Ananas comosus (L) Merrill (pineapple) fruit peel extract demonstrates antimalarial, anti-nociceptive and anti-inflammatory activities in experimental models.

ETHNOPHARMACOLOGY RELEVANCE: Pineapple (Ananas comosus) peel is a major waste in pineapple canning industry and it is reported to be used in ethnomedicine as a component of herbal remedies for malarial management. This study aimed to evaluate the antimalarial, antinociceptive and anti-inflammatory properties of Ananas comosus peel extract (PEAC). METHODS: Ananas comosus peel was extracted with 80% methanol. PEAC (100, 200 and 400 mg/kg) was investigated for antimalarial effect using Peter's 4-day suppressive test (4-DST) model in mice. Antinociceptive activity of PEAC was investigated in hot plate, acetic acid-induced writhing and formalin tests in mice. The anti-inflammatory activity was evaluated using the lipopolysaccharides-induced sickness behavior in mice and carrageenan-induced air pouch in rats' models. RESULTS: PEAC could not significantly (p > 0.05) suppressed parasitemia level at 7-day post-infection in 4-DST. PEAC (400 mg/kg) mildly prolongs survival of infected mice up till day 21. PEAC demonstrated significant (p < 0.05) antinociceptive activity by increasing latency to jump on the hot plate, reduced number of writhings in acetic acid test and reduced paw licking time in 2nd phase of formalin test. PEAC significantly reduced anxiogenic and depressive-like symptoms of sickness behavior in LPS-injected mice. PEAC demonstrated significant anti-inflammatory activity in carrageenan-induced air pouch experiment by reducing exudates formation, inflammatory cell counts, and nitrite, tumor necrosis factor-alpha and interleukin-6 levels. CONCLUSION: Ananas comosus peel extract demonstrated mild antimalarial activity but significant anti-nociceptive and anti-inflammatory properties probably mediated via inhibition of pro-inflammatory mediators.

Cnidoscolus aconitifolius-supplemented diet enhanced neurocognition, endogenous antioxidants and cholinergic system and maintains hippocampal neuronal integrity in male Wistar rats.

OBJECTIVES: Cnidoscolus aconitifolius have been investigated to have abundant phytochemicals. However, study on the effect of Cnidoscolus aconitifolius on neurobehavioral performance when supplemented with diet is lacking. The study is aimed at investigating the memory-enhancing effect of Cnidoscolus aconitifolius-supplemented diet (CAD) using Morris water maze and Novel object recognition test. METHODS: Ninety male Wistar rats (80-100 g) were fed with CAD (1, 2.5, 5 and 10%) continuously for a period of 4, 8 and 12 weeks respectively. Six animals per group were used for assessment of memory performance (Morris water maze [MWM] and Novel object recognition test [NORT]); afterwards the brain tissues were harvested for malondialdehyde (MDA), glutathione (GSH) and catalase (CAT) estimation. Acetylcholinesterase (AChE) concentration was also determined. Hippocampal architectural change in the neuron was examined using hematoxylin and eosin (H&E) and cresyl fast violet (Nissl) stain. RESULTS: Higher percentage of CAD significantly (p<0.05) improve memory performance with time-dependent effects in rats fed with CAD on MMW and NORT. MDA significantly (p<0.05) reduce in 1 and 2.5% CAD groups at 4th weeks and in 2.5 and 5% CAD groups at 8th weeks while GSH concentration significantly (p<0.05) increase at 12th weeks in 2.5 and 10% CAD groups. However, CAT concentration significantly (p<0.05) increase in 2.5, and 5%, CAD groups, 1, 5, and 10% CAD groups and in 5, and 10% CAD groups at 4th, 8th and 12th weeks. AChE significantly (p<0.05) reduce at 4th and 12th weeks. Histological assessment reveals no neuronal and pyramidal degeneration (chromatolysis) at the hippocampal Cornu Ammonis 3 (CA3) region. CONCLUSIONS: The results suggest that CAD boost memory performance in rats through positive modulation of oxidative stress, cholinergic system and degeneration of hippocampal neurons.