Rheumatoid arthritis (RA) is common autoimmune disease characterised by chronic inflammation in the joints that mainly affects the small diarthrodial joints of the hands and feet that ultimately leads with marked destruction of cartilage and underline bone. It affects about 1 % of the world population, females are more prone to develop arthritis than men [1]. As mentioned above RA is autoimmune disease, it means auto-antigens such as Rheumatoid factor (RF), Anti-collagen type II (a-CII), Anti-cyclic citrullinated peptide antibody (a-CCP) etc. are formed which act against own body cells/tissues [1]. Synoviocytes are resident macrophages of joint that on activation releases various inflammatory mediators such as cytokine IL-1β and TNF-α and oxygen/nitrogen free radicals (ROS/NOS). ROS/RNS having unpaired electron which causes significant damage to cell structures, and cumulate into oxidative stress [2]. In this regard, these inflammatory mediators and ROS/RNS is primarily intricate in the onset of pain, inflammation and development of disease [3], [4]. Expression of these cytokines is under the control of transcription factor NF-kB [5]. So, targeting the cytokine and ROS might signify a proper way to control the disease progression.

To date, using of allopathic conventional drugs such as Methotrexate (MTX) provide symptomatic relief and cause serious side effects [6]. In this regard, new therapeutic strategies are important. Nowadays, Nanotechnology paying much attention and has become one of the encouraging research field, bring a vital improvement into material, device development. It is use in the area of medicine, chemistry, agriculture, information technology, electronics, heavy industry and consumer goods [7]. It can foray into singularization of medications either by making a new drug or by developing new delivery technique with already use in drug by enhancing therapeutic efficacy, specificity of corresponding drugs [8].

Ocimum sanctum (holy basil) is a well-known medicinal plant used as a folk medicine in treating arthritis and asthma. It has also been employed in treating various diseases such as anxiety, back pain, cardiac disorders, cough, dysentery etc. Many chemical constituents like Caffeic acid and Rosmerinic acid, oleanolic acid, β caryophyllene, etc., are present in Ocimum sanctum. Recently study from Ahmad et al.,2018 shown that Ocimum sanctum contains promising molecule having anti-inflammatory, analgesic and potential anti-arthritic activity [9]. These are essential for synthesizing nanoparticles therapeutic properties and are used as pharmaceutical ingredients to treat diseases. Our purpose for the current research is broadly based on value addition to agriculture products by simple techniques. We used Ocimum sanctum leaves to synthesize narrow polydisperse ZnO nanoparticles (ZnO NPs). Discovery of therapeutic nanoparticles (NPs) carries a deep impact in medical sciences and unties a new therapeutic window for the treatment of inflammatory disorders [10]. Synthesized ZnO NPs characterized by UV–visible spectroscopy, Dynamic light scattering, high-resolution transmission electron microscope (HR-TEM), and XRD and investigate the effect of ZnO NPs on CIA rat.