Page 141 - วารสารการแพทย์แผนไทย ปีที่ 21 ฉบับที่ 2

J Thai Trad Alt Med Vol. 21 No. 2 May-Aug 2023 357

A Comparison of Antibacterial Activity Against Acne-Inducing Bacteria,
Anti-inflammatory Activity, and Total Phenolic Content of Fresh and Dried
Leaves of Thunbergia laurifolia Lindl Extracts

Natthakan Chitkrachang , Sumalee Panthong , Supidcha Ploysombun , Sirinad Choosrichom ,
*,§
†
†
*
Natsima Ngamkham , Duangpacharaporn Kwanchian*, Reawfang Sriyom ‡
†
* Department of Applied Thai Traditional Medicine, Faculty of Medicine, Thammasat University,
Khlong Nueng Subdistrict, Khlong Luang District, Pathum Thani 12120, Thailand.
† Bachelor of Applied Thai Traditional Medicine Program, Faculty of Medicine, Thammasat University, Khlong Nueng
Subdistrict, Khlong Luang District, Pathum Thani 12120, Thailand.
‡ Doctor of Philosophy Program in Applied Thai Traditional Medicine, Faculty of Medicine, Thammasat University,
Khlong Nueng Subdistrict, Khlong Luang District, Pathum Thani 12120, Thailand
§ Corresponding author: psumalee@tu.ac.th

Abstract

Introduction and Objectives: Acne is a skin disease with swelling, redness, inflammation, or bacterial
infection caused by Cutibacterium acnes and Staphylococcus aureus. In Thai traditional medicine, herbs have
been employed to treat such diseases. Thunbergia laurifolia Lindl. (rang chued in Thai), with a main ingredient of
phenolic compounds, is used for treating/relieving skin diseases, fever, pain, and swelling. The dried leaf extract of
T. laurifolia has been reported on inhibition of C. acnes. However, a comparison of antibacterial activities of fresh
and dried leaves of T. laurifolia has not yet been reported. Therefore, this study aimed to investigate T. laurifolia
extract’s antibacterial activity against bacteria-inducing acne, anti-inflammatory activity, and total phenolic content,
and to compare the effects of fresh and dried T. laurifolia extracts obtained with various solvents.
Methods: Antibacterial activity determination was performed using broth microdilution assay to detect
minimal inhibitory concentration. Total phenolic content was evaluated using Folin-Ciocalteu technique and anti-
inflammatory activity was detected in nitric oxide released from RAW264.7 cells.
Results: The comparative examination was made of fresh and dried leaves and the solvent effect on biologi-
cal activity of T. laurifolia. Fresh leaf extract was found to have a higher phenolic content than dried leaf extract.
Ethanolic fresh leaf extract showed the highest inhibitory effect on C. acnes growth and nitric oxide production.
In addition, only fresh leaf extract could inhibit S. aureus growth.
Discussion: The biological activity of fresh leaves of T. laurifolia was better than dried leaves; and the
biological activity of ethanolic extract was better than the aqueous extract. High temperatures might cause the
degradation of active ingredients in T. laurifolia. Thus, the biological activity of dried leaf extracts and the aqueous
extracts was lower than in the ethanolic extract of fresh leaves of T. laurifolia.
Conclusion: Of T. laurifolia, fresh leaves have better antibacterial and anti-inflammatory activities than
dried leaves. The suitable extraction is maceration in 95% ethanol. Thus, ethanolic T. laurifolia fresh leaf extract
is more suitable for developing anti-acne products in the future.
Key words: Thunbergia laurifolia Lindl, anti-inflammatory activity, antibacterial activity, acne