Background: Whey is a by-product of cheese production; it is one of the components which separate from milk after curdling, when rennet or an edible acidic substance is added. Whey protein (WP) is typically a mixture of beta-lactoglobulin (-lg) (~65%), alpha-lactalbumin (-la) (~25%), and serum albumin (~8%), which are soluble in their native culture forms and it has the highest biological value of any known protein.
Materials and Methods: Comparative studies were performed to assess the efficacy of WP, -la and -lg (100, 200 and 300 mg/Kg, Os) in tow animal models: hot plate-induced thermal pain and
carrageenan-induced paw inflammation and antioxidant activities in rats.
Results: Results revealed that the higher doses of WP, -la and -lg caused significant analgesic effect versus paracetamol (50 mg/Kg) especially after 3 hr-post treatment (potency: 3.01, 3.21 and 3.45, respectively). Whereas after 4hr., WP and -la (300 mg/Kg) treatments had similar analgesic effect. While, -lg (200 and 300 mg/Kg) was the most potent in its analgesic effect when compared with the paracetamol and the other treated groups.
In acute anti-inflammatory activity, it was shown that the two doses of -lg (100 and 200 mg /kg) significantly reduced paw oedema after 30 min (potency versus indomethacine was: 1.11 and 1.13). While after 4 hr, the higher dose of -la (300 mg/Kg) had similar effect to that induced by the two doses of -lg (200 and 300 mg/Kg) treatment. The potency of the two doses (100 and 200 mg/Kg) of WP nearly had similar anti-inflammatory effect (time dependent effect).
All treatments caused significant antioxidant activity when compared with the control group. The increase in SOD value was dose dependent manner. In which, 300 mg/Kg showed remarkable increase in SOD level with the following rank, -la > -lg > WP > indomethacine (5 mg/Kg) treated groups. These results indicated that -lg produced powerful analgesic and anti-inflammatory activities than - la and WP. As well as, -la possess strong antioxidant activity than -lg and WP treatments. Conclusion: It suggested that -lg, -la and WP could be used safely as natural analgesic and anti- inflammatory drug instead of NSAIDs, which have side effects when used for chronic disorders.