Potential of neuroprotective antioxidant-based therapeutics from Peltophorum africanum Sond. (Fabaceae)

A Review of African Medicinal Plants and Functional Foods for the Management of Alzheimer's Disease-related Phenotypes, Treatment of HSV-1 Infection and/or Improvement of Gut Microbiota

Alzheimer's disease (AD), which is a progressive neurodegenerative disorder is the most common form of dementia globally. Several studies have suggested alteration in the gut microbiota and HSV-1 infection as contributing factors to the development of the disease. As at now, there are no AD attenuating agents and AD pharmacotherapy is focused on managing symptoms while plants used in ethnomedicine remain potential sources of drugs for the treatment of the condition. Here, we reviewed published databases for African ethnomedicinal plants and functional foods of African origin that are used in the management of AD-related phenotypes, treatment of herpes simplex virus −1 (HSV-1) and/or improvement of gut microbiota. A total of 101 unique plant species and 24 different types of traditionally prepared African functional foodstuff were identified. Of the 101 identified plant species, 50 species serve as functional foodstuffs. Twenty-three (23) of the ethnomedicinal plant families were successfully identified for the treatment and management of AD-related phenotypes and age-related dementia. Eighteen (18) African plant species from 15 families were also identified as potent remedies for HSV-1; while many African wild fruits (3 species), roots and tubers (7 species), leafy vegetables (14 species), and seaweeds (26 species) were functional foods for modifying AD-related phenotypes. It was concluded that African medicinal plants are potential sources of both AD attenuating agents and phytocompounds that may be used against HSV-1 infection and alteration of gut microbiota. Additionally, a number of African functional foods are important sources of prebiotics and probiotics.

Phytochemical content, antioxidant activities and androgenic properties of four South African medicinal plants

Introduction:This study aimed to investigate the phytochemical contents, antioxidant activities, and androgenic properties ofPeltophorum africanumSond,Trichilia emeticaVahl,Terminalia sambesiaca, andXimenia caffra.Methods:The finely powdered leaves of the selected plants were extracted using acetone, aqueous, and methanol as solvents. The total phenolics and flavonoids contents were determined from gallic acid and quercetin standard curves. The antioxidant activities of these extracts were evaluated using 1, 1-Diphenyl-2-picrylhydrazyl ( DPPH) assay. The effect of plant extracts (100-1000 µg/mL) on TM3 Leydig cells was assessed using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay. Testosterone levels were measured using ELISA kit.Results:The methanol extracts ofT. sambesiacaandX. caffrarevealed higher total phenolic and flavonoid contents (102.13±2.32 mg/g GAE and 1.05±0.04 mg/g QE, respectively) than other plant extracts. The acetone and methanol extracts ofP. africanumrevealed the best IC50value (12.50 ± 0.052 µg/mL) against DPPH than the other plant extracts and ascorbic acid. The MTT assay results showed that all varying concentrations of plant extracts maintained cell viability and were not cytotoxic with IC50values of greater than 20 µg/mL. The methanol extract ofT. sambesiacahad the highest testosterone production at 500 µg/mL (0.399 ng/mL) when compared with the basal control while at the concentration of 500 µg/mL the acetone extracts ofP. africanumandT. sambesiacahad significantly high testosterone production 0.147 and 0.188 ng/mL respectively when compared with basal control.Conclusion:The results reveal that these plants possess antioxidants and androgenic property and suggest the potential use for the treatment of male infertility.

Chemical Constituents of the Leaves of Peltophorum pterocarpum and Their Bioactivity

Two new sesquiterpenoids peltopterins A and B (compounds 1 and 2) and fifty-two known compounds were isolated from the methanol extract of P. pterocarpum and their chemical structures were established through spectroscopic and mass spectrometric analyses. The isolates 40, 43, 44, 47, 48, 51 and 52 exhibited potential inhibitory effects of superoxide anion generation or elastase release.

Novel therapeutic approaches: Rett syndrome and human induced pluripotent stem cell technology

Recent advances in induced pluripotent stem cell (iPSC) technology target screening and discovering of therapeutic agents for the possible cure of human diseases. Human induced pluripotent stem cells (hiPSC) are the right kind of platform for testing potency of specific active compounds. Ayurveda, the Indian traditional system of medicine developed between 2,500 and 500 BC, is a science involving the intelligent formulations of herbs and minerals. It can serve as a "goldmine" for novel neuroprotective agents used for centuries to treat neurological disorders. This review discusses limitations in screening drugs for neurological disorders and the advantages offered by hiPSC integrated with Indian traditional system of medicine. We begin by describing the current state of hiPSC technology in research on Rett syndrome (RTT) followed by the current controversies in RTT research combined with the emergence of patient-specific hiPSC that indicate an urgent need for researchers to understand the etiology and drug mechanism. We conclude by offering recommendations to reinforce the screening of active compounds present in the ayurvedic medicines using the human induced pluripotent neural model system for research involving drug discovery for RTT. This integrative approach will fill the current knowledge gap in the traditional medicines and drug discovery.

Protective Effect of Standardized Extract of Passiflora incarnata Flower in Parkinson's and Alzheimer's Disease

Background:

Oxidative stress plays an important role in the pathogenesis of neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease. Flavonoids exert their antioxidant effects by neutralizing all types of oxidizing radicals including the superoxide and hydroxyl radicals. Passiflora incarnata Linn. (Passifloraceae) is an important plant used in Ayurveda for the treatment of various disorders of the CNS and is a rich source of flavonoids.

Aim:

In the present study, we investigated the antioxidant, antiparkinsonian, and memory enhancing activity of flavonoid rich n-butanol extract of P. incarnata flowers (BEPIF).

Materials and Methods:

Antioxidant activity was assessed using DPPH and hydrogen peroxide scavenging assay. The antiparkinsonian activity was evaluated using haloperidol induced catalepsy and tacrine induced vacuous chewing movement and memory enhancing activity was assessed using elevated plus maze and object recognition test.

Statistical Analysis:

The results were analyzed by Analysis of Variance test followed by Dunnett’s test.

Results:

Administration of BEPIF decreased transfer latency on day 2 and 9 significantly in elevated plus maze test and showed a significant increase in discrimination index in the object recognition test which is suggestive of its cognitive improvement action. Pretreatment with BEPIF showed a significant reduction in the haloperidol induced catalepsy and the tacrine induced jaw movements which are suggestive of its antiparkinsonian activity. In DPPH and H₂O₂ scavenging assay, BEPIF exhibited significant free radical scavenging activity.

Conclusions:

It can be concluded that the butanolic extract of P. incarnata flowers has significant antiparkinsonian and cognition enhancing activity which may be associated with its antioxidant potential. Thus, P. incarnata flowers may be employed in treatment of dementia and parkinsonism.

In vitro determination of the anti-aging potential of four southern African medicinal plants

Background

Aging is an inevitable process for all living organisms. During this process reactive oxygen species generation is increased which leads to the activation of hyaluronidase, collagenase and elastase, which can further contribute to skin aging. Four southern African medicinal plants; Clerodendrum glabrum, Schotia brachypetala, Psychotria capensis and Peltophorum africanum, were investigated to assess their anti-aging properties.

Methods

Anti-elastase, anti-collagenase and anti-hyaluronidase activities of twenty-eight samples, consisting of methanol and ethyl acetate extracts of the four plants, were determined using spectrophotometric methods. Radical scavenging activity was determined by the ability of the plant extracts to scavenge the ABTS^•+ radical.

Results

The majority of the samples in the anti-elastase assay and nine in the anti-collagenase assay showed more than 80% inhibition. The ethyl acetate extract of S. brachypetala bark and leaves of P. capensis inhibited elastase activity by more than 90%. The methanol extract of S. brachypetala bark contained the highest anti-hyaluronidase activity (75.13 ± 7.49%) whilst the ethyl acetate extract of P. africanum bark exhibited the highest antioxidant activity (IC₅₀: 1.99 ± 0.23 μg/ml).

Conclusion

The free radical scavenging activity and enzyme inhibitory activity of the plant extracts investigated suggests that they can help restore skin elasticity and thereby slow the wrinkling process. P. africanum was the plant with the most promising activity and will be subjected to further testing and isolation of the active compound/s.

Ethnopharmacological Survey of Plants Used in the Traditional Treatment of Gastrointestinal Pain, Inflammation and Diarrhea in Africa: Future Perspectives for Integration into Modern Medicine

There is a growing need to find the most appropriate and effective treatment options for a variety of painful syndromes, including conditions affecting the gastrointestinal tract, for treating both veterinary and human patients. The most successful regimen may come through integrated therapies including combining current and novel western drugs with acupuncture and botanical therapies or their derivatives. There is an extensive history and use of plants in African traditional medicine. In this review, we have highlighted botanical remedies used for treatment of pain, diarrheas and inflammation in traditional veterinary and human health care in Africa. These preparations are promising sources of new compounds comprised of flavonoids, bioflavanones, xanthones, terpenoids, sterols and glycosides as well as compound formulas and supplements for future use in multimodal treatment approaches to chronic pain, gastrointestinal disorders and inflammation. The advancement of plant therapies and their derivative compounds will require the identification and validation of compounds having specific anti-nociceptive neuromodulatory and/or anti-inflammatory effects. In particular, there is need for the identification of the presence of compounds that affect purinergic, GABA, glutamate, TRP, opioid and cannabinoid receptors, serotonergic and chloride channel systems through bioactivity-guided, high-throughput screening and biotesting. This will create new frontiers for obtaining novel compounds and herbal supplements to relieve pain and gastrointestinal disorders, and suppress inflammation.

Wound healing properties and kill kinetics of Clerodendron splendens G. Don, a Ghanaian wound healing plant

As part of our general objective of investigating indigenous plants used in wound healing in Ghana, we hereby report our findings from some in vitro and in vivo studies related to wound healing activities of Clerodendron splendens G. Don (Verbanaceae). Methanolic extract of the aerial parts of the plant was tested for antimicrobial activity against Gram positive bacteria (Bacillus subtilis, Staphylococcus aureus, Streptococcus faecalis, Micrococcus flavus, as well as resistant strains of Staph. aureus SA1199B, RN4220 and XU212), Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Proteous mirabilis, Klebsiella pneumoniae) and Candida albicans using the micro-well dilution method. Survivor–time studies of the microorganisms, radical scavenging activity using 2,2’-diphenylpicrylhydrazyl (DPPH) and various in vivo wound healing activity studies were also conducted on the extract. The extract exhibited biostatic action against all the test microorganisms with a Minimum Inhibition Concentration (MIC) ranging between 64 and 512 μg/ml and a free radical scavenging property with an IC₅₀ value of 103.2 μg/ml. The results of the in vivo wound healing tests showed that upon application of C. splendens ointment, there was a reduction in the epithelization period from 26.7 days (control) to 13.6 days along with a marked decrease in the scar area from 54.2 mm² (control) to 25.2 mm². Significant increase in the tensile strength and hydroxyproline content were also observed as compared to the control and was comparable to nitrofurazone. The above results appear to justify the traditional use of C. splendens in wound healing and treatment of skin infections in Ghana.

Detoxifying effect of Nelumbo nucifera and Aegle marmelos on hematological parameters of Common Carp (Cyprinus carpio L.)

The objective of this study was to investigate the efficacy of Nelumbo nucifera and Aegle marmelos on common carp exposed to sub-lethal concentrations of combined heavy metals (5 ppm) under laboratory conditions. The fish were treated with Nelumbo nucifera (500 mg/kg bwt) and Aegle marmelos (500 mg/kgbwt) for 30 days as a dietary supplement. The blood biochemical parameters of the fish were evaluated by analyzing the level of red blood cells (RBC), packed cell volume (PCV), hemoglobin concentration, glucose, cholesterol, iron and copper. The findings of the present investigation showed significant increase in hemoglobin (p<0.001), RBC (p<0.01) and PCV (p<0.01) of herbal drug-treated groups compared with metal-exposed fish. Conversely, glucose and cholesterol level in blood of common carp showed significant reduction compared with heavy-metal-exposed groups. All the values measured in Nelumbo nucifera and Aegle marmelos treated fish were restored comparably to control fish. Our results confirmed that Nelumbo nucifera and Aegle marmelos provide a detoxification mechanism for heavy metals in common carp.