Neuroprotective effects of Caralluma tuberculata on ameliorating cognitive impairment in a d-galactose-induced mouse model

Studies on neurobehavioural properties of Caralluma dalzielii N.E Br. aqueous aerial parts extract in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Caralluma dalzielii (Asclepiadiaceae) is a shrub used in folkloric medicine to treat epilepsy, pain and infertility in sub-Saharan Africa. Previous studies demonstrated its analgesic, antiulcer, anticonvulsant, and anti-inflammatory activities.

AIM

This study aimed to determine the neurobehavioural properties of Caralluma dalzielii aqueous aerial parts extract (CDAE) in mice using standard experimental models.

MATERIALS AND METHODS

Neurobehavioural activities of CDAE were evaluated (100, 200, and 400 mg/kg) in Swiss Albino mice using the beam walk, staircase, hole board, object recognition, open field assay, Y-maze and forced swimming tests. Phytochemical constituents were analysed using GC-MS.

RESULTS

CDAE significantly increased the mean number of head dips, recognition index and spontaneous alternation in hole board (14.03 at 400 mg/kg and 6.01 in distilled water group; p < 0.05), object recognition (68.16% at 400 mg/kg compared with 51.66% of distilled water group) and Y maze (9.16 at 400 mg/kg as against 4.66 of distilled water group; p < 0.05) tests respectively. It decreased the rearing counts as well as the peripheral and central square crossing in the staircase (4.2 at 400 mg/kg as against 7.87 of the distilled water group; p < 0.05) and open field tests (central, 0.81; peripheral, 1.66 at 400 mg/kg as against central, 5.23; peripheral 11.83 of the distilled water control group; p < 0.05), respectively. There were no significant effects on beam walk assays and forced swim tests. The GC-MS analysis identified a hundred compounds in CDAE. Some compounds which have been reported to possess neurobehavioural activity that were identified include 3,5-Dimethylpyrazole, 2-Amino-5-methylbenzoic acid, Acetophenone, and Tetrahydropyran.

CONCLUSION

CDAE demonstrated anxiolytic, anti-hyperactivity, and memory-improving effects in mice. The extract may possess GABAergic and glutamatergic properties. More studies are needed to confirm this. Isolation of the bioactive compounds is currently ongoing to unravel the bioactive constituents present in C. dalzielii extract.

An in silico scheme for optimizing the enzymatic acquisition of natural biologically active peptides based on machine learning and virtual digestion

BACKGROUND

As a potential natural active substance, natural biologically active peptides (NBAPs) are recently attracting increasing attention. The traditional proteolysis methods of obtaining effective NBAPs are considerably vexing, especially since multiple proteases can be used, which blocks the exploration of available NBAPs. Although the development of virtual digesting brings some degree of convenience, the activity of the obtained peptides remains unclear, which would still not allow efficient access to the NBAPs. It is necessary to develop an efficient and accurate strategy for acquiring NBAPs.

RESULTS

A new in silico scheme named SSA-LSTM-VD, which combines a sparrow search algorithm-long short-term memory (SSA-LSTM) deep learning and virtually digested, was presented to optimize the proteolysis acquisition of NBAPs. Therein, SSA-LSTM reached the highest Efficiency value reached 98.00 % compared to traditional machine learning algorithms, and basic LSTM algorithm. SSA-LSTM was trained to predict the activity of peptides in the proteins virtually digested results, obtain the percentage of target active peptide, and select the appropriate protease for the actual experiment. As an application, SSA-LSTM was employed to predict the percentage of neuroprotective peptides in the virtual digested result of walnut protein, and trypsin was ultimately found to possess the highest value (85.29 %). The walnut protein was digested by trypsin (WPTrH) and the peptide sequence obtained was analyzed closely matches the theoretical neuroprotective peptide. More importantly, the neuroprotective effects of WPTrH had been demonstrated in nerve damage mouse models.

SIGNIFICANCE

The proposed SSA-LSTM-VD in this paper makes the acquisition of NBAPs efficient and accurate. The approach combines deep learning and virtually digested skillfully. Utilizing the SSA-LSTM-VD based strategy holds promise for discovering and developing peptides with neuroprotective properties or other desired biological activities.

Caralluma edulis (Apocynaceae): A comprehensive review on its Traditional uses, Phytochemical profile and pharmacological effects

Caralluma edulis is a well-known species of the genus Caralluma from Apocynaceae, commonly known as chunga. Caralluma species are mostly succulent perennial herbs, several of which are edible species. The plant has an outstanding therapeutic background in the traditional system of treatment. It has been recommended for the treatment of a number medical disorder such as hypertension, Alzheimer disease, rheumatism, gastric problems and leprosy. Traditionally the stem was boiled in water and this extract was then used to cure diabetes. The pharmacological effects of C.edulis have also been explored in various in vitro and in vivo experiments. In this regard, the extract of the plant exhibited strong antioxidant activity, analgesic, against inflammation as well as xylene mediated ear edema for topical effects. The significant anti-hyperlipidemic effect of the plant extract is also reported. However, the extract was found insignificant in the reversal of alloxan-induced diabetes in rabbit model at test doses. These pharmacological effects are strongly supported by the presence of different bioactive phytochemicals in the plant. These groups of compounds include sterols, terpenoids, flavonoids, and pregnane glycosides. C.edulis is a very potential member of the genus Caralluma with strong traditional history, phytochemistry and phytopharmacology, needed further exploration for clinically used lead compounds. In this review, we have focused to combined different reported data on the traditional uses of the plant, phytochemical profile and pharmacological effects in different experimental assay and subsequent future prospects.

Bone marrow mesenchymal stem cells-derived exosomes reduce Aβ deposition and improve cognitive function recovery in mice with Alzheimer's disease by activating sphingosine kinase/sphingosine-1-phosphate signaling pathway

Exosomes are associated with the development and progression of Alzheimer's disease (AD), although the impact of these extracellular vesicles in brain pathological condition remains incompletely understood. Therefore, this study aimed to investigate the role and mechanism of exosomes signaling in AD. Double transgenic APP/PS1 mice were injected with bone marrow mesenchymal stem cells (BM-MSCs)-derived exosomes or combined with SKI-Ⅱ (sphingosine kinase [SphK] inhibitor) or VPC23019 (sphingosine-1-phosphate [S1P] 1 receptor blocker). We observed the spatial learning and memory ability of mice, and assessed the levels of amyloid and proteins. We found that exosomes improved spatial learning and memory ability of APP/PS1 mice, and enhanced the expression of SphK1 and S1P1. Moreover, exosomes inhibited the levels of amyloid and enhanced the expression of NeuN in cortex and hippocampus of APP/PS1 mice. Exosomes repressed the levels of Aβ1-40, Aβ1-42, BACE1, and PS1, and promoted the expression of neprilysin in APP/PS1 mice. The influence conferred by exosomes was abolished by SKI-Ⅱ or VPC23019. In conclusion, our article confirms that BM-MSCs-derived exosomes reduce Aβ deposition and promote cognitive function recovery in AD mice by activating SphK/S1P signaling pathway. Thus, our data suggest that S1P/SphK-containing exosomes should be explored as potential AD cure.

Pharmacological Basis for Use of Armillaria mellea Polysaccharides in Alzheimer's Disease: Antiapoptosis and Antioxidation

Armillaria mellea, an edible fungus, exhibits various pharmacological activities, including antioxidant and antiapoptotic properties. However, the effects of A. mellea on Alzheimer's disease (AD) have not been systemically reported. The present study aimed to explore the protective effects of mycelium polysaccharides (AMPS) obtained from A. mellea, especially AMPSc via 70% ethanol precipitation in a L-glutamic acid- (L-Glu-) induced HT22 cell apoptosis model and an AlCl₃ plus D-galactose- (D-gal-) induced AD mouse model. AMPSc significantly enhanced cell viability, suppressed nuclear apoptosis, inhibited intracellular reactive oxygen species accumulation, prevented caspase-3 activation, and restored mitochondrial membrane potential (MMP). In AD mice, AMPSc enhanced horizontal movements in an autonomic activity test, improved endurance times in a rotarod test, and decreased escape latency time in a water maze test. Furthermore, AMPSc reduced the apoptosis rate, amyloid beta (Aβ) deposition, oxidative damage, and p-Tau aggregations in the AD mouse hippocampus. The central cholinergic system functions in AD mice improved after a 4-week course of AMPSc administration, as indicated by enhanced acetylcholine (Ach) and choline acetyltransferase (ChAT) concentrations, and reduced acetylcholine esterase (AchE) levels in serum and hypothalamus. Our findings provide experimental evidence suggesting A. mellea as a neuroprotective candidate for treating or preventing neurodegenerative diseases.

Toxicological Evaluation of the Aqueous Extract of Caralluma europaea and Its Immunomodulatory and Inflammatory Activities

Background:

Caralluma europaea (CE) has been studied for its chemical constituents, and no information is available on its toxicity or its pharmacological activities.

Objective:

To determine the toxicity of an aqueous extract of CE stems in vitro and in vivo after acute and subchronic oral gavages in Swiss albino's mice and its immunomodulatory and inflammatory activities.

Materials and Methods:

The extract was administrated in single oral dose at 5 g/kg body weight for the acute toxicity test and by gavages daily at doses of 1, 2.5, or 5 g/kg for 30 consecutive days for the subchronic toxicity test. The immunomodulatory activities and inflammatory activities were tested by the evaluation of hemagglutination antibodies (HAs) titers and delayed-type hypersensitivity (DTH) response.

Results:

For the dose of 1 g/kg, no visible toxic effects were observed. However, for the higher doses, clinical observations of toxicity were noted after 1 week of treatment. This was confirmed by the biochemical parameters values and the histology analyses of the spleen, liver, and kidney tissues. The high cellular mortality rate in vitro when treated with CE extract confirmed their toxicity potential. There was also increase of “HA titer” and “DTH” response in mice treated with nontoxic dose of CE (1 g/kg) compared to control group. This immune activity was confirmed by the high number of lymphocytes infiltrates noted in the different organs.

Conclusion:

We conclude that CE at the dose up of 1 g/kg produced toxic effect in mice that induced an immune inflammatory reaction.

SUMMARY

Caralluma europaea (CE) has been studied for its chemical constituents, and no information is available on its toxicity or its pharmacological activities. The objective is to determine the toxicity of an aqueous extract of CE stems in vitro and in vivo after acute and subchronic oral gavages in Swiss albino's mice and its immunomodulatory and inflammatory activities. For the dose of 1 g/kg, no visible toxic effects were observed. However, for the higher doses, clinical observations of toxicity were noted after 1 week of treatment. This was confirmed by the biochemical parameters values and the histology analyses of the spleen, liver, and kidney tissues. The high cellular mortality rate in vitro confirmed their toxicity potential. There was also increase of “hemagglutination antibody titer” and “delayed-type hypersensitivity” response in mice treated with nontoxic dose of CE (1 g/kg) compared to control group. This immune activity was confirmed by the high number of lymphocytes infiltrates noted in the different organs. We conclude that CE at the dose up of 1 g/kg produced toxic effect in mice that induced an immune inflammatory reaction.

Abbreviations Used: CE: Caralluma europaea, ALT: Alanine aminotransferase, AST: Aspartate aminotransferase, RRBCs: Rat red blood cells, DTH: Delayed-type hypersensitivity response, PBS: Phosphate buffer solution.