In Vitro Antimicrobial Activity of Medicinal Plant Rumex Nervosus Against Selected Oral Pathogens.

Background: Rumex nervosus is a plant found and used in Saudi Arabia as traditional herbal medicine. Various types of plant extracts with inherent synergistic properties are being used against oral diseases. Thus, in the present study, the anti-microbial activity of Rumex nervosus extracts was studied against six common oral pathogenic bacterial strains and a pathogenic fungus. Materials and Method: Plants of R. nervosus were collected and air-dried, and extracts from various plant parts were obtained. Six clinical isolates of bacteria, namely Staphylococcus aureus, Streptococcus mutans, S. salivarius, S. sanguis, E. faecalis, and Lactobacillus acidophilus), and one pathogenic Candida (C. albicans) were obtained. Antibacterial and antifungal activity of R. nervosus was determined using the Kirby-Bauer agar disc diffusion method. Zones of inhibition were recorded after 48 h of incubation. Data collected were analyzed. A two-way analysis of variance (ANOVA) was applied. P < 0.05 was considered statistically significant. Results: Methanol extract from leaves were highly effective against S. aureus, with a mean inhibition zone of 33 mm, followed by a 28-mm zone of inhibition using an extract from roots and a minimum inhibition zone using an extract from stems. Zones of inhibition using methanol extract from roots were effective against S. mutans, S. sanguinis, E. faecalis, and L. acidophilus, with mean inhibition zones being 19, 17, 33, and 31 mm, respectively. Conclusion: The study has provided insight into a new potential herbal anti-microbial agent that may benefit dental care.

Alpha-glucosidase and amylase inhibitory effects of Eruca vesicaria subsp. longirostris essential oils: synthesis of new 1,2,4-triazole-thiol derivatives and 1,3,4-thiadiazole with potential inhibitory activity.

Context: The substantial increase in the number of diabetics has encouraged the search for new pharmacological strategies to face this problem. In this regard, triazole and its derivatives have attracted considerable attention for the past few decades due to their pharmacological significance. Objective: Evaluation of the inhibitory activity of α-glucosidase and α-amylase in essential oils extracted from plant Eruca vesicaria (L) Cav. subsp. longirostris (Brassicaceae) (EVL) and to verify whether the triazoles and thiadiazol bearing the lipophilic 4-methylthiobutyl group synthesized from the essential oil contribute to this activity. Materials and methods: The essential oils were extracted by hydrodistillation from leaf, stem, root, and fruit of EVL, and their chemical compositions were analyzed by gas chromatography and gas chromatography-mass spectrometry. We present here the synthesis of three new types of 1,2,4-triazole-thiol and 1,3,4-thiadiazol and the structures were confirmed by NMR, mass spectrometry. The α-glucosidase and α-amylase inhibitory activities were investigated in vitro. Results: The main compound in fruit, stem, and root was erucin (96.6, 85.3, and 83.7%, respectively). The three essential oils of the fruit, stem, and root have strong inhibitory activity on α-glucosidase and α-amylase; IC50 values of roots were 0.81 ± 0.02 µg/mL and 0.13 ± 0.01 µg/mL, respectively. Derivatives 1 b, 2 b, 3 b, and 2c showed remarkable inhibitory activity against α-glucosidase with potencies better than that of acarbose with IC50 values ranging between 0.49 and 1.43 µM. Conclusions: Current results indicate that ECL fruit essential oil can be used as a natural precursor for the synthesis of triazoles as potential hypoglycemic agents.

New cytotoxic sesquiterpene lactones from Achillea cretica L. growing in Tunisia.

The phytochemical study of Achillea cretica growing in Tunisia led to the isolation of two novel sesquiterpene lactones, which have been designated achicretin 1 and achicretin 2. Their chemical structures were further confirmed by mass spectroscopy (ESI-MS) and by extensive application of one- and two-dimensional NMR spectroscopy. The isolated compounds were tested for their cytotoxic activity against four human cancer cell lines, IGROV-1, OVCAR-3, MCF-7, and HCT-116 using the MTT assay. It has been found that achicretin 2 exhibited more potent inhibitory activity with IC50 = values of 14.0 ± 1.0 and 16.0 ± 2.0 µM against OVCAR-3 and HCT-116 cells, respectively.

Semi-synthesis of new antimicrobial esters from the natural oleanolic and maslinic acids.

In this article, we report an effective procedure for the selective isolation of oleanolic acid 1 and maslinic acid 2 (3.4 and 8.5mg/g DW, respectively) from pomace olive (Olea europaea L.) using an ultrasonic bath, and the synthesis of a series of new triterpenic acid esters. The compounds were characterized by their spectral data and were evaluated for their antimicrobial activity. Among the compounds tested, those having sulfur and chlorine atoms were found to be antibacterial. They showed activity against two Gram-positive bacteria Staphylococcus aureus and Enterococcus faecalis and two Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa (MICs within a range of 5-25µg/mL). The fungus Penicillium italicum was found to be the most sensitive to both sulfur derivatives: (3ß)-3-((thiophene-2-carbonyl)oxy)-olean-12-en-28-oic acid (1a) (IZ=22mm) and (2α,3ß-2,3-bis((thiophene-2-carbonyl)oxy)olean-12-en-28-oic acid (2a) (IZ=24mm).