Optimization protocol for the extraction of antioxidant components from Origanum vulgare leaves using response surface methodology.

In the present work, the response surface methodology (RSM) based on a central composite rotatable design (CCRD), was used to determine optimum conditions for the extraction of antioxidant compounds from Origanum vulgare leaves. Four process variables were evaluated at three levels (31 experimental designs): methanol (70%, 80%, and 90%), the solute:solvent ratio (1:5, 1:12.5, 1:20), the extraction time (4, 10, 16 h), and the solute particle size (20, 65, 110 micron). Using RSM, a quadratic polynomial equation was obtained by multiple regression analysis for predicting optimization of the extraction protocol. Analysis of variance (ANOVA) was applied and the significant effect of the factors and their interactions were tested at 95% confidence interval. The antioxidant extract (AE) yield was significantly influenced by solvent composition, solute to solvent ratio, and time. The maximum AE was obtained at methanol (70%), liquid solid ratio (20), time (16 h), and particle size (20 micron). Predicted values thus obtained were closer to the experimental value indicating suitability of the model. Run 25 (methanol:water 70:30; solute:solvent 1:20; extraction time 16 h and solute particle size 20) showed highest TP contents (18.75 mg/g of dry material, measured as gallic acid equivalents) and DPPH radical scavenging activity (IC50 5.04 µg/mL). Results of the present study indicated good correlation between TP contents and DPPH radical scavenging activity. Results of the study indicated that phenolic compounds are powerful scavengers of free radical as demonstrated by a good correlation between TP contents and DPPH radical scavenging activity.

ANTIOXIDANT ACTIVITY AND FREE RADICAL SCAVENGING CAPACITY OF L-ARGININE AND NAHS: A COMPARATIVE IN VITRO STUDY.

In the family of gaseous transmitters, hydrogen sulfide (H2S) is considered as third member beside nitric oxide (NO) and carbon monoxide (CO), which can play physiological role in different organs. The present study was designed to elucidate the antioxidant and free radical scavenging potentials of L-arginnine (a source for endogenous production of NO in vivo) and NaHS (a source H2S) individually and in combination. Different assays like 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, percent inhibition of linoleic acid peroxidation and reducing power assays were used to evaluate the free radical scavenging capacity and antioxidant activity of L-arginine and NaHS. Furthermore, study was aimed to know the antioxidant potential of both compounds at their effective doses in human body, which is 56 µM for H2S and 1.2 g/mL for L-arginine. The study also aimed to clear whether either NaHS, L-arginine or the mixture of NaHS and L-arginine in vitio (in the form of new compounds) is responsible for their therapeutic action. Results showed that NaHS, L-arginine and combination of NaHS + L-arginine showed good radical scavenging activity i.e., 55.60%, 52.10% and 52.32%, respectively. Moreover, NaHS was found to have ability to inhibit linoleic acid peroxidation by 53.98% at effective dose while L-arginine did not show inhibition of linoleic acid peroxidation. Combination of NaHS + L-arginine showed 54.15% inhibition of linoleic acid peroxidation, which is similar to that of H2S. Reducing power of NaHS was 0.073 and L-arginine showed 0.037, combination of NaHS + L-arginine showed 0.063. It can be concluded that NaHS showed better antioxidant potential in vitio as compared to L-arginine and the antioxidant activity of the mixture of NaHS + L-arginine is closed to the antioxidant activity of NaHS, which reflects that NaHS is a dominant factor in combination mixture that is responsible for antioxidant activity.

Citrullus colocynthis (L.) Schrad (bitter apple fruit): a review of its phytochemistry, pharmacology, traditional uses and nutritional potential.

ETHNOPHARMACOLOGICAL RELEVANCE: Citrullus colocynthis (L.) Schrad is a valuable cucurbit plant, widely distributed in the desert areas of the world. Citrullus colocynthis fruits are usually recognized for its wide range of medicinal uses as well as pharmaceutical and nutraceutical potential. This review aims to appraise the published information on the ethnobotanical knowledge, phytochemistry, ethnopharmacology, nutraceutical potential and safety studies of Citrullus colocynthis (bitter apple) fruit, with critical analysis on the gaps and potential for future studies. MATERIAL AND METHODS: A literature survey was performed by searching the scientific databases including PubMed, Scopus, SciFinder, Google Scholar, Web of Science, ACS as well as published books. RESULTS: The plant has been reported to possess a wide range of traditional medicinal uses including in diabetes, leprosy, common cold, cough, asthma, bronchitis, jaundice, joint pain, cancer, toothache, wound, mastitis, and in gastrointestinal disorders such as indigestion, constipation, dysentery, gastroenteritis, colic pain and different microbial infections. Several bioactive chemical constituents from fruits were recorded, such as, glycosides, flavonoids, alkaloids, fatty acids and essential oils. The isolation and identification of curcurbitacins A, B, C, D, E, I, J, K, and L and Colocynthosides A, and B were also reported. The fruit of Citrullus colocynthis has been studied extensively for its wide range of biological activities, which include antioxidant, cytotoxic, antidiabetic, antilipidemic, insecticide, antimicrobial and anti-inflammatory. The plant was also shown to be rich in nutritional value with high protein contents and important minerals as well as edible quality of seed oil. CONCLUSION: It is evident from the literature that Citrullus colocynthis possesses a wide range of medicinal uses and has been well studied for its antidiabetic, anticancer, antioxidant, antimicrobial and anti-inflammatory activities, while its therapeutic potential for gut, airways and cardiovascular disorders remains to be explored. Critical analysis revealed that the plant has the huge potential for pharmaceutical and nutraceutical application, with some indications for the presence of synergistic and /or side effects neutralizing combinations of activities.

Antimicrobial activity of Calendula officinalis petal extracts against fungi, as well as Gram-negative and Gram-positive clinical pathogens.

The aim of the present study was to assess the antimicrobial activity of methanol and ethanol extracts of pot marigold (Calendula officinalis) petals against clinical pathogens. The antimicrobial potential of C. officinalis extracts was evaluated against a panel of microorganisms isolated from patients at the Belfast City Hospital (BCH), including bacteria and fungi, using disc diffusion assay. Methanol extract of C. officinalis exhibited better antibacterial activity against most of the bacteria tested, than ethanol extract. Both methanol and ethanol extracts showed excellent antifungal activity against tested strains of fungi, while comparing with Fluconazole.

Composition, antioxidant and chemotherapeutic properties of the essential oils from two Origanum species growing in Pakistan

The GC-MS analyses of Origanum majorana L. (OME) and Origanum vulgare L. (OVE), Lamiaceae, essential oils helped identification of 39 (96.4 percent of the total oils) and 43 (92.9 percent of the total oils) components, respectively. The major constituents of OME were terpinene-4-ol (20.9 percent), linalool (15.7 percent), linalyl-acetate (13.9 percent), limonene (13.4 percent) and α-terpineol (8.57 percent), whereas, thymol (21.6 percent), carvacrol (18.8 percent), o-cymene (13.5 percent) and α-terpineol (8.57 percent) were the main components of OVE. In the disc diffusion and the resazurin microtitre assays, OME showed better antibacterial activity than OVE with larger zones of inhibition (16.5-27.0 mm) and smaller MIC (40.9-1250.3 μg/mL) against the tested bacterial strains. Only OVE displayed anti-heme biocrystallization activity with an IC50 at 0.04 mg/mL. In the DPPH assay, OVE showed better radical-scavenging activity than OME (IC50=65.5 versus 89.2 μg/mL) and both OME and OVE inhibited lionleic acid oxidation. However, in the bleaching β-carotene assay, OVE exhibited better antioxidant activity than OME. In the MTT assay, OME was more cytotoxic than OVE against different cancer cell types, such as MCF-7, LNCaP and NIH-3T3, with IC50s of 70.0, 85.3 and 300.5 μg/mL, respectively. Overall, some components of OME and OVE may have antiparasitic and chemotherapeutic activity.

Seasonal variation in content, chemical composition and antimicrobial and cytotoxic activities of essential oils from four Mentha species.

BACKGROUND: The aim of the present study was to appraise variation in the chemical composition, and antimicrobial and cytotoxic activities of essential oils from the leaves of four Mentha species-M. arvensis, M. piperita, M. longifolia and M. spicata-as affected by harvesting season. Disc diffusion and broth microdilution susceptibility assays were used to evaluate the antimicrobial activity of Mentha essential oils against a panel of microorganisms. The cytotoxicity of essential oils was tested on breast cancer (MCF-7) and prostate cancer (LNCaP) cell lines using the MTT assay. RESULTS: The essential oil contents of M. arvensis, M. piperita, M. longifolia and M. spicata were 17.0, 12.2, 10.8 and 12.0 g kg(-1) from the summer and 9.20, 10.5, 7.00 and 9.50 g kg(-1) from the winter crops, respectively. Gas chromatographic-mass spectrometric analysis revealed that mostly quantitative rather than qualitative variation was observed in the oil composition of each species. The principal chemical constituents determined in M. arvensis, M. piperita, M. longifolia and M. spicata essential oils from both seasons were menthol, menthone, piperitenone oxide and carvone, respectively. The tested essential oils and their major components exhibited notable antimicrobial activity against most of the plant and human pathogens tested. The tested essential oils also exhibited good cytotoxicity potential. CONCLUSION: Of the Mentha essential oils tested, M. arvensis essential oil showed relatively better antimicrobial and cytotoxic activities. A significant variation in the content of most of the chemical components and biological activities of seasonally collected samples was documented.