Assessment of phytochemical screening, antibacterial, analgesic, and antipyretic potentials of Litsea glutinosa (L.) leaves extracts in a mice model.

Background: 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.

Methods: 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.

Results: 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.

Conclusion: 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.