Anti-inflammatory effect of Piper longum L. fruit methanolic extract on lipopolysaccharide-treated RAW 264.7 murine macrophages

Traditional Knowledge and Efficacy Analysis of an Emerging Medicinal Food Plant: Disporopsis aspersa

Disporopsis aspersa (Hua) Engl. ex K. Krause, locally known as kucai (bitter greens) or yexiahua, is a widely consumed wild vegetable and traditional herbal medicine in western Yunnan. Despite its local significance, its nutrient composition and bioactive properties have not been investigated. This study aims to determine the nutritional content and evaluate the antioxidant and anti-inflammatory activities of the aerial parts extracts of D. aspersa. The levels of protein, amino acids, vitamins, and minerals were measured and compared to those of common vegetables. The results showed that D. aspersa contains 16 amino acids, with a total content of up to 19.13 g/100 g, including 3.0 g/100 g of lysine. In vitro evaluations of its antioxidant and anti-inflammatory activities demonstrated that the ethanolic extract exhibited low cytotoxicity against mouse RAW 264.7 murine macrophages cell line at concentrations of 0-120 μg/mL. The IC50 for nitric oxide (NO) scavenging activity was 72.7 ± 7.43 μg/mL, showing dose dependence. Additionally, the ethanolic extract also exhibited ABTS+· scavenging capacity and total antioxidant capacity. These findings suggest that D. aspersa is rich in carbohydrates, fat, dietary fiber, and amino acids. It also contains various bioactive substances, supporting its traditional practices for both medicinal and dietary purposes by local people. D. aspersa has the potential to be developed into a novel anti-hypertensive food, nutraceutical, or dietary supplement in western Yunnan and neighboring regions, promoting local development.

Alkaloids from Piper longum L and their Anti-inflammatory Properties

Piper longum L. (PL) is considered one of the most important species traditionally used for treating various ailments and has indicated the presence of alkaloids, flavonoids, and steroids. In this study, we isolated the chemical compounds of PL leaves, and measured NO, IL-6, iNOS, as well as COX-2 protein levels. In addition, molecular docking analysis was used to further understand the anti-inflammation effect of the compounds. We identified one new alkaloid named piperlongumine A (1) with ten known compounds (2-11). The new compound (1) and two other alkaloids 2E)-3-(4-hydroxy-3-methoxyphenyl)-1-(pyrrol-1-yl) propanone (7) and piperchabamide A (8) significantly reduced NO production in LPS-stimulated RAW 264.7 cells with the IC50 values of 0.97±0.05 μM, 0.91±0.07 μM, 1.63±0.14 μM, respectively. Moreover, at concentration of 2 μM, compound 1 inhibited approximately 98±0.64 % of IL-6 secretion, and decreased iNOS and COX-2 protein level by about 96 and 19 folds compared to LPS treatment alone, respectively. Furthermore, compounds 1, 7, and 8 were predicted to bind and inhibit IL-6, TNF-α, and iNOS, with compound 1 showing the highest binding energy of -7.09 kcal/mol. This study provides new insights for potential anti-inflammatory drug design and warrants further investigation.

Piper longum L. ameliorates gout through the MAPK/PI3K-AKT pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Gout, a painful joint disease with a prevalence ranging from 0.86% to 2.2% in China over the past decade. Traditional medicine has long utilized the medicinal and edible Piper longum L. (PL) fruit spikes for treating gout and other joint conditions like rheumatoid arthritis. However, the exact mechanisms behind its effectiveness remain unclear.

AIM OF THE STUDY

This study aimed to investigate the potential of alcoholic extracts from PL fruit spikes as a safe and effective treatment for gout. We used a combined network pharmacology and experimental validation approach to evaluate the mechanisms behind the anti-gout properties of PL.

MATERIALS AND METHODS

UPLC-Q/TOF-MS analysis determined the major components of PL. Subsequently, network pharmacology analysis predicted potential molecular targets and related signaling pathways for the anti-gout activity of PL. Molecular docking simulations further explored the interactions between PL compounds and proteins and characterized the properties of potential bioactive secondary metabolites. Mouse models of air pouch inflammation and hyperuricemia were further established, and the anti-gout mechanism of PL was confirmed by examining the expression of proteins related to the MAPK and PI3K-AKT pathways in the tissue.

RESULTS

Our analysis revealed 220 bioactive secondary metabolites within PL extracts. Network pharmacology and molecular docking results indicated that these metabolites primarily combat gout by modulating the PI3K-AKT and MAPK signaling pathways. In vivo experiments have also proven that PL at a dose of 100 mg/kg can optimally reduce acute inflammation of gout and kidney damage caused by high uric acid. The anti-gout mechanism involves the PI3K-AKT/MAPK signaling pathway and its downstream NF-κB pathway.

CONCLUSION

This study provides compelling evidence for PL's therapeutic potential in gout management by modulating key inflammatory pathways. The findings offer a strong foundation for future clinical exploration of PL as a gout treatment option.