Strengthening the Immune System (The Body's Internal Battle: Immune Health)

A separate double blind, randomized, placebo-controlled study confirmed vitamin C’s ability to assist immune health, noting the vitamin C from an encapsulated fruit and vegetable juice powder concentrate may have been responsible for a 30-percent increase in circulating gamma delta-T cells and a 40-percent reduction in DNA damage in lymphocytes, as well as significantly increased plasma levels of vitamin C beta-carotene, lycopene and lutein.¹³

In contrast, a 2007 study found an antioxidant supplement comprising of beta-carotene (9 mg/d), vitamin C (1,500 mg/d), vitamin E (130 mg/d), zinc (45 mg/d), selenium (76 mcg/d) and garlic (150 mg/d) “significantly increased levels of vitamin C, vitamin E, beta-carotene and selenium, but no change in immune responses, serum AC or plasma F(2)-isoprostanes.”¹⁴

Echinacea is a flower widely used as a supplement for immune health. In a randomized, double blind, placebo-controlled, prospective four-week clinical trial, 48 healthy female volunteers, 22 to 51 years old, were randomly assigned to one of six groups: standardized extract of E. purpurea (EP); ultra-refined E. purpurea/E. angustifolia (urEPA); E. purpurea/E. angustifolia (EPA); E. purpurea/E. angustifolia plus larch arabinogalactan (EPALA); larch arabinogalactan (LA); or placebo.¹⁵ Complement properdin increased by 21 percent in the EPA group (P<0.05) and by 18 percent in the EPALA group (P<0.05), compared to the placebo group (P>0.05). SF-36 showed improvements in overall physical health, vitality and emotional health in the same two groups (EPA and EPALA). Researchers concluded an increased complement properdin may be an indication of one aspect of immune system stimulation in patients treated with either E. purpurea/E. angustifolia or E. purpurea/E. angustifolia plus larch arabinogalactan.

Echinacea contains arabinogalactan, a phytochemical that can also be extracted from the timber of the larch tree. A study published in International Immunopharmacology used an arabinogalactan polysaccharide, G1-4A, from the stem of Tinospora cordifolia, for protection against endotoxin-induced sepsis.¹⁶ There was 100-percent protection against LPS-induced mortality in mice pretreated with G1-4A. G1-4A was shown to bind to the murine macrophages leading to their activation and reciprocally inhibited binding of LPS to macrophages. Following treatment with G1-4A, there was a small increase in serum TNF-alpha and IL-1beta levels. However, challenge with LPS elicited significantly reduced levels of TNF-alpha in G1-4A pretreated mice as compared to the controls while the level of soluble TNFR was enhanced. An increase in serum IL-1beta, IL-6, IFN-gamma levels and decrease in that of IL-10 was observed following challenge with LPS in mice pretreated with G1-4A as compared to the controls. In addition, G1-4A also modulated the release of nitric oxide (NO) by murine macrophages. A similar phenomenon was observed in a human monocytic cell line, U937. G1-4A appeared to induce tolerance against endotoxic shock by modulation of cytokines and NO.