Anti-inflammatory properties of extracts from plants of the Rubiaceae family

Rubiaceae species are widely distributed, mainly concentrated in tropical regions. They contain various alkaloids, flavonoids, and other active compounds that have significant therapeutic effects on many diseases. In this study a meta-analysis of the existing experimental data on the therapeutic effects of Rubiaceae was conducted using Cochrane, PubMed, Google Scholar, and Web of Science databases for report retrieval. The search contained “Gardenia”, “Hedyotis”, “Morinda”, “Nauclea”, and “Paederia” species of Rubiaceae, which were used in animal inflammation models. A total of 348 papers were analyzed, duplicate studies were removed, data reliability and adequate sample sizes were filtered. Proinflammatory cytokines (PCs), and the expression of inflammatory gene NF-κB were used to evaluate the inflammatory levels in two animal models, the Rubiaceae-treated (RT) and Inflammation Model (IM). Subgroup analysis was used to explore: 1) the anti-inflammatory effects of different genera; 2) the anti-inflammatory effects of different extracts. The results from meta-analysis show that Rubiaceae extracts exert significant anti-inflammatory effects in animal models, with the RT group exhibiting lower levels of PCs (IL-1β, IL-6, TNF-α) and NF-κB expression than the IM group (p < 0.05). Subgroup analysis found that Gardenia, Hedyotis, and Morinda all significantly reduced IL-1β and TNF-α levels, while only Morinda had a notable inhibitory effect on IL-6; aqueous, ethanol, and terpenoid extracts all showed significant anti-inflammatory activity. Substantial heterogeneity was observed, which subgroup and meta-regression analyses identified as being primarily due to intergeneric differences. Begg’s and Egger’s tests indicated the presence of publication bias across the included studies. Further in vivo and in vitro experiments are therefore required to verify the anti-inflammatory effects of various medicinal plants of the Rubiaceae family.

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