Statistical optimization of microwave-assisted extraction of phytochemicals from Retama raetam (White Weeping Broom) twigs and their biological properties
Background: Several phytochemicals derived from the genus Retama reported to possess diverse biological activities, including antioxidant, anti-inflammatory, and antibacterial properties.
Aims: The aim of this study was to optimize microwave-assisted extraction (MAE) of polyphenols from Retama raetam twigs using response surface methodology.
Methods: A Box-Behnken design was utilized for determining the effect of MAE factors on total polyphenol content (TPC), including ethanol concentration (50 – 70%), irradiation time (4 – 6 min), power (400 – 600 W), and solvent-to-sample ratio (15 – 25 mL/g). The optimal extract (OE) was further analyzed for total flavonoid content (TFC), total tannin content (TTC), and antioxidant activity (DPPH• scavenging and FRAP) and in vitro anti-inflammatory activity assessment of the OE was evaluated using two complementary assays (albumin denaturation and membrane stabilization).
Results: The following conditions: ethanol concentration of 64.73%, irradiation time of 5.57 min, power of 569.16 W, and solvent-to-sample ratio of 22.91 mL/g, resulted in the highest TPC (181.48 ± 1.59 mg GAE/g DR). The effectiveness and statistical validity of the derived quadratic model indicated no significant discrepancies between experimental and predicted results, demonstrating its high degree of accuracy. The obtained OE demonstrated a TFC of 31.25 ± 1.5 mg EC/g DR and a TTC of 15.17 ± 1.56 mg EC/g DR. The OE showed a significant capacity to scavenge DPPH• and an appreciable ferric-reducing power, where the IC50 and EC50 values were respectively 0.44 ± 0.08 and 0.61 ± 0.03 mg/mL. At a concentration of 1.5 mg/mL, the OE displayed moderate anti-inflammatory activity by red blood cell membrane stabilization (72.72 ± 0.73%) and reduction of heat-induced albumin denaturation (50.89 ± 0.66%).
Conclusion: The MAE of TPC from Retama raetam twigs was primarily influenced by EtOH concentration, irradiation time, and power. The OE exhibited moderate antioxidant and anti-inflammatory properties, suggesting its potential as a source of phytopharmaceuticals.
How to Cite
Awen, B. Z. S., Unnithan, C. R., Ravi, S., Kermagy, A., Sasikumar, J. M., Khrbash, A. S., & Ekreem, W. L. (2011). Essential oils of Retama raetam from Libya: chemical composition and antimicrobial activity. Natural Product Research, 25(9), 927-933. https://doi.org/10.1080/14786419.2010.503612
[Crossref] [Google Scholar] [PubMed] [Publisher]
Belmokhtar, Z., & Harche, M. K. (2014). In vitro antioxidant activity of Retama monosperma (L.) Boiss. Natural Product Research, 28(24), 2324–2329. https://doi.org/10.1080/14786419.2014.934237
[Crossref] [Google Scholar] [PubMed] [Publisher]
Boateng, I. D. (2024). Mechanisms, capabilities, limitations, and economic stability outlook for extracting phenolics from agro-byproducts using emerging thermal extraction technologies and their combinative effects. Food and Bioprocess Technology, 17(5), 1109-1140. https://doi.org/10.1007/s11947-023-03171-5 [Crossref] [Google Scholar] [Publisher]
Brand-Williams, W., Cuvelier, M. E., Berset, C.,1995. Use of a free radical method to evaluate antioxidant activity. LWT - Food Science and Technology, 28(1), 25–30. https://doi.org/10.1016/s0023-6438(95)80008-5 [Crossref] [Google Scholar] [Publisher]
Čanadanović‐Brunet, J. M., Djilas, S. M., Ćetković, G. S., Tumbas, V. T., Mandić, A. I., & Čanadanović, V. M. (2006). Antioxidant activities of different Teucrium montanum L. Extracts. International Journal of Food Science & Technology, 41(6), 667–673. https://doi.org/10.1111/j.1365-2621.2006.01133.x [Crossref] [Google Scholar] [Publisher]
Cavalloro, V., Martino, E., Linciano, P., &Collina, S. (2021). Microwave-assisted solid extraction from natural matrices. Microwave heating - electromagnetic fields causing thermal and non-thermal effects. IntechOpen. https://doi.org/10.5772/intechopen.95440 [Crossref] [Google Scholar] [Publisher]
Chandrasekar, V., Martín-González, M.F.S., Hirst, P. and Ballard, T.S. (2015), Microwave Extraction of Apple Polyphenols. Journal of Food Process Engineering, 38: 571-582. https://doi.org/10.1111/jfpe.12187 [Crossref] [Google Scholar] [Publisher]
Chiorcea‐Paquim, A. M., Enache, T. A., De Souza Gil, E., & Oliveira‐Brett, A. M. (2020). Natural phenolic antioxidants electrochemistry: Towards a new food science methodology. Comprehensive Reviews in Food Science and Food Safety, 19(4), 1680-1726. https://doi.org/10.1111/1541-4337.12566 [Crossref] [Google Scholar] [PubMed] [Publisher]

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