Purpose: The purpose of this research was to examine the effects of Persicaria lapathifolia (Pale smartweed) leaf and bark extracts prepared with methanol on in vitro activities like antioxidant, antimicrobial, anti-arthritis, anti-inflammatory, and cytotoxic, as well as on some in vivo activities like analgesic and neuropharmacological properties in animal model.
Methodology: The primary method for the methanolic extract of Persicaria lapathifolia leaf (MEPLL) and methanolic extract of Persicaria lapathifolia bark (MEPLB) were investigated for phytochemical screening. It was determined to look into the plant's potential for in vitro activities, such as phytochemical screening, antioxidant, anti-arthritis, anti-inflammatory, anti-bacterial, and cytotoxic, due to the pharmaceutical interest in its component parts. Its described effects on its in vivo analgesic and neuropharmacological activities in animal models are significant compared to the standard. This research was conducted between July 2022 and November 2022 in the Stamford University Bangladesh, Dhaka, Laboratory of Physiology and Pharmacology, Department of Pharmacy, and Laboratory of Microbiology. Antioxidant, anti-arthritic, anti-inflammatory, antibacterial, cytotoxic, analgesic, and neuropharmacological activities of MEPLL and MEPLB were investigated. Phytochemical screening was performed utilizing a variety of test reagents. Antioxidant, total phenolic content, anti-arthritic, anti-inflammatory, antibacterial, and cytotoxic activities were measured at various doses using the DPPH Free Radical Scavenging Assay, the Folin-Ciocalteu technique, the Inhibition of Protein Denaturation Assay, Egg Albumin Protein Denaturation Assay, the Disk Diffusion Method, and the Brine Shrimp Lethality Bioassay. The analgesic effectiveness was evaluated by using acetic acid to elicit writhing in Swiss albino mice and then testing the animals on a hot plate. Locomotor activity was measured by open field and hole cross tests as part of the neuropharmacological investigation.
Results: Research performed on MEPLL and MEPLB's phytochemical screening yielded results that revealed the presence of a variety of different phytochemical components. In comparison to MEPLL's IC50 value of 1.49 µg/mL, MEPLB's value of 30.45 µg/mL indicates its superior antioxidant activity. Both extracts demonstrated significant anti-arthritic and anti-inflammatory effectiveness in comparison to the standard drug. When compared to MEPLB, MEPLL exhibited much more antibacterial activity. In a lethality test using brine shrimp, MEPLL and MEPLB both had much higher LC50 values than the standard vincristine sulfate. Their respective values were 1.42 and 0.66 µg/mL. In contrast, MEPLL inhibited peripheral nociception in the acetic acid-induced writhing nociceptive paradigm with percent inhibitions of 60.72 and 67.56, respectively, while MEPLB inhibited 48.22 and 67.28, respectively, at the aforementioned doses. In addition, the hot plate test revealed a significant analgesic effect. The extract was also shown to have a more negative impact on motor coordination in the Open Field and Hole Cross Tests than the standard Diazepam.
Conclusion: This research demonstrates a relationship between the existence of anti-oxidative, anti-arthritis, and anti-bacterial activities, as well as a strong cytotoxic, analgesic, and neuropharmacological activity, which substantiates all previously made claims against Persicaria lapathifolia.
