Ethnomedicinal uses, phytoconstituents and pharmacological importance of pteridophytes used by Malayalis in Kolli hills, India: A quantitative survey

Assessment of microwave drying for rapid and convenient analysis of medicinal plants for quality assurance

INTRODUCTION

The safety and quality of many medicinally important herbs are compromised since farmers and small organizations are involved in the cultivation, aggregation, and primary processing of these herbs. Such organizations often lack adequate quality control facilities. To improve the safety and quality of herbal products, simple, rapid, and affordable quality control systems are required.

OBJECTIVES

The aim of this study was to assess the suitability of microwave oven-drying for moisture content (MC) determination and sample preparation of herbs in small organizations.

METHODS

Microwave oven-drying (720 W) and convective oven-drying at 105°C for MC determination were compared. The effects of three different drying methods (microwave oven-drying, low-temperature convective drying, and freeze-drying) on in vitro antioxidant and polyphenol oxidase (PPO) activity were determined, similarity analysis was conducted using HPLC signature spectra, and validation was performed with LC-MS focusing on one herb.

RESULTS

Microwave oven-drying at 720 W significantly reduced the drying time (from hours to minutes), whereas the spatial variation of temperature in convective ovens set at 105°C can cause about 10% underestimation of MC. Microwave oven-drying showed similar macro-properties like freeze-drying and higher extractability (10%-20%) and in vitro antioxidant capacity (33%-66%) and lower PPO activity compared to low-temperature convective drying. HPLC signature spectra revealed strong similarity of soluble components between freeze-dried and microwave oven-dried herbs. LC-MS analysis demonstrated more common compounds between freeze-dried and microwave oven-dried Centella asiatica extracts, whereas convective tray-dried samples had fewer compounds common with samples obtained by freeze-drying or microwave oven-drying.

CONCLUSIONS

Microwave oven-drying is rapid (tens of min) and shows small batch-to-batch variation compared to oven-drying at 105°C. The in vitro antioxidant assays and signature spectra can be used for assessing the source and purity or quality of a specific herb variety.

Phytochemical composition, anti-microbial, anti-oxidant and anti-diabetic effects of Solanum elaeagnifolium Cav. leaves: in vitro and in silico assessments

The aim of this study was to screen the chemical components of Solanum elaeagnifolium leaves and assess their therapeutic attributes with regard to their antioxidant, antibacterial, and antidiabetic activities. The antidiabetic effects were explored to determine the α-amylase and α-glucosidase inhibitory potential of the leaf extract. To identify the active antidiabetic drugs from the extracts, the GC-MS-screened molecules were docked with diabetes-related proteins using the glide module in the Schrodinger Tool. In addition, molecular dynamics (MD) simulations were performed for 100 ns to evaluate the binding stability of the docked complex using the Desmond module. The ethyl acetate had a significant total phenolic content (TPC), with a value of 79.04 ± 0.98 mg/g GAE. The ethanol extract was tested for its minimum inhibitory concentration (MIC) for its bacteriostatic properties. It suppressed the growth of B. subtilis, E. coli, P. vulgaris, R. equi and S. epidermis at a dosage of 118.75 µg/mL. Moreover, the IC50 values of the ethanol extract were determined to be 17.78 ± 2.38 in the α-amylase and and 27.90 ± 5.02 µg/mL in α-glucosidase. The in-silico investigation revealed that cyclolaudenol achieved docking scores of -7.94 kcal/mol for α-amylase. Likewise, the α-tocopherol achieved the docking scores of -7.41 kcal/mol for glycogen phosphorylase B and -7.21 kcal/mol for phosphorylase kinase. In the MD simulations, the cyclolaudenol and α-tocopherol complexes exhibited consistently stable affinities with diabetic proteins throughout the trajectory. Based on these findings, we conclude that this plant could be a good source for the development of novel antioxidant, antibacterial, and antidiabetic agents.Communicated by Ramaswamy H. Sarma.

Genus Equisetum L: Taxonomy, toxicology, phytochemistry and pharmacology

INTRODUCTION

The genus Equisetum (Equisetaceae) is cosmopolitan in distribution, with 41 recognized species. Several species of Equisetum are widely used in treating genitourinary and related diseases, inflammatory and rheumatic problems, hypertension, and wound healing in traditional medicine practices worldwide. This review intends to present information on the traditional uses, phytochemical components, pharmacological activities, and toxicity of Equisetum spp. and to analyze the new insights for further study.

METHODS

Relevant literature has been scanned and collected via various electronic repositories, including PubMed, Science Direct, Google Scholar, Springer Connect, and Science Online, from 1960 to 2022.

RESULTS

Sixteen Equisetum spp. were documented as widely used in traditional medicine practices by different ethnic groups throughout the world. A total of 229 chemical compounds were identified from Equisetum spp. with the major group of constituents being flavonol glycosides and flavonoids. The crude extracts and phytochemicals of Equisetum spp. exhibited significant antioxidant, antimicrobial, anti-inflammatory, antiulcerogenic, antidiabetic, hepatoprotective, and diuretic properties. A wide range of studies have also demonstrated the safety of Equisetum spp.

CONCLUSION

The reported pharmacological properties of Equisetum spp. support its use in traditional medicine, though there are gaps in understanding the traditional usage of these plants for clinical experiments. The documented information revealed that the genus is not only a great herbal remedy but also has several bioactives with the potential to be discovered as novel drugs. Detailed scientific investigation is still needed to fully understand the efficacy of this genus; hence, very few Equisetum spp. were studied in detail for phytochemical and pharmacological investigation. Moreover, its bioactives, structure-activity connection, in vivo activity, and associated mechanism of action ought to be explored further.

Grapevine Plants Management Using Natural Extracts and Phytosynthesized Silver Nanoparticles

Starting from the well-known antimicrobial properties of silver nanoparticles, the goal of this study is to evaluate the influence of two "green" recipes, namely an alcoholic extract of Dryopteris filix-mas (L.) Schott and a dispersion of silver nanoparticles phytosynthesized using the extract on grapevine pathogens. The influence of some grapevine parameters (pith/wood rapport, soluble sugars, starch, total sugars, total water content, length of young shoots, number of grapes) in field experiments was also studied. The study was conducted on four clones (Feteasca alba 97 St., Feteasca neagra 6 St., Feteasca regala 72 St., and Cabernet Sauvignon 131 St.) located in vegetation pots inside a greenhouse. For the phytosynthesis of the silver nanoparticles (AgNPs) we used a scaled-up technology, allowing us to obtain large quantities of nanoparticles-containing solution. The AgNPs analysis by X-ray diffraction and transmission electron microscopy confirmed the synthesis of spherical and quasi-spherical nanoparticles of 17 nm average diameter and 6.72 nm crystallite size. The field experiments registered different responses of the four clones to the treatment, using both the natural extracts and phytosynthesized nanoparticles solution. Both recipes exhibited a protective effect against the Uncinula necator pathogen. For the treatment using phytosynthesized nanoparticles, significant increases in the pith/wood ratio for white wine clones (Feteasca alba 97 St. and Feteasca regala 72 St.) were observed. The biochemical analyses revealed other significant increases of soluble sugars (red wine clones-Feteasca neagra and Cabernet Sauvignon/second year), starch (Feteasca alba and Cabernet Sauvignon in 2021 for both clones), total sugars (Feteasca alba and Feteasca neagra in 2021 for both clones), and of total water content (Feteasca alba and Feteasca neagra in 2021 for both clones), respectively. The applied treatments also led to an increase of young shoots length and grape numbers for all clones as compared to the control (chemical pesticide), which would suggest a potential biostimulant effect of the recipes.

Chemical profiling and antioxidant activity of Equisetum ramosissimum Desf. stem extract, a potential traditional medicinal plant for urinary tract infections

Background

Equisetum ramosissimum Desf. (E. ramosissimum) is a widely used traditional medicinal plant to treat urinary tract infections (UTIs) by ethnic people throughout the world. The utility of the plant in treating urinary-related disorders was evaluated against selected pathogenic bacteria which has major role in causing UTIs. Hence, the present study executed to extract phytochemicals like total phenolics and flavonoids, chemical profiling by GC–MS analysis and to test their antioxidant activity from stem extracts of E. ramosissimum. The extraction process was directed by petroleum ether, chloroform, ethyl acetate, methanol, and aqueous solvents.

Results

The GC–MS analysis yielded 24 phytoconstituents with linoleic acid, palmitic acid, nonacosane, hexahydrofarnesyl acetone, and octacosane as major compounds. Methanolic extract yielded maximum amount of phenolics (TPC) and flavonoids (TFC) with 600.02 ± 0.22 mg GAE/g and 631.38 ± 0.69 mg QE/g, respectively. Methanolic extract also exhibited notable free radical scavenging activity with an IC50 of 123.89 ± 0.73, 150.10 ± 1.02, 146.01 ± 0.54, and 63.73 ± 6.12 µg/mL for DPPH, FRAP, ABTS, and O2− assays, respectively. The minimum inhibitory concentration (MIC) required to inhibit the growth of tested pathogenic bacteria was observed in aqueous and methanolic extracts with the value being 31.25 µg/mL against R. equi and V. cholerae. As like, methanolic and petroleum ether extracts efficiently inhibited the growth of B. subtilis with the MIC of 31.25 µg/mL.

Conclusion

It was concluded that the notable effect of methanolic and aqueous extracts against the uropathogenic bacteria reported in this study supported the traditional uses of this plant in treating UTIs. The results acquired from this investigation revealed that E. ramosissimum stem extract might be considered as an interesting candidate in the development of antibacterial agent against UTIs coupled with antioxidant properties.