ABSTRACT
Background and Aims: Manotes expansa Sol. ex Planch. and Aframomum alboviolaceum (Ridl.) Schum. are two plants belonging respectively to the family Connaraceae R.Br. and Zingiberaceae Martino widely used in traditional medicine for the treatment of eye diseases, fever, headaches, gastritis as well as asthma. The aim of the present study is the valorization of these two plants collected in the Democratic Republic of Congo by a quantitative and qualitative analysis of secondary metabolites and mineral elements in their leaves. Materials and Methods: The determination of secondary metabolites in the leaves of Manotes expansa and Aframomum alboviolaceum was carried out by UV-Visible spectrophotometry and X-ray fluorescence spectrophotometry for the identification and quantitative analysis of mineral elements. Results: The results showed that the leaves of these two plants are rich in phenolic compounds, i.e. 442.2 mgEqAG/g for the leaves of A. alboviolaceum, 370.64 mgEqAG/g for the red leaves and 282.64 mgEqAG/g green leaves of M. expansa. Although being part of the same plant, the red and green leaves of M. expansa presented a totally different phytochemical profile. The contents of condensed tannins, anthocyanins and flavonoids are respectively 0.3%, 0.68% and 3.29% for the leaves of A. alboviolaceum; 0.58%, 0.36% and 6.89% for the red leaves, and 0.65%, 0.26% and 7.55% for the green leaves of M. expansa. The mineral content in the leaves of both plants remains dominated by the high concentration of potassium (K), calcium (Ca), Magnesium (Mg), Manganese (Mn) and Iron (Fe). Conclusion: The high content of phenolic compounds and essential trace elements makes the leaves of M. expansa and A. alboviolaceum potential candidates to alleviate several health problems in Africa in general and particularly in the Democratic Republic of Congo.
ABSTRACT
Aim: The objective of this study was to determine the phytochemical profile of Senna alata LINN using chemical screening in solution and thin-layer chromatography, and to assess the antioxidant and anthelmintic activities of the plant抯 aqueous extracts. Methodology: All the analyses performed in this study were, respectively, done as described by the standard protocols. These were: the microscopic examination of the plant powders performed using a light microscope, the search for secondary metabolites carried out by chemical screening in solution and by thin-layer chromatography, the determination of the secondary metabolites, and the antioxidant activity carried out by UV-visible spectroscopy and the anthelmintic activity performed by dilution in decreasing order of concentration. Results: Micrographic analysis of the powder of Senna alata revealed the histological elements rich in unicellular covering hairs with a punctate surface and in fragments of palisade parenchyma, with elongated cells. The presence of polyphenols (flavonoids, anthocyanins, tannins, leuco anthocyanins, free quinones), steroids, terpenoids, and iridoids was detected by phytochemical screening in solution and confirmed by thin-layer chromatography. The determination of total phenolic compounds, flavonoids, total tannins, and anthocyanins showed that Senna alata contains 254.64 mg EQ/g, 12.3%, 9.5%, and 6.5%, respectively, of these metabolites. The aqueous extract of the leaves of Senna alata showed a good anthelmintic activity after 41 minutes of exposure to 5.00 mg/mL of the extract and the antioxidant activity was reported, of which the value of IC50 ( g/mL) of the extract for the DPPH tests is 91.42 15.56. Conclusion: Histological elements rich in unicellular covering hairs with a punctate surface and in fragments of palisade parenchyma, with elongated cells were revealed in the micrographic analysis of Senna alata. The plant抯 leaf methanol extract showed good antioxidant activity, while the anthelmintic activity was demonstrated in its aqueous extract.