Preparation and evaluation of a polymeric nanocarrier for thymoquinone extracted from nigella sativa l Seed oil a thesi

Abstract

Nigella sativa L. Is an annual herb belonging to the family Ranunculaceae. It is commonly known as the black seed or black cumin. It is traditionally used for culinary and medicinal purposes in the Indian Sub-continent, Arab Countries and other parts of the world. The seed oil of Nigella sativa has been used in Arab traditional medicine for the treatment of arthritis, lung diseases and hypercholesterolemia. Studies have shown that the biological activities of Nigella sativa seeds are due to its essential oil component thymoquinone, which is of about 30-48%. Large number studies on thymoquinone has revealed that thymoquinone possess anti-inflammatory, anti-oxidant and antimicrobial activities. However, the usage of thymoquinone in clinical applications has not yet been brought to practice due to its low stability and bioavailability. Most drugs, especially the nutrients or components which are extracted from natural sources such as thymoquinone are hydrophobic in nature and are having poor oral bioavailability. Improving the bioavailability of thymoquinone that has the properties to efficiently prevent diseases, would greatly contribute for its clinical applications. Hence an effective formulation to develop a carrier to improve the bioavailability and stability of thymoquinone is the need of the hour. In this work, a biodegradable polymeric carrier made of water soluble Low Molecular Weight (LMW) or Low Molecular Mass (LMM) chitosan and Poly(ethylene glycol) (PEG) were used for nanoencapsulation and the formulated nanocapsules were evaluated for its stability, bioavailability and therapeutic efficiency. Presence of thymoquinone in the black seed oil was identified using differential pulse polarogram of cyclic voltammetric studies. Thymoquinone was extracted from the cold pressed Nigella sativa L. Seed oil by solvent separation method and the separated thymoquinone was identified and confirmed using Thin Layer Chromatographic (TLC) technique, UV-visible spectrophotometer and High Performance Liquid Chromatography