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Background: Stem bark and leaves of Lophira alata (Family: Ochnaceae) have been used traditionally for their anti-psychotic, anti-convulsant and anxiolytic properties. Since no existing data was found on the neurobehavioural properties, this study was carried out to evaluate some neurobehavioural properties of the aqueous extract of the stem bark of L. alata in animal models. Methods: The oral mean lethal dose (LD50) of the extract was estimated, and preliminary phytochemical screening was conducted. Lophira alata extract (200, 400 and 800 mg/kg, p.o.) was investigated for antidepressant effect using the forced swim and tail suspension tests, and the anxiolytic potential was assessed using the stair case and hole board tests. Pentylenetetrazole-induced convulsion test was used to investigate the anticonvulsant potential of the extract. Results: The LD50 was estimated to be > 5000 mg/kg. Oral administration of L. alata extract produced a significant (p < 0.05) non-dose-dependent decrease in the period of immobility in both the forced swim and tail suspension tests. While a significant decrease (p < 0.05) in episodes of grooming was recorded in the staircase test, the number of head dips was not significantly reduced (p > 0.05) in the hole board test. In the pentylenetetrazole-induced convulsion, a non-dose-dependent increase in onset of tonicclonic seizures and protection from death was recorded. Conclusions: The results obtained suggest that the aqueous stem bark extract of L. alata possesses neurobehavioural properties which may account for its use in ethnomedicine. [ABSTRACT FROM AUTHOR]

Objectives: Mode of subsistence is an important factor influencing dietary habits and the genetic structure of various populations through differential intensity of gene flow and selection pressures. Previous studies suggest that in Africa Taste 2 Receptor Member 16 (TAS2R16), which encodes the 7-transmembrane receptor protein for bitterness, might also be under positive selection pressure., Methods: However, since sampling coverage of populations was limited, we created a new TAS2R16 population dataset from across the African Sahel/Savannah belt representing various local populations of differing subsistence modes, linguistic affiliations, and geographic provenience. We sequenced the TAS2R16 exon gene and analyzed 2250 haplotypes among 19 populations., Results: We found no evidence for selection as a driving force of genetic variation at this locus; instead, we discovered a highly significant correlation between TAS2R16 genetic and geographical distances based on provenience of the sampled populations, strongly suggesting that genetic drift most likely prevailed over positive selection at this specific locus. We also found significant correlations with other independent loci, mainly in sedentary farmers., Discussion: Our results do not support the notion that the genetic diversity of TAS2R16 in Sahelian populations was shaped by selective pressures. This could result from several alternative and not mutually exclusive mechanisms, of which the possibility that, due to the pleiotropic nature of TAS2R16, selective pressures on other traits could counterbalance those acting on bitter taste perception, or that the change of diet in the Neolithic generally relaxed selective pressure on this gene., (© 2021 Wiley Periodicals LLC.)