acid. From the result, the seed extract contains phenol (149.40±9.93 mgGAE/g), flavonoids (97.84±2.84 mgCE/g), beta carotene (0.110±0.001 mg/g), lycopene (0.085±0.001 mg/g) and ascorbic acid (0.190±0.028 mgAA/g). In the antioxidant assays, the antioxidant activities were dependent on the concentration. At lower concentrations, the seed extract displayed higher activity in all the assays compared with the standard. The DPPH scavenging and lipid inhibition abilities of the seed were more potent with lower IC50 while the reductive potential of the standard was better. From the anti-inflammatory assays, the seed extract exhibited anti-proteinase activity of 0-8.78%, membrane stabilization (inhibition of heat-induced haemolysis) activity of 5.13-20.51% and percent inhibition of albumin denaturation of 0.78-16.15%. These results showed that ethanol extract of Cucumis metuliferus seed contains bioactive compounds which are beneficial to health and possess antioxidant and anti-inflammatory abilities.