Begum_2023_PeerJ_11_e14606

BACKGROUND: Kaempferia galanga (L.) is one of the prospective therapeutic plants with an aromatic rhizome, and belongs to the Zingiberaceae family. This herb is commonly used by local practitioners in traditional Asian medicine. METHODS: In the present investigation, the novel Kaempferia galanga rhizome essential oil rich in ethyl p-methoxy cinnamate (EMCKG) was evaluated using GC/MS for chemical composition analysis. EMCKG was analyzed for its possible antimicrobial, neurodegenerative inhibitory, acetylcholinesterase, anti-inflammatory, and antioxidant activities as well as for the genotoxic effects using the standard methodologies. ANOVA and post hoc was performed to test the statistical significance of the study. RESULTS: GC/MS analysis identified ethyl p-methoxy cinnamate as the major component of EMCKG essential oil with an area percentage of 66.39%. The EMCKG exhibited moderate (DPPH assay IC(50) = 15.64 +/- 0.263 microg/mL; ABTS assay IC(50) = 16.93 +/- 0.228 microg/mL) antioxidant activity than standard ascorbic acid (DPPH assay IC(50) = 21.24 +/- 0.413 microg/mL; ABTS assay IC(50) = 21.156 +/- 0.345 microg/mL). Similarly, EMCKG showed comparable activity in albumin denaturation (IC(50) = 2.93 +/- 0.59 microg/mL) and protease inhibitor assay (IC(50) = 17.143 +/- 0.506 microg/mL) to that of standard sodium diclofenac (IC(50) = 23.87 +/- 0.729 microg/mL and IC(50) = 19.18 +/- 0.271 microg/mL, respectively). The EMCKG exhibited a dose-dependent antimicrobial activity pattern with the highest inhibitory activity at 500 microg/mL against Staphylococcus aureus and considerable anticholinesterase activities (IC(50) = 21.94 +/- 0.109 microg/mL) compared to the standard galanthamine (IC(50) = 27.18 +/- 0.511 microg/mL). EMCKG also showed strong anti-diabetic activity (IC(50) = 18.503 +/- 0.480 microg/mL) and anti-tyrosinase activity (IC(50) = 14.756 +/- 0.325 microg/mL) as compared to the standards used (acarbose IC(50) = 20.39 +/- 0.231 microg/mL and kojic acid IC(50) = 17.73 +/- 0.192 microg/mL) in the study. Genotoxicity analysis of EMCKG revealed that at 1 microg/mL concentration has no toxic effects in mitosis of Allium cepa roots (Mitotic Index MI = 13.56% and chromosomal aberration CA = 07.60%). The ANOVA confirmed that except for the anticholinesterase activity, there is insignificant difference for essential oil and standards used for all the other bioactivities thus confirming their interchangeable applicability. CONCLUSIONS: Current research provides the basis for the fact that besides being a rich source of ethyl p-methoxycinnamate, EMCKG has the potential for future formulation and development of an inexpensive skin-care agent and for the preparation of anti-diabetic drugs.