Pharmacological basis of bergapten in gastrointestinal diseases focusing on H+/K+ ATPase and voltage-gated calcium channel inhibition: A toxicological evaluation on vital organs

Aim and objectives: This study aimed to establish a pharmacological basis for evaluating the effects of bergapten (5-methoxypsoralen) in gastrointestinal diseases and assessment of its toxicological profile.

Methods: The pharmacokinetic profile was evaluated using the SwissADME tool. AUTODOCK and PyRx were used for evaluating the binding affinities. The obtained results were further investigated for a post-dock analysis using Discovery Studio Visualizer 2016. The Desmond software package was used to conduct molecular dynamic simulations of best bound poses. Bergapten was further investigated for antidiarrheal, anti-secretory, charcoal meal transit time, anti-ulcer, anti-H. pylori activity.

Results: Bergapten at a dose of 50, 100, and 200 mg/kg was proved effective in reducing diarrheal secretions, intestinal secretions, and distance moved by charcoal meal. Bergapten at the aforementioned doses acts as a gastroprotective agent in the ethanol-induced ulcer model that can be attributed to its effectiveness against H. pylori. Bergapten shows concentration-dependent relaxation of both spontaneous and K+ (80 mM)-induced contractions in the isolated rabbit jejunum model; the Ca2+ concentration–response curves (CRCs) were shifted to the right showing potentiating effect similar to papaverine. For molecular investigation, the H+/K+ ATPase inhibitory assay indicated inhibition of the pump comparable to omeprazole. Oxidative stress markers GST, GSH, and catalase showed increased expression, whereas the expression of LPO (lipid peroxidation) was reduced. Histopathological examination indicated marked improvement in cellular morphology. ELISA and western blot confirmed the reduction in inflammatory mediator expression. RT-PCR reduced the mRNA expression level of H+/K+ ATPase, confirming inhibition of the pump. The toxicological profile of bergapten was evaluated by an acute toxicity assay and evaluated for behavioral analysis, and the vital organs were used to analyze biochemical, hematological, and histopathological examination.

Conclusion: Bergapten at the tested doses proved to be an antioxidant, anti-inflammatory, anti-ulcer, and antidiarrheal agent and relatively safe in acute toxicity assay.

A new bioactive cocrystal of coumarin-3-carboxylic acid and thiourea: detailed structural features and biological activity studies

Cocrystallization is a phenomenon widely used to enhance the biological and physicochemical properties of active pharmaceutical ingredients (APIs). The present study deals with the synthesis of a cocrystal of coumarin-3-carboxylic acid (2-oxochromene-3-carboxylic acid, C₁₀H₆O₄), a synthetic analogue of the naturally occurring antioxidant coumarin, with thiourea (CH₄N₂S) using the neat grinding method. The purity and homogeneity of the coumarin-3-carboxylic acid-thiourea (1/1) cocrystal was confirmed by single-crystal X-ray diffraction, FT-IR analysis and thermal stability studies based on differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Detailed geometry analysis via density functional theory (DFT) demonstrated that the 1:1 cocrystal stoichiometry is sustained by N-H...O hydrogen bonding between the amine (-NH₂) groups of thiourea and the carbonyl group of coumarin. The synthesized cocrystal exhibited potent antioxidant activity (IC₅₀ = 127.9 ± 5.95 µM) in a DPPH radical scavenger assay in vitro in comparison with the standard N-acetyl-L-cysteine (IC₅₀ = 111.6 ± 2.4 µM). The promising results of the present study highlight the significance of cocrystallization as a crystal engineering tool to improve the efficacy of pharmaceutical ingredients.

Comprehensive Biological and Chemical Evaluation of Two Seseli Species (S. gummiferum and S. transcaucasicum)

Seseli L. is one of the largest genera of the Apiaceae family widely known for their traditional uses as herbal remedies. In the present study, the methanolic and water extracts of two Seseli species, S. gummiferum and S. transcaucasicum were evaluated for their bioactive contents and biological activities. The total phenolic and flavonoid contents in the extracts ranged from 19.09 to 24.33 mg GAE/g and from 0.45 to10.09 mg RE/g, respectively. Moreover, while narcissin was detected as the most abundant component in the methanolic extract of S. transcaucasicum (261.40 µg/g), chlorogenic acid was identified as the major component in all the other extracts, although a high amount was also present in the methanolic S. transcaucasicum extract (107.48-243.12 µg/g). The total antioxidant capacity was also determined by the phosphomolybdenum assay (0.66-1.18 mM TE/g). Other antioxidant assays such as the radical scavenging assays (DPPH: 5.51-11.45 mg TE/g; ABTS: 43.46-51.91 mg TE/g), reducing assays (CUPRAC: 41.67-53.20 mg TE/g; FRAP: 31.26-34.14 mg TE/g), as well as the metal chelating activity assay (14.38-38.57 mg EDTAE/g) were conducted. All the extracts showed inhibitory potential against the enzyme's amylase (0.12-0.78 mM ACAE/g), acetyl- and butyryl-cholinesterase (0.15-9.71 mg GALAE/g), while only the methanolic extracts acted as inhibitors of tyrosinase (107.15 and 109.37 mg KAE/g) and only the water extract of S. gummiferum displayed anti-glucosidase activity (0.13 mM ACAE/g). Interestingly, the methanolic extracts of both Seseli species showed lower cytotoxicity towards HaCaT cells (IC50: >500 µg/mL), compared to the water extracts (IC50: 267.8 and 321.41 µg/mL). Besides, only the methanolic extracts showed a slight wound healing effect (28.21 and 31.23%). All extracts showed antibacterial action against Staphylococcus lugdunensis (minimum inhibitory and bactericidal concentrations: 0.025-2 mg/mL). S. gummiferum methanolic extract, which exhibited the highest antibacterial potency was found to inhibit adhesion and invasion of S. lugdunensis to HaCaT cells as well. Taken together, this study demonstrated the two Seseli species to harbour interesting bioactive components, in particular polyphenolics and to exhibit several biological properties that could be further investigated for their potential exploitation as healing agents as supported by various traditional medicinal uses.

Evaluation of the Antioxidant Potency of Seseli L. Species (Apiaceae)

Objectives

In the present study, the antioxidant potency of ethyl acetate (AcOEt) and methanol (MeOH) extracts from the aerial parts of Seseli L. species was investigated for the first time.

Materials and Methods

Seseli species L. such as Seseli andronakii Woronow ex Schischk., S. campestre Besser, S. corymbosum Boiss. & Heldr., S. gummiferum subsp. gummiferum Pall. ex Sm., S. hartvigii Parolly & Nordt, S. libanotis (L.) W.Koch, S. petraeum M.Bieb., S. peucedanoides (M.Bieb.) Koso-Pol., S. resinosum Freyn & Sint., and S. tortuosum L. growing in Turkey were collected and evaluated for their antioxidant capacity by using 1.1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and lipid peroxidation (LPO) inhibition methods.

Results

The highest activities as a scavenger of DPPH radicals were found in the AcOEt extracts of S. peucedanoides (M.Bieb.) Koso-Pol (IC₅₀=0.49 mg/mL), and S. libanotis (IC₅₀=0.75 mg/mL); α-tocopherol was used as a positive control. On the other hand, in the LPO assay, the highest activities were determined in AcOEt and MeOH extracts (at 5 mg/mL) of S. tortuosum and S. libanotis (84-94%).

Conclusion

This report gives important information about the antioxidant capacity of Seseli L. species. This research on antioxidant capacity proves that the use of some species used in Eastern Anatolia (in salads) is correct. With this screening study performed in Seseli L. species growing in Turkey, in the future, it is planned to isolate antioxidant compounds from the most active strains of Seseli L.

Natural compounds as angiogenic enzyme thymidine phosphorylase inhibitors: In vitro biochemical inhibition, mechanistic, and in silico modeling studies

Natural flora is the richest source of novel therapeutic agents due to their immense chemical diversity and novel biological properties. In this regard, eighteen natural products belonging to different chemical classes were evaluated for their thymidine phosphorylase (TP) inhibitory activity. TP shares identity with an angiogenic protein platelet derived endothelial cell growth factor (PD-ECGF). It assists tumor angiogenesis and is a key player in cancer progression, thus an ideal target to develop anti-angiogenic drugs. Eleven compounds 1–2, 5–10, 11, 15, and 18 showed a good to weak TP inhibitory activity (IC₅₀ values between 44.0 to 420.3 μM), as compared to standards i.e. tipiracil (IC₅₀ = 0.014 ± 0.002 μM) and 7-deazaxanthine (IC₅₀ = 41.0 ± 1.63 μM). Kinetic studies were also performed on active compounds, in order to deduce the mechanism of ligand binding to enzyme. To get further insight into receptor protein (enzyme) and ligand interaction at atomic level, in- sillico studies were also performed. Active compounds were finally evaluated for cytotoxicity test against mouse fibroblast (3T3) cell line. Compound 18 (Masoprocol) showed a significant TP inhibitory activity (IC₅₀ = 44.0 ± 0.5 μM). Kinetic studies showed that it inhibits the enzyme in a competitive manner (Ki = 25.6 ± 0.008 μM), while it adopts a binding pose different than the substrate thymidine. It is further found to be non-toxic in MTT cytotoxicity assay. This is the first report on TP inhibitory activity of several natural compounds, some of which may serve as leads for further research towards drug the development.

Protective and hypoglycemic effects of celery seed on streptozotocin-induced diabetic rats: experimental and histopathological evaluation

AIMS

Diabetes mellitus is a major manifestation of metabolic disorder which presents with hyperglycemia (high levels of serum blood sugar). In the present study, we aimed to investigate the effects of celery seed extract on different biochemical factors and histopathological changes in normal and streptozotocin (STZ)-induced diabetic rats.

METHODS

A total of 35 male Wistar rats were divided into five groups (one normal and four diabetic groups). STZ was injected intraperitoneally to induce diabetes. The effects of hexane extract of celery seed and glibenclamide (as a positive control) were compared. Blood samples were analyzed on days 0, 18, and 33, and histopathological evaluations were performed at the end of the study.

RESULTS

Glucose, triglycerides, and cholesterol levels significantly decreased, whereas insulin and high-density lipoprotein (HDL) levels increased in the extract-administered groups, as compared to the negative diabetic control group (P < 0.0001). The concentrations of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum of the extract-administered groups were significantly less than the negative control group (P < 0.0001). Histopathological reports revealed significantly less atrophy, necrosis, and inflammation in the rats receiving celery seed extract compared to the negative control group.

CONCLUSIONS

The results indicated that celery seed extract can be effective in controlling hyperglycemia and hyperlipidemia in diabetic rats, and demonstrated its protective effects against pancreatic toxicity resulting from STZ-induction.

Anti-inflammatory effect of corymbocoumarin from Seseli gummiferum subsp. corymbosum through suppression of NF-κB signaling pathway and induction of HO-1 expression in LPS-stimulated RAW 264.7 cells

This study investigated the anti-inflammatory activity of corymbocoumarin, an angular-type pyranocoumarin isolated from Seseli gummiferum subsp. corymbosum in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Corymbocoumarin not only inhibited the production of nitric oxide (NO) and prostaglandin E2 (PGE2), but also inhibited the protein and mRNA expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Corymbocoumarin also attenuated pro-inflammatory cytokine tumor necrosis factor-α (TNF-α). Investigation of the effect on nuclear factor κB (NF-κB) signaling pathway showed that corymbocoumarin inhibited the phosphorylation of Akt and inhibitory κB (IκB)-α and decreased the subsequent translocation of the p65 and p50 NF-κB subunits to the nucleus. A further study revealed that corymbocoumarin exerted anti-inflammatory activity through induction of heme oxygenase (HO)-1 expression. The in vivo study showed that corymbocoumarin (20mg/kg, i.p.) reduced paw swelling in carrageenan-induced acute inflammation model. Taken together, these results suggest that corymbocoumarin exerts its anti-inflammatory effect in LPS-stimulated RAW 264.7 cells by suppressing NF-κB activation and inducing HO-1 expression. Corymbocoumarin may provide a useful therapeutic approach for inflammation-associated diseases.

Isolation and evaluation of the myorelaxant effect of bergapten on isolated rat jejunum

CONTEXT

Plants of the genus Heracleum L. (Apiaceae) have a long history of being used in traditional medicines for the treatment of alimentary tract disorders, and these biological effects have been ascribed to the presence of furanocoumarins (including bergapten).

OBJECTIVES

This study aimed to develop an efficient, preparative, counter-current chromatographic separation of bergapten in order to characterize its spasmolytic activity in isolated rat jejunum strips.

MATERIALS AND METHODS

Successful separation of the dichloromethane extract of the fruits of Heracleum leskovii Grossh. was achieved by high-performance countercurrent chromatography (HPCCC) using a two-phase solvent system composed of n-heptane/EtOAc/MeOH/H2O (6:5:6:5, v/v/v/v). The pharmacological assessment of bergapten (0.0001-50 μM) on jejunum smooth muscle strips isolated from rats was conducted under isotonic conditions, following up to three hours of incubation.

RESULTS

The separation method was scaled up six-fold from analytical to semi-preparative conditions, affording bergapten of >99% purity in less than 30 min. This permitted bergapten to be available in quantity for spasmolytic tests on isolated jejunum strips from rats. Bergapten caused myorelaxation of the intestine preparations in the concentration range of 0.0001-1 μM. At higher doses, bergapten caused either relaxation or contraction of the smooth muscle.

DISCUSSION AND CONCLUSION

Bergapten was successfully isolated by rapid HPCCC and its spasmolytic activity was confirmed, thereby providing a preliminary evidence base for the traditional medicine application. The data suggest that bergapten causes no irreversible changes to intestinal tissue.

Growth-disrupting, larvicidal and neurobehavioral toxicity effects of seed extract of Seseli diffusum against Aedes aegypti (L.) (Diptera: Culicidae)

Plant extracts that kill, deform the post-embryonic molting stages of mosquitoes could be a valuable approach in integrated vector management programmes to replace synthetic chemical pesticides, containing persistent toxic substances. Crude ethanolic seed extract was obtained by maceration of seeds of Indian celery, Seseli diffusum (Apiaceae). The ethanolic seed extract induced strong neurobehavioral toxicity against the 4th instar larvae of Aedes aegypti which resulted in a high level of larval knock-down with EC(50) of 238.15 ppm, after 4h of treatment. The extract at concentration of 200 ppm exhibited a potent larvicidal effect against 4th instar A. aegypti, produced 88% and 96% mortality, after 24 and 48 h of treatment with LC(50) of 126.13 ppm and LC(50) of 112.53 ppm, respectively. The ethanolic seed extract at higher concentration (>400 ppm) produced 100% mortality, after 24 h and 48 h of treatment. At lower concentration of 100 ppm, extract induced a high level of morphological deformities in larvae, after 48 h of treatment. A high level of growth and/or molting disrupting effect of extract against larvae was also observed which resulting in the formation of larval-pupal intermediates, after 48 h of treatment. At concentrations of 200-300 ppm, ethanolic seed extract induced morphological deformities in dead pupae, after 72 h of treatment. The results showed that S. diffusum is a promising candidate for the development of new botanical biopesticide having multiple potentials for controlling insect pest of medical and agricultural importance.

Chemical composition of hexane extract of Citrus aurantifolia and anti-Mycobacterium tuberculosis activity of some of its constituents

The main aim of this study was to isolate and characterize the active compounds from the hexane extract of the fruit peels of Citrus aurantiifolia, which showed activity against one sensitive and three monoresistant (isoniazid, streptomycin or ethambutol) strains of Mycobacterium tuberculosis H37Rv. The active extract was fractionated by column chromatography, yielding the following major compounds: 5-geranyloxypsoralen (1); 5-geranyloxy-7-methoxycoumarin (2); 5,7-dimethoxycoumarin (3); 5-methoxypsoralen (4); and 5,8-dimethoxypsoralen (5). The structures of these compounds were elucidated by 1D and 2D NMR spectroscopy. In addition, GC-MS analysis of the hexane extract allowed the identification of 44 volatile compounds, being 5,7-dimethoxycoumarin (15.79%), 3-methyl-1,2-cyclopentanedione (8.27%), 1-methoxy-ciclohexene (8.0%), corylone (6.93%), palmitic acid (6.89%), 5,8-dimethoxypsoralen (6.08%), a-terpineol (5.97%), and umbelliferone (4.36%), the major constituents. Four isolated coumarins and 16 commercial compounds identified by GC-MS were tested against M. tuberculosis H37Rv and three multidrug-resistant M. tuberculosis strains using the Microplate Alamar Blue Assay. The constituents that showed activity against all strains were 5 (MICs = 25-50 mg/mL), 1 (MICs = 50-100 mg/mL), palmitic acid (MICs = 25-50 mg/mL), linoleic acid (MICs = 50-100 mg/mL), oleic acid (MICs = 100 mg/mL), 4-hexen-3-one (MICs = 50-100 mg/mL), and citral (MICs = 50-100 mg/mL). Compound 5 and palmitic acid were the most active ones. The antimycobacterial activity of the hexane extract of C. aurantifolia could be attributed to these compounds.