Recent Advancements in the Analyses of Natural Products.

Since ancient times, medicinal plants and their active ingredients have played a key role in treating a wide array of ailments. Notably, in recent years, there has been a burgeoning interest in treatments using products derived from natural sources, and some have been studied as clinical treatments for a variety of disorders. The use of natural products to treat illness has gained increasing scientific and public interest. Not only to ensure quality control but also to verify their efficacy as active ingredients in various pharmaceutical formulations, the evaluation of natural products is of paramount importance. In this field, analytical methods like spectroscopy, electrophoresis, and chromatography are essential and are constantly being improved upon. Chromatographic techniques are essential for determining the quality and authenticity of natural products. Moreover, strict adherence to internationally recognized norms in validating analytical procedures guarantees the accuracy and dependability of results. Continual research initiatives are essential for tackling issues like adulteration and enhancing customer trust in natural products. This review navigates through the complex field of quality control methodologies and analytical techniques applied in evaluating plant-derived sources, which are generally used as natural products, and focuses on the analysis of Hypericum, Curcuma, and Cannabis species.

Antifungal and Anti-Virulent Activity of Origanum majorana L. Essential Oil on Candida albicans and In Vivo Toxicity in the Galleria mellonella Larval Model.

The aim of this study was to investigate and compare in detail both the antifungal activity in vitro (with planktonic and biofilm-forming cells) and the essential oil composition (EOs) of naturally growing (OMN) and cultivated (OMC) samples of Origanum majorana L. (marjoram). The essential oil composition was analyzed using GC-MS. The major constituent of both EOs was carvacrol: 75.3% and 84%, respectively. Both essential oils showed high antifungal activity against clinically relevant Candida spp. with IC50 and IC90 less than or equal to 0.5 µg mL-1 and inhibition of biofilm with a concentration of 3.5 µg mL-1 or less. Cultivated marjoram oil showed higher anti-biofilm activity against C. albicans. In addition, OMC showed greater inhibition of germ-tube formation (inhibition by 83% in Spider media), the major virulence factor of C. albicans at a concentration of 0.125 µg mL-1. Both EOs modulated cell surface hydrophobicity (CSH), but OMN proved to be more active with a CSH% up to 58.41%. The efficacy of O. majorana EOs was also investigated using Galleria mellonella larvae as a model. It was observed that while the larvae of the control group infected with C. albicans (6.0 × 108 cells) and not receiving treatment died in the controls carried out after 24 h, all larvae in the infected treatment group survived at the end of the 96th hour. When the treatment group and the infected group were evaluated in terms of vital activities, it was found that the difference was statistically significant (p < 0.001). The infection of larvae with C. albicans and the effects of O. majorana EOs on the hemocytes of the model organism and the blastospores of C. albicans were evaluated by light microscopy on slides stained with Giemsa. Cytological examination in the treatment group revealed that C. albicans blastospores were phagocytosed and morphological changes occurred in hemocytes. Our results indicated that the essential oil of both samples showed strong antifungal activities against planktonic and biofilm-forming C. albicans cells and also had an influence on putative virulence factors (germ-tube formation and its length and on CSH).

Sage tea-thyme-peppermint hydrosol oral rinse reduces chemotherapy-induced oral mucositis: A randomized controlled pilot study.

OBJECTIVE: This pilot study aimed to investigate the preventive effect of sage tea-thyme-peppermint hydrosol oral rinse used in conjunction with basic oral care on chemotherapy-induced oral mucositis. DESIGN: An open-label randomized controlled study. SETTING: Two oncology hospitals in Ankara, Turkey. INTERVENTIONS: Patients receiving 5-fluorouracil-based chemotherapy regimens were divided into the intervention group (N=30) and control group (N=30). Basic oral care was prescribed to the control group, while the intervention group was prescribed sage tea-thyme-peppermint hydrosol in addition to basic oral care. All patients were called to assess their compliance with the study instructions on day 5 and 14. MAIN OUTCOME MEASURES: Oral mucositis was evaluated using an inspection method or by assessing oral cavity photos based on the World Health Organization oral toxicity scale on day 5 and 14. RESULTS: Most of the patients in the intervention group did not develop oral mucositis on day 5. In addition, the incidence of grade 1 oral mucositis was statistically lower in the intervention group (10%) than the control group (53.3%) on day 5. By day 14, the majority of patients in both the groups had grade 0 oral mucositis. CONCLUSIONS: Sage tea-thyme-peppermint hydrosol oral rinse has promising results in alleviating oral mucositis. This hydrosol can be recommended for clinical use as it is well tolerated and cost-effective. However, further randomized controlled trials are needed to support the study.

In vitro effects of some flavonoids and phenolic acids on human pyruvate kinase isoenzyme M2.

Pyruvate kinase isoenzyme M2 (PKM2) is one of the most important control point enzyme in glycolysis pathway. Hence, its inhibitors and activators are currently considered as the potential anticancer agents. The effect of 28 polyphenolic compounds on the enzyme activity was investigated in vitro. Among these compounds, neoeriocitrin, (-)-catechin gallate, fisetin, (±)-taxifolin and (-)-epicatechin have the highest inhibition effect with IC50 value within 0.65-1.33 µM range. Myricetin and quercetin 3-ß-D-glucoside exhibited the highest activation effect with 0.51 and 1.34 µM AC50 values, respectively. Twelve of the compounds showed inhibition effect within 7-38 µM range of IC50 value. Sinapinic acid and p-coumaric acid showed an activation effect with 26.2 and 22.2 µM AC50 values, respectively. The results propose that the polyphenolics may be the potential PKM2 inhibitors/activators, and they may be used as lead compounds for the synthesis of new inhibitors or activators of this enzyme.

Tyrosinase and Cholinesterase Inhibitory Potential and Flavonoid Characterization of Viola odorata L. (Sweet Violet).

Inhibitory potential of the dichloromethane, ethyl acetate, ethanol, and aqueous extracts of Viola odorata L. (VO) was investigated against tyrosinase (TYR) and cholinesterases by microplate assays. The antioxidant activity was tested using six in vitro assays. Only the ethanol extract inhibited TYR (80.23 ± 0.87% at 100 µg mL-1 ), whereas none of them were able to inhibit cholinesterases. The extracts were more able to scavenge NO radical (31.98 ± 0.53-56.68 ± 1.10%) than other radicals tested, and displayed low to moderate activity in the rest of the assays. HPLC analysis revealed that the aqueous extract of VO contained a substantial amount of vitexin (18.81 ± 0.047 mg g-1 extract), while the ethanol extract also possessed rutin (1.31 ± 0.013 mg g-1 extract) and vitexin (4.65 ± 0.103 mg g-1 extract). Furthermore, three flavonoids (rutin, isovitexin, and kaempferol-6-glucoside) were isolated from the ethanol extract. This is the first report on TYR inhibitory activity of VO as well as presence of vitexin and isovitexin in this species. Copyright © 2015 John Wiley & Sons, Ltd.

Investigation of the effects of some drugs and phenolic compounds on human dihydrofolate reductase activity.

Dihydrofolate reductase (DHFR) plays a fundamental role in cellular metabolism and cell growth. Inhibition of this enzyme will cause a decrease in the amount of folate that occurs in many metabolic processes, and the deficiency of which may cause various diseases. This study investigated the effects of some drugs and phenolic compounds on DHFR activity in vitro. To determine the inhibitory effect of compounds, enzyme activity was measured with a final concentration of an inhibitor ranging from 10 µM to 51 mM. DHFR was inhibited effectively by naringin, ferulic acid, and levofloxacin with IC50 values under 660 µM. Syringic acid, cefepime, ceftizoxime, cefazolin, ceftriaxone, and ceftazidime exhibited inhibitory effects on the enzyme activity with IC50 values in the range of 3.840-30.224 mM. K(i) constants were calculated using the Cheng-Prusoff equation. K(i) constants calculated in the range of 0.009-2.024 mM with respect to nicotinamide adenine dinucleotide phosphate oxidase (NADPH) and in the range of 0.060-5.830 mM about FH2.

In vitro effects of some flavones on human pyruvate kinase isoenzyme M2.

PKM2 is an important target for designing anticancer drug. Inhibitors and activators of this enzyme are suitable molecules for use in treating cancer. The aim of the present study was to investigate the effect of certain flavones on PKM2. Apigenin, wogonin, flavone, 3-hydroxyflavone, 5-hydroxyflavone, 6-hydroxyflavone, and 7-hydroxyflavone effectively inhibited PKM2, with IC50 in the range of 0.99-2.120 µM. The kinetic study indicated that these compounds acted as noncompetitive with Ki values of 3.53-5.67 µM toward phosphoenolpyruvate. Scutellarin and tangeritin demonstrated strong activation effect with AC50 values < 2 µM. Diosmetin, baicalin, baicalein, and luteolin showed an intermediate-level activator effect. These results demonstrate that flavone and their analogs could serve as leading compounds to develop new potent and selective inhibitor and activator for PKM2.

Triterpene saponins from Eryngium kotschyi.

Four new oleanane-type saponins 3-O-α-L-rhamnopyranosyl-(1 → 4)-ß-D-glucuronopyranosyl-22-O-ß,ß-dimethylacryloylA1-barrigenol (1), 3-O-α-L-rhamnopyranosyl-(1 → 4)-ß-D-glucuronopyranosyl-22-O-angeloylA1-barrigenol (2), 3-O-ß-D-glucopyranosyl-(1 → 2)-[ß-D-glucopyranosyl-(1 → 6)]-ß-D-glucopyranosyl-21,22,28-O-triacetyl-(3ß,21ß,22α)-olean-12-en-16-one (3), and 3-O-ß-D-glucopyranosyl-(1 → 2)-glucopyranosyl-22-O-ß-D-glucopyranosylsteganogenin (4), along with the known 3-O-ß-D-galactopyranosyl-(1 → 2)-[α-L-arabinopyranosyl-(1 → 3)]-ß-D-glucuronopyranosyl-22-O-angeloylA1-barrigenol and 3-O-α-L-rhamnopyranosyl-(1 → 4)-ß-D-glucuronopyranosyloleanolic acid, were isolated from a methanol extract of the roots of Eryngium kotschyi by multiple chromatographic steps. Saponins 3 and 4 are unusual by the original structure of their aglycon. Compound 3 possessed an oleanane-type skeleton with a 21,22,28-triacetylation and a ketone function at the C-16 position. For compound 4, the 17,22-seco-oleanolic acid skeleton is rarely found in natural saponins.