Background: Quorum sensing is the key regulator of virulence factors of Pseudomonas aeruginosa such as biofilm formation, motility, productions of proteases, hemolysin, pyocyanin, and toxins. Material and Methods: Quorum sensing inhibitory (OSI) effect of the alcohol extracts of 20 medicinal plants was evaluated by Chromobacterium violaceum reporter using agar cup diffusion method. The efficient QSI extracts were tested for their activity against biofilm synthesis, motility, and synthesis of pyocyanin from P. aeruginosa PA14 Results: The extracts of Citrus sinensis, Laurus nobilis, Elettaria cardamomum, Allium cepa, and Coriandrum sativum exhibited potent quorum quenching effect. On the other hand, Psidium guajava and Mentha longifolia extracts showed lower QSI activity. These extracts exhibited significant elimination of pyocyanin formation and biofilm development of Pseudomonas aeruginosa PA14. In addition, they significantly inhibited twitching and swimming motilities of P. aeruginosa PA14. Conclusion: This study illustrated for the first time the importance of C. sinensis, L. nobilis, E. cardamomum, A. cepa, and C. sativum as quorum sensing inhibitors and virulence suppressors of P. aeruginosa.

A new prenylated xanthone, garcixanthone A (5), together with eight known compounds, mangostanaxanthones I (1) and II (2), garcinone E (3), β-mangostin (4), 8-hydroxycudraxanthone G (6), garcinone C (7), cudraxanthone G (8), and (-)-epicatechin (9) were isolated from the EtOAc-soluble fraction of the air-dried pericarps of Garcinia mangostana (family Clusiaceae). Their structures were verified on the basis of spectroscopic data interpretation as well as comparison with the literature. The cytotoxic and antimicrobial activities of the new compound were assessed using sulforhodamine B (SRB) and agar disk diffusion assays, respectively. Compound 5 showed significant cytotoxic potential against epithelial lung carcinoma (A549) and breast carcinoma (MCF7) cell lines with IC₅₀s 3.0 and 4.2 μM, respectively, compared to doxorubicin (0.74 and 0.41 μM, respectively).

Malaria is one of the major infectious diseases and foremost cause of mortality and morbidity in many subtropical and tropical regions. In the last years, the situation has become worse in many ways, due to increase the parasites resistance to various available antimalarial agents. Furthermore, the malaria`s control is beginning to be more sophisticated by the parallel spread of mosquito vector`s resistance to the available insecticides. Recently, there is a wide consensus to seek for target specific, safe, affordable, and effective new antimalarial agents, which can compete with synthetic ones. Endophytic fungi are of a growing interest as prominent sources of structurally unique bioactive natural products. The bio-metabolites isolated from endophytic fungi, possessing antimalarial potential may compose the base for the synthesis of novel drugs that might be utilized to withstand malaria and its resistance. For getting information on the various studies, PubMed, Google Scholar, ScienceDirect, SpringerLink, Scopus, and Wiley search was done using keywords (malaria, endophytic fungi, and antimalarial activity). The present review covers the literature published from 1996 to 2017 and highlights the metabolites for which antimalarial activities have been reported. Overall, 135 fungal metabolites and 73 references are cited. In addition, their structure, chemical class, fungal source, host, and activity have been presented. This review shows the significance of endophytic fungi as a wealthy pool of antimalarial agents.