Cantharis 200c counters heat stress in germinating seeds of Vigna unguiculata (L) Walp

ABSTRACT

Background Thermal stress during early imbibitional phase of germination causes disruption of redox-homeostasis by increasing accumulation of ROS Reactive Oxygen species (assessed in terms of hydrogen peroxide) and significant reduction of antioxidative defense (assessed in terms of catalase and peroxidase) in germinating tissues of cowpea (Vigna ungiculata). It also induces oxidative damage to newly assembled membrane system by aggravating membrane lipid peroxidation [measured in terms of thiobarbituric acid reactive substances (TBARS)]. Cantharis is a homeopathic remedy used for treating burn injuries in humans. The objective is to see whether potentized Cantharis could ameliorate heat stress in germinating seeds of cowpea. Methodology Seeds, imbibed in water overnight, were divided into four groups (n=50/group) Control I (Water 200c), Control II (Ethanol 200c), treated with Cantharis 200c and untreated and unstressed. Water soaked seeds were dipped in control/drug solution for 5 min and then washed. Control II and Cantharis 200c were diluted with water 11000 to minimize the ethanol effect. Except the fourth group, all other groups were subjected to heat stress (450C for 8 hours). All the groups were allowed to germinate for 5 days in germination chamber at 25 ± 20C. Groups 1 and 2 (Control I and II) served as systematic negative controls throughout the experiment. Ten independent replications were performed for each group in parallel. All experiments were randomized and blinded. Results The systematic negative controls (I, II) did not produce any significant effect. The results in terms of germination, growth, soluble sugar, protein, accumulation of reactive oxygen species and loss of membrane permeability clearly exhibit that Cantharis 200c could mitigate heat stress significantly (p<0.05) as compared to the controls I, II. Final germination percentage after 120 hrs was found to be 60%, 48%, 86%, 88%, for groups 1, 2, 3, 4, respectively. Total chlorophyll (Chl-a + Chl-b), carotenoids and total chl/carotenoid ratio were found to be highest in groups 3 and 4. Assessment of membrane lipid peroxidation in terms of TBARS and accumulation of reactive oxygen species (H2O2) showed minimum concentration in group 3 and 4. Conclusion Cantharis 200c can counteract the deleterious effects of heat stress on juvenile tissues and membranes and can be used effectively to counter heat stress in tropical countries especially during summer. (AU)