Evaluation of the Nutraceutical Potential of Rytidophyllum tomentosum (L.) Mart.: HPTLC Fingerprinting, Elemental Composition, Phenolic Content, and in vitro Antioxidant Activity

ABSTRACT

Rytidophyllum tomentosum (L.) Mart. (search-me-heart) is an aromatic Jamaican endemic herb traditionally consumed as a general tonic and for its medicinal properties. This present study evaluates the nutraceutical potential of R. tomentosum as a functional herbal tea, through the assessment of elemental composition, phenolic contents and in vitro antioxidant potential of samples collected from five locations in Jamaica. High Performance Thin Layer Chromatography (HPTLC) is used to fingerprint the aqueous plant extract for identification and the nutraceutical value of the herb is compared with two commercial black teas. Results provide a detailed summary of the elemental composition of the plant infusion. Total polyphenols were determined to be in the range of 12.19 ± 1.79 – 31.05 ± 0.65 mg gallic acid equivalent (GAE)/g dry powder, decreasing in the order of SMH/71/116 > SMH/82/28 >SMH/71/2 > SMH/71/76 > SMH/71/147. Total flavonoids ranged from 6.81 ± 0.07 – 21.41 ± 0.61 mg catechin equivalent (CE)/g dry powder and decreased in the order of SMH/71/116 > SMH/82/28 > SMH/71/2 > SMH/71/76 > SMH/71/147. Total tannins ranged from 10.60 ± 0.15 – 26.83 ± 0.35 mg tannic acid equivalent (TAE)/g dry powder and decreased in the order of: SMH/71/116 > SMH/82/28 > SMH/71/2 > SMH/71/76 > SMH/71/147. Search-me-heart from all locations possessed antioxidant activity irrespective of the method of analysis used. These findings along with the results of the comparative analysis to the two commercial black teas, suggest that search-me-heart could be an effective natural antioxidant and therefore could be positioned as a dietary herbal supplement in its herbal tea form.