Abstract
Maesa indica (Roxb.) Sweet is one of the well-known traditionally-used Indian plants. This plant is rich in secondary metabolites like phenolic acids, flavonoids, alkaloids, glycosides, saponins, and carbohydrates. It contains numerous therapeutically active compounds like palmitic acid, chrysophanol, glyceryl palmitate, stigmasterol, β-sitosterol, dodecane, maesaquinone, quercetin 3-rhaminoside, rutin, chlorogenic acid, catechin, quercetin, nitrendipine, 2,3-dihydroxypropyl octadeca-9,12-dienoate, kiritiquinon, and β-thujone. The Maesa indica plant has been reported to have many biological properties including antidiabetic, anticancer, anti-angiogenic, anti-leishmanial, antioxidant, radical scavenging, antibacterial, antiviral, and anti-coronavirus effects. One purpose of the current study was to investigate the leaves' metabolome via Triple-Time-of-Flight-Liquid-Chromatography-Mass Spectrometry (T-TOF LC/MS/MS) to identify the chemical constituents of the Maesa indica ethanolic extract (ME). Another purpose of this study was to explore the protective effect of ME against potassium dichromate (PD)-induced pulmonary damage in rats. Rats were assigned randomly into four experimental groups. Two different doses of the plant extract, (25 and 50 mg/kg), were administered orally for seven consecutive days before PD instillation injection. Results of our study revealed that ME enhanced cellular redox status as it decreased lipid peroxidation marker, MDA and elevated reduced glutathione (GSH). In addition, ME upregulated the cytoprotective signaling pathway PI3K/AKT. Moreover, ME administration ameliorated histopathological anomalies induced by PD. Several identified metabolites, such as chlorogenic acid, quercetin, apigenin, kaempferol, luteolin, and rutin, had previously indicated lung-protective effects, possibly through an antioxidant effect and inhibition of oxidative stress and inflammatory mediators. In conclusion, our results indicated that ME possesses lung-protective effects, which may be the result of its antioxidant and anti-inflammatory properties.