Pharmacological and bioanalytical aspects of galangin-a concise report

Exploring native arsenic (As)-resistant bacteria: unveiling multifaceted mechanisms for plant growth promotion under As stress

AIMS

This study explores the plant growth-promoting effect (PGPE) and potential mechanisms of the arsenic (As)-resistant bacterium Flavobacterium sp. A9 (A9 hereafter).

METHODS AND RESULTS

The influences of A9 on the growth of Arabidopsis thaliana, lettuce, and Brassica napus under As(V) stress were investigated. Additionally, a metabolome analysis was conducted to unravel the underlying mechanisms that facilitate PGPE. Results revealed that A9 significantly enhanced the fresh weight of Arabidopsis seedlings by 62.6%-135.4% under As(V) stress. A9 significantly increased root length (19.4%), phosphorus (25.28%), chlorophyll content (59%), pod number (24.42%), and weight (18.88%), while decreasing As content (48.33%, P ≤ .05) and oxidative stress of Arabidopsis. It also significantly promoted the growth of lettuce and B. napus under As(V) stress. A9 demonstrated the capability to produce ≥31 beneficial substances contributing to plant growth promotion (e.g. gibberellic acid), stress tolerance (e.g. thiamine), and reduced As accumulation (e.g. siderophores).

CONCLUSIONS

A9 significantly promoted the plant growth under As stress and decreased As accumulation by decreasing oxidative stress and releasing beneficial compounds.

Unveiling the Antioxidative Potential of Galangin: Complete and Detailed Mechanistic Insights through Density Functional Theory Studies

A comprehensive quantum mechanical investigation delved into the antioxidative activity of galangin (Glg). Thermochemical and kinetic data were used to assess antiradical, chelating, and renewal potential under physiological conditions. A brief comparison with reference antioxidants and other flavonoids characterized Glg as a moderate antioxidative agent. The substance showed significantly lower performance in lipid compared to aqueous solvent─the reaction rates for scavenging •OOH in both media were established at 3.77 × 103 M-1 s-1 and 6.21 × 104 M-1 s-1, respectively, accounting for the molar fraction of both interacting molecules at the given pH. The impact of pH value on the kinetics was assessed. Although efficient at chelating Cu(II) ions, the formed complexes can still undergo the Fenton reaction. On the other hand, they persistently scavenge •OH in statu nascendi. The flavonoid effectively repairs oxidatively damaged biomolecules except model lipid acids. All Glg radicals are readily restored by physiologically prevailing O2•-. Given this, the polyphenol is expected to participate in antiradical and regenerating activities multiple times, amplifying its antioxidative potential.

Investigation of Pharmacologically Important Polyphenolic Secondary Metabolites in Plant-based Food Samples Using HPLC-DAD

Polyphenolic compounds are vital components of plants. However, their analysis is particularly difficult and challenging due to their similar chemical and structural properties. In this study, we developed a simple and reproducible HPLC-DAD protocol for determining nineteen pharmacologically important polyphenols in plant-based food samples, including fruits (apple, banana, grapefruit, peach, grapes, plum, and pear), vegetables (onion, cabbage, capsicum, garlic, lemon, tomato, potato, and spinach), and other edible items (corn, kidney beans, green tea, black tea, and turmeric). The reference standards were pooled into four different groups based on logP values and expected retention time to avoid compound co-elution. These developed methods will be useful for the qualitative and quantitative analysis of biologically important polyphenolic compounds in various food samples and botanicals.

Enhanced extraction of bioactive compounds from propolis (Apis mellifera L.) using subcritical water

The bioactive compounds and antioxidant activities of propolis extracts were investigated using subcritical water extraction (SWE). SWE was performed by varying temperature (110-200 °C) and time (10-30 min). SWE using only water as solvent successfully to extracted bioactive compounds from propolis using high-purity glass thimbles. The concentrations of galangin (16.37 ± 0.61 mg/g), and chrysin (7.66 ± 0.64 mg/g) were maximal at 200 °C for 20 min, and 170 °C for 20 min, respectively. The antioxidative properties from propolis increased with the increasing extraction temperature and extraction time on SWE. The maximum yields of the total phenolics (226.37 ± 4.37 mg/g), flavonoids (70.28 ± 1.33 mg/g), and antioxidant activities (88.73 ± 0.58%, 98.86 ± 0.69%, and 858.89 ± 11.48 mg/g) were obtained at 200 °C for 20 min. Compared with using ethanol extraction (at 25 °C for 24 h, total phenolics = 176.28 ± 0.35, flavonoids = 56.41 ± 0.65, antioxidant activities = 72.74 ± 0.41%, 95.18 ± 0.11%, 619.51 ± 8.17 mg/g), all yields of SWE extracts obtained at 200 °C for 20 min were higher. SWE is suitable for a much faster and more efficient method extracting bioactive compounds from propolis compared to traditional extraction method.

Galangin as an inflammatory response modulator: An updated overview and therapeutic potential

Numerous chronic diseases, such as cancer, diabetes, rheumatoid arthritis, cardiovascular disease, and gastrointestinal disorders, all have an inflammation-based etiology. In cellular and animal models of inflammation, flavonols were used to show potent anti-inflammatory activity. The flavonols enhanced the synthesis of the anti-inflammatory cytokines transforming growth factor and interleukin-10 (IL-10) and reduced the synthesis of the prostaglandins IL-6, tumor necrosis factor-alpha (TNF-α), and prostaglandin E2 (PGE2), IL-1. Galangin (GAL), a natural flavonol, has a strong ability to control apoptosis and inflammation. GAL was discovered to suppress extracellular signal-regulated kinase (ERK) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)p65 phosphorylation, which results in anti-inflammatory actions. Arthritis, inflammatory bronchitis, stroke, and cognitive dysfunction have all been treated with GAL. The current review aimed to demonstrate the anti-inflammatory properties of GAL and their protective effects in treating various chronic illnesses, including those of the heart, brain, skin, lungs, liver, and inflammatory bowel diseases.

Repurposing of phyto-ligand molecules from the honey bee products for Alzheimer's disease as novel inhibitors of BACE-1: small molecule bioinformatics strategies as amyloid-based therapy

Alzheimer's disease (AD) is one of the neurodegenerative diseases, manifesting dementia, spatial disorientation, language, cognitive, and functional impairment, mainly affects the elderly population with a growing concern about the financial burden on society. Repurposing can improve the traditional progress of drug design applications and could speed up the identification of innovative remedies for AD. The pursuit of potent anti-BACE-1 drugs for AD treatment has become a pot boiler topic in the recent past and to instigate the design of novel improved inhibitors from the bee products. Drug-likeness characteristics (ADMET: absorption, distribution, metabolism, excretion, and toxicity), docking (AutoDock Vina), simulation (GROMACS), and free energy interaction (MM-PBSA, molecular mechanics Poisson-Boltzmann surface area) analyses were performed to identify the lead candidates from the bee products (500 bioactives from the honey, royal jelly, propolis, bee bread, bee wax, and bee venom) for Alzheimer's disease as novel inhibitors of BACE-1 (beta-site amyloid precursor protein cleaving enzyme (1) receptor using appropriate bioinformatics tools. Forty-four bioactive lead compounds were screened from the bee products through high throughput virtual screening on the basis of their pharmacokinetic and pharmacodynamics characteristics, showing favorable intestinal and oral absorption, bioavailability, blood brain barrier penetration, less skin permeability, and no inhibition of cytochrome P450 inhibitors. The docking score of the forty-four ligand molecules was found to be between -4 and -10.3 kcal/mol, respectively, exhibiting strong binding affinity to BACE1 receptor. The highest binding affinity was observed in the rutin (-10.3 kcal/mol), 3,4-dicaffeoylquinic acid (-9.5 kcal/mol), nemorosone (-9.5 kcal/mol), and luteolin (-8.9 kcal/mol). Furthermore, these compounds demonstrated high total binding energy -73.20 to -105.85 kJ/mol), and low root mean square deviation (0.194-0.202 nm), root mean square fluctuation (0.0985-0.1136 nm), radius of gyration (2.12 nm), number of H-bonds (0.778-5.436), and eigenvector values (2.39-3.54 nm²) in the molecular dynamic simulation, signifying restricted motion of Cα atoms, proper folding and flexibility, and highly stable with compact of the BACE1 receptor with the ligands. Docking and simulation studies concluded that rutin, 3,4-dicaffeoylquinic acid, nemorosone, and luteolin are plausibly used as novel inhibitors of BACE1 to combat AD, but further in-depth experimental investigations are warranted to prove these in silico findings.

Galangin-Loaded Gold Nanoparticles: Molecular Mechanisms of Antiangiogenesis Properties in Breast Cancer

Angiogenesis is important for tissue during normal physiological processes as well as in a number of diseases, including cancer. Drug resistance is one of the largest difficulties to antiangiogenesis therapy. Due to their lower cytotoxicity and stronger pharmacological advantage, phytochemical anticancer medications have a number of advantages over chemical chemotherapeutic drugs. In the current study, the effectiveness of AuNPs, AuNPs-GAL, and free galangin as an antiangiogenesis agent was evaluated. Different physicochemical and molecular approaches have been used including the characterization, cytotoxicity, scratch wound healing assay, and gene expression of VEGF and ERKI in MCF-7 and MDA-MB-231 human breast cancer cell line. Results obtained from MTT assay show cell growth reduction in a time- and dose-dependent aspect; also, in comparison to individual treatment, a synergistic impact was indicated. CAM assay results demonstrated galangin-gold nanoparticle capacity to suppress angiogenesis in chick embryo. Additionally, altering VEGF and ERKI gene expression was recorded. Taken together, all the results can conclude that galangin-conjugated gold nanoparticles can be a promising antiangiogenesis supplemental drug in breast cancer treatment.

In-Silico Exploration of Plant Metabolites as Potential Remedies of Norovirus

Research is still being carried out to develop specific medications or vaccinations to fight norovirus, a key contributor to foodborne illness. This study evaluated certain plant-based active chemicals as prospective candidates for such treatments using virtual screening techniques and other computer assessments. Twenty (20) plant metabolites were tested against the norovirus VP1, VP2, P48, and P22 protein domains using the molecular docking method. In terms of the lowest global binding energy, Asiatic acid, avicularin, guaijaverin, and curcumin exhibited the highest binding affinity with all selected proteins. Each viral protein's essential binding sites with the potential drugs and drug surface hotspots were uncovered. The ADMET (absorption, distribution, metabolism, excretion, and toxicity) analysis was used to further analyze the pharmacological profiles of the top candidates. According to the results, none of the substances showed any adverse consequences that would reduce their drug-like properties. According to the analysis of the toxicity pattern, no detectable tumorigenic, mutagenic, irritating, or reproductive effects of the compounds were discovered. However, among the top four alternatives, curcumin exhibited the highest levels of cytotoxicity and immunotoxicity. These discoveries may open the way for the development of effective norovirus therapies and safety measures. Due to the positive outcomes, we strongly propose more in vivo experiments for the experimental validation of our findings.

Identification of potential inhibitory analogs of metastasis tumor antigens (MTAs) using bioactive compounds: revealing therapeutic option to prevent malignancy

The deeper understanding of metastasis phenomenon and detection of drug targets could be a potential approach to minimize cancer mortality. In this study, attempts were taken to unmask novel therapeutics to prevent metastasis and cancer progression. Initially, we explored the physiochemical, structural and functional insights of three metastasis tumor antigens (MTAs) and evaluated some plant-based bioactive compounds as potent MTA inhibitors. From 50 plant metabolites screened, isoflavone, gingerol, citronellal and asiatic acid showed maximum binding affinity with all three MTA proteins. The ADME analysis detected no undesirable toxicity that could reduce the drug likeness properties of top plant metabolites. Moreover, molecular dynamics studies revealed that the complexes were stable and showed minimum fluctuation at molecular level. We further performed ligand-based virtual screening to identify similar drug molecules using a large collection of 376,342 compounds from DrugBank. The results suggested that several structural analogs (e.g., tramadol, nabumetone, DGLA and hydrocortisone) may act as agonist to block the MTA proteins and inhibit cancer progression at early stage. The study could be useful to develop effective medications against cancer metastasis in future. Due to encouraging results, we highly recommend further in vitro and in vivo trials for the experimental validation of the findings.

Phytochemicals That Interfere With Drug Metabolism and Transport, Modifying Plasma Concentration in Humans and Animals

Phytochemicals (Pch) present in fruits, vegetables and other foods, are known to inhibit or induce drug metabolism and transport. An exhaustive search was performed in five databases covering from 2000 to 2021. Twenty-one compounds from plants were found to modulate CYP3A and/or P-gp activities and modified the pharmacokinetics and the therapeutic effect of 27 different drugs. Flavonols, flavanones, flavones, stilbenes, diferuloylmethanes, tannins, protoalkaloids, flavans, hyperforin and terpenes, reduce plasma concentration of cyclosporine, simvastatin, celiprolol, midazolam, saquinavir, buspirone, everolimus, nadolol, tamoxifen, alprazolam, verapamil, quazepam, digoxin, fexofenadine, theophylline, indinavir, clopidogrel. Anthocyanins, flavonols, flavones, flavanones, flavonoid glycosides, stilbenes, diferuloylmethanes, catechin, hyperforin, alkaloids, terpenes, tannins and protoalkaloids increase of plasma concentration of buspirone, losartan, diltiazem, felodipine, midazolam, cyclosporine, triazolam, verapamil, carbamazepine, diltiazem, aripiprazole, tamoxifen, doxorubicin, paclitaxel, nicardipine. Interactions between Pchs and drugs affect the gene expression and enzymatic activity of CYP3A and P-gp transporter, which has an impact on their bioavailability; such that co-administration of drugs with food, beverages and food supplements can cause a subtherapeutic effect or overdose. Therefore, it is important for the clinician to consider these interactions to obtain a better therapeutic effect.

Galangin attenuates cadmium-evoked nephrotoxicity: Targeting nucleotide-binding domain-like receptor pyrin domain containing 3 inflammasome, nuclear factor erythroid 2-related factor 2, and nuclear factor kappa B signaling

The kidney is highly vulnerable to cadmium-evoked oxidative injury. Galangin is a natural flavone with reported antioxidant properties. This study investigated the potential modulating activity of galangin against cadmium-induced nephrotoxicity and explored the underlining mechanisms. Western blot analysis, spectrophotometric, ELISA, and histopathological techniques were employed. The results revealed that galangin suppressed tubular injury and improved glomerular function in the cadmium-intoxicated rats as evidenced by downregulation of kidney injury molecule-1, serum creatinine, and blood urea nitrogen. Galangin reduced cadmium-evoked inflammatory response and oxidative stress as indicated by reduced levels of interleukin-1 beta and TNF-α, decreased DNA damage, and improved antioxidant potential of the renal tissues. Mechanistically, galangin suppressed the nucleotide-binding domain-like receptor pyrin domain containing 3 inflammasome and efficiently decreased caspase-1 activity in the cadmium-intoxicated rats. Equally important, it inhibited the cadmium-induced nuclear translocation of nuclear factor kappa B and upregulated nuclear factor erythroid 2-related factor 2 signaling. The results highlight the ability of galangin to attenuate cadmium-evoked nephrotoxicity and support its therapeutic implementation although clinical investigations are warranted.

Galangin mitigates iron overload-triggered liver injury: Up-regulation of PPARγ and Nrf2 signaling, and abrogation of the inflammatory responses

AIM

Hepatotoxicity is a critical consequence of the iron overload conditions such as hemochromatosis and blood transfusion-requiring anemia. Iron induces hepatotoxicity largely through disruption of cellular redox homeostasis and induction of inflammatory responses. The present work explored the hepatoprotective activity of the bio-active flavone galangin against iron-evoked hepatotoxicity.

MAIN METHODS

Iron overload model was established in male Wistar rats via intraperitoneal injection of 150 mg/kg iron-dextran subdivided over a ten-day experimental period. Galangin was administered in a daily oral dose of 15 mg/kg throughout the experimental period. Blood and liver tissue samples were collected on day eleven and subjected to biochemical and molecular investigations.

KEY FINDINGS

Galangin significantly reduced liver iron content and serum ferritin level, and alleviated the iron-evoked oxidative stress. It enhanced the liver cell integrity as reflected by decreased serum activity of the liver enzymes. Mechanistically, galangin up-regulated the redox-regulating transcription factor Nrf2 and its responsive proteins HO-1 and NQO1. Interestingly, galangin up-regulated the antioxidant and anti-inflammatory protein PPARγ and serum hepcidin levels under the iron overload conditions. Equally important, it diminished the nuclear shift of the inflammatory transcription factor NF-κB p65 and down-regulated the levels of the pro-inflammatory cytokines TNF-α and IL-1β.

SIGNIFICANCE

The results of the present study highlight the mitigating activity of galangin against iron-induced hepatotoxicity. The study accentuated targeting of Nrf2, PPARγ, and NF-κB signaling as potential contributing mechanisms. While clinical studies are still required, the current study supports the possible implementation of galangin in controlling iron overload-associated hepatotoxicity.

Green extraction techniques from fruit and vegetable waste to obtain bioactive compounds-A review

Food wastes imply significant greenhouse gas emissions, that increase the challenge of climate change and impact food security. According to FAO (2019), one of the main food wastes come from fruit and vegetables, representing 0.5 billion tons per year, of the 1.3 billion tons of total waste. The wastes obtained from fruit and vegetables have plenty of valuable components, known as bioactive compounds, with many properties that impact positively in human health. Some bioactive compounds hold antioxidant, anti-inflammatory, and anti-cancer properties and they have the capacity of modulating metabolic processes. Currently, the use of fruit and vegetable waste is studied to obtain bioactive compounds, through non-conventional techniques, also known as green extraction techniques. These extraction techniques report higher yields, reduce the use of solvents, employ less extraction time, and improve the efficiency of the process for obtaining bioactive compounds. Once extracted, these compounds can be used in the cosmetic, pharmaceutical, or food industry, the last one being focused on improving food quality.

Identification of potential inhibitory analogs of metastasis tumor antigens (MTAs) using bioactive compounds: revealing therapeutic option to prevent malignancy.. [DOI: 10.1101/2020.10.19.345975]

The deeper understanding of metastasis phenomenon and detection of drug targets could be a potential approach to minimize cancer mortality. In this study, attempts were taken to unmask novel therapeutics to prevent metastasis and cancer progression. Initially, we explored the physiochemical, structural and functional insights of three metastasis tumor antigens (MTAs) and evaluated some plant based bioactive compounds as potent MTA inhibitors. From 50 plant metabolites screened, isoflavone, gingerol, citronellal and asiatic acid showed maximum binding affinity with all three MTA proteins. The ADME analysis detected no undesirable toxicity that could reduce the drug likeness properties of top plant metabolites. Moreover, molecular dynamics studies revealed that the complexes were stable and showed minimum fluctuation at molecular level. We further performed ligand based virtual screening to identify similar drug molecules using a large collection of 3,76,342 compounds from DrugBank. The results suggested that several structural analogs (e.g. Tramadol, Nabumetone, DGLA, Hydrocortisone) may act as agonist to block the MTA proteins and inhibit cancer progression at early stage. The study could be useful to develop effective medications against cancer metastasis in future. Due to encouraging results, we highly recommend furtherin vitroandin vivotrials for the experimental validation of the findings.

Screening and druggability analysis of some plant metabolites against SARS-CoV-2: An integrative computational approach

The sudden outbreak of novel coronavirus has caused a global concern due to its infection rate and mortality. Despite extensive research, there are still no specific drugs or vaccines to combat SARS-CoV-2 infection. Hence, this study was designed to evaluate some plant-based active compounds for drug candidacy against SARS-CoV-2 by using virtual screening methods and various computational analyses. A total of 27 plant metabolites were screened against SARS-CoV-2 main protease proteins (MPP), Nsp9 RNA binding protein, spike receptor binding domain, spike ecto-domain and HR2 domain using a molecular docking approach. Four metabolites, i.e., asiatic acid, avicularin, guajaverin, and withaferin showed maximum binding affinity with all key proteins in terms of lowest global binding energy. The crucial binding sites and drug surface hotspots were unravelled for each viral protein. The top candidates were further employed for ADME (absorption, distribution, metabolism, and excretion) analysis to investigate their drug profiles. Results suggest that none of the compounds render any undesirable consequences that could reduce their drug likeness properties. The analysis of toxicity pattern revealed no significant tumorigenic, mutagenic, irritating, or reproductive effects by the compounds. However, withaferin was comparatively toxic among the top four candidates with considerable cytotoxicity and immunotoxicity. Most of the target class by top drug candidates belonged to enzyme groups (e.g. oxidoreductases hydrolases, phosphatases). Moreover, results of drug similarity prediction revealed two approved structural analogs of Asiatic acid i.e. Hydrocortisone (DB00741) (previously used for SARS-CoV-1 and MERS) and Dinoprost-tromethamine (DB01160) from DrugBank. In addition, two other biologically active compounds, Mupirocin (DB00410) and Simvastatin (DB00641) could be an option for the treatment of viral infections. The study may pave the way to develop effective medications and preventive measure against SARS-CoV-2. Due to the encouraging results, we highly recommend further in vivo trials for the experimental validation of our findings.

Phenolic composition and biological activities of geographically different type of propolis and black cottonwood resins against oral streptococci, vaginal microbiota and phytopathogenic Fusarium species

AIMS

A multidisciplinary approach was used to compare phenolic composition, radical scavenging and antimicrobial activity of propolis samples from different geographical localities, and plant resin against various microorganisms.

METHODS AND RESULTS

Using UHPLC-qqqMS quantitative analysis, 28 phenolic compounds were determined. Caffeic and p-coumaric acids were identified as main phenolic acids in poplar propolis samples, except samples from Russia (P6) and China (P7). Radical scavenging activity (applying DPPH spectrophotometric assay) showed the highest activity of Serbian (40·51%) and Chinese (53·21%) propolis samples. Broth microdilution method was used for the oral cavity, fungal phytopathogenic and human vaginal isolates which have been identified at a molecular level. The most sensitive bacterial isolates were Lactobacillus acidophilus (MIC of 0·03-0·13 mg ml^-1 ) and the oral streptococci isolates (MIC values of 0·19-0·13 mg ml^-1 ). The most sensitive fungal phytopathogenic isolate was Fusarium oxysporum (MIC 0·003 mg ml^-1 ). All samples, except propolis from Serbia (P4) and Turkey (P5), showed a strong antifungal activity against Fusarium sporotrichioides, Fusarium subglutinans and Fusarium proliferatum.

CONCLUSION

The results of various tests indicate good radical scavenging and antimicrobial activity against important human and plant pathogens.

SIGNIFICANCE AND IMPACT OF THE STUDY

A detailed propolis analysis is important when proposing a preparation of new biological antimicrobial products which have a positive impact on human health and reduce antibacterial resistance.

The new buzz: Investigating the antimicrobial interactions between bioactive compounds found in South African propolis

ETHNOPHARMACOLOGICAL RELEVANCE

Propolis, a resinous substance produced by the Apis mellifera bee, contains a number of flavonoids sourced from plants found in the surrounding region. Whilst bees use this substance to seal off and protect the beehive, humans have used propolis therapeutically for centuries, making use of its antibacterial, antiseptic, antipyretic and wound healing properties, among others. South African propolis is rich in the flavonoids pinocembrin, galangin, and chrysin and very little previous research has been conducted on the antimicrobial effects of these compounds.

AIM OF THE STUDY

To obtain an understanding of the antimicrobial activity of the compounds pinocembrin, galangin, and chrysin, both independently and in combination.

MATERIALS AND METHODS

The compounds pinocembrin, galangin and chrysin were investigated for interactive antimicrobial activity by determining the minimum inhibitory concentrations (MIC), minimum bactericidal concentrations (MBC), anti-quorum sensing activity, biofilm studies, and toxicity studies (brine shrimp lethality assay).

RESULTS

Minimum inhibitory concentration results demonstrated that combinations of compounds showed better inhibitory activity than single compounds. When the flavonoids were tested in combination using the MIC assay, synergy was noted for 22% of the 1:1 ratio combinations and for 66% of the triple 1:1:1 ratio combinations. Similarly, MBC results showed bactericidal activity from selected combinations, while the compounds on their own demonstrated no cidal activity. Quorum sensing studies showed that compound combinations are more effective at inhibiting bacterial communication than the individual compounds. Biofilm assays showed that the highest percentage inhibition was observed for the triple combination against E. coli at 24 h. Finally, brine shrimp lethality studies revealed that combinations of the three compounds had reduced cytotoxicity when compared to the individual compounds.

CONCLUSION

The results obtained in this study demonstrate that the compounds found in South African propolis work synergistically to achieve an optimal antimicrobial effect, whilst simultaneously minimizing cytotoxicity.

Galangin loaded galactosylated pluronic F68 polymeric micelles for liver targeting

Galangin possess wide range of pharmacological activities including antiarthritic, hepatoprotective, anti-inflammatory, antibacterial, and anticancer especially in hepatocellular carcinoma. However, its biological use has been limited owing to its poor aqueous solubility, P-gp efflux and rapid in vivo metabolism by cytochrome enzymes. In order to address the drawbacks of galangin, the current work was designed with an objective to prepare liver targeted galangin loaded galactosylated pluronic F68 polymeric (GF68-Gal) micelles. Galactosylated pluronic F68 copolymer was successfully synthesized usi reduction amination method and used for micelle preparation. The prepared micelles were evaluated for micelle size, entrapment efficiency, zeta potential, in vitro galangin release and in vivo biodistribution. The average size of GF68-Gal micelles was found to be around 242±4.6 nm with an entrapment efficiency of about 77.5± 0.34% w/w. In vitro dissolution profile of GF68-Gal micelles revealed controlled release of galangin. Further, biodistribution studies of GF68-Gal micelles showed significant improvement in the amount of galangin in liver at 15 min (around 2.6 folds) and after 30 min (around 7.18 folds) as compared to galangin solution. Such significant increase in galangin amount in the liver for GF68-Gal micelles could be attributed to their efficient targeting to the liver by galactose moieties having affinity towards ASGPR receptor, P-gp and cytochrome enzyme inhibition activity of pluronic F68 reducing the rate of metabolism and in turn elimination. Thus, galactosylated pluronic F68 copolymer can act as a promising carrier system for improving liver targeting of hydrophobic drugs susceptible to P-gp efflux and cytochrome enzyme associated metabolism.

Galangin induces cell death by modulating the expression of glyoxalase-1 and Nrf-2 in HeLa cells

The present study was designed to understand the anticancer property and molecular mechanisms associated with chemo preventive effects of galangin. The anticancer effect was evaluated in vitro using human cervical cancer cell line (HeLa). Galangin was found to be effective in inducing cell death and inhibiting proliferation & migration significantly. The inhibitory effect of galangin could be correlated with the increase in ROS production & induction of apoptosis. Besides this the activity of glyoxalase-1, an enzyme important for the detoxification of cytotoxic metabolite methy glyoxal and Nrf-2 (a trascription factor), involved in redox signalling were found to be decreased. We concluded that galangin exerts its chemo preventive effect via redox signalling by inhibiting glyoxalase-1 & increasing oxidative & carbonyl stress.

Galangin ameliorates cisplatin induced nephrotoxicity in vivo by modulation of oxidative stress, apoptosis and inflammation through interplay of MAPK signaling cascade

BACKGROUND AND PURPOSE

Cisplatin is a widely used chemotherapeutic agent but now-a-days its usage is limited in clinical chemotherapy because of its severe nephrotoxic effect on renal tissues. Galangin, a flavonoid obtained from ginger family has been demonstrated to have antioxidant, anti-apoptotic and anti-inflammatory properties. This study is aimed to investigate the possible ameliorative effect of galangin in a rodent model of cisplatin-induced nephrotoxicity.

MATERIAL AND METHODS

Adult male albino wistar rats were divided into six groups (n=6) viz normal, cisplatin-control, galangin (25, 50 and 100mg/kg p.o.) and per se (100mg/kg galangin, p.o.). Galangin was administrated orally to the rats for a period of 10 days. On the 7th day of the treatment, nephrotoxicity was induced in all the groups by a single dose of cisplatin (8mg/kg, i.p.) (except normal and per se group). On the 11th day, the rats were anaesthetized and blood was withdrawn via direct heart puncture for biochemical estimation. Rats were sacrificed and kidneys were isolated and preserved for evaluation of histopathological, ultra structural immunohistochemical studies and western blot analysis.

RESULTS

Cisplatin significantly impaired renal function and increased oxidative stress and inflammation. It also increased expression of pro-apoptotic proteins Bax and caspase-3 and decreased the expression of the anti-apoptotic protein Bcl-2. Histological and ultrastructural findings were also supportive of renal tubular damage. Pretreatment with galangin (100mg/kg p.o.) preserved renal function, morphology, suppressed oxidative stress, inflammation and the activation of apoptotic pathways. TUNEL assay showed decreased DNA fragmentation on galangin pre-treatment. Furthermore, galangin (100mg/kg) pre-treatment also reduced the expression of NFκB along with proteins MAPK pathway i.e. p38, JNK and ERK1/2.

CONCLUSION

In conclusion, Galangin (100mg/kg, p.o.) significantly ameliorated cisplatin induced nephrotoxicity by suppressing MAPK induced inflammation and apoptosis.

Molecular structure and anti-proliferative effect of galangin in HCT-116 cells: In vitro study

Galangin is a naturally occurring plant flavonoid with potential anticancer activity. In present work, the Becke three-parameter hybrid exchange functional method and the Lee-Yang-Parr correction functional methods were used to investigate the structural properties of galangin. The structure-activity relationship analysis has been performed to determine its antioxidant pharmacophore by using density functional theory method and quantum chemical calculations. The free radical scavenging activities of galangin were analyzed with the use of 2, 2-diphenyl-1-picrylhydrazyl and compared with Vitamin C as a control. Galangin decreased the cell proliferation rate in HCT-116 cells and showed concentration- and time-dependent response. Galangin significantly increase the inhibitory effect on HCT-116 clonogenicity and promotes cell cycle arrest at the G2/M or G1 phase, as confirmed by flow cytometry analysis.

Forest biorefinery: Potential of poplar phytochemicals as value-added co-products

The global forestry industry after experiencing a market downturn during the past decade has now aimed its vision towards the integrated biorefinery. New business models and strategies are constantly being explored to re-invent the global wood and pulp/paper industry through sustainable resource exploitation. The goal is to produce diversified, innovative and revenue generating product lines using on-site bioresources (wood and tree residues). The most popular product lines are generally produced from wood fibers (biofuels, pulp/paper, biomaterials, and bio/chemicals). However, the bark and other tree residues like foliage that constitute forest wastes, still remain largely an underexploited resource from which extractives and phytochemicals can be harnessed as by-products (biopharmaceuticals, food additives and nutraceuticals, biopesticides, cosmetics). Commercially, Populus (poplar) tree species including hybrid varieties are cultivated as a fast growing bioenergy crop, but can also be utilized to produce bio-based chemicals. This review identifies and underlines the potential of natural products (phytochemicals) from Populus species that could lead to new business ventures in biorefineries and contribute to the bioeconomy. In brief, this review highlights the importance of by-products/co-products in forest industries, methods that can be employed to extract and purify poplar phytochemicals, the potential pharmaceutical and other uses of >160 phytochemicals identified from poplar species - their chemical structures, properties and bioactivities, the challenges and limitations of utilizing poplar phytochemicals, and potential commercial opportunities. Finally, the overall discussion and conclusion are made considering the recent biotechnological advances in phytochemical research to indicate the areas for future commercial applications from poplar tree species.