Presentation on theme: "Anti-inflammatory Drugs # Lab 4 #. Inflammation: it is a biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells,"— Presentation transcript:
Inflammation: it is a biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation may ends with either : Complete healing of tissues Permanent destruction of tissues
Signs of inflammation Redness: Due to vasodilatation by effects of releasing of histamine, bradykinin and prostaglandin. Hotness: Due to increased blood flow.
Signs of inflammation Swelling: due to increased vascular permeability by the released mediators and increased the exudate in the inflammed area Pain: due to irritation of nerve ending by inflammation and the pressure of the swelling on the nerve ending.
Inflammatory mediators: –histamine –5-HT (serotonin) –Bradykinin –Prostaglandins (eg PGE2 ) –Interleukines –Substance P –Nitrous oxide Main inflammatory mediator
Phases of Inflammation Fluid phase (vascular phase): Increased vasodilatation leads to increased permeability of the vascular bed to plasma protein. - Increasing fluid will help in: 1- dilution of the irritant 2- increase conc. of antibodies from blood to inflamed area 3- supply nutrients to the immune cells.
Cellular phase (exudative phase): Involves migration of tissue macrophages and polymorphonuclear leukocytes (PMNL) to the inflamed area. Fibrous phase (proliferative phase): A new connective tissue (fibrous) containing fibroblast and capillaries is formed. Phases of Inflammation
Classification of the Inflammation Non – immunological : Induced by chemical irritants such as formalin Immunological : Induced by infections such as bacterial infection
Glucocorticoids (GC) Mechanism of Action : They act by indirect inhibition of the enzyme phospholipase A2 which activate synthesis of arachidonic acid with subsequent formation of prostaglandins. They induce synthesis of a protein “lipocortin-1” which has the inhibitory effect on phospholipase A2. - -
Side Effects : Immunosuppression Hyperglycemia due to increased gluconeogensis, insulin resistance, and impaired glucose tolerance ("steroid diabetes"); Steroid-induced osteoporosis: reduced bone density (osteoporosis, Osteoporosis, higher fracture risk, slower fracture repair) Redistribution of body fat: moon face, buffalo hump and truncal obesity. Adrenal insufficiency Muscle breakdown (proteolysis), weakness; reduced muscle mass and repair Anovulation, irregularity of menstrual periods Growth failure, pubertal delay Increased plasma amino acids, increased urea formation; Glaucoma due to increased cranial pressure
Non-Steroidal Anti-inflammatory Drugs (NASID) They don’t contain steroid moiety They also have analgesic and antipyretic activity
Mechanism of Action : NSAIDs inhibit synthesis of PGs which are the main factors Playing a role in the inflammaltion. Inhibit synthesis of PGs through inhibition of cyclooxygenase Enzymes which are responsible for production of PGs
Side Effects : Unwanted effects, owing largely to inhibtion of COX1 Particularly in the elderly and include : - Despepsia, nausea and vomiting, ulceration and gastric damage in chronic users, with risk of hemorrhage - Reversible renal insufficiency - Analgesic-associated nephropathy ( irreversible ) - Liver disorders, in high doses, e.g. acetaminophen
Measurement the activity of anti-inflammatory drugs - Method : Paw Oedema Method - Principle : induction a chemical inflammation by injecting an irritant ( formalin ) into rat’s paw - Objective : measure the anti-inflammatory activity of diclofenac and hydrocortisone with different doses )
-Procedure : 1- select 5 rats 2- inject each rat 1 ml urethane for anesthesia. 3- select one as control and inject the rest of them intraperitoneal rat 1 >>> control rat 2 >>> 40 mg/kg diclofenac rat 3 >>> 80 mg/kg diclofenac rat 4 >>> 20 mg/kg hydrocortisone rat 5 >>> 40 mg/kg hydrocortisone 4- after 1 hr, inject 0.1 ml formalin in each rat ( 2 to 5 ) into their paws >>> to induce inflammation. 5- after 1 hr, take the reading using the plythysmometer of each rat paw ( right and left ). 6- calculate the inflammation and response % for each drug.
Response % inflammat ion LPRPDose ___Ccontrol T140 mg/kg vol. T280 mg/kg vol. T320 mg/kg hydro. T440 mg/kg hydro. Inflammation = RP - LP Response % = ــــــــــــــــــــــــــــــــــــــــ X 100 C - T C Response % >>>> Anti-inflammatory activity