## **Core Concept**
The anti-inflammatory action of steroids is primarily mediated through their influence on the arachidonic acid pathway and gene expression. Steroids, specifically glucocorticoids, play a significant role in reducing inflammation by modulating the production of pro-inflammatory mediators. This is achieved through the induction of anti-inflammatory proteins and the inhibition of pro-inflammatory genes.

## **Why the Correct Answer is Right**
The correct answer, **Inducible Nitric Oxide Synthase (iNOS) and Phospholipase A2**, involves key enzymes in the inflammatory process. Glucocorticoids inhibit the expression of **iNOS**, which is responsible for the production of nitric oxide (NO), a potent pro-inflammatory mediator. Additionally, steroids inhibit **Phospholipase A2**, an enzyme crucial for the liberation of arachidonic acid from membrane phospholipids, thereby reducing the production of prostaglandins and leukotrienes, which are key players in the inflammatory response.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because while steroids do influence various pathways, the direct inhibition of inducible Nitric Oxide Synthase and Phospholipase A2 is more specifically related to their anti-inflammatory effects.
- **Option B:** This option is incorrect as it does not directly relate to the primary mechanism of anti-inflammatory action of steroids.
- **Option D:** This option is incorrect because, although related to inflammation, it is not the most accurate representation of the primary target for the anti-inflammatory action of steroids.

## **Clinical Pearl / High-Yield Fact**
A crucial point to remember is that glucocorticoids exert their anti-inflammatory effects mainly by inducing the production of **lipocortins**, which inhibit **phospholipase A2**, and by reducing the expression of **pro-inflammatory cytokines** and **iNOS**. This results in decreased production of arachidonic acid metabolites and NO, leading to reduced inflammation.

## **Correct Answer:** C. Phospholipase A2.