Gauravi Agarkar

Endophytic actinobacteria of medicinal plants: diversity and bioactivity

Endophytes are the microorganisms that exist inside the plant tissues without having any negative impact on the host plant. Medicinal plants constitute the huge diversity of endophytic actinobacteria of economical importance. These microbes have huge potential to synthesis of numerous novel compounds that can be exploited in pharmaceutical, agricultural and other industries. It is of prime importance to focus the present research on practical utilization of this microbial group in order to find out the solutions to the problems related to health, environment and agriculture. An extensive characterization of diverse population of endophytic actinobacteria associated with medicinal plants can provide a greater insight into the plant-endophyte interactions and evolution of mutualism. In the present review, we have discussed the diversity of endophytic actinobacteria of from medicinal plants their multiple bioactivities.

Fungal growth promotor endophytes: a pragmatic approach towards sustainable food and agriculture

Agricultural productivity suffers a heavy loss due to plant pathogens, insect pests and various abiotic stresses. Agriculture being the world’s largest economic sector, it is the need of time to find and establish the ideal strategy for sustainable agriculture and improvement in crop growth. Endophytes are microorganisms that asymptomatically grow within the plant tissues without causing any disease to the host. Endophytic fungi live in symbiotic association with plants and play an important role in plant growth promotion, higher seed yield and plants resistant to various biotic, abiotic stresses and diseases. Many are able to produce antimicrobial compounds, plant growth hormones and various agrochemical bioactive metabolites. These mycoendophytes hold enormous potential for the development of eco-friendly and economically viable agricultural products. In this review we focused on the endophytic fungi recovered from different medicinal plants, their active principles involved in plant growth enhancement and the applications of fungal endophytes in agriculture. Moreover, we also discussed about endophytic fungi and their pragmatic approach towards sustainable food and agriculture.

Anticancer activities of Withania somnifera: Current research, formulations, and future perspectives

Abstract Context: Cancer, being a cause of death for major fraction of population worldwide, is one of the most studied diseases and is being investigated for the development of new technologies and more accurate therapies. Still the currently available therapies for cancer have many lacunae which affect the patient’s health severely in the form of side effects. The natural drugs obtained from the medicinal plants provide a better alternative to fight against this devastating disease. Withania somnifera L. Dunal (Solanaceae), a well-known Ayurvedic medicinal plant, has been traditionally used to cure various ailments for centuries. Objectives: Considering the immense potential of W. somnifera, this review provides a detail account of its vital phytoconstituents and summarizes the present status of the research carried out on its anticancerous activities, giving future directions. Methods: The sources of scientific literature were accessed from various electronic databases such as PubMed, Google Scholar, Science Direct, and library search. Results: Various parts of W. somnifera especially the roots with its unique contents have been proved effective against different kinds of cancers. The most active components withanolides and withaferins along with a few other metabolites including withanone (WN) and withanosides have been reported effective against different types of cancer cell lines. Conclusion: This herb holds an important place among various anticancer medicinal plants. It is very essential to further screen and to investigate different formulations for anticancer therapy in vitro as well as in vivo in combination with established chemotherapy.

Synergistic antimicrobial potential of essential oils in combination with nanoparticles: Emerging trends and future perspectives

The development of resistance to different antimicrobial agents by bacteria, fungi, viruses, parasites, etc. is a great challenge to the medical field for the treatment of infections caused by them, and therefore, there is a pressing need to search for new and novel antimicrobials. The antimicrobial activity of essential oils and biogenic nanoparticles is well known. Recent studies have demonstrated that nanoparticles functionalized with essential oils have significant antimicrobial potential against multidrug- resistant pathogens. The aim of the present review is to discuss various studies on the broad-spectrum antimicrobial activity of essential oils used singly and in combination with nanoparticles. The brief explanation of their mechanism has also been discussed.

Plant–fungal interactions: What triggers the fungi to switch among lifestyles?

Abstract Up till now various plant–fungal interactions have been extensively studied in the form of mycorrhizal, parasitic or endophytic lifestyles. Many of those interactions are beneficial to the host plants and a few are detrimental. Several investigations have pointed towards the interconversion of one fungal lifestyle into another while interact the plant system meaning endophyte may become parasite or vice versa. In such case, it is necessary to realize whether these different lifestyles are interconnected at some points either by physiological, biochemical or molecular routes and to identify the factors that trigger the change in fungal lifestyle, which is entirely different than earlier one and affects the host plant significantly. This review highlights the possible mechanisms of switching among the lifestyles of fungi based on recent findings and discusses the factors affecting plant fungal interactions. It also underlines the need for studying this important facet of plant–fungal interactions in depth which may in future help to fetch more advantages and to avoid the severe consequences in agriculture and other related fields.

Curcumin nanoparticles: physico-chemical fabrication and its in vitro efficacy against human pathogens

Curcumin is one of the polyphenols, which has been known for its medicinal use since long time. Curcumin shows poor solubility and low absorption, and therefore, its use as nanoparticles is beneficial due to their greater solubility and absorption. The main aim of the present study was the formation of curcumin nanoparticles (Nano curcu), evaluation of their antibacterial activity against human pathogenic bacteria and formulation of Nano curcu-based cream. We synthesized Nano curcu by sonication method. The synthesis of Nano curcu was assessed for their solubility in water and by UV–visible spectrophotometry. Further, the nanoparticles were characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, nanoparticle tracking and analysis, and zeta potential analysis. In vitro antibacterial activity of Nano curcu was evaluated against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. The cream containing Nano curcu was found to be effective against human bacterial pathogens and hence can be used for treatment of bacterial diseases.

Interaction of copper nanoparticles and an endophytic growth promoter Piriformospora indica with Cajanus cajan

BACKGROUND In recent years, agro-bionanotechnology has paved the way towards revolutionizing current practices in the food and agricultural fields. In the present study, the effect of copper nanoparticles (CuNPs) alone and in combination with the growth-promoting fungus Piriformospora indica on 2-week-old seedlings of Cajanus cajan was evaluated. Gelatin-coated stable CuNPs were synthesized by the chemical reduction method using hydrazine hydrate as a reducing agent. RESULTS CuNPs were characterized by using UV-visible spectroscopy, zeta potential measurement and transmission electron microscopy. The nanoparticles were found to be quite spherical with a diameter within the range 40 ± 10 nm. After the application of CuNPs and P. indica to the host plant C. cajan, the vitality of plants was determined using a Handy-PEA (plant efficiency analyzer) instrument. Handy-PEA analysis (which measures chlorophyll a fluorescence) indicated that seedlings inoculated with a combination of CuNPs and P. indica were the healthiest and also showed maximum vitality as compared to seedlings inoculated with CuNPs or P. indica alone. CONCLUSION These results suggest that CuNPs in combination with P. indica can serve as a nanobiofertilizer for enhancement of the growth and productivity of C. cajan.