Sterols and Triterpenes from Dobera glabra Growing in Saudi Arabia and Their Cytotoxic Activity

Chemical constituents from Centaurothamnus maximus and their antimicrobial activity

A new sesquiterpene lactone, 3β,10α-dihydroxy-10β-(hydroxymethyl)-8α-(4-hydroxymethacrylate)-1αH,5αH,6βH,7αH-guai-4(15), 11(13)-dien-6,12-olide (1), along with twenty-one known compounds, were identified from the aerial parts of Centaurothamnus maximus. The structures of the isolated compounds were elucidated on the basis of spectroscopic evidences and correlated with known compounds. Compounds (2, 3, 5‒13 and 15‒22) were identified from C. maximus for the first time. Antibacterial and antifungal activities of the isolated compounds were tested using the agar disc diffusion method. Compounds that demonstrated promising antimicrobial activity were evaluated for their minimum inhibitory concentration (MIC). The results showed that compounds 3 and 7 were the most effective antibacterial compounds against B. subtilis ATCC 6633, S. aureus ATCC 25923 and S. pyogenes ATCC 27736, with MIC estimates between 8 and 32 mg/mL. In addition, compound 2 exhibited the strongest antifungal activity against C. albicans ATCC 14243 and C. krusei ATCC 14243 with MIC 8 mg/mL.

Saudi Arabian Plants: A Powerful Weapon against a Plethora of Diseases

The kingdom of Saudi Arabia (SA) ranks fifth in Asia in terms of area. It features broad biodiversity, including interesting flora, and was the historical origin of Islam. It is endowed with a large variety of plants, including many herbs, shrubs, and trees. Many of these plants have a long history of use in traditional medicine. The aim of this review is to evaluate the present knowledge on the plants growing in SA regarding their pharmacological and biological activities and the identification of their bioactive compounds to determine which plants could be of interest for further studies. A systematic summary of the plants' history, distribution, various pharmacological activities, bioactive compounds, and clinical trials are presented in this paper to facilitate future exploration of their therapeutic potential. The literature was obtained from several scientific search engines, including Sci-Finder, PubMed, Web of Science, Google Scholar, Scopus, MDPI, Wiley publications, and Springer Link. Plant names and their synonyms were validated by 'The Plant List' on 1 October 2021. SA is home to approximately 2247 plant species, including native and introduced plants that belong to 142 families and 837 genera. It shares the flora of three continents, with many unique features due to its extreme climate and geographical and geological conditions. As plants remain the leading supplier of new therapeutic agents to treat various ailments, Saudi Arabian plants may play a significant role in the fight against cancer, inflammation, and antibiotic-resistant bacteria. To date, 102 active compounds have been identified in plants from different sites in SA. Plants from the western and southwestern regions have been evaluated for various biological activities, including antioxidant, anti-cancer, antimicrobial, antimalarial, anti-inflammatory, anti-glycation, and cytotoxic activities. The aerial parts of the plants, especially the leaves, have yielded most of the bioactive compounds. Most bioactivity tests involve in vitro assessments for the inhibition of the growth of tumour cell lines, and several compounds with in vitro antitumour activity have been reported. More in-depth studies to evaluate the mode of action of the compounds are necessary to pave the way for clinical trials. Ecological and taxonomical studies are needed to evaluate the flora of SA, and a plan for the conservation of wild plants should be implemented, including the management of the protection of endemic plants.

Cytotoxic Activities and the Allantoinase Inhibitory Effect of the Leaf Extract of the Carnivorous Pitcher Plant Nepenthes miranda

Nepenthes are carnivorous pitcher plants that have several ethnobotanical uses, such as curing stomachache and fever. Here, we prepared different extracts from the stem, leaf, and pitcher of Nepenthes miranda to further investigate their pharmacological potential. The leaf extract of N. miranda obtained by 100% acetone (N. miranda-leaf-acetone) was used in this study to analyze the cytotoxic activities, antioxidation capacity, antibacterial activity, and allantoinase (ALLase) inhibitory effect of this plant. The cytotoxic effects of N. miranda-leaf-acetone on the survival, apoptosis, and migration of the cancer cell lines PC-9 pulmonary adenocarcinoma, B16F10 melanoma, and 4T1 mammary carcinoma cells were demonstrated. Based on collective data, the cytotoxic activities of N. miranda-leaf-acetone followed the order: B16F10 > 4T1 > PC-9 cells. In addition, the cytotoxic activities of N. miranda-leaf-acetone were synergistically enhanced when co-acting with the clinical anticancer drug 5-fluorouracil. N. miranda-leaf-acetone could also inhibit the activity of ALLase, a key enzyme in the catabolism pathway for purine degradation. Through gas chromatography−mass spectrometry, the 16 most abundant ingredients in N. miranda-leaf-acetone were identified. The top six compounds in N. miranda-leaf-acetone, namely, plumbagin, lupenone, palmitic acid, stigmast-5-en-3-ol, neophytadiene, and citraconic anhydride, were docked to ALLase, and their docking scores were compared. The docking results suggested plumbagin and stigmast-5-en-3-ol as potential inhibitors of ALLase. Overall, these results may indicate the pharmacological potential of N. miranda for further medical applications.

Investigation of cytotoxic and apoptotic effects of 63 compounds obtained from Salvia species: Promising anticancer agents

Since ancient time, Salvia L. species have been commonly used to treat colds, bronchitis, tuberculosis, heart diseases, and menstrual and digestive disorders in traditional medicine all around the world. They have been also used as tea and spice. Studies indicated that diterpenes and triterpenes isolated from Salvia species possess various pharmacological and biological effects such as anti-inflammatory, antiviral, cytotoxic, antioxidant, and hepatotoxic activities. Flavones were also shown to have antimicrobial, antioxidant, and cytotoxic potentials. Salvia extracts also exhibit anti-Alzheimer, antiseptic, cardiovascular, antihypertensive, and antituberculous effects. To investigate the effects of 63 secondary metabolites from Salvia species on cell viability and apoptosis, Salvia secondary metabolites including 25 phenolics, 4 fatty acids, 19 abietane diterpenoids, 12 triterpenoids, and three steroids were examined on healthy cell line (PDF), breast cancer (MCF-7), and colon cancer (HT-29) cell lines using MTT method. In addition, the effects of rosmarinic acid, 6,7-dehydroroyleanone, acetyl royleanone, ferruginol, carnosic acid, carnosol, cryptotanshinone, β-sitosterol, and ursolic acid on pro-apoptotic Bax and antiapoptotic Bcl-2 protein expression levels were investigated by Western Blot method. PRACTICAL APPLICATIONS: Phenolic compounds (apigenin, chrysin, and luteolin) and diterpenes (especially dihydrotanshinone I, carnosic acid, and carnosol), and almost all of the triterpenes exhibited high toxic effects on healthy cell line. Cytotoxic effects of cryptotanshinone, 12-hydroxy abieta-1,3,5(10),8,11,13-hexaene, 12-demethylmulticauline, 6,7-dehydroroyleanone, acetyl royleanone, ferruginol, ursolic acid, and 3-acetyl lupeol were relatively higher than their toxic effects. Acetyl royleanone, 6,7-dehydroroyleanone, carnosic acid, and cryptotanshinone were found to have anticancer potential based on their modulating effects on the expression levels of Bax and Bcl-2 proteins which play important roles in the regulation of apoptosis. The results of the present study showed that acetyl royleanone, cryptotanshinone, 6,7-dehydroroyleanone, carnosic acid, and cryptotanshinone have potential to be used in the pharmaceutical industry.

Determination of fingerprints contents of different extracts and parts of six endemic Salvia taxa by GC-MS: Source species for valuable compounds with drug or drug potential

Public use of Salvia species and their importance in the scientific world is continually increasing. It is known that this use and the importance of Salvia species are mostly due to the terpenoid compounds that they contain. In this context, the terpenoid-steroid-flavonoid contents of extracts of six endemic Salvia (S. kurdica, S. pseudeuphratica, S. rosifolia, S. siirtica, S. cerino-pruinosa var. cerino-pruinosa and S. cerino-pruinosa var. elazigensis) species prepared with different solvents were determined by gas chromatography-mass spectrometry. Within the framework of the ingredient analysis, content analysis of the ethanol extracts of the root, branch, leaf and flower parts of the species collected in the same period between 2015 and 2017 years was performed. In general, extracts prepared with chloroform and ethanol were found to contain a wide variety of compounds while petroleum ether extracts were found to contain much less varied compounds. In addition, in general, root extracts are richer in terpenoid compounds than aerial part extracts. Some species can be used as source species in terms of ferruginol, cryptanol, 6,7-dehydroroyleanone, lup-(20)29-ene-2α-hydroxy-3β-acetate, salvigenin and β-sitosterol contents (52,114.28, 75,979.08, 101,247.41, 40,071.29, 33,952.13 and 34,010.90 μg analyte/g extract, respectively).