Synthesis of anthraquinone-capped TiO2 nanoparticles using R. emodi roots: preparation, characterization and cytotoxic potential

Biomacromolecule-based nanocarrier strategies to deliver plant-derived bioactive components for cancer treatment: A recent review

The quest for safe chemotherapy has attracted researchers to explore anticancer potential of herbal medicines. Owing to upsurging evidence of herbal drug's beneficial effects, hopes are restored for augmenting survival rates in cancer patients. However, phytoconstituents confronted severe limitations in terms of poor absorption, low-stability, and low bioavailability. Along with toxicity issues associated with phytoconstituents, quality control and limited regulatory guidance also hinder the prevalence of herbal medicines for cancer therapy. Attempts are underway to exploit nanocarriers to circumvent the limitations of existing and new herbal drugs, where biological macromolecules (e.g., chitosan, hyaluronic acid, etc.) are established highly effective in fabricating nanocarriers and cancer targeting. Among the discussed nanocarriers, liposomes and micelles possess properties to cargo hydro- and lipophilic herbal constituents with surface modification for targeted delivery. Majorly, PEG, transferrin and folate are utilized for surface modification to improve bioavailability, circulation time and targetability. The dendrimer and carbon nanotubes responded in high-loading efficiency of phytoconstituent; whereas, SLN and nanoemulsions are suited carriers for lipophilic extracts. This review emphasized unveiling the latent potential of herbal drugs along with discussing on extended benefits of nanocarriers-based delivery of phytoconstituents for safe cancer therapy owing to enhanced clinical and preclinical outcomes without compromising safety.

Identification and low-frequency vibrational analysis of three free anthraquinones via terahertz spectroscopy

In this study, terahertz time-domain spectroscopy (THz-TDS) was used to obtain the terahertz absorption spectra of three free anthraquinones (Chrysophanol, Emodin, Physcion) in the frequency range of 0.2-4.3 THz. The results show that terahertz spectroscopy is an effective detecting such compounds. Meanwhile, the theoretical spectrum using density functional theory calculations agrees well with the experimental spectrum. A modal decoupling method was used to identify each low-frequency vibrational mode and determine the average contribution of different atoms and groups. Modal decoupling provides a better understanding of molecules' mixed vibrational modes and enables quantifying the atoms' vibrational contributions. Results show that the substituent group facilitates the transition between the fundamental vibrational modes; subsequently, the substituent group shifts the vibrational centre of gravity of the three molecules and affects the vibrational contribution of hydrogen bonds. Furthermore, insignificant Emodin absorption is related to the nearly symmetrical structure formed by the substituents. The feasibility of terahertz analysis of differential molecular structures has also been confirmed.

Structural and physicochemical properties of Rheum emodi mediated Mg(OH)2 nanoparticles and their antibacterial and cytotoxic potential

In the present investigation, Rheum emodi roots extract mediated magnesium hydroxide nanoparticles [Mg(OH)2 NPs] through the bio-inspired experimental technique were synthesised. Mg(OH)2 NPs were characterised by using various characterisation techniques such as field emission scanning electron microscopy, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and ultraviolet-visible spectroscopy. The formation of Mg(OH)2 NPs was confirmed by X-ray diffraction. The structural analysis confirmed the hexagonal crystal symmetry of Mg(OH)2 NPs with space group P-3m1 and space group no. 164 using the Rietveld refinement technique. TEM micrographs illustrated the nano-size formation of Mg(OH)2 NPs of spherical shape and size ∼14.86 nm. With the aid of FTIR data, plant metabolites such as anthraquinones have been identified as a stabilising and reducing agent for the synthesis of biogenic Mg(OH)2 NPs. The synthesised Mg(OH)2 NPs showed antimicrobial and cytotoxic potential against Gram-negative and Gram-positive bacteria such as Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923) and MDA-MB-231 human breast cancer cell lines.

Efficiency of the Green Synthesized Nanoparticles as New Tools in Cancer Therapy: Insights on Plant-Based Bioengineered Nanoparticles, Biophysical Properties, and Anticancer Roles

The aim of this work is to review the current knowledge on the efficiency of plant-based synthesized nanoparticles in medical field, particularly in the prevention, diagnosis, and therapy of cancer. For this, we examine the advantages of nanotechnological tools. Besides, a particular attention was given to understand the mechanism by which plant-based bioengineered nanoparticles can interact with components of cancerous cells. Green biosynthesized nanoparticles seem to be novel tool for prognostic biomarkers for cancer diagnosis and drug delivery in tumor cells. They can act either by leading to the damage of tumor cells, or by the protection of healthy cells, via mechanisms involving the specific properties of nanoparticles themselves and the antioxidative and antitumor properties found in plants. However, special attention should be given to the choice of plant species, extracts, and the toxic dose of some phytocompounds during the biosynthesis process. An increase in metal or trace element release from metal and metal oxide biosynthesized nanoparticles can lead to greater oxidative stress, which is associated with higher risk of cancer. Hence, plant-based nanosystems should be more developed to increase their specific targeting of the cancerous cells, in order to preserve the healthy ones.

Anthraquinone: a promising scaffold for the discovery and development of therapeutic agents in cancer therapy

Cancer, characterized by uncontrolled malignant neoplasm, is a leading cause of death in both advanced and emerging countries. Although, ample drugs are accessible in the market to intervene with tumor progression, none are totally effective and safe. Natural anthraquinone (AQ) equivalents such as emodin, aloe-emodin, alchemix and many synthetic analogs extend their antitumor activity on different targets including telomerase, topoisomerases, kinases, matrix metalloproteinases, DNA and different phases of cell lines. Nano drug delivery strategies are advanced tools which deliver drugs into tumor cells with minimum drug leakage to normal cells. This review delineates the way AQ derivatives are binding on these targets by abolishing tumor cells to produce anticancer activity and purview of nanoformulations related to AQ analogs.

Biosynthesis of hematite nanoparticles using Rheum emodi and their antimicrobial and anticancerous effects in vitro

The synthesis of magnetic Hematite nanoparticles (α-Fe2O3) via green route has been a long lasting challenge for the scientific and technological fascination of many researchers. In the present investigation, iron oxide nanoparticles (α-Fe2O3) were synthesized using Rheum emodi roots in a cost effective and ecofriendly method. Their physicochemical property orchestration involved techniques such as UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), Field emission scanning electron microscopy (FESEM), Energy-dispersive X-ray (EDX), X-ray diffraction (XRD), Thermogravimetric Analysis (TGA), Vibrating sample magnetometer (VSM), and Atomic force microscopy (AFM). Through TEM, FESEM and AFM analysis, α-Fe2O3NPs were confirmed spherical in shape and the average diameter of particle is ~12 nm as depicted through TEM image. Thermal property was investigated by TGA. Magnetic behavior was observed in R. emodi mediated α-Fe2O3NPs by magnetic hysteresis measurements. FTIR analysis revealed the presence of anthraquinones in R. emodi roots extract which play the central role in stabilization of the α-Fe2O3NPs. Further, the crystalline nature of the nanoparticle sample was determined with XRD experiment and SAED fringes calculation. The crystal was also confirmed with Rietveld refinement of XRD profile fitted with R-3c model Additionally, magnetic interaction with bacterial cell wall showed antimicrobial property against Escherichia coli, Gram-negative and Staphylococcus aureus, Gram-positive species. The approach transcribed in this paper reveals a novel methodology that utilizes α-Fe2O3 NPs to initiate apoptosis and inhibition of cervical cancer cells.

Biological synthesis of silver nanoparticles using Rheum ribes and evaluation of their anticarcinogenic and antimicrobial potential: A novel approach in phytonanotechnology

This paper reports the anticarcinogenic and antimicrobial properties of silver nanoparticles (Ag NPs) obtained by green synthesis using the extract of Rheum ribes (R. ribes), a medicinal plant. For the synthesis of Ag NPs, the ethanolic extracts of R. ribes were used as a reducing as well as the stabilizing agent. For the characterization of Ag NPs, advanced analytical methods such as transmission electron microscopy (TEM), X-Ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and UV-vis spectrophotometry were performed. The synthesized Ag NPs obtained from R. ribes were evaluated as a cytotoxic agent against MDA-MB-231 breast carcinoma cell line. The IC₅₀ values of the nanoparticles were ranged from 165 to 99 μg/mL against MDA-MB 231 cell line for 24 h and 48 h, respectively. The results show that the use of Ag NPs at low concentrations show the toxic effect in the cancer cells. In addition, the results of experiments on gram-positive (Staphylococcus aureus (S. aureus), Methicillin-resistant Staphylococcus aureus (MRSA) and Bacillus subtilis (B. subtilis)) and gram-negative (Escherichia coli (E. coli)) bacteria showed that the Ag NPs had high antimicrobial activity. The results suggest that Ag NPs can be developed as potential anticancer and antibacterial agents.