Chemical composition of Prunus padus L. flower extract and its anti-inflammatory activities in primary bone marrow-derived macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

Prunus padus L. has been traditionally used in European ethnomedicine as a treatment for internal and external purposes and is mainly used to reduce inflammation, pain and fever. The activities of P. padus flower extracts are not well characterized, and additional experimental studies at the molecular level are needed to confirm the ethnobotanical findings.

AIM OF THE STUDY

To assess the potential of P. padus flower extract (PPFE) as a source of bioactive compounds through the characterization of its chemical composition and antioxidant, anti-collagenase, and anti-inflammatory activities.

MATERIALS AND METHODS

The ethanolic extract (1:10 w/v in ethanol solution) from P. padus flowers was subjected to phytochemical analysis and evaluation of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. Anti-collagenase activity was determined using a spectrophotometric method in vitro. The effect of PPFE on inflammation was evaluated by measuring specific markers using flow cytometry and assessing pro-inflammatory cytokine (IL-6) release by bone marrow-derived macrophages (BMDMs) ex vivo.

RESULTS

The major components of the ethanolic extract of P. padus flowers were quercetin diglycosides, chlorogenic acid and N',N″-dicaffeoyl,N‴-coumaroyl spermidine. The total phenolic content of PPFE was 85.19 mg GAE/g extract, and the EC₅₀ value in the DPPH assay was 0.55 mg/ml. PPFE exhibited the ability to inhibit collagenase activity in a dose-dependent manner. Preincubation of BMDMs with PPFE reduced the population of M1 (pro-inflammatory) and increased the population of M2 (anti-inflammatory) macrophages. Furthermore, PPFE decreased pro-inflammatory cytokine IL-6 release from BMDMs.

CONCLUSIONS

PPFE is a rich source of bioactive compounds and possesses considerable anti-inflammatory properties, supporting its use in ethnomedicine for the reduction of inflammatory processes.

Medicinal plants and their uses recorded in the Archives of Latvian Folklore from the 19th century

ETHNOPHARMACOLOGICAL RELEVANCE

The records of folk medicine present historical evidence of medicinal plant usage in the territory of Latvia and describe native and imported plants and plant products that were used as medicine.

AIM OF THE STUDY

To collect and analyse the ethnobotanical knowledge found in records of Latvian folk medicine available in the Archives of Latvian Folklore.

MATERIALS AND METHODS

Following the International Classification of Primary Care, plant uses were grouped into one of the 17 categories based on the body systems and psychological and social problems. Each plant was identified by its scientific name according to The Plant List website. Additionally, the plant parts used, dosage forms of herbal medicines and routes of administration were analysed.

RESULTS

In total, 211 genera belonging to 71 families were mentioned in the analysed materials. The most common health conditions were digestive system disorders, respiratory system disorders and skin disorders. The plant families with the largest number of taxa were Asteraceae, Rosaceae, Lamiaceae, and Apiaceae. The most frequently mentioned native plant taxa were Achillea millefolium L., Matricaria chamomilla L., Allium cepa L., Artemisia absinthium L., and Plantago sp. L. Leaves and flowers were the most commonly used parts, and herbal tea was the most common dosage form. Only 59 out of 211 taxa mentioned in this study are included in the official herbal monographs of the European Medicines Agency.

CONCLUSIONS

One hundred and fifty-two plant taxa mentioned in the records of Latvian folk medicine are not included in the European Union herbal monographs providing scientific information on the safety and efficacy and deserve further exploration as traditional herbal medicines.

Data on medicinal plants in the records of Latvian folk medicine from the 19th century

The data presented in this article is in support of the research paper "Medicinal plants and their uses recorded in the Archives of Latvian Folklore from the 19th century" [1]. This article provides the list of plant species and disorders treated with medicinal plants mentioned in the records of Latvian folk medicine and used by indigenous people of Latvia in the 19th century. In total, the data include 211 genera belonging to 71 plant families. The accepted scientific names of plant species, plant parts used, dosage forms of herbal medicines, and routes of administration are reported in the table. Plant uses are grouped into one of the 17 categories based on the body systems and psychological and social problems. The frequency of citations is indicated for each use of medicinal plant.

Acute anti-hyperglycaemic effects of an unripe apple preparation containing phlorizin in healthy volunteers: a preliminary study

BACKGROUND

The health-promoting properties of apples are directly related to the biologically active compounds that they contain, such as polyphenols. The objective of this study was to prepare a low-sugar, fibre- and phlorizin-enriched powder from unripe apples and to gain insight regarding its anti-hyperglycaemic activity in healthy volunteers.

RESULTS

The unripe apples (Malus domestica Borkh.) were collected 30 days after the full bloom day; blanched and pressed to obtain apple pomace which was then processed with a food cutter, oven-dried and milled to prepare apple powder. The concentrations of total sugars, water-soluble pectin and phlorizin in the apple preparation were 153.44 ± 2.46, 27.73 ± 0.51 and 12.61 ± 0.15 g kg(-1), respectively. Acute ingestion of the apple preparation improved glucose metabolism in the oral glucose tolerance test (OGTT) in six healthy volunteers by reducing the postprandial glucose response at 15 to 30 min by approximately two-fold (P < 0.05) and by increasing urinary glucose excretion during the 2- to 4-h interval of the OGTT by five-fold (P < 0.05).

CONCLUSION

The results obtained indicate that the dried and powdered pomace of unripe apples can be used as a health-promoting natural product for the reduction of postprandial glycaemia and to improve the health of patients with diabetes.

Evaluation of Antiradical Activity and Reducing Capacity of Synthesised Bispyridinium Dibromides Obtained by Quaternisation of 4-Pyridyl-1,4-dihydropyridines with Propargyl Bromide

New bispyridinium dibromides based on the 1,4-dihydropyridine (1,4-DHP) cycle were synthesised in the reaction between 4-pyridyl-1,4-DHP derivatives and propargyl bromide. It has been shown that variation of the substituent position on the pyridine as well as small changes in the electronic nature of the 1,4-DHP cycle as a result of the substituent nature at the 3 and 5 positions do not affect the course of the reaction and in all cases the corresponding bispyridinium dibromides 4a–e were formed. The antiradical activity, using 1,1-diphenyl-2-picrylhydrazine as a free radical scavenger, and the reducing capacity using phosphomolybdenum complexes have been evaluated for the newly synthesised compounds 4a–e. It has been shown that all tested 1,4-DHP bispyridinium dibromides 4a–e possess reducing capacity and antiradical properties. Moreover, the reducing capacity results could be explained by the influence of the electronic nature of the substituent at the 3 and 5 positions of the 1,4-DHP cycle.

Bioactive 1,4-dihydroisonicotinic acid derivatives prevent oxidative damage of liver cells

1,4-Dihydroisonicotinic acid derivatives (1,4-DHINA) are compounds closely related to derivatives of 1,4-dihydropyridine, a well-known calcium channel antagonists. 1,4-DHINA we used were derived from a well-known antioxidant Diludin. Although some compounds have neuromodulatory or antimutagenic properties, their activity mechanisms are not well known. This study was performed to obtain data on antioxidant and bioprotective activities of: 2,6-dimethyl-3,5-diethoxycarbonyl-1,4-dihydroisonicotinic acid (Ia); sodium 2-(2,6-dimethyl-3,5-diethoxycarbonyl-1,4-dihydropyridine-4-carboxamido)glutamate (Ib) and sodium 2-(2,6-dimethyl-3,5-diethoxycarbonyl-1,4-dihydropyridine-4-carboxamido)ethane-sulphate (Ic). 1,4-DHINA's activities were studied in comparison to Trolox by: N,N-Diphenyl-N'-picrylhydrazyl (DPPH*), deoxyribose degradation, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical scavenging and antioxidative capacity assays; copper-induced lipid peroxidation of cultured rat liver cells (malondialdehyde determination by high performance liquid chromatography and 4-hydroxynonenal-protein conjugates by dot-blot); (3)H-thymidine incorporation and trypan blue assay for liver cells growth and viability. In all assays used Ia was the most potent antioxidant. Ia was also a potent antioxidant at non-toxic concentrations for liver cell cultures. It completely abolished, while Ic only slightly decreased copper-induced lipid peroxidation of liver cells. Thus, antioxidant capacities are important activity principle of Ia, which was even superior to Trolox in the cell cultures used, while activity principles of Ic and Ib remain yet to be determined.

Influence of some quaternised 1,4-dihydropyridine derivatives on liposomes and erythrocyte membranes

1,4-Dihydropyridine derivatives possess various physiological activities but their mechanism of membranotropic action is not completely investigated yet. We have examined the membranotropic effects of 4-beta-pyridyl-1,4-Dihydropyridine derivatives containing different length alkyl chain substituent at N-quaternised 4-beta-pyridyl moiety. The results show the relation between incorporation of 1,4-dihydropyridine derivatives in the liposomal membranes and influence on bilayer fluidity. The compound with hexadecyl (C16H33) substituent in the 4-beta-pyridyl moiety possess the most pronounced incorporation ability and fluidizing effect. This compound causes the remarkable release of fluorescent probe calcein from liposomes and induces the hemolysis of human erythrocytes as well. The obtained results suggest that the length of alkyl chain at quaternized 4-beta-pyridyl moiety is significant for the expression of membranotropic effects of tested compounds.

The effect of 1,4-dihydropyridine and 1,4-dihydroindeno[1,2-b]pyridine derivatives on glutathione S-transferase activity in vitro

The 1,4-dihydropyridine (1,4-DHP) and 1,4-dihydroindeno[1,2-b]pyridine (1,4-DHIP) derivatives were investigated as glutathione S-transferase (GT) inhibitors. The obtained results indicate that some of the 1,4-DHP's containing lipophylic and bulky substituents have inhibitory effects on GT in vitro. The derivatives of 1,4-DHIP are more pronounced inhibitors.