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Melaleuca polandii, commonly known as "Gold-tipped Bottlebrush", is widely grown in Indian gardens and parks as an ornamental plant. In the present study, the chemical composition, antioxidant, antimicrobial and cytotoxic activities of M. polandii leaf essential oil (MPLEO) have been investigated. GC-MS analysis of MPLEO isolated from plants grown along the coastal plains of Eastern India revealed the presence of 50 constituents with α-pinene (46.17%), 3Z-hexenyl acetate (10.10 %), α-terpineol (5.43%), limonene (3.63%) and ρ-cymene (2.44 %) as the major constituents. MPLEO exhibited moderate antioxidant capacity in DPPH, ABTS and Reducing ability assays with IC50 values of 7.94 ± 0.34 μg/mL, 5.71 ± 0.21 μg/mL and EC50 7.09 ± 0.35 μg/mL, respectively. Of the 5 bacterial strains tested, the EO exhibited highest sensitivity against Bacillus subtilis with the ZOI of 12.66 ± 0.57 mm and strong antimicrobial activity against Staphylococcus saprophyticus with MIC value of 6.25 μg/mL. MPLEO exhibited significant cytotoxic effects against Human alveolar lung adenocarcinoma (A549), Human hepato-cellular carcinoma (HepG2), Human cervix adenocarcinoma (HeLa) and normal Human Embryonic Kidney cell (HEK-293) as evaluated through MTT assay with IC50 values of 9.5 ± 0.38 μg/mL, 22.73 ± 0.95 μg/mL, 20.41 ± 0.82 μg/mL and 237.68 ± 9.26 μg/mL, respectively. The findings of the present study demonstrated that MPLEO could be considered as a potential bioresource having applications in pharmaceutical industries as an antibacterial and antiproliferative agent. [ABSTRACT FROM AUTHOR]

Mesosphaerum suaveolens (L.) Kuntze (Syn. Hyptis suaveolens (L.) Poit.) is a wild essential-oil-bearing plant having multiple uses in traditional medicine, perfumery, food, agriculture, and pharmaceutical industries. The present paper is the first report on the in vitro anti-inflammatory effects of the leaf essential oil of M. suaveolens (MSLEO) and unravels its molecular mechanism in LPS-stimulated RAW 264.7 macrophage cells. GC-MS analysis of the essential oil (EO) isolated from the leaves by hydro-distillation led to the identification of 48 constituents, accounting for 90.55% of the total oil, and β-caryophyllene (16.17%), phyllocladene (11.85%), abietatriene (11.46%), and spathulenol (7.89%) were found to be the major components. MSLEO treatment had no effect on the viability of RAW 264.7 cells up to a concentration of 100 μg/mL, and the EO was responsible for a reduction in proinflammatory cytokines like IL-6, IL-1β, and TNF-α, a decrease in intracellular ROS production, and the restoration of oxidative damage by elevating the levels of endogenous antioxidative enzymes like CAT, SOD, GPx, and GSH. RT-qPCR analysis indicated that MSLEO reduced the mRNA expression levels of iNOS and COX-2 as compared to the LPS-induced group. In addition, a confocal microscopy analysis showed that MSLEO inhibited the translocation of NF-κB from the cytosol to the nucleus. The results of this experiment demonstrate that MSLEO possesses significant anti-inflammatory potential by preventing the activation of NF-κB, which, in turn, inhibits the downstream expression of other inflammatory mediators associated with the activation of the NF-κB pathway in LPS-induced RAW 264.7 cells. Thus, the leaf essential oil of M. suaveolens may prove to be a promising therapeutic agent for the treatment of inflammation, and targeting the NF-κB signaling pathway may be considered as an attractive approach for anti-inflammatory therapies. [ABSTRACT FROM AUTHOR]

Neocinnamomum caudatum (Lauraceae) plant is used in the traditional system of medicine and is considered a potential source of edible fruits, spices, flavoring agents and biodiesel. The leaves, bark and roots of the species are used by local communities for the treatment of inflammatory responses, such as allergies, sinusitis and urinary tract infections. However, there is no scientific evidence to support the molecular mechanism through which this plant exerts its anti-inflammatory effect. The aim of the current research was to characterize the chemical constituents of bark (NCB) and leaf (NCL) essential oil of N. caudatum and to elucidate its anti-inflammatory action in lipopolysaccharide (LPS)-treated RAW 264.7 cells. Essential oils extracted by hydrodistillation were further subjected to gas chromatography mass spectrometry (GC-MS) analysis. The major constituents in bark essential oil identified as β-pinene (13.11%), α-cadinol (11.18%) and α-pinene (10.99%), whereas leaf essential oil was found to be rich in β-pinene (45.21%), myrcene (9.97%) and α-pinene (9.27%). Treatment with NCB and NCL at a concentration of 25 µg/mL exerted significant anti-inflammatory activity by significantly reducing LPS-triggered nitric oxide (NO) production to 45.86% and 61.64%, respectively, compared to the LPS-treated group. In the LPS-treated group, the production of proinflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β, decreased after treatment with essential oil, alleviating the mRNA levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2. The essential oil also inhibited the production of intracellular ROS and attenuated the depletion of mitochondrial membrane potential in a concentration-dependent manner. Pretreatment with NCB also reduced nuclear factor kappa-B (NF-κB)/p65 translocation and elevated the levels of endogenous antioxidant enzymes in LPS-induced macrophages. The present findings, for the first time, demonstrate the anti-inflammatory potential of both bark and leaf essential oils of N. caudatum. The bark essential oil exhibited a significantly more important anti-inflammatory effect than the leaf essential oil and could be used as a potential therapeutic agent for the treatment of inflammatory diseases. [ABSTRACT FROM AUTHOR]