Stachytarpheta jamaicensis leaf extract: Chemical composition, antioxidant, anti-arthritic, anti-inflammatory and bactericidal potentials

Abstract

Stachytarpheta jamaicensis is an important plant with multi therapeutic properties. Hence, this study seeks to screen the leaf extract of S. jamaicensis for its chemical composition and pharmacological activities in order to find possible sources for novel phytochemicals in food and pharmaceutical formulations. The chemical composition, pH, TPC, TFC, TTC, TAA, carotenoid, antioxidant, anti-arthritic, anti-inflammatory and bactericidal potential were measured using GC-MS, pH meter, Folin-Ciocalteu’s, AlCl3, FeCl3/gelatine, 2,4- DNPH, acetone-hexane, DPPH, PTAC, BSA and agar-well diffusion methods respectively. The pH of the aqueous solution was 6.02. The GC and GC-MS analyses revealed the presence of 30 organic compounds. The most abundant components were 3,5-dihydroxy-6-methyl-2,3-dihydro-4H-pyran-4-one (13.7%), D-arabinitol (13.5%), 2-benzylidenemalonic acid (11.9%), 1,3-cyclopentadione (8.9%), α-5-ethyl-2-furylglycine (6.8%), 4,5-dihydro-5-methoxy-4-(2,3-dimethyl-2-buten-4-yl)-2(3H)-furanone (6.4%) and 3-methyl-2H-indazol-2-ol (5.8%). The TPC, TFC, TTC, TAA, β-carotene and lycopene values were 31,882.80 ±0.00 µgmg-1 GAE, 29.29±0.00 µgmg-1 QE, 126.47 µgmg-1 TAE, 53.75±0.01 µgmg-1 AAE, 0.17 mgg-1 and 0.14 mgg-1 , respectively. The antioxidant IC50 and AAI values of the leaf extract were 5.0 µgml-1 and 8.0. The extract was capable of scavenging free radicals in a range between 51.30-78.99%. The PTAC value was 396.15±0.00 µgmg-1 AAE. The extract also gave high egg albumin and BSA anti-arthritic/anti-inflammatory values between 22-80% with IC50 values of 0.04 and 0.15 mgml-1 , respectively. The extract was active against all the tested bacteria with high zones of inhibition (14.0-25.0 mm). These results showed that the leaf extract of S. jamaicensis could be used for the formulation of active compounds with broad activities for food and pharmaceutical industries.