Co-administration of resveratrol rescued lead-induced toxicity in Drosophila melanogaster.

Lead toxicity poses a significant environmental concern linked to diverse health issues. This study explores the potential mitigating effects of resveratrol on lead-induced toxicity in Drosophila melanogaster. Adult fruit flies, aged three days, were orally exposed to lead (60 mg/L), Succimer (10 mg), and varying concentrations of resveratrol (50, 100, and 150 mg). The investigation encompassed the assessment of selected biological parameters, biochemical markers, oxidative stress indicators, and antioxidant enzymes. Resveratrol exhibited a dose-dependent enhancement of egg-laying, eclosion rate, filial generation output, locomotor activity, and life span in D. melanogaster, significantly to 150 mg of diet. Most of the investigated biochemical parameters were significantly rescued in lead-exposed fruit flies when co-treated with resveratrol (p < 0.05). However, oxidative stress remained unaffected by resveratrol. The findings suggest that resveratrol effectively protects against lead toxicity in Drosophila melanogaster and may hold therapeutic potential as an agent for managing lead poisoning in humans.

Anemia amelioration by lactose infusion during trypanosomosis could be associated with erythrocytes membrane de-galactosylation.

African trypanosomosis is a potentially fatal disease that is caused by extracellular parasitic protists known as African trypanosomes. These parasites inhabit the blood stream of their mammalian hosts and produce a number of pathological features, amongst which is anemia. Etiology of the anemia has been partly attributed to an autoimmunity-like mediated erythrophagocytosis of de-sialylated red blood cells (dsRBCs) by macrophages. Lactose infusion to infected animals has proven effective at delaying progression of the anemia. However, the mechanism of this anemia prevention is yet to be well characterized. Here, the hypothesis of a likely induced further modification of the dsRBCs was investigated. RBC membrane galactose (RBC m-GAL) and packed cell volume (PCV) were measured during the course of experimental trypanosomosis in mice infected with Trypanosoma congolense (stb 212). Intriguingly, while the membrane galactose on the RBCs of infected and lactose-treated mice (group D) decreased as a function of parasitemia, that of the lactose-untreated infected group (group C) remained relatively constant, as was recorded for the uninfected lactose-treated control (group B) animals. At the peak of infection, the respective cumulative percent decrease in PCV and membrane galactose were 30 and 185 for group D, and 84 and 13 for group C. From this observed inverse relationship between RBCs membrane galactose and PCV, it is logical to rationalize that the delay of anemia progression during trypanosomosis produced by lactose might have resulted from an induction of galactose depletion from dsRBCs, thereby preventing their recognition by the macrophages.

Evidence for late Pleistocene population expansion of the malarial mosquitoes, Anopheles arabiensis and Anopheles gambiae in Nigeria.

Anopheles gambiae Giles s.s. and Anopheles arabiensis Patton (Diptera: Culicidae) are major vectors of malaria in Nigeria. We used 1115 bp of the mitochondrial COI gene to assess their population genetic structures based on samples from across Nigeria (n = 199). The mtDNA neighbour-joining tree, based on F(ST) estimates, separated An. gambiae M and S forms, except that samples of An. gambiae M from Calabar clustered with all the An. gambiae S form. Anopheles arabiensis and An. gambiae could be combined into a single star-shaped, parsimonious haplotype network, and shared three haplotypes. Haplotype diversity values were high in An. arabiensis and An. gambiae S, and intermediate in An. gambiae M; all nucleotide diversities were relatively low. Taken together, patterns of haplotype diversity, the star-like genealogy of haplotypes, five of seven significant neutrality tests, and the violation of the isolation-by-distance model indicate population expansion in An. arabiensis and An. gambiae S, but the signal was weak in An. gambiae M. Selection is supported as an important factor shaping genetic structure in An. gambiae in Nigeria. There were two geographical subdivisions in An. arabiensis: one included all southern localities and all but two central localities; the other included all northern and two central localities. Re-analysing an earlier microsatellite dataset of An. arabiensis using a Bayesian method determined that there were two distinctive clusters, northern and southern, that were fairly congruent with the mtDNA subdivisions. There was a trend towards decreasing genetic diversity in An. arabiensis from the northern savannah to the southern rainforest that corroborated previous data from microsatellites and polytene chromosomes.

The distribution of M and S molecular forms of Anopheles gambiae in Nigeria.

The distribution of M and S molecular forms of Anopheles gambiae sensu stricto across Nigeria was determined. The molecular form of 40 to 45 specimens per locality from 9 localities was determined using mostly the same specimens from our recent study of genetic differentiation of A. gambiae across Nigeria (Onyabe & Conn, 2001). These samples were previously genotyped at 10 microsatellite loci, 5 located within chromosome inversions and 5 outside inversions. Both molecular forms occurred throughout the country, with no apparent relationship to the ecological transition from dry savannah in the north to humid forest in southern Nigeria. In all localities, however, 1 form or the other occurred virtually exclusively. No hybrids between forms were found. Across all loci, F(ST) values were as high within molecular forms as between forms. Regardless of molecular form, F(ST) values calculated across loci within inversions were much higher (range 0.0016 to 0.1988) than those calculated across loci outside inversions (range -0.0035 to 0.0260). Genetic distance was not significantly correlated with geographical distance within either form (P> 0.05). These observations suggest that, in addition to partial reproductive barriers between molecular forms, selection is a major factor shaping genetic differentiation of A. gambiae across Nigeria.

Modulation of the calcium pump of the kidney and testes of rats infected with Trypanosoma congolense.

The activity of the CaMgATPase (Ca-pump) of the kidney and testes of Wistar rats infected with Trypanosoma congolense was studied during the course of infection. The activity of the enzyme in both organs was found to decrease with increase in parasitaemia. The transition temperature (Tc) decreased and activation energy (Ea) of the enzyme increased with increase in parasitaemia. The relevance of the Ca-pump in the pathogenesis of trypanosomiasis is discussed.