Search results

Chilli pepper (Capsicum annum), an extensively cultivated vegetable, is commonly used to spice many dishes prepared in several parts of the world. It contains capsaicinoids. The most active amongst these capsaicinoids is capsaicin (8-methyl-N-vanillyl-6-nonenamide), which is neurogenic and so may affect nervous function. Therefore, the purpose of this paper is to investigate the effects of long-term consumption of chilli pepper and capsaicin diets on pain and social behaviour in CD-1 Swiss white mice.

In total, 30 male mice were randomly assigned into three groups of ten mice each, namely, control, pepper-diet (20 per cent w/w) and capsaicin-diet (10 per cent w/w) groups. Tail immersion, hot plate and formalin tests were conducted to assess pain perception, while nesting behaviour test was used to evaluate the social behaviour of the mice.

The latency of tail flick of both the pepper and capsaicin groups were significantly longer (p < 0.01 and p < 0.001, respectively) compared to control. The hind paw lick frequency, duration and flinching of both the pepper and capsaicin groups were also significantly reduced compared to control. The nesting score of the capsaicin group was significantly higher (p < 0.01) compared to control. However, the nesting score for pepper group was significantly lower (p < 0.05) compared to capsaicin group.

Long-term consumption of capsaicin and pepper diets suppressed pain and enhanced organized social behaviour in mice. One of the active principles responsible for the effects obtained with pepper on pain and social behaviour in mice may be capsaicin.

Plantain (Musa paradisiaca), a staple food source for many people especially in the tropics, contains the neurotransmitter, serotonin which has analgesic and antidepressant effects. Therefore, this study aims to investigate the effects of chronic consumption of plantain diet on pain perception and social behavior in mice.

In the first set of experiments, three groups of mice were either fed rodent chow (control) or 50 or 100 per cent plantain diet, while in a second set of experiments, another three groups of mice were fed either rodent chow (control) or 100 per cent plantain or plantain + ritanserin (serotonin antagonist) for 30 days. Response to pain stimuli was studied by hot plate and formalin tests. Also, the ability of the mice to fluff up suitable beds to build nestle from nesting material was used as an index for social behavior. Serotonin concentration in mice brain was measured using high performance liquid chromatography.

The results showed that plantain diet-fed mice consumed less food but gained more body weight than control mice. Pain perception was significantly reduced in the plantain diet-fed mice compared to the control. Social behavior was enhanced in the plantain diet-fed mice when compared to control (p < 0.05). There was significant increase in serotonin concentration in the brains of 100 per cent diet-fed mice. Administration of serotonin blocker, ritanserin reversed the effects observed in pain and social behavior tests.

Chronic consumption of plantain diet increases serotonin concentration in the brain, suppresses spontaneous perception of pain and improves social behavior in mice. These actions may involve serotonergic pathway.