Nootropic and anti-stress effects of rice bran oil in male rats

Abstract

Rice bran oil (RBO) is an important product of rice bran. It is considered to be one of the most important nutritious oil due to its favorable fatty acid composition and unique composition of naturally occurring biologically active antioxidant compounds. This study was designed to monitor the effects of oral intake of RBO on stress response in rats. RBO was extracted using hexane. Rats were divided into Control and test (RBO-treated). RBO-treated rats were given 0.2 ml/day RBO for 6 weeks. Food intake and body weight changes were monitored weekly. After 6 weeks open field activity and Morris Water Maze (MWM) test were performed. Results showed that weekly cumulative food intake but not body weight were lower in RBO-treated rats during 1st to 5th week of treatment, which were normalized at the end of treatment. Exploratory activity of RBO-treated rats in an open field was increased. Spatial memory in Morris water maze was enhanced in RBO-treated than control rats. An episode of 2 h restraint stress decreased the 24 h food intake of both control and RBO-treated animals. Behavioral deficits were lower in RBO-treated rats. Exposure of 2 h restraint stress increased brain serotonin (5-hydroxytryptamine: 5-HT) metabolism. These increases were lower in RBO-treated restrained than their respective control animals. Serotonergic neurotransmitter mechanism is implicated in stress. The findings of the study show beneficial effects of RBO in learning and memory functions. Moreover, the study also highlights the attenuating effect of RBO on stress induced behavioral and neurochemical effects in rats.

The involvement of TGF-β1 /FAK/α-SMA pathway in the antifibrotic impact of rice bran oil on thioacetamide-induced liver fibrosis in rats

“…After a one-week of acclimatization, rats were divided into five groups, each with six animals, according to the following scheme: Group 1: the negative control group; rats were injected intraperitoneally ( ip ) with saline three times per week for two successive weeks, Group 2: the positive control (TAA) group; rats were ip injected with TAA (100 mg/kg) three times per week for two successive weeks to provoke liver fibrosis [ 27 ] () with some modification based on our preliminary studies. Group 3 and 4: treatment groups; rats received orally RBO (0.2 and 0.4 mL/kg, orally) [ 28 , 29 ] daily for 2 weeks after 2 weeks of TAA injection. Group 5: reference group; rats received silymarin (100 mg/kg, orally) [ 30 ], daily for 2 weeks after 2 weeks of TAA injection.…”

Long-Term Administration of Rice Bran Oil Attenuates 5-HT1A Receptor Dependent Responses in Rats

“…It is tempting to relate the down regulation of presynaptic 5-HT1A receptors in RBO treated rats with the stress reducing effect of RBO, reported previously from our laboratory [17], because long term administration of selective serotonin reuptake inhibitors [39][40][41] and adaptation to stress [13,14,29,42] both down regulate presynaptic 5-HT1A auto receptors. On the other hand, it may be noted that a down regulation of presynaptic 5-HT1A receptors is expected to increase 5-HT and 5-HIAA levels in RBO treated saline injected animals, but the levels in the present study were smaller in these rats.…”

“…The activation of presynaptic receptors decreases 5-HT metabolism while activation of postsynaptic receptors elicits 5-HT syndrome and increases plasma corticosterone and glucose [15]. Previously we have shown that long term administration of stabilized rice bran as well as RBO produces antidepressant like effects and facilitate adaptation to stress in rats [16,17]. For further evaluation mechanism concerned in the antidepressant like actions of RBO, the present study focuses 5-HT1A receptor dependent responses in rats treated with RBO for six weeks.…”

“…Rice bran was obtained through their milling process, stabilized by heating and then oil was separated out by the same method [17,21,22]. Microwave heating was used for stabilization to inactivate the lipases and oil was extracted through solvent (hexane BP 68°C) extraction.…”

Oral Administration of Rauwolfia serpentina Plant Extract Mitigated Immobilization Stress-Induced Behavioral and Biochemic and Deficits in Rats

“…Previously, numerous studies have been reported from our laboratory that establish the capability of phytochemicals present in rice bran oil [26], olive oil [27] and the aqueous fruit extract of sea buckthorn [28] to attenuate/or reverse anxiety in rats. Similarly, our laboratory also observed that the oral administration of red rice bran oil averted haloperidol-induced anxiety syndrome in rats [29].…”