New amides from seeds of Silybum marianum with potential antioxidant and antidiabetic activities

Lignanamides: A comprehensive review of chemical constituents, biological activities, extraction methods and synthetic pathway

Lignanamides are a class of compounds containing amide functional groups in lignans. These compounds have excellent anti-inflammatory and neuroprotective, which have shown great potential in terms of food additives, medicine and health supplement. We summarized the recent progress of lignanamides, including chemical constituents, extraction methods, biological activities, and synthetic pathways. The structures were classified according to an updated nomenclature system, can be classified into sixteen types and have certain roles in many respects such as anti-inflammatory, anti-cancer, and antioxidative, which may be important source of materials for functional food. The potential and limitations of different extraction method, chromatographic packing, and synthetic pathway are analyzed. Notably, this review provides an overview of synthesis pathways and applications of lignanamides, further research is needed to improve extraction efficiency and synthesis method, especially in a greener way for better application.

Flavonoids as dual-target inhibitors against α-glucosidase and α-amylase: a systematic review of in vitro studies

Diabetes mellitus remains a major global health issue, and great attention is directed at natural therapeutics. This systematic review aimed to assess the potential of flavonoids as antidiabetic agents by investigating their inhibitory effects on α-glucosidase and α-amylase, two key enzymes involved in starch digestion. Six scientific databases (PubMed, Virtual Health Library, EMBASE, SCOPUS, Web of Science, and WHO Global Index Medicus) were searched until August 21, 2022, for in vitro studies reporting IC50 values of purified flavonoids on α-amylase and α-glucosidase, along with corresponding data for acarbose as a positive control. A total of 339 eligible articles were analyzed, resulting in the retrieval of 1643 flavonoid structures. These structures were rigorously standardized and curated, yielding 974 unique compounds, among which 177 flavonoids exhibited inhibition of both α-glucosidase and α-amylase are presented. Quality assessment utilizing a modified CONSORT checklist and structure-activity relationship (SAR) analysis were performed, revealing crucial features for the simultaneous inhibition of flavonoids against both enzymes. Moreover, the review also addressed several limitations in the current research landscape and proposed potential solutions. The curated datasets are available online at https://github.com/MedChemUMP/FDIGA .

Can Polyherbal Medicine be used for the Treatment of Diabetes? - A Review of Historical Classics, Research Evidence and Current Prevention Programs

Diabetes mellitus (DM), a chronic medical condition, has attained a global pandemic status over the last few decades affecting millions of people. Despite a variety of synthetic drugs available in the market, the use of herbal medicines for managing diabetes is gaining importance because of being comparatively safer. This article reviews the result of a substantial literature search on polyherbal formulations (PHFs) developed and evaluated with potential for DM. The accumulated data in the literature allowed us to enlist 76PHFs consisting of different parts of 147 plant species belonging to 58 botanical families. The documented plant species are laden with bioactive components with anti-diabetic properties and thus draw attention. The most favoured ingredient for PHFs was leaves of Gymnema sylvestre and seeds of Trigonella foenum-graecum used in 27 and 22 formulations, respectively. Apart from herbs, shilajit (exudates from high mountain rocks) formed an important component of 9 PHFs, whereas calcined Mytilus margaritiferus and goat pancreas were used in Dolabi, the most commonly used tablet form of PHF in Indian markets. The healing properties of PHFs against diabetes have been examined in both pre-clinical studies and clinical trials. However, the mechanism(s) of action of PHFs are still unclear and considered the pitfalls inherent in understanding the benefits of PHFs. From the information available based on experimental systems, it could be concluded that plant-derived medicines will have a considerable role to play in the control of diabetes provided the challenges related to their bioavailability, bioefficacy, optimal dose, lack of characterization, ambiguous mechanism of action, and clinical efficiency are addressed.

Assessment of Quality and Efficiency of Cold-Pressed Oil from Selected Oilseeds

In this present study, an oil press was used to process 200 g each of sesame, pumpkin, flax, milk thistle, hemp and cumin oilseeds in order to evaluate the amount of oil yield, seedcake, sediments and material losses (oil and sediments). Sesame produced the highest oil yield at 30.60 ± 1.69%, followed by flax (27.73 ± 0.52%), hemp (20.31 ± 0.11%), milk thistle (14.46 ± 0.51%) and pumpkin (13.37 ± 0.35%). Cumin seeds produced the lowest oil yield at 3.46 ± 0.15%. The percentage of sediments in the oil, seedcake and material losses for sesame were 5.15 ± 0.09%, 60.99 ± 0.04% and 3.27 ± 1.56%. Sediments in the oil decreased over longer storage periods, thereby increasing the percentage oil yield. Pumpkin oil had the highest peroxide value at 18.45 ± 0.53 meq O2/kg oil, an acid value of 11.21 ± 0.24 mg KOH/g oil, free fatty acid content of 5.60 ± 0.12 mg KOH/g oil and iodine value of 14.49 ± 0.16 g l/100 g. The univariate ANOVA of the quality parameters against the oilseed type was statistically significant (p-value < 0.05), except for the iodine value, which was not statistically significant (p-value > 0.05). Future studies should analyze the temperature generation, oil recovery efficiency, percentage of residual oil in the seedcake and specific energy consumption of different oilseeds processed using small-large scale presses.

Pharmaceutical prospects of Silymarin for the treatment of neurological patients: an updated insight

Background

Silymarin is a polyphenolic flavonoid complex extricated from dried fruits and seeds of the plant Silybum marianum L. Chemically, it is a mixture of flavonolignan complexes consisting of silybin, isosilybin, silychristin, silydianin, a minor quantity of taxifolin, and other polyphenolic compounds, which possess different bio medicinal values.

Purpose

This review critically looks into the current status, pharmaceutical prospects and limitations of the clinical application of Silymarin for treating neurological disorders. In particular, Silymarin's medicinal properties and molecular mechanisms are focused on providing a better-compiled understanding helpful in its neuro-pharmacological or therapeutic aspects.

Methods

This review was compiled by the literature search done using three databases, i.e., PubMed (Medline), EMBASE and Science Direct, up to January 2023, using the keywords-Silymarin, neurological disorders, cognitive disorders, Type 2 Diabetes, pharmaceutical prospects and treatment. Then, potentially relevant publications and studies (matching the eligible criteria) were retrieved and selected to explain in this review using PRISMA 2020 (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) study flow chart.

Result

Since its discovery, it has been widely studied as a hepatoprotective drug for various liver disorders. However, in the last 10-15 years, several research studies have shown its putative neuroprotective nature against various brain disorders, including psychiatric, neurodegenerative, cognitive, metabolic and other neurological disorders. The main underlying neuroprotective mechanisms in preventing and curing such disorders are the antioxidant, anti-inflammatory, anti-apoptotic, pro-neurotrophic and pro-estrogenic nature of the bioactive molecules.

Conclusion

This review provides a lucid summary of the well-studied neuroprotective effects of Silymarin, its underlying molecular mechanisms and current limitations for its usage during neurological disorders. Finally, we have suggested a future course of action for developing it as a novel herbal drug for the treatment of brain diseases.

Modulation of Insulin Resistance by Silybum marianum Leaves, and its Synergistic Efficacy with Gymnema sylvestre, Momordica charantia, Trigonella-foenum graecum Against Protein Tyrosine Phosphatase 1B

Prolonged insulin resistance is considered one of the reasons for Type 2 Diabetes Mellitus. Upregulation of Protein tyrosine phosphatase 1B (PTP1B), a negative regulator of insulin signalling, has been well studied as a key regulator in prognosis to insulin resistance. It has been widely studied as a desirable molecular therapeutic target. The study aimed to evaluate the efficacy of leaf extract of the medicinal plants Silybum marianum on the inhibition of PTP1B activity. It also explored the synergistic effect with extracts of Gymnema sylvestre (leaves), Momordica charantia (seeds), and Trigonella foenum graecum (seeds). The S. marianum leaves showed dose-dependent inhibition of PTP1B ranging from 9.48-47.95% (25-1000 μg mL-1). Assay with individual plant extracts showed comparatively lesser inhibition of PTP1B as compared to metformin as a control (38% inhibition). However, a synergistic effect showed nearly 45% PTP1B inhibition (higher than metformin) after the assay was done with selected four plant extracts in combination. The effect of leaf extracts of S. marianum was studied for glucose uptake efficiency in yeast cell lines which was found to be increased by 23% as compared to the control (without extract). Metformin improves glucose upake by yeast cells by ~15-31%. GC-MS analysis revealed 23 phytochemicals, some of which possessed anti-diabetic properties. A dose-dependent increase in antioxidant activity of S. marianum leaves extracts was observed (40-53%). The findings of the study highlighted the presence of various phytochemicals in leaves extracts that are effective against PTP1B inhibition and may help in reinvigorating drug development.

A Critical Review on Role of Available Synthetic Drugs and Phytochemicals in Insulin Resistance Treatment by Targeting PTP1B

Insulin resistance (IR) is a condition of impaired response of cells towards insulin. It is marked by excessive blood glucose, dysregulated insulin signalling, altered pathways, damaged pancreatic β-cells, metabolic disorders, etc. Chronic hyperglycemic conditions leads to type 2 diabetes mellitus (T2DM) which causes excess generation of highly reactive free radicals, causing oxidative stress, further leading to development and progression of complications like vascular dysfunction, damaged cellular proteins, and DNA. One of the causes for IR is dysregulation of protein tyrosine phosphatase 1B (PTP1B). Advancements in drug therapeutics have helped people manage IR by regulating PTP1B, however have been reported to cause side effects. Therefore, there is a growing interest on usage of phytochemical constituents having IR therapeutic properties and aiding to minimize these complications. Medicinal plants have not been utilized to their full potential as a therapeutic drug due to lack of knowledge of their active and effective chemical constituents, mode of action, regulation of IR parameters, and dosage of administration. This review highlights phytochemical constituents present in medicinal plants or spices, their potential effectiveness on proteins (PTP1B) regulating IR, and reported possible mechanism of action studied on in vitro models. The study gives current knowledge and future recommendations on the above aspects and is expected to be beneficial in developing herbal drug using these phytochemical constituents, either alone or in combination, for medication of IR and diabetes.

Comparative Assessment of Phytoconstituents, Antioxidant Activity and Chemical Analysis of Different Parts of Milk Thistle Silybum marianum L

Silybum marianum L. is a therapeutic plant belonging to the family Asteraceae, which has exhibited silymarin, a principal component used to cure various physiochemical disorders. The study appraised the phytochemical analysis, antioxidant activity and chemical analysis of an extract from the seed, stem and leaves. Qualitative and quantitative phytochemical analysis was evaluated by the Folin-Ciocalteu reagent method and aluminum chloride colorimetric method, respectively. While the antioxidant activity was determined by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and acetate buffer in ferric chloride (FRAP) assay, respectively, the chemical profile was evaluated by Gas Chromatography-Mass Spectrometry (GC-MS) assay. The study outcomes identified that alkaloids, glycosides, flavonoids, terpenoids, steroids and catcholic tannins were present in seed, stem and leaves extracts except for saponins and Gallic tannins. Whereas, phenols were absent only in seed extract. Quantitative analysis revealed the presence of phenols and flavonoids in appreciable amounts of 21.79 (GAE/g), 129.66 (QE/g) and 17.29 (GAE/g), 114.29 (QE/g) from the leaves and stem extract, respectively. Similarly, all extracts expressed reasonable DPPH inhibition (IC50) and FRAP reducing power such as 75.98, 72.39 and 63.21% and 46.60, 51.40 and 41.30 mmol/g from the seeds, stem and leaves extract, respectively. Additionally, chemical analysis revealed the existence of 6, 8 and 9 chemical compounds from the seeds, stem and leaves extract, respectively, corresponding to 99.95, 99.96 and 98.89% of the whole extract. The chemical compound, Dibutyl phthalate was reported from all extracts while, Hexadecanoic acid, methyl ester and Silane, (1,1-dimethylethyl), dimethyl (phenylmethoxy) were reported only from the seed and leaves extract. Moreover, Methyl stearate was also a major compound reported from all extracts except for seed extract. It is demonstrable that extracts from different parts of S. marianum possess significant antioxidant activity, as well as valuable chemical compounds accountable for therapeutic effects that might be incorporated as an alternative to synthetic chemical agents.

Approaches to Decrease Hyperglycemia by Targeting Impaired Hepatic Glucose Homeostasis Using Medicinal Plants

Liver plays a pivotal role in maintaining blood glucose levels through complex processes which involve the disposal, storage, and endogenous production of this carbohydrate. Insulin is the hormone responsible for regulating hepatic glucose production and glucose storage as glycogen, thus abnormalities in its function lead to hyperglycemia in obese or diabetic patients because of higher production rates and lower capacity to store glucose. In this context, two different but complementary therapeutic approaches can be highlighted to avoid the hyperglycemia generated by the hepatic insulin resistance: 1) enhancing insulin function by inhibiting the protein tyrosine phosphatase 1B, one of the main enzymes that disrupt the insulin signal, and 2) direct regulation of key enzymes involved in hepatic glucose production and glycogen synthesis/breakdown. It is recognized that medicinal plants are a valuable source of molecules with special properties and a wide range of scaffolds that can improve hepatic glucose metabolism. Some molecules, especially phenolic compounds and terpenoids, exhibit a powerful inhibitory capacity on protein tyrosine phosphatase 1B and decrease the expression or activity of the key enzymes involved in the gluconeogenic pathway, such as phosphoenolpyruvate carboxykinase or glucose 6-phosphatase. This review shed light on the progress made in the past 7 years in medicinal plants capable of improving hepatic glucose homeostasis through the two proposed approaches. We suggest that Coreopsis tinctoria, Lithocarpus polystachyus, and Panax ginseng can be good candidates for developing herbal medicines or phytomedicines that target inhibition of hepatic glucose output as they can modulate the activity of PTP-1B, the expression of gluconeogenic enzymes, and the glycogen content.

Evaluation of variability of silymarin complex in Silybi mariani fructus harvested during two production years

Milk thistle [Silybum marianum (L.) Gaertn.], a member of Asteraceae family, is one of the most cultivated medicinal plants widespread throughout the world. The pharmacological drug is a ripe fruit without pappus – Silybi mariani fructus – containing flavonolignans and generating silymarin complex. In folk medicine, it is used for the treatment of liver disorders, kidney problems, rheumatism as well as gastronomic disturbances, cardiac and neurotic disorders, and fever. The components of silymarin complex are useful in cancer prevention and treatment. The aim of the study was to determine the amount of silymarin complex contained in the fruit of the harvest of two consecutive years and how much they differ from one another. Representative samples of fruit were collected in 2015 and 2016 and distributed by a company Agrofos (Slovakia). Regarding the analytical method, we used a high-performance liquid chromatography (HPLC); the method was approved by the European Pharmacopoeia 10. The statistical significance was on the level P < 0.05. The total content of silymarin complex was 15.28 ± 0.06 g.kg−1 (in 2015) and 16.65 ± 0.09 g.kg−1 (in 2016). In both studied years, the highest representation of silybin B was observed (7.04 ± 0.07 g.kg−1 versus 5.92 ± 0.08 g.kg−1). The differences between the individual fractions of the silymarin complex were statistically significant. There was also a significant difference of 9% in the total silymarin content between 2015 and 2016. In conclusion, we can state that both samples of Silybi mariani fructus meet the requirements of the European Pharmacopoeia.

Toward a Systematic Nomenclature for (Neo)Lignanamides

Phenylalkenoic acid amides, often referred to as phenol amides or hydroxycinnamic acid amides, are bioactive phytochemicals, whose bioactivity can be enhanced by coupling to form dimers or oligomers. Phenylalkenoic acid amides consist of a (hydroxy)cinnamic acid derivative (i.e., the phenylalkenoic acid subunit) linked to an amine-containing compound (i.e., the amine subunit) via an amide bond. The phenylalkenoic acid moiety can undergo oxidative coupling, either catalyzed by oxidative enzymes or due to autoxidation, which leads to the formation of (neo)lignanamides. Dimers described in the literature are often named after the species in which the compound was first discovered; however, the naming of these compounds lacks a systematic approach. We propose a new nomenclature, inspired by the existing system used for hydroxycinnamic acid dimers and lignin. In the proposed systematic nomenclature for (neo)lignanamides, compound names will be composed of three-letter codes and prefixes denoting the subunits, and numbers that indicate the carbon atoms involved in the linkage between the monomeric precursors. The proposed nomenclature is consistent, future-proof, and systematic.

Giganteone A and malabaricone C as potential pharmacotherapy for diabetes mellitus

The use of antidiabetic agents which control glycemic levels in the blood and simultaneously inhibit oxidative stress is an important strategy in the prevention of Diabetes Mellitus and its complications. In our previous study, malabaricone C (3) and its dimer, giganteone A (5) exhibited significant DPPH free radical scavenging activities which were lower than the activity of the positive control, ascorbic acid. These compounds were evaluated for their α-glucosidase inhibitory activities at different concentrations (0.02-2.5 mM) in the present study. Compounds 3 (IC₅₀ 59.61 µM) and 5 (IC₅₀ 39.52 µM) were identified as active alpha-glucosidase inhibitors, each respectively being 24 and 37 folds more potent than the standard inhibitor, acarbose. Based on the molecular docking studies, compounds 3 and 5 docked into the active site of the α-glucosidase enzyme, forming mainly hydrogen bonds in the active site.

A comprehensive review on the antidiabetic activity of flavonoids targeting PTP1B and DPP-4: a structure-activity relationship analysis

Type 2 diabetes (T2D) is an expanding global health problem, resulting from defects in insulin secretion and/or insulin resistance. In the past few years, both protein tyrosine phosphatase 1B (PTP1B) and dipeptidyl peptidase-4 (DPP-4), as well as their role in T2D, have attracted the attention of the scientific community. PTP1B plays an important role in insulin resistance and is currently one of the most promising targets for the treatment of T2D, since no available PTP1B inhibitors were still approved. DPP-4 inhibitors are among the most recent agents used in the treatment of T2D (although its use has been associated with possible cardiovascular adverse events). The antidiabetic properties of flavonoids are well-recognized, and include inhibitory effects on the above enzymes, although hitherto not therapeutically explored. In the present study, a comprehensive review of the literature of both synthetic and natural isolated flavonoids as inhibitors of PTP1B and DPP-4 activities is made, including their type of inhibition and experimental conditions, and structure-activity relationship, covering a total of 351 compounds. We intend to provide the most favorable chemical features of flavonoids for the inhibition of PTP1B and DPP-4, gathering information for the future development of compounds with improved potential as T2D therapeutic agents.

Chitosan Elicitation Impacts Flavonolignan Biosynthesis in Silybum marianum (L.) Gaertn Cell Suspension and Enhances Antioxidant and Anti-Inflammatory Activities of Cell Extracts

Silybum marianum (L.) Gaertn is a rich source of antioxidants and anti-inflammatory flavonolignans with great potential for use in pharmaceutical and cosmetic products. Its biotechnological production using in vitro culture system has been proposed. Chitosan is a well-known elicitor that strongly affects both secondary metabolites and biomass production by plants. The effect of chitosan on S. marianum cell suspension is not known yet. In the present study, suspension cultures of S. marianum were exploited for their in vitro potential to produce bioactive flavonolignans in the presence of chitosan. Established cell suspension cultures were maintained on the same hormonal media supplemented with 0.5 mg/L BAP (6-benzylaminopurine) and 1.0 mg/L NAA (α-naphthalene acetic acid) under photoperiod 16/8 h (light/dark) and exposed to various treatments of chitosan (ranging from 0.5 to 50.0 mg/L). The highest biomass production was observed for cell suspension treated with 5.0 mg/L chitosan, resulting in 123.3 ± 1.7 g/L fresh weight (FW) and 17.7 ± 0.5 g/L dry weight (DW) productions. All chitosan treatments resulted in an overall increase in the accumulation of total flavonoids (5.0 ± 0.1 mg/g DW for 5.0 mg/L chitosan), total phenolic compounds (11.0 ± 0.2 mg/g DW for 0.5 mg/L chitosan) and silymarin (9.9 ± 0.5 mg/g DW for 0.5 mg/L chitosan). In particular, higher accumulation levels of silybin B (6.3 ± 0.2 mg/g DW), silybin A (1.2 ± 0.1 mg/g DW) and silydianin (1.0 ± 0.0 mg/g DW) were recorded for 0.5 mg/L chitosan. The corresponding extracts displayed enhanced antioxidant and anti-inflammatory capacities: in particular, high ABTS antioxidant activity (741.5 ± 4.4 μM Trolox C equivalent antioxidant capacity) was recorded in extracts obtained in presence of 0.5 mg/L of chitosan, whereas highest inhibitions of cyclooxygenase 2 (COX-2, 30.5 ± 1.3 %), secretory phospholipase A2 (sPLA2, 33.9 ± 1.3 %) and 15-lipoxygenase (15-LOX-2, 31.6 ± 1.2 %) enzymes involved in inflammation process were measured in extracts obtained in the presence of 5.0 mg/L of chitosan. Taken together, these results highlight the high potential of the chitosan elicitation in the S. marianum cell suspension for enhanced production of antioxidant and anti-inflammatory silymarin-rich extracts.

The food plant Silybum marianum (L.) Gaertn.: Phytochemistry, Ethnopharmacology and clinical evidence

ETHNOPHARMACOLOGICAL RELEVANCE

Silybum marianum (L.) Gaertn. or Milk thistle is a medicinal plant native to Northern Africa, Southern Europe, Southern Russia and Anatolia. It also grows in South Australia, North and South America. In traditional knowledge, people have used S. marianum for liver disorders such as hepatitis, liver cirrhosis and gallbladder diseases. The main active compound of the plant seeds is silymarin, which is the most commonly used herbal supplement in the United States for liver problems. Nowadays, S. marianum products are available as capsules, powders, and extracts.

AIM OF STUDY

The aim of our study is to draw a more comprehensive overview of the traditional heritage, pharmacological benefits and chemical fingerprint of S. marianum extracts and metabolites; as well as their metabolism and bioavailability.

MATERIALS AND METHODS

An extensive literature search has been conducted using relavant keywords and papers with rationale methodology and robust data were selected and discussed. Studies involving S. marianum or its main active ingredients with regards to hepatoprotective, antidiabetic, cardiovascular protection, anticancer and antimicrobial activities as well as the clinical trials performed on the plant, were discussed here.

RESULTS

S. marianum was subjected to thousands of ethnopharmacological, experimental and clinical investigations. Although, the plant is available for use as a dietary supplement, the FDA did not yet approve its use for cancer therapy. Nowadays, clinical investigations are in progress where a global evidence of its real efficiency is needed.

CONCLUSION

S. marianum is a worldwide used herb with unlimited number of investigations focusing on its benefits and properties, however, little is known about its clinical efficiency. Moreover, few studies have discussed its metabolism, pharmacokinetics and bioavailability, so that all future studies on S. marianum should focus on such areas.

Bassiamide A, a new alkaloid from xero-halophyte Bassia indica Wight

N-[(3-(3-methyl-1-oxo-butyl)amino)propyl]-3-(3,4-dihydroxyphenyl)prop-2-enamide (7), named 'Bassiamide A', a new alkaloid, together with six known compounds including one lignan (1) and five lignanamides (2-6), were isolated from the aerial parts of Bassia indica Wight. The study also reported an optimal separation of a rare occurring R-isomer lignanamide derivative (6) from a natural origin, in addition to its known corresponding S-isomer (5). Structures of isolated compounds were elucidated based on NMR spectroscopic data, HR-MS, and comparison with known related ones, and they were identified as syringaresinol (1), N-trans-feruloyl-3-methoxytyramine (2), N-trans-feruloyltyramine (3), S-(-)-N-trans-feruloyl normetanephrine (4), S-(-)-N-trans-feruloyl octopamine (5), R-(+)-N-trans-feruloyl octopamine (6). The isolated compounds were evaluated for their anti-acetylcholinesterase activity, and they showed weak inhibitory activity.

Flavonoids as potential agents in the management of type 2 diabetes through the modulation of α-amylase and α-glucosidase activity: a review

Type 2 diabetes (T2D) is one of the most prevalent metabolic diseases worldwide and is characterized by increased postprandial hyperglycemia (PPHG). α-Amylase and α-glucosidase inhibitors have been shown to slow the release of glucose from starch and oligosaccharides, resulting in a delay of glucose absorption and a reduction in postprandial blood glucose levels. Since current α-glucosidase inhibitors used in the management of T2D, such as acarbose, have been associated to strong gastrointestinal side effects, the search for novel and safer drugs is considered a hot topic of research. Flavonoids are phenolic compounds widely distributed in the Plant Kingdom and important components of the human diet. These compounds have shown promising antidiabetic activities, including the inhibition of α-amylase and α-glucosidase. The aim of this review is to provide an overview on the scientific literature concerning the structure-activity relationship of flavonoids in inhibiting α-amylase and α-glucosidase, including their type of inhibition and experimental procedures applied. For this purpose, a total of 500 compounds is covered in this review. Available data may be considered of high value for the design and development of novel flavonoid derivatives with effective and potent inhibitory activity against those carbohydrate-hydrolyzing enzymes, to be possibly used as safer alternatives for the regulation of PPHG in T2D.

Lignanamides: sources, biosynthesis and potential health benefits - a minireview

Lignanamides are natural plant secondary metabolites derived from oxidative coupling mechanism with hydroxycinnamic acid amides as intermediates. These compounds display powerful anti-inflammatory, antioxidant, anti-cancer and anti-hyperlipidemic capacities in vitro, cell culture and in vivo studies. With strong potential to be utilized as protective agents against human chronic diseases, these compounds have attracted the interest of researchers. This review aims to discuss current understanding on the sources, classification, biosynthesis of lignanamides in plants, and importantly their biological activity and potential health benefits. The general biosynthesis pathway for lignanamides is comprehensively summarized, though some details in molecular regulation of the coupling process have yet to be elucidated. Lignanamides deserves additional clinical studies involving animal and human subjects, to prove its health benefits.

Silychristin derivatives conjugated with coniferylalcohols from silymarin and their pancreatic α-amylase inhibitory activity

Silymarin is a mixture of flavonolignans extracted from the fruit of Silybum marianum (milk thistle). The latter is used as a medicinal plant to treat liver and gallbladder disorders. Recently, silymarin has been investigated for its effects against diabetes mellitus, and shown to reduce serum levels of glucose in model animals and in clinical trials. This effect can be explained mainly by the protective effect of silymarin against pancreatic beta-cells, but the involvement of other mechanisms is possible. We demonstrated the α-amylase inhibitory activity of silymarin and investigated the components responsible for this effect. Two major flavonolignans, silibinin and silychristin, did not show inhibition against α-amylase, but two novel silychristin derivatives conjugated with dehydrodiconiferyl alcohol were isolated as the mildly inhibiting components of silymarin. Further analyses indicated the presence of various silychristin derivatives in silymarin that may act synergistically to show α-amylase inhibitory activity.[Formula: see text].

First total synthesis of mariamide A

Mariamide A, a lignanamide isolated from the seeds of Silybum marianum, has demonstrated potential utility as an antioxidant and antidiabetic agent and possesses an 8-O-4′ neolignan skeleton. Herein, a first total synthesis of mariamide A is presented that proceeds in nine steps using vanillin as the starting material. The key steps for the preparation of mariamide A involve an I2-catalyzed bromomethoxylation of an alkene group, a nucleophilic substitution followed by a sequential elimination and a monoacylation reaction.

The Synthesis Followed by Spectral and Calorimetric Evaluation of Stability of Human Milk Fat Substitutes Obtained from Thistle Milk and Lard

The central point of current investigations was the first time ever synthesis of modern substitutes of human milk fat followed by versatile evaluation of their oxidative properties. The enzymatic interesterification conducted at 70°C for 2, 4, and 6 hours, respectively, with milk thistle oil and lard blend as starting reactants was catalyzed by 1,3-specific lipase Lipozyme RM IM, obtained from Rhizomucor miehei. Pressure Differential Scanning Calorimetry (PDSC) and Fourier Transform Infrared Spectroscopy (FT-IR) were applied to evaluate quality of products formed. Although PDSC curves showed lower oxidative stability of newly synthesized fats as compared to both starting materials separately, they can be considered adequate substitutes of human fat milk fat, as distribution of fatty acids in triacylglycerol molecules of substitutes obtained is much alike human milk fat itself, as resulted from analysis of GC data collected. Obvious changes in chemical structure of fats occurring during interesterification resulted in specific alterations in IR spectra of processed materials. Spectral data accompanied by PLS technique were successfully used for accurate determination of oxidative stability of new fats through indirect procedure, i.e., IR-PDSC-reference analysis of induction time. Additionally IR data exclusively, i.e., without any reference data, occurred powerfully in discrimination of human fat milk substitutes obtained.

Interactive Effects of Light and Melatonin on Biosynthesis of Silymarin and Anti-Inflammatory Potential in Callus Cultures of Silybum marianum (L.) Gaertn

Silybum marianum (L.) Gaertn. is a well-known medicinal herb, primarily used in liver protection. Light strongly affects several physiological processes along with secondary metabolites biosynthesis in plants. Herein, S. marianum was exploited for in vitro potential under different light regimes in the presence of melatonin. The optimal callogenic response occurred in the combination of 1.0 mg/L α-naphthalene acetic acid and 0.5 mg/L 6-benzylaminopurine under photoperiod. Continuous light associated with melatonin treatment increased total flavonoid content (TFC), total phenolic content (TPC) and antioxidant potential, followed by photoperiod and dark treatments. The increased level of melatonin has a synergistic effect on biomass accumulation under continuous light and photoperiod, while an adverse effect was observed under dark conditions. More detailed phytochemical analysis showed maximum total silymarin content (11.92 mg/g dry weight (DW)) when placed under continuous light + 1.0 mg/L melatonin. Individually, the level of silybins (A and B), silydianin, isolsilychristin and silychristin was found highest under continuous light. Anti-inflammatory activities were also studied and highest percent inhibition was recorded against 15-lipoxygenase (15-LOX) for cultures cultivated under continuous light (42.33%). The current study helps us to better understand the influence of melatonin and different light regimes on silymarin production as well as antioxidant and anti-inflammatory activities in S. marianum callus extracts.

Prevalence and current therapy in chronic liver disorders

BACKGROUND

Herbal medicine plays an important role in health, particularly in remote parts of developing areas with few health facilities. According to WHO estimates, about three-quarters of the world's population currently use herbs or traditional medicines to treat various ailments, including liver diseases. Several studies have found that the use of medicinal plants was effective in the treatment of infectious and non-infectious diseases. Hepatitis and liver cirrhosis associated with many clinical manifestations can be treated with allopathic medicines, but reports of a number of side effects including immunosuppression, bone marrow suppression, and renal complications have motivated researchers to explore more natural herbal medicines with low or no side effects and with high efficacy in treating hepatic diseases.

METHODS

Databases including PubMed, Medline, and Google Scholar were searched for findings on the hepatoprotective effects of plants.

RESULTS

Various medicinal plants are used for the treatment of liver disorders. The range of alternative therapies is huge, and they are used worldwide, either as part of primary health care or in combination with conventional medicine. Hepatoprotective plants contain a variety of chemical constituents including flavonoids, alkaloids, glycosides, carotenoids, coumarins, phenols, essential oil, organic acids, monoterpenes, xanthenes, lignans, and lipids.

CONCLUSION

This review shows that numerous plants are found to contain hepatoprotective compounds. However, further studies are needed to determine their association with existing regimes of antiviral medicines and to develop evidence-based alternative medicine to cure different kinds of liver disease in humans.

Nutraceuticals and Diet-based Phytochemicals in Type 2 Diabetes Mellitus: From Whole Food to Components with Defined Roles and Mechanisms

BACKGROUND

Over the past decades, the development and use of an array of prescription medications have considerably improved the clinical management of type 2 diabetes mellitus and the quality of life of patients. However, as our knowledge of the associated risk factors and approaches to its management increases, the increasing roles of diet and the composition of the diet in the etiology and successful management of diabetes mellitus are being illuminated. Presently, a lot of attention is being given to nutraceuticals and certain phytochemicals that are integral parts of the human diet. It is believed that a clearer understanding of their roles may be crucial to 'non-invasive' or minimallyintrusive management, with regards to daily living of patients. In this review, an overview of nutraceutical components and phytochemicals that may be of benefit, or had been known to be beneficial in diabetes mellitus is given. Also, how the roles of such dietary components are evolving in the management of this disorder is highlighted. Lastly, the obstacles that need to be overcome before nutraceuticals can be considered as options for the clinical management of diabetes mellitus areconsidered.

CONCLUSION

Despite studies that demonstrate their efficacy, no nutraceutical or food-derived compound has been formally adopted as a direct replacement for any class of antidiabetic drugs.

Molecular insights of genetic variation in milk thistle (Silybum marianum [L.] Gaertn.) populations collected from southwest Iran

Milk thistle (Silybum marianum) is among the world's popular medicinal plants. Start Codon Targeted (SCoT) marker system was utilized to investigate the genetic variability of 80 S. marianum genotypes from eight populations in Iran. SCoT marker produced 255 amplicons and 84.03% polymorphism was generated. The SCoT marker system's polymorphism information content value was 0.43. The primers' resolving power values were between 4.18 and 7.84. The percentage of polymorphic bands was between 33.3 and 100%. The Nei's gene diversity (h) was 0.19-1.30 with an average 0.72. The Shannon's index (I) ranged from 0.29 to 1.38 with an average value of 0.83. The average gene flow (0.37) demonstrated a high genetic variation among the studied populations. The variation of 42% was displayed by the molecular variance analysis among the populations while a recorded variation of 58% was made within the populations. Current investigation suggested that SCoT marker system could effectively evaluate milk thistle genotypes genetic diversity.

Differential accumulation of silymarin induced by exposure of Silybum marianum L. callus cultures to several spectres of monochromatic lights

Silybum marianum L. (Milk thistle) is one of the most extensively studied medicinal herbs with well-known hepatoprotective activity. Light is considered as a key abiotic elicitor influencing several physiological processes in plants, including the biosynthesis of secondary metabolites. In this study, we investigated the influence of light quality on morphological and biochemical aspects in in vitro grown leaf-derived callus cultures of S. marianum. Combination of 6-benzylaminopurine (BAP 2.5 mg/L) and α-naphthalene acetic acid (NAA 1.0 mg/L) resulted in optimum callogenic response (97%) when placed under cool-white light with 16 h light and 8 h dark. Red light significantly increased the total phenolic content (TPC), total flavonoid content (TFC), antioxidant and superoxide dismutase (SOD) activities while highest peroxidase (POD) activity was recorded for the dark grown cultures, followed by green light grown cultures. HPLC analysis revealed enhanced total silymarin content under red light (18.67 mg/g DW), which was almost double than control (9.17 mg/g DW). Individually, the level of silychristin, isosilychristin, silydianin, silybin A and silybin B were found greatest under red light, whereas green spectrum resulted in highest accumulation of isosilybin A and isosilybin B. Conversely, the amount of taxifolin was found maximum under continuous white light (0.480 mg/g DW) which was almost 8-fold greater than control (0.063 mg/g DW). A positive correlation was found between the TPC, TFC and antioxidant activities. This study will assist in comprehending the influence of light quality on production of valuable secondary metabolites in in vitro cultures of S. marianum L.

Assessment of the Antioxidant Activity and Quality Attributes of Yogurt Enhanced with Wild Herbs Extracts

The milk and yogurt products assortment has expanded by their enhancement with herb extracts, fibres extracted from by-products of the fruit processing industry and also fresh spices. The aim of the present study was to test to what extent the addition of different herb extracts in yogurt will improve its qualitative characteristics and antioxidant activity. The aqueous extracts obtained from the four plants are considered in this study, respectively, thistle (Silybum marianum L.), hawthorn (Crataegus monogyna), sage (Salvia officinalis L.), and marjoram (Origanum vulgare L.). It was examined the effect of aqueous extracts prepared from four herbs (0.25/1%) (w/w) on yogurt’s qualitative characteristics (pH, titratable acidity, syneresis, water holding capacity, antioxidant activity, colour parameters, and rheological parameters) on both one day and 28 days after preparation. The final results show that the physicochemical and rheological properties of the yoghurt with herb extracts addition were improved compared to the control sample after 28 days of storage. The best results in terms of antioxidant properties were obtained when marjoram extract (Origanum vulgare L.) was incorporated. According to the data obtained, the best quality in terms of the physicochemical and rheological properties were in the case of the sample with 0.5% thistle extract (Silybum marianum L.) addition, while from point of view of the nutritional value, the best quality was in the case of the sample with 1% marjoram extract (Origanum vulgare L.) addition. The present study leads to the conclusion that yogurts enhanced with natural extracts may serve as functional food products, with significant health benefits.