Comparison of Herbal Quality, Total Phenolic Content, Total Flavonoid Content, and Antioxidant Activity of Neem Bark Extracts Harvested at Different Times According to Thai Traditional Pharmaceutical textbooks
Keywords:
Neem bark, Harvesting herbs at the appropriate times, Antioxidant activity, Total phenolic content, Total flavonoid contentAbstract
The increasing trend in the use of herbal medicine for healthcare has led to a focus on quality control of herbs, from cultivation to harvesting, according to established standards. Traditional Thai medical theories specify optimal harvesting times for herbs. This research aims to compare the quality of herbs based on the Thai Herbal Pharmacopoeia, total phenolic content, total flavonoid content, and antioxidant activity of 80% ethanol extracts collected at eight different times. Results are presented as the mean ± SD, and variance was analyzed using one-way ANOVA (p-value < 0.05). The study found that:
The quality of the herbs at each time point met the standards. The highest levels of phenolic compounds were found in extracts collected at N2 (21:00 - 24:00), with values of 983.41 ± 14.83 mg GAE/g dry extract. For flavonoid content, all eight time periods showed concentrations of less than 20 mg QE/g dry extract. The highest antioxidant activity was observed in N1 (18:00 - 21:00), with an IC50 of 3.99 ± 0.55 µg/mL. This finding does not align with traditional Thai medical theory, which states that harvesting herbs during the periods of 12:00 - 15:00 (D3) and 21:00 - 24:00 (N2) (21:00 - 24:00) is considered the most suitable time for harvesting herbal bark.
Therefore, further investigations should be conducted to evaluate other pharmacological activities consistent with its traditional therapeutic uses.
References
ธีร์ หะวานนท์, & เกียรติสุดา เหลืองวิลัย. (2562). ผลของเวลาเก็บเกี่ยวและฤดูกาลต่อกิจกรรมการต้านอนุมูลอิสระ ปริมาณแอนโทไซยานิน และสารฟีนอลิกทั้งหมดในดอกอัญชัน. วารสารเกษตรพระจอมเกล้า, 37(4), 133-160.
นรินทร์ ท้าวแก่นจันทร์, ภาวิณี อารีศรีสม, เทิดศักดิ์ โทณลักษณ์, วาริน สุทนต์, และ กอบลาภ อารีศรีสม. (2560). ผลของอายุการเก็บเกี่ยวและความเข้มแสงต่อปริมาณสารประกอบฟีนอลและฤทธิ์ต้านอนุมูลอิสระของ ใบเตยหอม. แก่นเกษตร, 45(3), 433-438.
มูลนิธิฟื้นฟูส่งเสริมการแพทย์แผนไทยเดิมฯ โรงเรียนอายุรเวท (ชีวกโกมารภัจจ์). (2548). ตำราเภสัชกรรมไทย (พิมพ์ครั้งที่ 1). พิฆเณศ พริ้นติ้ง เซ็นเตอร์.
Abubakar, A. R., & Haque, M. (2020). Preparation of medicinal plants: Basic extraction and fractionation procedures for experimental purposes. Journal of Pharmacy and Bioallied Sciences, 12(1), 1-10. https://doi.org/10.4103/jpbs.JPBS_175_19
Alzohairy, M. A. (2016). Therapeutic role of Azadirachta indica (Neem) and their active constituents in diseases prevention and treatment. Evidence-Based Complementary and Alternative Medicine,2016, 1-11. https://doi.org/10.1155/2016/7382506
Ashafa, A. O. T., Yakubu, M. T., Grierson, D. S., & Afolayan, A. J. (2012). Toxicological evaluation of the aqueous extract of Azadirachta indica stem bark in Wistar rats. African Journal of Biotechnology, 11(22), 6112-6118. https://doi.org/10.5897/AJB11.4144
Bondet, V., Brand-Williams, W., & Berset, C. L. W. T. (1997). Kinetics and mechanisms of antioxidant activity using the DPPH. free radical method. LWT-Food Science and Technology, 30(6), 609-615. https://doi.org/10.1006/fstl.1997.0240
Department of medical sciences, Ministry of Public Health. (2018). Thai Herbal Pharmacopoeia 2018. The Agriculural Co-operative Federation of Thailand.
Department of Medical Sciences, Ministry of Public Health. (2023). Thai Herbal Pharmacopoeia 2021 Supplement 2023. Bangkok: Author.
Duda, S. C., Mărghitaş, L. A., Dezmirean, D., Duda, M., Mărgăoan, R., & Bobiş, O. (2015). Changes in major bioactive compounds with antioxidant activity of Agastache foeniculum, Lavandula angustifolia, Melissa officinalis and Nepeta cataria: Effect of harvest time and plant species. Industrial Crops and Products, 77, 499-507. https://doi.org/10.1016/j.indcrop.2015.09.045
Folin, O., & Ciocalteu, V. (1927). On tyrosine and tryptophane determinations in proteins. Journal of Biological Chemistry, 73(2), 627-650.
Khan, M. R., Kihara, M., Omoloso, A. D., & Akhtar, S. (2012). Antioxidant activity of different parts of Annona muricata (soursop). Journal of Medicinal Plants Research, 6(31), 4591-4599. https://doi.org/10.5897/JMPR11.1172
Muhammad, H. L., Yusuf, A. M., & Abdulkadir, U. (2020). Phytochemical screening and antioxidant activities of Azadirachta indica bark extract and its fractions. Nigerian Journal of Pharmaceutical Sciences, 19(2), 123-132.
Tristantini, D., & Amalia, R. (2019). Antioxidant activity of plant extracts using DPPH method. IOP Conference Series: Earth and Environmental Science, 299(1), 012021. https://doi.org/10.1088/1755-1315/299/1/012021
Uzzaman, S. (2020). Pharmacological activities of neem (Azadirachta indica): A review. International Journal of Pharmacognosy and Life Science, 1(1): 38-41. https://doi.org/10.33545/27072827.2020.v1.i1a.8.
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2025 Praboromarajchanok Institute

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.