Immunomodulatory activity of Bryonia alba 6C and 30C in sheep red blood cell-immunised mice: Insights from humoral and delayed-type hypersensitivity responses

Background: Malnutrition and infectious diseases compromise immune responses, increasing vulnerability to infections. The introduction of plant-derived immunomodulators, such as Bryonia alba (Bry. alba), is attracting attention due to their lower side effects compared with chemical drugs. In Homoeopathy, Bry. alba has long been utilised to treat a wide range of illnesses, including viral infections, and is recognised for its immunomodulatory properties. Objectives: To evaluate the immunomodulatory effects of Bry. alba 6C and 30C potencies on humoral and delayed-type hypersensitivity (DTH) in sheep red blood cell (SRBC)-immunised BALB/c mice. Materials and methods: Fifty BALB/c mice were divided into five groups, receiving either distilled water, SRBC control vehicle, or Bry. alba at 6C and 30C. After SRBC immunisation, the humoral immune response was evaluated by haemagglutination (HA) titre assay, and the DTH response was determined by measuring paw volume following SRBC challenge. Results: Bry. alba 30C significantly increased the primary antibody titre compared with the SRBC control on day 21 (p = 0.012) and the secondary antibody titre on day 27 (p = 0.008). The antibody titres in the Bry. alba 30C group were also significantly higher than those in the vehicle control group on both day 21 and day 27 (p < 0.001 for both comparisons). In the DTH assay, both Bry. alba 6C and 30C significantly reduced the paw volume ratio at 24 h compared with the SRBC control (p = 0.011 and p = 0.004, respectively). The paw volume ratios were also significantly lower than those in the vehicle control group (p = 0.045 and p = 0.019, respectively). No significant difference was observed between the Bry. alba 6C and 30C groups. Conclusion: Bry. alba demonstrated significant preclinical immunostimulatory effects, particularly at the 30C potency, by significantly enhancing humoral immune responses and reducing inflammation, demonstrating its potential for use in homoeopathic therapy as a natural immunomodulator.