Which anaphylatoxin is considered the most potent?

C5a is considered the most potent anaphylatoxin due to its strong ability to trigger inflammatory responses and recruit immune cells to sites of infection or injury. Anaphylatoxins are small peptide fragments produced during the complement activation process, and they play crucial roles in mediating inflammation and enhancing immune responses.

C5a has several biological activities that make it particularly effective: it promotes the release of histamine from mast cells and basophils, which contributes to increased vascular permeability and smooth muscle contraction. Additionally, C5a serves as a powerful chemotactic factor, drawing neutrophils, eosinophils, and other immune cells to sites of infection. This action is vital for mounting an effective immune response against pathogens.

In contrast, while C3a and C4a also act as anaphylatoxins and have some pro-inflammatory effects, their potency and ability to recruit immune cells are less pronounced compared to C5a. C5b, on the other hand, is not classified as an anaphylatoxin since it is involved in the formation of the membrane attack complex rather than direct inflammatory signaling.

In summary, the potency of C5a as an anaphylatoxin is due to its effective role in promoting inflammation