Neuroinflammation and acetylcholinesterase inhibition potentials of acyclic monoterpenoids isolated from Cymbopogon distans (Nees ex Steud.) Will. Watson.

Cymbopogon distans (Nees ex Steud.) Will. Watson (Poaceae) is a promising aromatic plant distributed in the Himalayas. In this study, five acyclic monoterpenoids, namely geranyl acetate (RS1), neral (RS2), geranial (RS3), citral (RS4) and geraniol (RS5) were isolated from the essential oil of C. distans. The isolated compounds were tested for in-vitro neuroinflammation inhibitory potential in LPS-stimulated BV2 microglial cells. RS1-RS4 exhibited significant neuroinflammation inhibition without any cytotoxic effect at the dose of 10 µM. RS4, the most active anti-neuroinflammatory compound (TNF-α 31.48 ± 1.00%; IL-6 24.02 ± 0.63%; IL-1ß 42.15 ± 1.76%) was also able to inhibit acetylcholinesterase (AChE) in a dose-dependent manner. The results showed that RS4 (an isomeric mixture of neral and geranial) has the potential to inhibit neuroinflammation and AChE, which are the biomarkers of neurodegenerative disorders.

Acyclic monoterpenoid-rich essential oil of Cymbopogon distans mitigates skin inflammation: a chemico-pharmacological study.

The topical application of essential oils is considered an effective treatment for skin diseases. Cymbopogon distans (Nees ex Steud.) Wats (Poaceae) is a promising aromatic grass widespread in the Himalayan temperate zone. Therefore, using in-vitro and in-vivo bioassays, we examined the chemical and pharmacological characteristics of essential oil hydro-distilled from C. distans coded as CDA-01, specifically concerning skin inflammation. Characterization using GC-FID and GC-MS provided a chemical fingerprint for CDA-01, enabling the identification of 54 compounds; amongst them, citral (34.3%), geranyl acetate (21.2%), and geraniol (16.4%) were the most abundant. To examine the anti-inflammatory potential, CDA-01 treatment on LPS-stimulated macrophage cells in addition to 12-O-tetradecanoylphorbol-13-acetate (TPA) generated cutaneous inflammatory reaction in the mouse ear was assessed through quantification of the inflammatory markers. Consequently, CDA-01 demonstrated protection against inflammation caused by LPS by lowering the pro-inflammatory cytokines (IL-6 and TNF-α) level in HaCaT cells with negligible cytotoxicity. Consistent with the in-vitro findings, CDA-01 treatment reduced pro-inflammatory mediators (TNF-, IL-6, and NO) and lipid peroxidation in an in-vivo investigation. Subcutaneous inflammation in TPA-treated mice ears was similarly decreased, as evidenced by the histological and morphological studies. As a result of our findings, it is possible that CDA-01 could be an effective treatment for skin inflammation disorders.

Comparative Chemical Composition and Acetylcholinesterase (AChE) Inhibitory Potential of Cinnamomum camphora and Cinnamomum tamala.

Cinnamomum species have applications in the pharmaceutical and fragrance industry for wide biological and pharmaceutical activities. The present study investigates the chemical composition of the essential oils extracted from two species of Cinnamomum namely C. tamala and C. camphora. Chemical analysis showed E-cinnamyl acetate (56.14 %), E-cinnamaldehyde (20.15 %), and linalool (11.77 %) contributed as the major compounds of the 95.22 % of C. tamala leaves essential oil found rich in phenylpropanoids (76.96 %). C. camphora essential oil accounting for 93.57 % of the total oil composition was rich in 1,8-cineole (55.84 %), sabinene (14.37 %), and α-terpineol (10.49 %) making the oil abundant in oxygenated monoterpenes (70.63 %). Furthermore, the acetylcholinesterase inhibitory activity for both the essential oils was carried out using Ellman's colorimetric method. The acetylcholinesterase inhibitory potential at highest studied concentration of 1 mg/mL was observed to be 46.12±1.52 % for C. tamala and 53.61±2.66 % for C. camphora compared to the standard drug physostigmine (97.53±0.63 %) at 100 ng/ml. These multiple natural aromatic and fragrant characteristics with distinct chemical compositions offered by Cinnamon species provide varied benefits in the development of formulations that could be advantageous for the flavor and fragrance industry.

Taxoids-rich extract from Taxus wallichiana alleviates high-fat diet-induced insulin resistance in C57BL/6 mice through inhibition of low-grade inflammation.

The needle powder of Taxus wallichiana is in use for the management of diabetes and inflammation-related complications in the Indian and Chinese Systems of Traditional Medicine but the lack of proper pharmacological intervention has prompted us to investigate the pharmacological mechanism against inflammation-induced insulin resistance in high-fat diet-fed C57BL/6 mice. Hexane (Tw-H), chloroform (Tw-C), and ethyl acetate (Tw-EA) extracts were prepared from a needle of T. wallichiana and its effect on glucose uptake against TNF-α-induced insulin resistance in skeletal muscle cells was studied. Among all, Tw-EA extract has shown promising glucose uptake potential. Tw-EA treatment is also able to decrease the lipid accumulation in adipocytes. Chemical signature of Tw-EA using HPLC showed the presence of taxoids. Efficacy of taxoids-rich extract from T. wallichiana (Tw-EA) was further validated in in vivo system against high-fat diet (HFD)-induced insulin resistance in C57BL/6 mice. Oral treatment of Tw-EA showed significant reduction in blood glucose, pro-inflammatory cytokine production and body weight gain when compared with vehicle-treated HFD-induced insulin resistance in C57BL/6 mice. Histopathology and immunohistochemistry study in skeletal muscle and adipose tissue revealed that oral treatment of Tw-EA is able to reduce the infiltration of inflammatory cells in skeletal muscles, ameliorate the hypertrophy in adipose tissue and upregulate the GLUT4 protein expression. Treatment with Tw-EA significantly up-regulated mRNA expression of insulin signaling pathway (IRS-1, PI3K, AKT, GLUT 4). This study suggested the beneficial effect of taxoids-rich extract from Taxus wallichiana against the inflammation-associated insulin resistance condition.

p-Menthadienols-rich essential oil from Cymbopogon martini ameliorates skin inflammation.

Cymbopogon martini variety sofia, commonly known as ginger-grass, is an important aromatic crop used by the perfumery, medicinal and cosmetic industries worldwide. This study explores the chemical and possible pharmacological profile of hydro-distilled essential oil of C. martini variety sofia against skin inflammation. The essential oil extracted by the hydrodistillation process was analyzed by gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (NMR) to identify its constituents, and was coded as CMA-01 for further in vitro and in vivo pharmacological study related to skin inflammation. The chemical fingerprint revealed that CMA-01 oil has (E)-p-mentha-2,8-dien-1-ol (21.0%), (E)-p-mentha-1(7),8-dien-2-ol (18.1%), (Z)-p-mentha-1(7),8-dien-2-ol (17.4%), (Z)-p-mentha-2,8-dien-1-ol (9.0%), limonene (7.7%), and (E)-carveol (5.7%) as major components. The pre-treatment of CMA-01 showed significant inhibition of pro-inflammatory markers in activated HaCat cells without cytotoxic effect. The in vivo study revealed the ameliorative impact of CMA-01 against skin inflammation induced by TPA in mouse ears as evidenced by a reduction of ear edema, pro-inflammatory mediators (IL-6, TNF-α), oxidative stress markers (malondialdehyde and nitric-oxide) and histological changes in ear tissues without any skin irritation response on rabbit skin. These findings suggest the suitability of CMA-01 as a valuable therapeutic candidate for the treatment of skin inflammation.

Chemical composition and antimicrobial activity of the leaf essential oil of Ravenia spectabilis Engl. (Rutaceae).

Ravenia spectabilis Engl. belongs to the family Rutaceae is known to possess several biologically active phytomolecules. This study was planned to investigate the chemical composition and antimicrobial activity of the leaf essential oil of R. spectabilis. The hydrodistillation of fresh leaves of R. spectabilis gave 0.19 ± 0.02% essential oil. The resulting essential oil was analysed by gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Altogether, thirty-one constituents forming 97.6 ± 1.72% of the total oil composition were identified. Major components of the oil were sabinene (60.8 ± 0.36%), α-pinene (5.4 ± 0.30%), myrcene (4.8 ± 0.25%), δ-3-carene (4.7 ± 0.62%) and ß-pinene (4.3 ± 0.17%). The in-vitro antimicrobial potential of the oil was examined against eight human pathogenic bacterial and fungal strains. The essential oil showed significant activity against Staphylococcus aureus, Staphylococcus epidermidis, methicillin-resistant Staphylococcus aureus, methicillin-resistant Staphylococcus epidermidis, Candida albicans, and Candida kefyr. This is the first report on R. spectabilis leaf essential oil composition and its antimicrobial activity. The essential oil could be a promising natural source of sabinene and antimicrobial for developing new phytotherapeutics.

New Insights into the Chemical Composition, Pro-Inflammatory Cytokine Inhibition Profile of Davana (Artemisia pallens Wall. ex DC.) Essential Oil and cis-Davanone in Primary Macrophage Cells.

Artemisia pallens Wall. ex DC., popularly known as davana, has gained considerable attention because of its unique fragrance, high economic value, and pharmacological properties. The compositional complexity of davana essential oil (DO) has been a challenge for quality control. In this study, the chemical profile of DO was developed using polarity-based fractionation and a combination of gas chromatographic (GC-FID), hyphenated chromatographic (GC/MS), and spectroscopic (Fourier-Transform Infra-Red, 1D, 2D-Nuclear Magnetic Resonance) techniques. The analysis led to the identification of ninety-nine compounds. Major components of the DO were cis-davanone (D3, 53.0 %), bicyclogermacrene (6.9 %), trans-ethyl cinnamate (4.9 %), davana ether isomer (3.4 %), spathulenol (2.8 %), cis-hydroxy davanone (2.4 %), and trans-davanone (2.1 %). The study led to identifying several co-eluting novel minor components, which could help determine the authenticity of DO. The rigorous column-chromatography led to the isolation of five compounds. Among these, bicyclogermacrene, trans-ethyl cinnamate, and spathulenol were isolated and characterized by spectroscopic methods for the first time from DO. Pharmacological profile revealed that the treatment of DO and D3 inhibited the production of pro-inflammatory cytokines (TNF-α, IL-6) induced by lipopolysaccharide (LPS) in primary macrophages without any cytotoxic effect after administration of their effective concentrations. The result of this study indicates the suitability of DO and D3 for further investigation for the treatment of chronic skin inflammatory conditions.

Volatile constituents of Origanum vulgare L., 'thymol' chemotype: variability in North India during plant ontogeny.

Essential oils derived from six different phenophases, namely early vegetative stage, late vegetative stage, early flowering stage, full flowering stage (FFS), late flowering stage and seed shattering stage of Origanum vulgare L. grown in Kumaon region of Uttarakhand, India were investigated by GC and GC-MS. A total of 38 constituents, representing 97.4-99.7% of the total oil composition, were identified. Major components of oils were thymol (40.9-63.4%), p-cymene, (5.1-25.9%), γ-terpinene (1.4-20.1%), bicyclogermacrene (0.2-6.1%), terpinen-4-ol (3.5-5.9%), α-pinene (1.6-3.1%), 1-octen-3-ol (1.4-2.7%), α-terpinene (1.0-2.2%), carvacrol (<0.1-2.1%), ß-caryophyllene (0.5-2.0%) and ß-myrcene (1.2-1.9%). Thymol, terpinen-4-ol, 3-octanol, α-pinene, ß-pinene, 1,8-cineole, α-cubebene and (E)-ß-ocimene were observed to be higher during FFS. The study showed that plant stage had a significant effect on the essential oil content and composition of O. vulgare grown in the hilly tracks of Northern India.

Variation in the volatile terpenoids of two industrially important basil (Ocimum basilicum L.) cultivars during plant ontogeny in two different cropping seasons from India.

BACKGROUND: Two Ocimum basilicum cultivars, 'Vikarsudha' and 'CIM-Saumya', grown in the Kumaon region of western Himalaya were evaluated for their essential oil yield and composition at different stages of plant growth during two distinct cropping seasons (spring-summer and rain-autumn). RESULTS: The highest yield of essential oil was obtained at full bloom stage in both cultivars in both cropping seasons. The essential oils obtained from different stages in two cropping seasons were analysed by capillary gas chromatography with flame ionisation detection, and gas chromatography-mass spectrometry. The major component of cultivar 'Vikarsudha' was methyl chavicol (84.3-94.3%), while for cultivar 'CIM-Saumya' the main components were methyl chavicol (62.5-77.6%) and linalool (14.4-34.1%). CONCLUSION: This study clearly indicated that cultivar, cropping season, plant ontogeny and plant part had significant effects on the yield and quality of the essential oil of O. basilicum. Further, the amount of methyl chavicol in the cultivars grown in this region was higher than in cultivars from other parts of India.

Volatile constituents of essential oil and rose water of damask rose (Rosa damascena Mill.) cultivars from North Indian hills.

Rosa damascena Mill. is an important aromatic plant for commercial production of rose oil, water, concrete and absolute. The rose water and rose oil produced under the mountainous conditions of Uttarakhand were investigated for their chemical composition. The major components of rose water volatiles obtained from the bud, half bloom and full bloom stages of cultivar 'Ranisahiba' were phenyl ethyl alcohol (66.2-79.0%), geraniol (3.3-6.6%) and citronellol (1.8-5.5%). The rose water volatiles of cultivar 'Noorjahan' and 'Kannouj' also possessed phenyl ethyl alcohol (80.7% and 76.7%, respectively) as a major component at full bloom stage. The essential oil of cultivar 'Noorjahan' obtained from two different growing sites was also compared. The major components of these oils were citronellol (15.9-35.3%), geraniol (8.3-30.2%), nerol (4.0-9.6%), nonadecane (4.5-16.0%), heneicosane (2.6-7.9%) and linalool (0.7-2.8%). This study clearly showed that the flower ontogeny and growing site affect the composition of rose volatiles. The rose oil produced in this region was comparable with ISO standards. Thus, it was concluded that the climatic conditions of Uttarakhand are suitable for the production of rose oil of international standards.