Does the Pentose Phosphate pathway reduce or increase glutathione levels?

The Pentose Phosphate Pathway (PPP) primarily functions in the production of NADPH and ribose-5-phosphate. NADPH is crucial for reductive biosynthesis and serves as a reducing agent in various biochemical reactions, including the reduction of oxidized glutathione (GSSG) back to its reduced form (GSH). This process is essential for maintaining cellular redox homeostasis and protecting cells from oxidative stress.

When NADPH levels are adequate, the regeneration of reduced glutathione from its oxidized form can occur, thus contributing to increased levels of reduced glutathione within the cell. Therefore, the pathway itself typically supports the maintenance or enhancement of glutathione levels rather than leading to their reduction.

Thus, the assertion that the Pentose Phosphate Pathway reduces glutathione levels is not aligned with its biochemical role. The primary function of the PPP is to generate the necessary reducing equivalents (NADPH) that ultimately aid in maintaining or increasing the levels of reduced glutathione, which is critical for cellular defense against oxidative stress. This makes the option stating that the PPP reduces glutathione levels inaccurate.