Leaves of Hippophae Rhamnoides Prevent Taste Aversion in Gamma-Irradiated Rats

ABSTRACT

Hippophae rhamnoides (Sea buckthorn), a traditionally known plant for nutritional and therapeutic values, is under active investigation for radioprotective properties. This study investigated effects of aqueous leaf extract from H. rhamnoides on ⁶⁰Co-γ-radiation induced changes in behavior, oxidative stress and serotonin levels in jejunum and plasma of rats. Conditioned taste aversion (CTA) was chosen as the assay to record behavioral changes and was assessed in terms of saccharine preference ratio (SPR). Whole body ⁶⁰Co-γ-irradiation (2 Gy) induced significant nonrecoverable CTA (25.6 ± 3.6% SPR, t(6) = 3.499, p < .05) and loss in body weight (b.w.). One time treatment with leaf extract before irradiation, countered radiation induced CTA and loss in body weight. The 12 mg/kg b.w. concentration of leaf extract caused complete extinction of CTA [100.3 ± 6.4% SPR, t(6) = 5.879, p < .01] after day 3 and the effect was significantly higher than positive control, Ondansetrone (70.0 ± 8.9% SPR). Treatment with leaf extract before irradiation significantly countered radiation induced (1) decrease in antioxidant protection, (2) increase in levels of corticosterone (CS) in plasma, (3) increase in levels of serotonin in jejunum and plasma. Present investigation demonstrated that H. rhamnoides leaf extract prevented behavioral changes induced at clinical radiation doses. Hippophae leaves are nontoxic and are being consumed as tea and other beverages. CTA in rats is a considered parallel process to nausea and vomiting in human beings. These findings, put together, suggest that dietary supplements from Hippophae leaves could be developed for preventing behavioral changes in subjects exposed to radiation.

KEYWORDS. :

• behavior
• ⁶⁰Co-γ-irradiation
• conditioned taste aversion
• corticosterone
• ondansetrone
• serotonin
• sea buckthorn leaves

ACKNOWLEDGMENT

The grant for the study was provided by Defence Research and Development Organization (DRDO), Ministry of Defence, Government of India (Project 1.2/INM-311). Efforts of Dr(s) O.P. Chaurasia, S.K.Dwivedi, and Director of DIHAR in procurement of plant material are greatfully acknowledged.

Declaration of interest: Authors declare that there are no conflicts of interest.

ABOUT THE AUTHORS

Dr. Vanita Gupta received PhD in year 2010 and is involved as a team member in studies directed towards understanding radioprotective action of Hippophae rhamnoides leaves on neuronal system. Dr. Madhu Bala is the team leader and Principal Investigator of projects on development of radioprotective formulations from plants growing in high altitude regions of India. She has more than 22 years of Post Doctoral research experience. Sh. Jagdish Prasad, B.Sc. and Sh. Surinder Singh B.Sc. are jointly involved as team members in investigations on total body irradiation and survival benefits by radio-protective plants. Sh. Manish Gupta, M.Sc. is a team member and is presently pursuing PhD programme under supervision of Dr Madhu Bala on radioprotective effects of herbal formulations on GI tract.