Which herb is immunomodulatory, hypotensive, and antitumor, used as adjunctive cancer therapy and to support the immune system?

• A. Vitex agnus-castus
• B. Withania somnifera
• C. Viscum album
• D. Vinca major

Answer: (C)

Viscum album (mistletoe) is known for both immunomodulatory effects and direct anti-tumor activity, and it is used as adjunctive cancer therapy to support the immune system. Mistletoe extracts stimulate immune cells such as natural killer cells and macrophages and increase cytokine activity, helping the body's defenses respond to cancer. They also contain compounds like mistletoe lectins that can directly promote tumor cell death and inhibit tumor growth. In clinical use, mistletoe preparations are often given to help bolster immune function and improve quality of life for cancer patients, and they may cause hypotensive effects in some individuals. The other herbs listed don’t fit all three described roles as clearly: vitex agnus-castus is mainly used for hormonal regulation; withania somnifera can modulate immunity and has some anti-tumor research but is not classically an adjunctive cancer therapy with this exact profile; and vinca major is notable for its alkaloids used in chemotherapy rather than as an immune-supportive botanical.