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Alzheimer’s disease (AD), which largely affects the elderly, has become a global burden. Patients with AD have both short- and long-term memory impairments. The neuronal loss in AD occurs due to abnormally folded amyloid beta proteins and aggregation of hyperphosphorylated tau proteins in the brain. Eventually, amyloid plaques and neurofibrillary tangles are formed, which subsequently disintegrate the neuronal transport system. There are several factors which are involved in AD pathogenesis, including oxidative stress, inflammation and the presence of metal ions. The modern therapies utilized for AD treatment have many adverse effects, driving the quest for more safe and effective medications. Many dietary components, including different types of fruits, vegetables, spices, and marine products as well as a Mediterranean diet, are a good source of antioxidants and have anti-inflammatory properties, with many showing substantial potential against AD pathogenesis. In this review, we discuss the potential of these foods for treating AD and opportunities for developing disease-targeted drugs from active compounds extracted from natural dietary products.

Parkinson’s disease (PD) is characterized by neurodegeneration and a progressive functional impairment of the midbrain nigral dopaminergic neurons. The cause remains unknown; however, several pathological processes and central factors, such as protein aggregation, mitochondrial dysfunction, iron accumulation, neuroinflammation and oxidative stress, have been reported. The current treatment method primarily targets symptoms by using anti-Parkinson drugs such as levodopa, carbidopa, dopamine (DA) agonists, monoamine oxidase type B inhibitors and anticholinergics to replace DA. When drug therapy is not satisfactory, surgical treatments are recommended. Unfortunately, the existing conventional strategies that target PD are associated with numerous side effects and possess an economic burden. Therefore, novel therapeutic approaches that regulate the pathways leading to neuronal death and dysfunction are necessary. For many years, nature has provided the primary resource for the discovery of potential therapeutic agents. Remarkably, many natural products from medicinal plants, fruits and vegetables have been demonstrated to be efficacious anti-Parkinson agents. These products possess neuroprotective properties as a result of not only their wellrecognized anti-oxidative and anti-inflammatory activities but also their inhibitory roles regarding iron accumulation, protein misfolding and the maintenance of proteasomal degradation, as well as mitochondrial homeostasis. The aim of this review is to report the available anti-Parkinson agents based on natural products and delineate their therapeutic actions, which act on various pathways. Overall, this review emphasizes the types of natural products that are potential future resources in the treatment of PD as novel regimens or supplementary agents.

Globally, thrombosis-associated disorders are one of the main contributors to fatalities. Besides genetic influences, there are some acquired and environmental risk factors dominating thrombotic diseases. Although standard regimens have been used for a long time, many side effects still occur which can be life threatening. Therefore, natural products are good alternatives. Although the quest for antithrombotic natural products came to light only since the end of last century, in the last two decades, a considerable number of natural products showing antithrombotic activities (antiplatelet, anticoagulant and fibrinolytic) with no or minimal side effects have been reported. In this review, several natural products used as antithrombotic agents including medicinal plants, vegetables, fruits, spices and edible mushrooms which have been discovered in the last 15 years and their target sites (thrombogenic components, factors and thrombotic pathways) are described. In addition, the side effects, limitations and interactions of standard regimens with natural products are also discussed. The active compounds could serve as potential sources for future research on antithrombotic drug development. As a future direction, more advanced researches (in quest of the target cofactor or component involved in antithrombotic pathways) are warranted for the development of potential natural antithrombotic medications (alone or combined with standard regimens) to ensure maximum safety and efficacy.

Goose bone is traditionally used in the treatment of many ailments including in bone fracture. The aim of the present study was to evaluate the subacute toxicity of goose bone in a rat model by investigating some hematological and biochemical parameters in rats. Subsequently, a histopathological study was performed to confirm the presence of pathological lesions in the rat’s vital organs including the liver, kidney, heart, brain, pancreas, lung, spleen, and stomach. Adult Wistar rats were divided into four groups (n = 8) and were orally administrated with three doses (30, 60, and 120 mg/kg) of goose bone once daily for 21 days as compared to control animals (received only drinking water). Goose bone did not cause any significant changes on body weight, relative organ weight, and percentage water content at any of the administered doses. There were also no significant alterations in hematological parameters seen. All three doses administered significantly reduced the triglyceride levels as well as the atherogenic index of plasma (AIP). Animals treated with 120 mg/kg doses had significantly reduced alkaline phosphatase (ALP) activity as compared to the control group. There was no significant alteration on other serum biochemical parameters seen. Additionally, histopathological findings confirmed that there was no inflammatory, necrotic, or other toxicological feature seen for all three doses. It is concluded that goose bone is nontoxic and is safe for consumption besides having the potential to be investigated for the treatment of high triglycerides or liver-related disorder.

The study reports on major and trace elements as well as antioxidant properties of honey samples from Bangladesh. Four major cationic elements, seven trace elements, and three heavy metals were determined in the 12 honey samples using atomic absorption spectrophotometer. Nutritional values in these honey samples were further investigated according to their antioxidant properties. The content of major elements was in the range of 62.75–616.58, 579.48–2219.43, 69.42–632.25, and 0.13–1.20 mg/kg for sodium, potassium, magnesium, and calcium, respectively. The trace elements varied in the range of 0.41–28, 0.12–3.54, 1.54–2.85, 0.29–0.59, 0.02–0.35, and 0.01–0.06 mg/kg for iron, zinc, copper, nickel, cobalt, and cadmium, respectively. Among the heavy metals, only lead (0.17–2.19 mg/kg) was detected. The results of antioxidant analysis based on phenolics, flavonoids, ascorbic acid, reducing sugar, and proteins (as nonphenolic antioxidants) revealed that multifloral raw honey samples contain significantly higher levels of reducing agents than monofloral and commercial brand honeys. The study provides a useful insight on the minerals, heavy metals, and antioxidant properties of honey samples commonly consumed in Bangladesh and found to be rich source of antioxidants and minerals. Some samples might pose some risk to the health due to lead contamination.

Since diabetes mellitus (DM) is one of the most common and serious endocrine metabolic disorders, it is important to elucidate novel antidiabetic therapeutic agents from various sources, including natural products. Bee venom (BV) is a complex mixture of proteins, peptides, and low molecular components, and melittin is the main constituent. Melittin is a peptide consisting of 26 amino acids with the sequence GIGAVLKVLTTGLPALISWIKRKRQQ. It has several important biological effects and has a relatively low toxicity. Recent studies using animal models have confirmed that melittin has significant glucose and lipid lowering activities by acting on several mechanistic pathways. The main antidiabetic activity of melittin is increasing insulin secretion via depolarization of pancreatic β-cells. Other possible mechanisms may involve stimulation of phospholipase A2, increase of glucose uptake, improving lipid profile, and/or reduction of inflammation. This review summarizes the various sources, proteomics, biological roles, adverse effects, and medical applications of melittin and its mechanism of action in combating DM.

A comparative study of the extraction efficiency of nine known polyphenols [phenolic acids (benzoic acid, dihydroxybenzoic acid, gallic acid, trans-cinnamic acid, and vanillic acid) and flavonoids (naringenin, naringin, quercetin, and rutin)] was conducted by deliberately adding the polyphenols to an artificial honey solution and performing solid phase extraction (SPE). Two SPE methods were compared: one using Amberlite XAD-2 resin and another one using a C18 cartridge. A gradient high performance liquid chromatography system with an RP18 column and photodiode array detector was utilized to analyze the extracted polyphenols. The mean percent of recovery from the C18 cartridges was 74.2%, while that from the Amberlite XAD-2 resin was 43.7%. The recoveries of vanillic acid, naringin, and rutin were excellent (>90%); however, gallic acid was not obtained when C18 cartridges were used. Additionally, the reusability of Amberlite XAD-2 resin was investigated, revealing that the mean recovery of polyphenols decreased from 43.7% (1st extraction) to 29.3% (3rd extraction). It was concluded that although Amberlite XAD-2 resin yielded a higher number of compounds, C18 cartridges gave a better extraction recovery. The lower recovery seen for the Amberlite XAD-2 resin also cannot be compensated by repeated extractions due to the gradual decrease of extraction recovery when reused.

Residual levels of seven frequently used pesticides were investigated in 140 samples of two common vegetables, eggplants and tomatoes, from agricultural fields in the Narayanganj district of Bangladesh. The analysis of pesticide residues was performed by high-performance liquid chromatography with photodiode array detection. A large percentage of the eggplants (50%) and tomatoes (60%) from the Narayanganj district were contaminated with pesticides, and all of the levels were above the maximum residual limit (MRL) proposed by the EC regulation. Diazinon was the most common (35%) pesticide detected in the vegetable samples at a concentration of 45–450 times higher than the MRL. The health risk index for diazinon was highest for both eggplant and tomato samples, which may be due to its physiochemical properties. Fenitrothion and linuron are the two second most common types of pesticides detected in the vegetable samples. Regular monitoring of the use of common pesticides on vegetables should be conducted.