Elemental analysis of some edible medicinal plants serving as a source of nutrition for sustainable good health and wellbeing

Abstract Sustainable Development Goal three (SDG 3) is good health and well-being. Edible medicinal plants are a significant source of good health and well-being as many of them can pass for nutraceuticals, serving as a source of nutrition and providing health benefits. Qualitative phytochemical screening, proximate evaluation, and elemental analysis of methanol extracts of Albizia zygia (AZ), Trema orientalis (TO), and Psidium guajava (PG) leaves were carried out to determine their nutritive and medicinal values. Preliminary qualitative phytochemical screening and percentage proximate composition were determined using standard methods. Their elemental composition was determined using inductively coupled plasma optical emission spectroscopy. The leaves contained tannins, flavonoids, reducing sugars, cardiac glycosides, saponins, terpenoids, and alkaloids. AZ, TO, and PG had 73.62 ± 0.64, 69.83 ± 0.60 and 70.75 ± 0.34 % of carbohydrate, 3.76 ± 0.13, 4.21 ± 0.04, and 5.35 ± 0.16 % of protein, 0.39 ± 0.04, 0.52 ± 0.05, 0.61 ± 0.07 % of crude fat, 4.67 ± 0.08, 6.68 ± 0.30, and 5.2 0 ± 0.03 %of moisture content, 5.29 ± 0.25, 6.32 ± 0.03, and 5.65 ± 0.23 %, of ash content and, 12.27 ± 0.22, 12.45 ± 0.34, and 12.42 ± 0.19 % of crude fibre respectively. Aluminium, arsenic, cadmium, and mercury were absent, while iron, copper, magnesium, manganese, chromium, thorium, silicon, and zinc, were present in the three leaf samples. Lead and selenium were present in TO but absent in AZ and PG. Calcium was absent in AZ and TO but present in PG in a significant amount (3.895 mg/L). The proximate composition reveals their nutritive values, while the composition of constituent elements and phytochemicals qualify them as probable therapeutic sources, useful for the good health and well-being of humans.