Anti-inflammatory Drugs # Lab 4 #

Permanent destruction 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: Hotness: Due to vasodilatation by effects of releasing of histamine, bradykinin and prostaglandin. Hotness: Due to increased blood flow.

Signs of inflammation Swelling: Pain: 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.

Phases of Inflammation 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.

Classification of the Inflammation Non – immunological : Induced by chemical irritants such as formalin Immunological : Induced by infections such as bacterial infection

Anti-inflammatory Drugs Steroidal Non-steroidal - Cortisone - Hydrocortisone - Acetaminophen - Aspirin

Steroids (SAIDs) - Containing steroid moiety in their sturcure Glucocorticoids (GC) Cortisone

Glucocorticoids (GC) Synthetic Natural - Cortisone - Betamethasone - Hydrocortisone - Betamethasone Dexamethasone - Predinsone Fluorinated Glucocorticoids Liver enzymes Prednisolone

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. -

GC inhibition 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

Side Effects : Moon face buffalo hump

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

GC inhibition phospholipase A2

Cyclooxygenese ( COX ) Isoforms : - Constitutive - Many tissues ( blood vessels stomach and kidney ) - inducible By inflammatory processes and mediators COX 3 has recently been described

Non-Steroidal Anti-inflammatory Drugs (NASID) Non-selective COX inhibitors selective COX2 inhibitors - Aspirin - Ibuprofen - Diclofenac - Meloxicam - Celecoxib - Rofecoxib

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 % = ــــــــــــــــــــــــــــــــــــــــ X 100 C inflammation LP RP Dose ___ C control T1 40 mg/kg vol. T2 80 mg/kg vol. T3 20 mg/kg hydro. T4 40 mg/kg hydro. Inflammation = RP - LP C - T Response % = ــــــــــــــــــــــــــــــــــــــــ X 100 C Response % >>>> Anti-inflammatory activity