Aims: A significant number of tropical rainforest shrubs and lianes are inextricably linked to human use as food, spices and/or medicine. This study evaluates phytochemical and mineral constituents and ethnomedicinal uses of Piper guineense Schum. & Thonn and Piper umbellatum Linn.          Methods: Two phased investigations – ethnomedicinal uses and phytochemical/mineral constituents of P. guineense and P. umbellatum – were carried out in Benin City, Edo State, Nigeria. Firstly, key informants’ interview and questionnaire were used to elicit reactions from respondents (vendors and end users) on ethnomedicinal and sundry uses of P. guineense and P. umbellatum in nine purposively selected markets out of 27. Secondly, samples of leaves and stems of P. guineense and P. umbellatum were collected and analysed in the laboratory for selected phytochemicals (alkaloid, cyanogenic glycosides, tannin, flavonoid, tannins, anthraquinones, saponin and phenol), and minerals (Ca, Mg, Na, K, P, Fe, Zn). Results: Market survey revealed that vendor/end users (85%) were well-informed on the uses of the plants for food (spices, condiments) and ethnomedicine. Most respondents (80%) affirmed that the leaves were frequently used for flavouring; and for preparing traditional medicinal soups when combined with assorted vegetables. Respondents (80%) averred that the leaf was the most frequently used followed by stems (10.9%), roots (5.5%) and seeds (3.6%). P. guineense was considered best for stomach disorder/ulcer, respiratory/urinary tract infections; P. umbellatum most preferred for arthritis, fever and fertility/womb cleansing. Phytochemical analysis revealed P. umbellatum stem had more alkaloids, flavonoids and phenol; and anthraquinone in the leaf while P. guineense stem had more saponins and tannins. However, mineral analyses revealed more Ca and Mg in P. guineense leaf; and K, Na, Zn and P in P. umbellatum stem while Fe was higher in the leaf. Conclusion: P. guineense and P. umbellatum are aromatic liane and shrub used for flavouring and spicing of food, and medicine. These fairly ubiquitous and underutilized plants can contribute significantly to food and health needs of forest dependent people in Nigeria and elsewhere in West Africa. The study has revealed that these aromatic plants are rich sources of phytomedicines and important minerals. Further investigation on the phytochemical/pharmacological potentials and ecological idiosyncrasies of these underutilized aromatic rainforest liane and shrub is recommended.

The effectiveness of three different extractants soil mixtures—HCl, HCl + H2S04, and DTPA-TEA, in order to determine Si from soil and the forms of Silicon as influenced by different parent materials under acidic medium. Seven forms of Silicon; namely water soluble, specifically adsorbed, oxides bound, organic matter bound, exchangeable, residual, total viz sequential fractionation. Extractable Si value established in this study was (50.0 mg kg-1), indicating negative effect on plant physiology. The physico-chemical properties decreased significantly with increase in soil depth vs soil parent materials. In addition, the forms of Si in the parent materials decreased in the pattern RES, bound residual fractions > EXC, soluble & exchangeable fractions > OM, organic matter fraction. Among the properties the silt fraction, pH & OM significantly and positively correlated with the forms of silicon, with negative correlation vs clay which maybe due to silicon adsorption by clayey fraction of the soil (redox). Therefore the soil maybe be maintained and conserved for farming activities.