Senna alata leaves display various biological activities as a result of their rhein and phenolic composition. The objective of this study was to develop bioactive de-chlorophyll rhein-rich S. alata extracts. The rhein content was quantified using a validated high-performance liquid chromatography–diode array detection (HPLC–DAD) method. The best process parameters for maximizing rhein were established using ultrasound-assisted extraction (UAE). The optimal conditions for the parameters were determined using the Box–Behnken design (BBD); 95% v/v ethanol was used as the extraction solvent at 59.52 °C for 18.4 min with a solvent-to-solid ratio of 25.48:1 (mL/g) to obtain the predicted value of rhein at 10.44 mg/g extract. However, the color of the rhein-rich extract remained dark brown. For the removal of chlorophyll, liquid–liquid extraction with vegetable oils and adsorption with bleaching agents were employed. The bleaching agents were significantly more effective at removing chlorophyll and had less of an effect on the reduction in rhein content than vegetable oils. The presence of rhein and phenolics in the de-chlorophyll extracts might be responsible for their antioxidant, anti-inflammatory, and antibacterial activities. These findings indicate that rhein-rich extract and its de-chlorophyll extracts possess sufficient biological activities for the further development of cosmeceuticals and pharmaceuticals.

The present review explores the growing interest in the techniques employed for extracting natural products. It emphasizes the limitations of conventional extraction methods and introduces superior non-conventional alternatives, particularly ultrasound-assisted extraction. Characterization and quantification of bioactive constituents through chromatography coupled with spectroscopy are recommended, while the importance of method development and validation for biomarker quantification is underscored. At present, electrospun fibers provide a versatile platform for incorporating bioactive extracts and have extensive potential in diverse fields due to their unique structural and functional characteristics. Thus, the review also highlights the fabrication of electrospun fibers containing bioactive extracts. The preparation of biologically active extracts under optimal conditions, including the selection of safe solvents and cost-effective equipment, holds promising potential in the pharmaceutical, food, and cosmetic industries. Integration of experimental design into extraction procedures and formulation development is essential for the efficient production of health products. The review explores potential applications of encapsulating natural product extracts in electrospun fibers, such as wound healing, antibacterial activity, and antioxidant properties, while acknowledging the need for further exploration and optimization in this field. The findings discussed in this review are anticipated to serve as a valuable resource for the processing industry, enabling the utilization of affordable and environmentally friendly, natural, and raw materials.

Senna alata leaf is used as an active ingredient in various Ayurvedic preparations due to its bioactive components. This study examined the effect of extracting solvents on total phenolic and rhein contents as well as antioxidant and anti-inflammatory capacities in S. alata leaf extracts. 95% v/v and 50% v/v ethanol (EtOH) solutions were used as extracting solvents. In spite of its lower extraction yield, 95% EtOH extract with a lower moisture content should be considered more microbiologically stable than 50% EtOH extract. As a result of the analysis using thin-layer chromatography (TLC), Fourier-transform infrared (FTIR) spectrophotometry, and high performance liquid chromatographic diode array (HPLC-DAD), phytochemicals including anthrones, coumarins, and anthraquinones were found in both extracts. Additionally, the 95% EtOH extract possessed higher phytochemical contents and biological activities than the 50% EtOH extract. Thus, the 95% v/v EtOH was a powerful extracting solvent for preparation of S. alata leaf extractscontaining high contents of phenolics and rhein, together with antioxidant and anti-inflammatory activities.