Labu Zubair Khalid, Karim Samira, Rahman Md Tarekur, Hossain Md Imran, Arifuzzaman Sarder, Shakil Md
Department of Pharmacy, World University of Bangladesh, Dhaka, Bangladesh.
PLoS One. 2025 Jan 31;20(1):e0309857. doi: 10.1371/journal.pone.0309857. eCollection 2025.
Litsea glutinosa (LG) leaves have been traditionally used in ethnomedicine for the treatment of various ailments, including pain, fever, and microbial infections. This study aims to scientifically evaluate the therapeutic potential of cold methanol extracts of LG leaves, specifically focusing on their analgesic, antipyretic, and antibacterial activities. In addition, the research includes preliminary phytochemical screening to identify key bioactive compounds and an acute toxicity test to assess the safety profile of the extract.
In this study, we conducted an initial investigation of the major phytochemical groups present in L. glutinosa leaves using both modern chromatographic techniques, specifically High-Performance Liquid Chromatography (HPLC), and conventional phytochemical screening methods applied to cold methanol extracts. Both approaches consistently identified phenols and flavonoids as the predominant bioactive compounds. Following this phytochemical characterization, we assessed the analgesic efficacy of the extracts using acetic acid-induced writhing and electrical heat-induced nociceptive pain stimuli, evaluated antipyretic effects through Brewer's yeast-induced pyrexia, and determined antibacterial activity via the disc diffusion method. Additionally, the toxicity of the extracts was evaluated through preclinical testing.
In hot plate method, the highest pain inhibitory activity was found at a dose of 500 mg/kg of crude extract (3.37 ± 0.31 sec) which differed significantly (P < 0.01 and P < 0.001) with that of the standard drug morphine (6.47 ± 0.23 sec). The extract significantly prolonged reaction latency to thermal-induced pain in hotplate model. Analgesic activity at 500 mg/kg, LG extract produced a 70% suppression of writhing in mice, which was statistically significant (p < 0.001) compared to standard morphine's (77.5%) inhibition. In antipyretic activity assay, the crude extract showed notable reduction in body temperature (36.17 ± 0.32 °C) at dose of 300 mg/kg-body weight, when the standard (at dose 100 mg/kg-body weight) exerted (36.32 ± 0.67 °C) after 3 h of administration. In antibacterial studies, results showed that inhibition of bacterial growth at 400 μg dose of each extract clearly inhibited growth of bacteria from 11 to 22 mm. The extractives carbon tetrachloride fraction, chloroform soluble fraction, ethyl acetate fraction demonstrated notably greater inhibitory zone widths (p < 0.05) against tested strains.
Overall, the cold methanol extract of LG leaves demonstrates the therapeutic potential in preclinical settings. Future research is warranted to isolate the specific bioactive compounds and elucidate their mechanisms of action to further support the development of new treatments and contributing to modern medicinal practices based on this plant leaves.
潺槁木姜子（LG）叶在民族医学中传统上用于治疗各种疾病，包括疼痛、发热和微生物感染。本研究旨在科学评估LG叶冷甲醇提取物的治疗潜力，特别关注其镇痛、解热和抗菌活性。此外，该研究还包括初步的植物化学筛选以鉴定关键生物活性化合物，以及急性毒性试验以评估提取物的安全性。
在本研究中，我们使用现代色谱技术，特别是高效液相色谱（HPLC），以及应用于冷甲醇提取物的传统植物化学筛选方法，对潺槁木姜子叶中存在的主要植物化学基团进行了初步研究。两种方法均一致鉴定出酚类和黄酮类为主要生物活性化合物。在此植物化学特征分析之后，我们使用醋酸诱导扭体和电热诱导伤害性疼痛刺激评估提取物的镇痛效果，通过啤酒酵母诱导发热评估解热作用，并通过纸片扩散法测定抗菌活性。此外，通过临床前测试评估提取物的毒性。
在热板法中，发现粗提取物剂量为500mg/kg时具有最高的疼痛抑制活性（3.37±0.31秒），与标准药物吗啡（6.47±0.23秒）相比有显著差异（P<0.01和P<0.001）。提取物在热板模型中显著延长了对热诱导疼痛的反应潜伏期。在500mg/kg剂量下，LG提取物对小鼠扭体产生了70%的抑制作用，与标准吗啡（77.5%）的抑制作用相比具有统计学意义（p<0.001）。在解热活性试验中，粗提取物在剂量为300mg/kg体重时显示出显著的体温降低（36.17±0.32°C），而标准药物（剂量为100mg/kg体重）在给药3小时后体温为（36.32±0.67°C）。在抗菌研究中，结果表明，每种提取物剂量为400μg时对细菌生长的抑制作用明显抑制了细菌生长11至22mm。提取物的四氯化碳馏分、氯仿可溶馏分、乙酸乙酯馏分对受试菌株显示出明显更大的抑菌圈宽度（p<0.05）。
总体而言，LG叶冷甲醇提取物在临床前环境中显示出治疗潜力。未来有必要进行研究以分离特定的生物活性化合物并阐明其作用机制，以进一步支持新治疗方法的开发，并为基于这种植物叶的现代医学实践做出贡献。
