South Asian Journal of Experimental Biology

In vitro antimicrobial, antioxidant and molecular study of Nostoc punctiforme isolated from the rice field

Jayanta Kumar Sahu — 2024-03-03

Cyanobacteria are photosynthetic prokaryotes and are reservoir of bioactive compounds having substantial antimicrobial and antioxidant activity. They serve as a rich source of structurally novel and biologically active metabolites, holding great potential for various pharmaceutical applications. The aim of this study is to investigate in vitro antimicrobial and antioxidant activities of the extracts of Nostoc punctiforme, a filamentous heterocystous cyanobacterium predominant in the rice fields of Lakhanpur (Bargarh District), Odisha. The heterocystous cyanobacteria was collected from rice field and identified by means of morphological and molecular approach (Nostoc punctiforme Jbr02). Subsequently, in vitro antimicrobial and antioxidant activity was assayed using acetone, methanol, and benzene extract. The cyanobacterial extracts established important antimicrobial actions against bacterial and fungal pathogens with significant MIC values from 62.5 to 500 μg/ml. The methanolic extract displayed better inhibitory activities against both V. Cholerae and P. verrucosun with the MIC value 62.5μg/ml while no such activity was recorded in benzene extract against B. subtilis, A. niger and F. oxysporum pathogens. The antioxidant study, depicted that the methanolic extract showed relatively higher antiradical activity of IC50 542±0.012 μg/ml among the three solvents. The Ferric reducing assay result was also maximum in methanolic extract (0.478±0.78) as compared to benzene and acetone extract. These findings infer that Nostoc punctiforme has potential antimicrobial and antioxidant activity, unveiling its potential as a valuable source of bioactive compounds. Thus, N. punctiforme in specific and cyanobacteria in general are one of the most promising candidates for commercial applications.

Enhanced bio-extraction of medicinally important plants using xylano-pectinolytic enzymes produced concurrently by Bacillus pumilus AJK

Nancy Sikodia — 2024-03-03

Medicinal plant extracts obtained by chemical methods have drawbacks such as high chemical, time and energy consumption, byproduct formation, lower quality and efficiency, high toxicity and lead to degradation of thermo-sensitive bioactive compounds. The purpose of this study was to investigate the ability of crude xylano-pectinolytic enzymes concoction in bio-extraction of medicinally important plant extracts, in order to reduce the use of chemical solvents for extraction. In this regard, various conditions including material to liquid ratio (MLR), enzyme dose, treatment time and stirring speed were optimized and several physico-chemical parameters including pH, total soluble solid (TSS), total dissolved solid (TDS), clarity, reducing sugar, polyphenolic content, viscosity and filterability were studied. The bio-extraction efficiency was found to be best at material-to-liquid ratio (MLR) 1:5-1:6 (g/mL), enzyme dose range between 15:60 to 20:80 (IU/g), treatment time range between 180- 240 min and stirring speed range between 50-60 rpm. Enzymatic extraction of medicinal plants resulted in 7-17% increase in clarity, 27-50% increase in TSS, 3-42% increase in reducing sugars, 20-42% increase in polyphenolic content, 13-53% increase in TDS, 15-22% increase in filterability along with decrease of 3-5% in pH and 18-43% in viscosity. Hence, this eco-friendly bio-extraction strategy could reduce the chemical usage, along with improvement of the physico-chemical properties of medicinally important extracts. The technique also enables the application of greener chemistry in the pharmaceuticals to optimize cleaner methods of extraction. This is the first report manifesting bio-extraction of medicinally important plant extracts using crude xylano-pectinolytic enzymatic concoction produced by a single bacterial isolate.

Sphingosine kinase 1, a potential drug target for breast cancer therapy in in silico models: A molecular docking verification

Prabhavathy Govindarajan — 2024-03-03

An important aspect of breast cancer therapy is selection of drug targets in the proliferating cells. Only few studies have focused on spingoshine kinase1 (SphK1); a potential target present in the cancer cells to bind with drug molecules. The structure and physicochemical properties of SphK1 were retrieved. The information of top 12 anticancer drugs were collected from National Cancer Institute (NCI) database and considered as reference drugs based on their drug likeness properties. The drug likeness property values of these drugs are in the range of 0.001 to 2.33, -0.7 to 7.4, -2 to -5.5, 2 to 13, 1 to 6 and 33 to 205 respectively for water solubility, partition coefficient, molar solubility, hydrogen acceptor and donor counts and polar surface area. The values were compared with 15 experimental drugs which were taken from a published article. The range of drug likeness property values of both groups match with each other. SphK1 shows strong binding affinity to the experimental drugs in the range of -8.8 and -5.1. Herein, we describe an effective solution for treating breast cancer by targeting the tumor marker, SphK1.

Increased antibacterial activity of silver nanoparticles synthesized from leaf extract of Isodon coetsa

Kalpana Thakur — 2024-03-03

Application of nanotechnology for the synthesis of silver nanoparticles using plant extract can be a promising alternative to traditional chemical methods. Products of biological origin have less side effects, thus are safe for human health besides being cost-effective and pollution-free. Keeping in view this, the current work was designed for the environment- friendly production of silver nanoparticles (AgNPs) utilising Isodon coetsa acetone leaf extract. The effect of some important variables including incubation time, pH, AgNO3 concentration, temperature and volume of plant extract were examined for the optimum production of AgNPs. Synthesized nanoparticles were further characterized using atomic force microscopy (AFM), X-ray diffraction spectroscopy (XRD), and UV-visible absorption spectroscopy. In addition, the antibacterial potential of nanoparticles was also determined by agar-well diffusion method. The optimal conditions for synthesis of AgNPs achieved after 24 h of incubation at pH 9.0, 2mM AgNO3, 60°C temperature, and using 10% I. coetsa leaf extract. X-ray diffraction spectroscopy revealed that the size of the strongest peak for AgNPs was 9.5 nm, while atomic force microscopy confirmed their spherical shape with smooth surface without any pinholes or cracks. AgNPs showed excellent antibacterial action against Gram-positive and Gram-negative bacteria. The current study has contributed to the development of a simple and fast bioprocess for the synthesis of AgNPs of the appropriate size and form which also have increased antibacterial activity in comparison to crude extract. Therefore, the process of biogenically synthesised AgNPs from plants is a straightforward, commercially feasible, and environmentally benign approach that can be used in disease control while utilizing their important role as therapeutic agent for treating various ailments caused by pathogenic bacteria.

Inhibitory Potential of Tribulus terrestris on Calcium Oxalate Crystals, Struvite Crystals and Bacterial Pathogens: A Preliminary Investigation

Vignesh Senguttuvan — 2024-03-03

Kidney stone formation and recurring urinary tract infection (UTIs) are common among the general population. An alternative herbal treatment potential was investigated in this study. This study aims to investigate anti-urolithiasis efficacy of herbal Tribulus terrestris (TT) plant leaf extract in reducing the growth of calcium oxalate and struvite crystal using in vitro methods. In vitro antiurolithiatic potential of TT leaf extract was studied using nucleation, aggregation, and crystal formation assays in synthetic media and in synthetic urine samples. In vitro antiurolithiasis potential of Tribulus terrestris (TT) plant leaf extract was investigated at concentrations ranging from 100 to 1000 μg/ml. Initially, the principal phytochemical constituents of TT methanolic leaf extract was examined. Then antibacterial properties of TT plant leaf extract were tested against common urinary tract pathogens such as Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The results of the nucleation assay revealed that TT leaf extract reduced up to 55% of calcium oxalate (CaOx) crystallization and inhibits struvite crystal formation up to 85% with 5% (0.43 g) of TT extract. This study revealed a dose-dependent suppression of crystal formation by increased TT plant leaf extract dosage. The antibacterial activity of TT plant leaf extract is greater against E. coli than S. aureus. This anti-urolithiasis potential of TT plant extract can be used as an antidote for individuals who are prone to urinary crystal formation as well as to control urinary tract infections.

In vitro antimicrobial and antioxidant potential of Dodonaea viscosa Plant extracts against selected pathogenic isolates

Mamta Pundeer — 2024-03-03

Medicinal plants can be used in the development of new drugs in addition to serving as an indigenous source of new compounds with beneficial effects. The medicinal plants and their parts constitute an important wealth. They play a significant role in healthcare services. The main objective of the study was to investigate the antimicrobial activity, antioxidant activity and phytochemical analysis of Dodonaea viscosa Jacq. Extraction was carried out by cold percolation method. The antimicrobial activity and minimum inhibitory concentration of plant extracts was determined by agar well diffusion and resazurin dye method against various pathogenic isolates. Antioxidant activity of most effective extract was measured by DPPH and hydrogen peroxide method. Among all the extracts, acetone extract of D. viscosa showed highest activity against B. cereus (24.12±0.94 mm at 40 μl) followed by S. aureus (18.78±0.59 mm) and S. flexneri (17.50±0.50 mm). The lowest concentration required to inhibit the growth of B. cereus was 0.1562 mg/100μl. Phytochemical analysis of most effective acetone extract of D. viscosa revealed the presence of alkaloids, flavonoids, phenols, terpenoids, glycosides and saponins. D. viscosa acetone extract showed highest DPPH scavenging activity i.e. 80.81±0.24% at a concentration of 300 μg/ml of plant extract. The results indicated that the crude extracts of D. viscosa have a effective antimicrobial potential that provide a source for development of new drug which may be used for the medicinal purposes. Further studies are required to purify the responsible biochemical constituents of important plant materials and also to characterize so as to explore their potential fully.