Volatile profiling coupled with multivariate analysis, antiproliferative and anti-inflammatory activities of rhizome essential oil of four Hedychium species from India.

ETHNOPHARMACOLOGICAL RELEVANCE: The genus Hedychium of family Zingiberaceae comprises several perennial rhizomatous species widely used in perfumery and traditional folk medicine to treat diseases related to asthma, diarrhoea, nausea, stomach disorders, inflammation and tumours. Several species of Hedychium have remained under-explored with respect to their chemical composition and biological activities. AIM OF THE STUDY: The current research aimed to explore the chemical composition and evaluate the antiproliferative and anti-inflammatory activities of rhizome essential oil from four Hedychium species (H. coccineum, H. gardnerianum, H. greenii and H. griffithianum). MATERIALS AND METHODS: Compound identification was accomplished using a Clarus 580 gas chromatography system in conjunction with mass spectrometry (GC-MS). The multivariate data statistics using chemometrics (PCA, PLS-DA, sPLS-DA) and cluster analysis (Dendrogram, Heat maps, K-means) were used to compare the similarity and relationship among Hedychium metabolomes. MTT assay was employed to visualize the antiproliferative property against MCF7, HepG2 and PC3 cancerous cell lines. The toxicity of essential oils was determined using 3T3-L1 non-tumorigenic/normal cells. Lipopolysaccharide (LPS)-induced RAW 264.7 cells were used to investigate the anti-inflammatory properties of Hedychium essential oils by measuring the production of nitric oxide (NO) using the Griess reagent method. Furthermore, the levels of prostaglandin (PGE2) and pro-inflammatory cytokines (TNF-α, IL-6, IL-1ß) was assessed using the ELISA technique. RESULTS: In total, 82 compounds were identified in four targeted species of Hedychium from which 1,8-cineole (52.71%), ß-pinene (32.83%), α-pinene (19.62%), humulene epoxide II (19.86%) and humulene epoxide I (19.10%) were the major constituents. Monoterpenes (8.5-59.9%) and sesquiterpenes (2.87-54.11%) were the two class of compounds, found as the most prevalent in the extracted essential oils. The multivariate analysis classified the four Hedychium species into three different clusters. Hedychium essential oils exhibited potent antiproliferative activity against MCF7, HepG2 and PC3 cancer cell lines with IC50 values less than 150 µg/mL where H. gardnerianum exhibited the highest selective cytotoxicity against human breast and prostate adenocarcinoma cells with an IC50 value of 44.04 ± 1.07 µg/mL and 56.11 ± 1.44 µg/mL, respectively. The essential oils on normal (3T3-L1) cells displayed no toxicity with higher IC50 values thereby concluding as safe to use for normal human health without causing any side effects. Besides, the essential oils at 100 µg/mL concentration revealed remarkable anti-inflammatory activity in LPS-activated RAW 264.7 murine macrophages by inhibiting the production of inflammatory mediators, with H. greenii exhibiting the maximum anti-inflammation response by significantly suppressing the levels of NO (84%), PGE2 (87%), TNF-α (94.3%), IL-6 (95%) and IL-1ß (85%) as compared to LPS treated group. CONCLUSION: The present findings revealed that the Hedychium species traditionally used in therapeutics could be a potential source of active compounds with antiproliferative and anti-inflammatory properties.

Variation in Yield, Chemical Composition and Biological Activities of Essential Oil of Three Curcuma Species: A Comparative Evaluation of Hydrodistillation and Solvent-Free Microwave Extraction Methods.

The essential oils of three medicinally important Curcuma species (Curcuma alismatifolia, Curcuma aromatica and Curcuma xanthorrhiza) were extracted using conventional hydro-distillation (HD) and solvent free microwave extraction (SFME) methods. The volatile compounds from the rhizome essential oils were subsequently analysed by GC-MS. The isolation of essential oils of each species was carried out following the six principles of green extraction and comparison was made between their chemical composition, antioxidant, anti-tyrosinase and anticancer activities. SFME was found to be more efficient than HD in terms of energy savings, extraction time, oil yield, water consumption and waste production. Though the major compounds of essential oils of both the species were qualitatively similar, there was a significant difference in terms of quantity. The essential oils extracted through HD and SFME methods were dominated by hydrocarbon and oxygenated compounds, respectively. The essential oils of all Curcuma species exhibited strong antioxidant activity, where SFME was significantly better than HD with lower IC50 values. The anti-tyrosinase and anticancer properties of SFME-extracted oils were relatively better than that of HD. Further, among the three Curcuma species, C. alismatifolia essential oil showed the highest rates of inhibition in DPPH and ABTS assay, significantly reduced the tyrosinase activity and exhibited significant selective cytotoxicity against MCF7 and PC3 cells. The current results suggested that the SFME method, being advanced, green and fast, could be a better alternative for production of essential oils with better antioxidant, anti-tyrosinase and anticancer activities for application in food, health and cosmetic industries.