Immunoadjuvant and Humoral Immune Responses of Garlic (Allium sativum L.) Lectins upon Systemic and Mucosal Administration in BALB/c Mice

Dietary food components have the ability to affect immune function; following absorption, specifically orally ingested dietary food containing lectins can systemically modulate the immune cells and affect the response to self- and co-administered food antigens. The mannose-binding lectins from garlic (Allium sativum agglutinins; ASAs) were identified as immunodulatory proteins in vitro. The objective of the present study was to assess the immunogenicity and adjuvanticity of garlic agglutinins and to evaluate whether they have adjuvant properties in vivo for a weak antigen ovalbumin (OVA). Garlic lectins (ASA I and ASA II) were administered by intranasal (50 days duration) and intradermal (14 days duration) routes, and the anti-lectin and anti-OVA immune (IgG) responses in the control and test groups of the BALB/c mice were assessed for humoral immunogenicity. Lectins, co-administered with OVA, were examined for lectin-induced anti-OVA IgG response to assess their adjuvant properties. The splenic and thymic indices were evaluated as a measure of immunomodulatory functions. Intradermal administration of ASA I and ASA II had showed a four-fold and two-fold increase in anti-lectin IgG response, respectively, vs. the control on day 14. In the intranasal route, the increases were 3-fold and 2.4-fold for ASA I and ASA II, respectively, on day 50. No decrease in the body weights of animals was noticed; the increases in the spleen and thymus weights, as well as their indices, were significant in the lectin groups. In the adjuvanticity study by intranasal administration, ASA I co-administered with ovalbumin (OVA) induced a remarkable increase in anti-OVA IgG response (~six-fold; p < 0.001) compared to the control, and ASA II induced a four-fold increase vs. the control on day 50. The results indicated that ASA was a potent immunogen which induced mucosal immunogenicity to the antigens that were administered intranasally in BALB/c mice. The observations made of the in vivo study indicate that ASA I has the potential use as an oral and mucosal adjuvant to deliver candidate weak antigens. Further clinical studies in humans are required to confirm its applicability.

Phenylpropanoid Glycoside and Phenolic Acid Profiles and Biological Activities of Biomass Extracts from Different Types of Verbena officinalis Microshoot Cultures and Soil-Grown Plant

Different types of microshoot cultures (agar, stationary liquid, agitated, and bioreactors) of Verbena officinalis were optimized for biomass growth and the production of phenylpropanoid glycosides and phenolic acids. Using ultra-high performance liquid chromatography with high-resolution time-of-flight mass spectrometry, the presence of verbascoside, isoverbascoside, leucoseptoside A/isomers, and cistanoside D/isomer was confirmed in the methanolic extracts obtained from all types of in vitro cultures. The compound’s content was determined by ultra-high-performance liquid chromatography. The main metabolites in biomass extracts were verbascoside and isoverbascoside (maximum 4881.61 and 451.80 mg/100 g dry weight (DW)). In the soil-grown plant extract, verbascoside was also dominated (1728.97 mg/100 g DW). The content of phenolic acids in the analyzed extracts was below 24 mg/100 g DW. The highest radical scavenging activity was found in the biomass extract from agitated cultures, the most effective reducing power in agar culture extract, and the highest chelating activity in extract from bioreactor cultures. The extracts showed significantly stronger bacteriostatic and bactericidal activity against Gram-positive bacteria (minimum inhibitory concentration (MIC) of 0.3–2.2 mg/mL and minimum bactericidal concentration (MBC) of 0.6–9 mg/mL) than against Gram-negative bacteria (MIC 0.6–9 mg/mL, MBC of 0.6–18 mg/mL). The biomass extract from liquid stationary culture showed the strongest antibacterial activity, while the extract from soil-grown herb had the lowest.

Impact of Safe Rock® Minerals, Mineral Fertilizers, and Manure on the Quantity and Quality of the Wheat Yield in the Rice-Wheat Cropping System

Rice-wheat (RW) rotation is the largest agriculture production system in South Asia with a multifaceted role in maintaining the livelihood of people. The customary practices and indiscriminate use of synthetic fertilizers have culminated in the decline of its productivity and profitability during the past two decades, thus affecting the sustainability of wheat. Safe Rock® Minerals (SRM) is a multi-nutrient rich natural rock mineral with great potential to manage soil degradation, reducing the input of fertilizers, improving soil fertility, and plant health. Thus, a field trial was conducted at the research farm of ICAR-Indian Agricultural Research Institute, New Delhi from 2016 to 2018 to evaluate the impact of Safe Rock® Minerals (SRM) on biometric parameters, productivity, quality, and nutrient uptake by conventional wheat and System of Wheat Intensification (SWI) in the wheat-rice cropping system. The results indicate that SWI performed better in terms of growth, yield, and quality parameters than conventional wheat. Among nutrient management practices; the highest growth, yield, and yield attributes of wheat were achieved with the use of SRM application 250 kg ha-1 + 100% Recommended Dose of Fertilizer (RDF). SRM application also increased grain protein content significantly. In conclusion, the integrated use of SRM with organic manures can serve as an eco-friendly approach for sustainable wheat production.

Fruit Bromelain-Derived Peptide Potentially Restrains the Attachment of SARS-CoV-2 Variants to hACE2: A Pharmacoinformatics Approach

Before entering the cell, the SARS-CoV-2 spike glycoprotein receptor-binding domain (RBD) binds to the human angiotensin-converting enzyme 2 (hACE2) receptor. Hence, this RBD is a critical target for the development of antiviral agents. Recent studies have discovered that SARS-CoV-2 variants with mutations in the RBD have spread globally. The purpose of this in silico study was to determine the potential of a fruit bromelain-derived peptide. DYGAVNEVK. to inhibit the entry of various SARS-CoV-2 variants into human cells by targeting the hACE binding site within the RBD. Molecular docking analysis revealed that DYGAVNEVK interacts with several critical RBD binding residues responsible for the adhesion of the RBD to hACE2. Moreover, 100 ns MD simulations revealed stable interactions between DYGAVNEVK and RBD variants derived from the trajectory of root-mean-square deviation (RMSD), radius of gyration (Rg), and root-mean-square fluctuation (RMSF) analysis, as well as free binding energy calculations. Overall, our computational results indicate that DYGAVNEVK warrants further investigation as a candidate for preventing SARS-CoV-2 due to its interaction with the RBD of SARS-CoV-2 variants.

Secondary Metabolite Profiling, Anti-Inflammatory and Hepatoprotective Activity of Neptunia triquetra (Vahl) Benth

The present study aimed to analyze the phytoconstituents of Neptunia triquetra (Vahl) Benth. Anti-inflammatory and hepatoprotective activities of ethanol (EE), chloroform (CE) and dichloromethane (DCME) of stem extracts were evaluated using in vivo experimental models. The extracts were analyzed for phytoconstituents using GC-HRMS. Anti-inflammatory activity of CE, EE and DCME was accessed using carrageenan-induced paw oedema, cotton pellet-induced granuloma and the carrageenan-induced air-pouch model in Wistar albino rats. The hepatotoxicity-induced animal models were investigated for the biochemical markers in serum (AST, ALT, ALP, GGT, total lipids and total protein) and liver (total protein, total lipids, GSH and wet liver weight). In the in vivo study, animals were divided into different groups (six in each group) for accessing the anti-inflammatory and hepatoprotective activity, respectively. GC-HRMS analysis revealed the presence of 102 compounds, among which 24 were active secondary metabolites. In vivo anti-inflammatory activity of stem extracts was found in the order: indomethacin > chloroform extract (CE) > dichloromethane extract (DCME) > ethanolic extract (EE), and hepatoprotective activity of stem extracts in the order: CE > silymarin > EE > DCME. The results indicate that N. triquetra stem has a higher hepatoprotective effect than silymarin, however the anti-inflammatory response was in accordance with or lower than indomethacin.

Evaluation of the most promising techniques overcoming the algal problems takes place during the purification of drinking water

This work aims to study the technical problems of algal blooms that hinder the purification process of surface water used for drinking purposes and not its harmful effect on human health and the surrounding environment. It is also related to the demonstration of the improved coagulation process as an efficient technique in the algal removal from surface water by its application in jar tests. The study was carried out in the water purification plant in Nazlet Abdellah near the city of Assiut, Egypt. To achieve that, many ores and natural materials which aid in the removing of the algal blooms from surface water during the purification processes were tested. The examined materials should be technically and economically proper for improving the removal of algae from treated surface water for drinking purposes. The results showed that the kaolinite and bentonite (K and B) when coupled separately with aluminum sulfate (alum.) (the main coagulant agent) associated with the raw surface water in the flocculation basin were more efficient in the algae removal from treated surface water before reaching the sand filters by ratio up to 90%.

Influence of sowing windows and genotypes on growth, radiation interception, conversion efficiency and yield of guar

Crop growth largely depends on radiation. Radiation is the main impetus for photosynthesis and movement of photosynthates from source to sink. Therefore, identification of the optimum sowing windows and suitable cultivars for efficient utilization of radiation is of prime importance. A field study was conducted in red clay soil during 2014 and 2015 Kharif season and the treatments consisted of three genotypes and three sowing windows by using randomized complete block design with three replications. The effect of genotypes and sowing windows was found significant with respect to number of trifoliate leaves, leaf area ratio, dry matter production, grain numbers, pod length, test weight, grain yield, and stover yield of guar during 2014 as compared to 2015 sown crop. Statistically significant plant height, number of trifoliate leaves, number of branches, leaf area ratio, absolute growth rate, leaf area index, dry matter, grain number, pod length, grain yield, stover yield and a higher cumulative radiation interception were recorded with 15th August sown crop as compared to other sowing windows. The plant height, number of trifoliate leaves, number of branches, leaf area ratio, absolute growth rate, leaf area index, dry matter, grain number, pod length, grain yield, stover yield and maximum cumulative interception of radiation were significant with RGC-1003 as compared to RGC-936 and HG-365. It is observed that the incident PAR to dry matter accumulation conversion efficiency was varied with cultivars and different sowing windows which ranges from 0.74 g MJ^-1 to 0.79 g MJ^-1.

Assessing the Impact of Higher Levels of CO2 and Temperature and Their Interactions on Tomato (Solanumlycopersicum L.)

Climate change has increasing effects on horticultural crops. To investigate the impact of CO2 and temperature at elevated levels on tomato production and quality of fruits an experiment was conducted by growing plants in open top chambers. The tomato plants were raised at EC550 (elevated CO2 at 550 ppm) and EC700 (elevated CO2 at 700 ppm) alone and in combination with elevated temperature (ET) + 2 °C in the open top chambers. These elevate CO2 and temperature treatment effects were compared with plants grown under ambient conditions. Outcome of the experiment indicated that growth parameters namely plant stature in terms of height (152.20 cm), leaf number (158.67), canopy spread (6127.70 cm2), leaf area (9110.68 cm2) and total dry matter (223.0 g/plant) were found to be high at EC700 compared to plants grown at ambient conditions in open field. The plants grown at EC700 also exhibited significantly higher number of flowers (273.80) and fruits (261.13), more fruit weight (90.46 g) and yield (5.09 kg plant-1) compared to plants grown at ambient conditions in open field. The percent increase in fruit yield due to EC varied from 18.37 (EC550) to 21.41 (EC700) percent respectively compared to open field and the ET by 2 °C has reduced the fruit yield by 20.01 percent. Quality traits like Total Soluble Solids (3.67 °Brix), reducing sugars (2.48%), total sugars (4.41%) and ascorbic acid (18.18 mg/100 g) were found maximum in EC700 treated tomato than other elevated conditions. Keeping quality was also improved in tomato cultivated under EC700 (25.60 days) than the open field (17.80 days). These findings reveal that CO2 at 700 ppm would be a better option to improve both quantitative as well as qualitative traits in tomato. Among the combinations, EC550 + 2 °C proved better than EC700 + 2 °C with respect to yield as well as for the quality traits. The tomato grown under ET (+2 °C) alone recorded lowest growth and yield attributes compared to open field conditions and rest of the treatments. The positive influence of EC700 is negated to an extent of 14.35 % when the EC700 combined with elevated temperature of + 2 °C. The present study clearly demonstrates that the climate change in terms of increased temperature and CO2 will have a positive effect on tomato by way of increase in production and quality of fruits. Meanwhile the increase in EC beyond 700 ppm along with ET may reduce the positive effects on yield and quality of tomato.

El-Ansary D. Mammillaria Species-Polyphenols Studies and Anti-Cancer, Anti-Oxidant, and Anti-Bacterial Activities

Discovering new natural resources of polyphenols is the aim of many recent studies in the field of natural product research. This study tentatively investigated the polyphenols profile of the stems of seven Mammillaria species (M. rhodantha, M. spinosissima, M. hahniana, M. crucigera, M. candida, M. albilanata, and M. muehlenpfordtii) using high performance liquid chromatography with DAD detector (HPLC-DAD) method. Furthermore, the anti-cancer, anti-oxidant, and anti-bacterial potentials of these extracts as well as major identified phenols were explored. The HPLC-DAD study confirmed the availability of six phenolic acids, including gentisic acid, chlorogenic acid, caffeic acid, protocatechuic acid, sinapic acid, and p-hydroxybenzoic acid. The dominant compounds were: gentisic acid in M. rhodantha and M. spinosissima; chlorogenic acid in M. muehlenpfordtii, M. crucigera, and M. rhodantha; and caffeic acid in M. rhodantha, M. crucigera, and M. spinosissima. Stems of Mammillaria sp. showed antiproliferative effects against HeLa, MCF-7, and Jurkat cells. In HeLa and MCF-7 cells, the best antiproliferative activities were found in the treatments with M. rhodantha, M. spinosissima, and M. muehlenpfordtii. The apoptotic assay of M. rhodantha, M. spinosissima, and M. muehlenpfordtii showed accumulation of necrotic cells in the early and late apoptotic phase. M. rhodantha, M. spinosissima, and M. muehlenpfordtii showed the highest anti-oxidant activities using 2,2-diphenyl-1-picrylhydrazyl (DPPH), β-carotene bleaching, and ferric reducing anti-oxidant power (FRAP) assays. M. rhodantha was the best source of antioxidants. Mammillaria sp. showed moderate anti-bacterial effects against bacteria and the highest effects were found using the extracts of M. rhodantha, M. spinosissima, M. crucigera and M. muehlenpfordtii against most bacteria. The anti-bacterial activities were attributed to other phenolic compounds (e.g., chlorogenic acid) than gentisic acid, which was not active against most bacteria. Mammillaria sp. could be considered to be an important natural source of phenolic acids with anti-cancer, anti-bacterial, and anti-oxidant activities.

Phenolic Compounds of Catalpa speciosa, Taxus cuspidate, and Magnolia acuminata have Antioxidant and Anticancer Activity

Tree bark represents an important source of medicinal compounds that may be useful for cancer therapy. In the current study, high-performance liquid chromatography with diode-array detection (HPLC-DAD) was used to determine the profile of the phenolic compounds of Catalpa speciosa, Taxus cuspidata, and Magnolia acuminata bark extracts. The antioxidant and anticancer bioactivities against different cancer cell lines were investigated. M. acuminata exerted significantly higher antioxidant activities in the diphenyl picrylhydrazine and β-carotene-linoleic acid assays than the other species. In C. speciosa, novel profiles of phenolic acids (ferulic acid was the predominant compound) and catechin were detected. In T. cuspidata, six phenolic acids were detected; the predominant compounds were hydroxycaffeic acid and protocatechuic acid. In M. acuminata, two phenolic acids and three catechins were detected; catechin was the predominant compound. The three species exerted clear anticancer activity against MCF-7, HeLa, Jurkat, T24, and HT-29 cells, with the strongest activity found in the extracts from M. acuminata. No antiproliferative activity against normal cells was found. Flow cytometry revealed greater accumulation of necrotic and early/late apoptotic cells in various treated cancer cells than in untreated control cells, and protocatechuic acid induced a similar accumulation of necrotic cells to that of the bark extracts. Caspase-3 and -7 activity was increased in cancer cells treated with different bark extracts; the highest activity was found in the M. acuminata treatment. Our results suggested that the treatment of cancer cells with bark extracts of M. acuminata, C. speciosa, and T. cuspidata, and protocatechuic acid induced apoptosis, suggesting an association between anticancer activities and individual phenolic compounds.

Effective antioxidant, antimicrobial and anticancer activities of essential oils of horticultural aromatic crops in northern Egypt

Background

Identifying ornamental plants as new natural antioxidant and antimicrobial sources is always of great importance for the ornamental and horticultural industries.

Methods

The antimicrobial activities of leaves and fruits peel essential oils of twelve ornamental and horticultural crops were determined by screening against wide spectrum of fungi and bacteria, and their respective in vitro antioxidant capacity was evaluated. Furthermore, the anticancer activities against several cancer cells, and one normal human cell line (HEK-293) were examined.

Results

Origanum vulgare L. essential oil showed the best antioxidant, antibacterial and anticancer activities compared to screened crops by means of the DPPH and linoleic acid assays for antioxidants, MIC and MBC values for antibacterial activities and IC₅₀ for antiproliferative activities. Such important activities in O. vulgare was attributed to high pulegone ratio (77.45%) as revealed by the GC/MS assay. Rosmarinus officinallis L. essential oil showed the highest antifungal activities by means of lowest MIC and MFC values which might be attributed to 1, 8-cineole (19.60%), camphor (17.01%) and α-pinene (15.12%).

Conclusion

We suggest that oxygenated monoterpenes (i.e. linalool, terpinen-4-ol and pulegone) and monoterpene hydrocarbons play an important role in the essential oil antioxidant, antibacterial, antifungal and anticancer activities of diverse Egyptian ornamental and horticultural crops. Some species showed bioactivities similar to standards compounds and might be suitable for pharmaceutical and food industries.

In vitro Antioxidant and Antimicrobial Effects of Ceratostigma plumbaginoides

Bioactive compounds, including phenols, flavonoids, and tannins, were quantified in leaves, stems and roots of methanol, n-butanol, diethyl ether and n- hexane extracts of Ceratostigina plumbaginoides Bunge. (Plumbaginaceae) ornamental plants. The antioxidant capacity was measured by the DPPH and linoleic acid assays. The total bioactive compounds, as well as the antioxidant capacities, were the highest in the leaves compared with stems and roots. The -methanolic, n-butanol, diethyl ether and n-hexane leaf extracts varied in their antibacterial and antifungal activities. In general, the most sensitive bacterium to leaf extracts was Bacillus cereus and the most resistant was Staphyllococcus aureus, while the most sensitive fungus was Aspergillusflavus and the most resistant one was Penicillium ochrochloron. As the methanolic leaf extract was the most active, it was subjected to column chromatography and two compounds were isolated and identified as 1 (5-hydroxy-2-methyl-1,4-naphthoquinone / plumbagin) and 2 (3,3'-biplumbagin). Compounds 1 and 2 showed the highest antibacterial and antifungal activities compared with other extracts tested. The MIC and MBC values for the most active compound 1 were in the range of 0.001 - 0.09 and 0.004 - 0.21 mg mL⁻¹, while MIC and MFC were determined as 0.001 - 0.11 and 0.002 - 0.19 mg mL⁻¹, respectively. The isolated compounds and leaf extracts showed also equal or higher antimicrobial activities compared with antibiotics/commercial reagents which indicate that the plant might be useful for drug development. This is the first report on the antibacterial and antifungal activities, as well as the antioxidant properties of the tested plant parts and isolated compounds.

In vitro Antioxidant and Antimicrobial Effects of Ceratostigma plumbaginoides

Bioactive compounds, including phenols, flavonoids, and tannins, were quantified in leaves, stems and roots of methanol, n-butanol, diethyl ether and n-hexane extracts of Ceratostigma plumbaginoides Bunge. (Plumbaginaceae) ornamental plants. The antioxidant capacity was measured by the DPPH and linoleic acid assays. The total bioactive compounds, as well as the antioxidant capacities, were the highest in the leaves compared with stems and roots. The methanolic, n-butanol, diethyl ether and n-hexane leaf extracts varied in their antibacterial and antifungal activities. In general, the most sensitive bacterium to leaf extracts was Bacillus cereus and the most resistant was Staphyllococcus aureus, while the most sensitive fungus was Aspergillus flavus and the most resistant one was Penicillium ochrochloron. As the methanolic leaf extract was the most active, it was subjected to column chromatography and two compounds were isolated and identified as 1 (5-hydroxy-2-methyl-1,4-naphthoquinone / plumbagin) and 2 (3,3′-biplumbagin). Compounds 1 and 2 showed the highest antibacterial and antifungal activities compared with other extracts tested. The MIC and MBC values for the most active compound 1 were in the range of 0.001 – 0.09 and 0.004 – 0.21 mg mL−1, while MIC and MFC were determined as 0.001 – 0.11 and 0.002 – 0.19 mg mL−1, respectively. The isolated compounds and leaf extracts showed also equal or higher antimicrobial activities compared with antibiotics/commercial reagents which indicate that the plant might be useful for drug development. This is the first report on the antibacterial and antifungal activities, as well as the antioxidant properties of the tested plant parts and isolated compounds.

Enhancement of Calibrachoa growth, secondary metabolites and bioactivity using seaweed extracts

Background

Calibrachoa x hybrida (Solanaceae) cultivars are widely used in North and South America as ornamental plants. Their potential as a source of antimicrobial compounds might be enhanced by seaweed extract (SWE) applications.

Methods

SWE of Ascophyllum nodosum were applied at 5 and 7 ml/L as a soil drench or foliar spray on Calibrachoa cultivars of Superbells® ‘Dreamsicle’ (CHSD) and Superbells® ‘Frost Fireʼ (CHSF). The total phenolics, tannins and antioxidants composition as well as specific flavonols in leaf extracts were determined. Further, the chemical composition of SWE was assessed.

Results

The drench and foliar SWE treatments significantly enhanced Calibrachoa cultivars leaf number and area, dry weight, plant height, antioxidant capacity as well as phenolic, flavonols and tannin content. The increased growth and composition of phenols, flavonols and tannins was attributed to the stimulatory effects of SWE mineral composition. The antifungal activity of Calibrachoa cultivars was significantly enhanced following SWE treatments and the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were in the range of 0.07–0.31 mg/ml and from 0.16 to 0.56 mg/ml, respectively. Moreover, antibacterial activity was significantly increased and the MIC and minimum bactericidal concentration (MBC) measurements were in the range of 0.06–0.23 mg/ml and from 0.10 to 0.44 mg/ml, respectively. The most sensitive fungus to SWE treatments was C. albicans and the most sensitive bacterium was E. cloacae.

Conclusion

The results suggest that enhanced antifungal and antibacterial activities might be attributed to significant increases of phenolic, flavonols and tannin contents, which ultimately enhance the potential of Calibrachoa as a natural source of alternative antibiotics.

Egyptian herbal tea infusions' antioxidants and their antiproliferative and cytotoxic activities against cancer cells

The antioxidant, antiproliferative and cytotoxic activities against different human cancer cells were investigated in local and recently introduced plants of Mentha sp., Rosmarinus officinalis L. (ROL) and Origanum majorana L. (OML). ROL exhibited the highest antioxidant activities (IC50 8.4 ± 0.2 μg/mL) followed by OML and mint species such as Mentha suaveolens 'apple mint' and Mentha longifolia L. exhibiting moderate antioxidant activities. HPLC analysis of leaf extract revealed that rosmarinic acid is the main component followed by caffeic acid. Herbal leaf extracts varied in their proliferation inhibition and cytotoxicity against HeLa, MCF-7 and Jurkat cancer cells in a dose-dependent matter. The highest antiproliferative inhibition and cytotoxic activity were detected in ROL and OML followed by mint. Local herbs might have a potential role as anticancer natural medicines in addition to their high antioxidant activities due to the presence of different phenolics in their aqueous tea extracts.

Cloning of a novel antifungal promoter from Phaseolus vulgaris and the determination of its activity in stably transformed Nicotiana tabacum plants

To investigate the transcriptional regulation of gene expression, chimeric fusions, between the beta-glucuronidase reporter gene (GUS) and the isolated promoter regions of the pvPDF gene (pvPDF-PRO: GUS), were constructed and introduced into Nicotiana tabacum. Analysis of transgenic pvPDF-PRO:GUS tobacco plants indicated that GUS activity was observed with all the promoter constructs with the strongest being in leaf followed by stem and roots. These results clearly demonstrate that pvPDF-PRO is a strong inducible and near-constitutive promoter and emphasize the great application potential for plant genetic engineering studies. Interestingly, a search for putative cis-acting elements in the pvPDF promoter architecture revealed the presence of some important transcription regulatory elements including: CAAT Box, TATA Box, CATA Box, and light regulatory elements (CCA1, GATA, GT-1). Taken together, these results further our understanding of the regulation of the pvPDF promoter activity.

Increasing bioavailability of silymarin using a buccal liposomal delivery system: preparation and experimental design investigation

Silymarin is a natural lipotropic agent of low bioavailability from oral products. The aim of our study is to prepare buccal liposomal delivery system of silymarin with higher bioavailability. The effect of lecithin:cholesterol molar ratio on the percentage drug encapsulated was investigated. The influence of fluctuating the amount of added drug was also determined. The effect of additives such as positive charge inducer, negative charge inducer and surfactants was studied using two different 2(3) full factorial designs. Furthermore, additives used to optimize liposomal product were also investigated for their optimal concentrations, release properties and in vitro permeation and absorption through chicken cheek pouch. Optimal liposomal encapsulation efficiency was found at 7:4 lecithin to cholesterol molar ratio. A decrease in entrapment efficiency with increasing cholesterol content was observed. Tween 20 or Tween 80 beyond 0.5 molar ratio decreased the entrapment efficiency. Positively charged liposomes showed superior entrapment efficiency over neutral and negatively charged liposomes. Release studies as well as permeation and absorption studies showed that hybrid liposomes prepared according to formula 3 containing lecithin, cholesterol, stearyl amine and Tween 20 in 9:1:1:0.5 molar ratio, respectively, gave the best drug absorption and permeation. It showed steady state permeation through chicken cheek pouch for 6h. This is expected to improve the bioavailability of silymarin in the developed liposomal buccal delivery system, as the results show an increase in drug penetration compared to free drug powder.