ABSTRACT
Medicinal plant-based cerium oxide nanoparticles (CeO2NPs) possessed excellent antimicrobial properties against multiple strains of Gram-positive and Gram-negative bacteria. The CeO2NPs are popular because their electropositive charged surface causes oxidation of plasma membrane and facilitates the penetration of CeO2NPs inside the pathogen body. In the present research work, CeO2NPs stabilized with Mentha leaf extract; as a result, nanoparticles surface-bonded with various functional groups of phytochemicals which enhanced the therapeutic potential of CeO2NPs. The inhibition percentage of CeO2NPs was evaluated against eight pathogenic Gram-positive bacteria Staphylococcus aureus and Streptococcus epidermidis; Gram-negative bacteria Escherichia coli, Stenotrophomonas maltophilia, Comamonas sp., Halobacterium sp., and Klebsiella pneumoniae; and plant bacteria Xanthomonas sp. The antifungal properties of CeO2NPs were evaluated against three pathogenic fungal species Bipolaris sorokiniana, Aspergillus flavus, and Fusarium oxysporum via the streak plate method. The antimicrobial inhibitory activity of CeO2NPs was good to excellent. The current research work clearly shows that three different medicinal plants Mentha royleana, Mentha longifolia, and Mentha arvensis based CeO2NPs, variation in nanoparticle sizes, and surface-to-volume ratio of green CeO2NPs are three factors responsible to generate and provoke antimicrobial activities of CeO2NPs against human pathogenic bacteria and plant infecting fungi. The results show that CeO2NPs possessed good antimicrobial properties and are effective to use for pharmaceutical applications and as a food preservative because of low toxicity, organic coating, and acceptable antimicrobial properties. This study showed a rapid and well-organized method to prepare stable phytochemical-coated CeO2NPs with three different plants M. royleana, M. longifolia, and M. arvensis with remarkable antibacterial and antifungal characteristics.
ABSTRACT
Majority of the mountain dwelling communities living in the Himalayas rely on traditional herbal medicines for primary healthcare needs. Present study was conducted in fairy meadows and allied valleys in District Diamir, Gilgit Baltistan autonomous territory in northern Pakistan. Documentation of traditional medicinal knowledge (TMK) of local communities for the treatment of gastrointestinal disorders was carried out as a component of a wider medico-botanical expedition conducted in the entire base camp of the great Nanga Parbat peak during 2016-19. Various ethnobotanical parameters i.e. use value (UV), informant consensus factor (ICF), Fidelity level (FL), direct matrix ranking test (DMRT) and preference ranking (PR) were applied to evaluate the data collected during field surveys. The plants were also subjected to a comparative review for novelty assessment. A total of 61 medicinal plant species belonging to 55 genera and 35 families are reported here for the treatment of GIDs. Compositae was the leading family with 8 (13%) species. Fourteen gastrointestinal disorders were cured with 32% taxon were reported for stomachic followed by diarrhea (15%) and constipation (14%). Highest use reports (5) and use citations (207) were reported for Mentha longifolia L. while highest UV (1.79) was obtained for Artemisia maritima L. Hylotelephium telephioides (Ledeb.), A. maritima, M. longifolia, M. piperita L., Allium cepa L., and A. annua L. exhibited 100% FL. Highest ICF was calculated against dysentery and flatulence. DMRT ranked Prunus persica L. first for its multipurpose uses. Taking constipation as a reference gastrointestinal disease, PR for ten plant species was calculated where H. telephioides was ranked first followed by A. maritima. Present study concluded that 19 out of 61 plant species were documented for the first time with novel medicinal uses to cure GIDs. These plant species could act as potential reservoirs of novel lead compounds for the treatments of gastrointestinal disorders.
