Withania somnifera is an important medicinal plant traditionally used in the treatment of many diseases. The present study was carried out to characterize the phenolic acids, flavonoids and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging activities in methanolic extracts of W. somnifera fruits, roots and leaves (WSFEt, WSREt and WSLEt).
Hypothesis. Withania somnifera is an herb with antioxidant, anti-inflammatory, anticancer, antistress, and adaptogenic properties. Previous studies have shown its antistress effects in animals. Traditional Indian medicine has used it for centuries to alleviate fatigue and improve general well-being.
Withania coagulans (W. coagulans) is well-known in herbal medicinal systems for its high biological potential. Different parts of the plant are used against insomnia, liver complications, asthma, and biliousness, as well as it is reported to be sedative, emetic, diuretic, antidiabetic antimicrobial, anti-inflammatory, antitumor, hepatoprotective, antihyperglycemic, cardiovascular, immuno-suppressive and central nervous system depressant. Withanolides present in W. coagulans have attracted an immense interest in the scientific field due to their diverse therapeutic applications. The current study deals with chemical and biological evaluation of chloroform, and n-butanol fractions of W. coagulans. The activity-guided fractionation of both extracts via multiple chromatographic steps and structure elucidation of pure isolates using spectroscopies (NMR, mass spectrometry, FTIR and UV-Vis) led to the identification of a new withanolide glycoside, withacogulanoside-B (1) from n-butanol extract and five known withanolides from chloroform extract [withanolid J (2), coagulin E (3), withaperuvin C (4), 27-hydroxywithanolide I (5), and ajugin E (6)]. Among the tested compounds, compound 5 was the most potent α-glucosidase inhibitor with IC50 = 66.7 ± 3.6 µM, followed by compound 4 (IC50: 407 ± 4.5 µM) and compound 2 (IC50: 683 ± 0.94 µM), while no antiglycation activity was observed with the six isolated compounds. Molecular docking was used to predict the binding potential and binding site interactions of these compounds as α-glucosidase inhibitors. Consequently, this study provides basis to discover specific antidiabetic compounds from W. coagulans.
The present work studies the profiling of phenolic bioactive and in vitro biological (anticancer, antioxidant, and antimicrobial) activities of different solvent extracts from Withania
somnifera fruit. Anticancer activity was performed using potato-disc assay and Agrobacterium tumefaciens. While antibacterial and antifungal evaluation was done by using disc diffusion method against bacterial (Staphylococcus aureus, S. epidermidis, Escherichia coli, and
Klebsiella pneumonia) and fungal (Aspergillus flavus and Fusarium oxysporum) strains.
Among different extraction solvents used, n-hexane extract exhibited the highest inhibition of
tumour initiation (64%), whereas ethyl acetate (15%) was the lowest by using potato-disc
assay. Highest total phenolic and total flavonoid contents were noted for methanolic (69.10
GAE mg/g DW%) and n-hexane (29.45 CE mg/g DW%) extracts, respectively. For antioxidant potential, 2,2,1-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging (IC50) and reducing power EC50 were noted to be superior (0.6 and 2.0 mg/mL, respectively) for n-hexane
extract. All the tested extracts showed considerable antibacterial and antifungal activity with
the highest growth inhibition zones for K. pneumoniae (31.70 mm) and A. flavus (27.09 mm)
were shown by n-hexane extract. High Performance Liquid Chromatographic (HPLC) analysis of individual phenolics (gallic acid, 2,288.48 mg/kg) indicated the highest contents of these
compounds in n-hexane extract, which might explain the potent biological activities of this
extract. Our findings revealed that the bioactive present in the tested fruit had significant
potential as anticancer, antibacterial, and antifungal agents. Further studies are needed to
elucidate the mechanism of actions of isolated bioactive against specific diseases such as
cancer, especially in the case of n-hexane fraction.