Nanotechnology Formulations Designed with Herbal Extracts and Their Therapeutic Applications - A Review.

Because of the increasing demand for natural products, the development of nanoformulations containing natural active ingredients requires in-depth knowledge of the substances used, methods of obtaining, and stability profiles to ensure product quality, efficacy, and safety. Considering this, the bibliography of the last five years presented in databases (PubMed and Science Direct) was discussed in this work, discussing the study with medicinal plants to obtain active metabolites with therapeutic properties, as well as the different nano-systems responsible for carrying these molecules. Due to the wealth of biodiversity found in the world, many species are submitted to the extraction process for several purposes. However, identifying, classifying, and quantifying the constituents of herbal matrices are crucial steps to verify their therapeutic potential. In addition, knowing the techniques of production and elaboration of nanotechnology products allows the optimization of the incorporation of herbal extracts as an innovation target. For studies to be successful, it is necessary to exhaust experimental results that guarantee the efficacy, safety, and quality of natural nanosystems, with the objective of obtaining reliable answers in nanotechnology therapy.

Phytochemical profile analysis by LC-ESI-MSn and LC-HR-ESI-MS and validated HPLC method for quantification of rutin in herbal drug and products from leaves of Croton blanchetianus.

Phytochemical analysis of Croton blanchetianus leaves was performed by. After that, a high performance liquid chromatography method was developed and validated for the determination of rutin in herbal drug and products of C. blanchetianus. The separation was achieved on a C18 column, and the mobile phase was composed of ultrapure water and methanol (acidified with trifluoroacetic acid) with a gradient of 0.8 ml/min. The method was validated following international guidelines. The chemical analysis revealed the presence of flavonoids. Among them rutin was used as the standard for validation. In the HPLC the presence of rutin was observed at 24.7 min. The method was robust, with no significant variations, and linear in the range evaluated with R2 > 0.99. Regarding the matrix effect, it was possible to prove the absence of interference of the constituents in the herbal drug. The precision was determined with a relative standard deviation of <1.34%. The recovery results were achieved between 89.29 and 101.21%. Furthermore, with partial validation, the method was proved to be suitable for the liquid extract, dry extract and effervescent granules. Therefore, this study demonstrated that the method is effective for the quality control analysis of C. blanchetianus leaves and products.

Safety evaluation of aqueous extract from Eugenia uniflora leaves: Acute and subacute toxicity and genotoxicity in vivo assays.

ETHNOPHARMACOLOGICAL RELEVANCE: Eugenia uniflora Linn (Myrtaceae) is the native species of Brazil. The leaves of this species are used in folk medicine to treat different inflammatory and gastrointestinal disorders. However, research on the safety of using E. uniflora leaves has been poorly explored. AIM OF THE STUDY: This approach aims to investigate the phytochemical composition as well as the acute, subacute toxicity, and in vivo genotoxic profile of the aqueous extract of E. uniflora leaves. MATERIALS AND METHODS: The chemical composition of E. uniflora leaf extract was determined by Fingerprint by High-Performance Thin Layer and High-Performance Liquid Chromatography. The acute toxicity in vivo was evaluated for 14 days after the administration of E. uniflora leaves extract (2000 mg/kg). For the evaluation of subacute toxicity, mice were daily treated for 28 days with E. uniflora extract (250, 500, or 1000 mg/kg). Signs of behavioral toxicity and biochemical and hematological alterations, including the multiple organ toxicities were investigated. In addition, the micronucleus assay was used to evaluate the in vivo genotoxicity of the leaves extract in murine erythrocytes. RESULTS: The phytochemical analysis showed the majority presence of phenolic compounds (gallic acid, ellagic acid, and myricitrin). Single or repeated doses of the aqueous extract of E. uniflora leaves did not reveal any signs of in vivo toxicity. Daily doses of the extract for 28 days induced a slight reduction in cholesterol and triglyceride levels. Furthermore, E. uniflora leaves extract (1000-2000 mg/kg) showed no genetic damage in the micronucleus assay, indicating the absence of genotoxicity of the herbal species. CONCLUSION: The aqueous extract of E. uniflora leaves showed a predominance of phenolic compounds, with non-toxic and non-genotoxic action in vivo. This approach sheds light on the chemical composition of the leaves of E. uniflora and suggests a high margin of safety in the popular use of the leaves of this plant species.

Chemical and antibacterial analysis of Cinnamomum verum leaves extract and fractions against multidrug resistant bacteria.

The chemical composition, the antioxidant and antimicrobial potential of crude extract from leaves Cinnamomum verum and their enriched fractions was studied. Phytochemical analyses were performed by TLC and HPLC, and the antioxidant capacity was verified by DPPH• and ABTS•+. The Minimal Inhibitory/Bactericidal Concentration was conducted against twenty-two bacteria to select five strains susceptible to extracts/fractions and resistant to the antibiotics tested. Interference of Ethyl Acetate Fraction (EAF) in resistance to synthetic antibiotic was assayed by modulatory and checkerboard model. The chromatographic data showed phenolic compounds in crude extract, as well the flavonoid enrichment in the EAF. The combination of EAF and synthetic antibiotics (ampicillin, azithromycin, ciprofloxacin, or gentamicin) provides a synergistic effect against multidrug resistant strains). The results are useful to obtain multi-targeting in a single therapy solution, which on antioxidants molecules plant-derivatives can act synergistically in antimicrobial combinations, a valuable aid as bacterial resistance modifying compounds.

Phytochemical analysis and evaluation of the antimicrobial and antioxidant activities of extracts and fractions of Hymenaea eriogyne Benth.

The objective of this study was to conduct phytochemical characterization and biological evaluation of Hymenaea eriogyne. Crude extracts and fractions from the bark, leaves and pods, were obtained for phytochemical screening by TLC and HPLC, and evaluation of antibacterial and antioxidant potential. Chromatographic data revealed the presence of several metabolites, notably from the flavonoid class. HPLC analysis confirmed the presence of the flavanonol astilbin (taxifolin 3-O-ramnoside) and other flavonoids derived from aglycone taxifolin. In addition, it was possible to quantify phytochemical markers in the extracts and fractions, which showed an increased content of flavonoid and catechin derivatives in the fraction. Better results of the minimum inhibitory/bactericidal concentrations were obtained with extracts and fractions from bark. In the antioxidant activity using the DPPH method, the enriched bark fraction presented an IC50 of 34.46 µg/mL. These results contribute to the continuity of studies on the chemical and biological composition of the species.

Quantification of polyphenols and evaluation of antimicrobial, analgesic and anti-inflammatory activities of aqueous and acetone-water extracts of Libidibia ferrea, Parapiptadenia rigida and Psidium guajava.

ETHNOPHARMACOLOGICAL RELEVANCE: Vast numbers of plant species from northeastern Brazil have not yet been phytochemically or biologically evaluated. AIM OF THE STUDY: The goal of this work was to obtain, characterize and show the antimicrobial, analgesic and anti-inflammatory activities of aqueous and acetone-water extracts of Libidibia ferrea, Parapiptadenia rigida and Psidium guajava. MATERIALS AND METHODS: The plant material (100g) was dried, and the crude extracts were obtained by using turbo-extraction (10%; w/v) with water or acetone:water (7:3, v/v) as the extraction solvent. High-performance liquid chromatography (HPLC) methods were used to screen the crude extracts for hydrolysable tannins (gallic acid) and condensed tannins (catechins). The antibacterial activity was evaluated by agar-diffusion and microdilution methods against Gram-positive strains (Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis INCQS 00016, Enterococcus faecalis ATCC 29212 and a clinical isolate of methicillin-resistant Staphylococcus aureus) as well as Gram-negative strains (Escherichia coli ATCC 25922, Salmonella enteritidis INCQS 00258, Shigella flexneri and Klebsiella pneumoniae). To evaluate the anti-inflammatory activity, a leukocyte migration model was used. Analgesic activity was determined by the hot plate test and the acetic acid-induced abdominal writhing test. Data were analyzed by analysis of variance (ANOVA) at a significance level of 5%. RESULTS: Parapiptadenia rigida presented the highest amount of total polyphenols (35.82 ± 0.20%), while the greatest catechin content was found in the acetone-water extract of Psidium guajava (EAWPg; 1.04 µg/g). The largest amounts of catechins were found in the aqueous extract of Libidibia ferrea (EALf; 1.07 µg/g) and the acetone-water extract of Parapiptadenia rigida (EAWPr; 1.0 µg/g). All extracts showed activity against Gram-positive bacteria. The aqueous and acetone-water extracts of Psidium guajava showed the greatest inhibition zones in the agar diffusion tests. In the evaluation of the minimum inhibitory concentration (MIC), the most susceptible Gram-positive bacterium was Staphylococcus epidermidis and the most susceptible Gram-negative bacterium was Shigella flexneri. EAPg and EAWPg showed the greatest MIC values. All extracts were significant inhibitors of leukocyte migration (p<0.05). Using the writhing test, significant analgesic activity was found for EAPr (50 mg/kg), EAWPr (100 mg/kg and 200 mg/kg) and EAWPg (50 mg/kg) (p<0.05). CONCLUSIONS: Thus, the appropriate extraction procedure preserves the chemical components such as gallic acid and catechin, and showed antimicrobial, anti-inflammatory and analgesic properties.