Journal of Herbmed Pharmacology
Volume:9 Issue: 3, Jul 2020

In the last few decades, Moringa oleifera, a multipurpose medicinal plant (MMP) has received increased research attention and commercial interest for its nutritional, therapeutic and pharmacological properties. Rigorous approaches including biological assays, animal and clinical trials are required towards safe usage as herbal therapy. We conducted a systematic review of the known pharmacological activities, toxicity, and safety of M. oleifera, usually used locally in the treatment and prevention of myriads of illnesses. Five major bibliographic databases (SCOPUS, Web of Science, Science Direct, PubMed, and Mendeley) were searched for studies reported on pharmacological activities, toxicity, and safety assessment of M. oleifera in the last 29 years (1990 – 2019). Studies on animals and humans involving aqueous leaf extracts and different preparations from M. oleifera seed and bark were also considered. All articles retained, and data collected were evaluated based on the period of the article, country where such studies were conducted and the document type. Our search results identified and analyzed 165 articles while 63 studies were eventually retained. Diverse pharmacological activities including neuroprotective, antimicrobial, antiasthmatic, anti-malaria, cardioprotective, antidiabetic, antiobesity, hepatoprotective and cytotoxic effects, amongst others, were recorded. Toxicity studies in animal models and few human studies showed that M. oleifera is safe with no adverse effect reported. The importance of the plant is highlighted in the search for new bioactive compounds to explore its therapeutic potentials towards drug discovery and development in the pharmaceutical and allied industries.

Free radicals are constructed by natural physiological activities in the human cells as well as in the environment. They may be produced as a result of diet, smoking, exercise, inflammation, exposure to sunlight, air pollutants, stress, alcohol and drugs. Imbalanced redox status may lead to cellular oxidative stress, which can damage the cells of the body, resulting in an incidence of various diseases. If the endogenous antioxidants do not stop the production of reactive metabolites, they will be needed to bring about a balance in redox status. Natural antioxidants, for example plants, play an important part in this context. This paper seeks to report the available evidence about oxidative stress and the application of plants as antioxidant agents to fight free radicals in the human body. For this purpose, to better understand oxidative stress, the principles of free radical production, the role of free radicals in diseases, antioxidant defense mechanisms, and the role of herbs and diet in oxidative stress are discussed.

There is a growing interest of industry to replace synthetic chemicals by natural products with bioactive properties from plant origin. The present study reported the antioxidant activity and scolicidal effects of the crude extracts from Mentha spicata, M. aquatica, M. longifolia, and M. × piperita var. citrata growing in Iran.

Total phenolic, flavonoid and flavonol contents of the four Mentha taxa were examined. Two antioxidant assays i.e. free radical scavenging activity (DPPH assay) and reducing power assay were used for determining the antioxidant capacity of the alcoholic extracts. Scolicidal activity of serial dilutions (15–200 mg/mL) of Mentha extracts was evaluated after 1, 5, 10, 20 and 30 minutes of exposure time.

Methanol was the solvent yielding the highest values of total phenolic (TPC), flavonoid (TFC) and flavonol contents (TFvC). On the other hand, the extracts from M. × piperita var. citrata gave the highest total phenolic content (191.6 mg gallic acid equivalent per g; GAE/g), total flavonoid content (57.0 mg quercetin per g; QE/g) and total flavonol content (15.3 mg QE/g) values. The methanol extracts of M. × piperita var. citrata also gave the strongest DPPH radical scavenging activity (83.2%), whereas the reducing power yielded absorbance values between 0.189 in M. spicata and 1.16 in M. × piperita var. citrata. The highest scolicidal activity (99.54%) was observed in 200 mg/mL methanol extract of M. aquatica after 30 minutes of application.

Overall, M. × piperita var. citrata and M. aquatica could be the taxa of choice for future supplementary studies.

Water and nitrogen deficits are the most important limiting factors for plant growth and crop production in the world. Drought stress would be amplified by the global warming. Moreover, nitrogen scarcity is occurred in most arid and semi-arid areas. Cumin (Cuminum cyminum L.) is an important plant due to export benefits and low water demand. This study was aimed to evaluate nitrogen fertilizer effect on yield and some physiological characteristics of cumin under different irrigation regimens.

The experiment was performed based on a split plot as randomized complete block design. Experiment treatments were irrigation regimens (field capacity, irrigation by draining 40% of soil water as middle stress, and irrigation by draining 80% of soil water as severe stress) and nitrogen fertilizers (60 kg ha-1 urea, 30 kg ha-1 urea, Nitroxin, and Nitroxin + 30 kg ha-1 urea).

Drought stress reduced cumin dry weight, seed yield, and chlorophyll content. In contrary, proline content, malondialdehyde (MDA) rate, phenol content, anthocyanin amount, and activity of catalase (CAT) and peroxidase (POX) increased by water stress. Increment urea use resulted in amending cumin growth and seed yield in the field capacity. Also, nitrogen use and raising its rate under the middle water stress caused to improve cumin drought tolerance. However, under the severe water stress, nitrogen application had not a significant impress on drought acclimation and seed yield.

Nitroxin inoculation with use of 30 kg ha-1 urea was the most effective treatment to ameliorate seed yield and drought tolerance.

Diabetic retinopathy is a late stage complication in diabetic patients and one which dramatically affects quality of life. Persistent hyperglycemia results in sorbitol accumulation due to increased activity of aldose reductase (AR), which leads to changes in membrane permeability and leakage of glutathione (GSH) from the lens which in turn results in the development of cataract and retinopathy. Hence, the present study was designed to assess the effect of Tribulus terrestris on AR activity and GSH level in diabetic rat lens, random blood glucose, hemoglobin A1c (HbA1c) and insulin.

Diabetes mellitus was induced by intra-peritoneal (i.p) injection of streptozotocinnicotinamide (STZ-NA). Animals were divided into 5 groups including normal controls (NC) treated with saline, untreated diabetic controls (DC), T. terrestris (150 and 300 mg/kg) and glibenclamide (500 µg/kg) treated diabetic rats. After 16 weeks of treatment, the rats were sacrificed, the lens was removed through posterior approach and homogenate was prepared for AR activity estimation. The lens tissue homogenate was prepared in normal saline for the estimation of GSH. Blood glucose was estimated by glucometer, HbA1c by nephelometry and insulin by ELISA kit.

AR activity was significantly reduced (P<0.004) in T. terrestris (both doses) treated groups compared to untreated diabetic controls. GSH levels were found significantly higher (P<0.005) in treated groups than the ones in diabetic controls. Glucose, HbA1c and insulin were significantly improved (P<0.004) in plant extract treated groups when compared to untreated diabetic rats.

Tribulus terrestris aqueous extract may be useful as AR inhibitor. It also has antioxidant and antidiabetic activities and thereby might be capable of controlling the hyperglycemia induced tissue damage.

In eastern Thailand, Amomum verum and Cinnamomum parthenoxylon are native plants used by local communities for their medical and culinary properties. This study determined the chemical composition and biological activities of the essential oils from A. verum shoots (AVSEO) and C. parthenoxylon wood (CPW-EO).

Essential oils were extracted using hydro-distillation and analyzed using gas chromatography-mass spectroscopy (GC-MS). The antimicrobial activity was evaluated using the disc diffusion method and broth microdilution assay. The cytotoxic activity of the essential oils was assessed against the human prostate adenocarcinoma (DU145) cell line using 3-(4,5-dimethylthiazol2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The antioxidant activity of the essential oils was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis-(3-ethylbenzothiazoline6-sulfonic acid) (ABTS) radical scavenging assays. The expression of antioxidant genes in the DU145 cells was evaluated using quantitative real-time polymerase chain reaction (qRT-PCR).

1,8-Cineole was the main component in AVS-EO and CPW-EO with 84.38, and 45.65 %, respectively. AVS-EO had stronger antimicrobial activity than CPW-EO. The lowest minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) values of AVSEO against Candida albicans were 0.3125 and 2.5 mg/mL, respectively. Both essential oils had timedependent and dose-dependent cytotoxic effects on the DU145 human prostate adenocarcinoma cells. CPW-EO had high antioxidant activity toward DPPH and ABTS radicals with IC50 values of 4.528±0.233 and 0.045±0.007 mg/mL, respectively. The two essential oils up-regulated glutathione peroxidase (GPx) and glutathione reductase (GRx) mRNA expression in the oxidative stress response of DU145 cells.

AVS-EO and CPW-EO might be added as natural ingredients in food or dietary supplement products for the benefit of microbial and prostate cancer inhibition.

The antiviral property of aqueous garlic extract against a virulent velogenic field isolate of Newcastle disease virus (NDV) was investigated in a time of addition assay in embryonated chicken eggs (ECEs).

The ECEs were inoculated with the lowest concentration of the virus with HA (haemagglutination) positive activity. After determination of extract toxicity in ECEs, administration of different concentrations of the extract (0.5, 1, 2, 4 mg/mL) or ribavirin (comparative control) was performed 8 hours before (pretreatment), simultaneously (cotreatment) or 8 hours after (post treatment) virus injection. Allantoic fluids were harvested for infectivity determination, transmission electron microscopy (TEM) and viral load (HA titer) assay. In vitro HA blocking activity test was also performed.

Allicin content of the extract was 16.6% by HPLC method. The best viability results were related to the extract in pretreatment and ribavirin in co-treatment trials (p<0.05 as compared to infected ECEs with no treatment). Pre and co-treatment assays showed better results on HA titer of garlic treated groups. In infectivity assay, the 50% embryo lethal dose (ELD50) values of NDV were roughly 500 and 50 folds of ELD50 of the untreated virus in pre and co-treatment, respectively. No change was observed in viral shapes in TEM analysis nor HA blocking activity in vitro.

Aqueous extract of garlic shows antiviral effects against a velogenic strain of NDV in ovo accompanied by a reduction in virus infectivity and titer. These effects are most pronounced in pretreatment trial.

The effectiveness of antioxidants on learning and memory improvement has been shown, previously. Due to the high level of antioxidants, available in Origanum vulgare, the present experiment aimed to examine the effect of aqueous extract of O. vulgare on passive avoidance learning (PAL) in male Wistar rats.

This study was performed on 30 male Wistar rats weighing 250 to 290 g. The rats were randomly assigned into five groups (n=6), as follows: the control, sham (saline), and three groups treated with different doses of O. vulgare extract (150, 250, and 350 mg/kg). The saline or extract was administered via daily oral gavage for 14 days. The groups were then subjected to the passive avoidance task, and their behaviors were recorded. The rats’ locomotor activity was also measured using the open field test.

The number of trials to acquisition was significantly lower in the “O. vulgare (350 mg/ kg)” group than the control group. The step-through latency and the time spent in the dark compartment in the retention test, was significantly higher and lower in the “O. vulgare (250 and 350 mg/kg)” groups than the control group, respectively. No significant differences were found in the distances traveled among the experimental groups in the open field test.

Aqueous extract of O. vulgare can enhance learning and memory. The high levels of antioxidants in O. vulgare extract may be responsible for its effectiveness in learning and memory.

This study aimed to investigate the phytochemical contents, antioxidant activities and androgenic properties of Peltophorum africanum Sond, Trichilia emetica Vahl, Terminalia sambesiaca, and Ximenia caffra.

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 effects of plant extracts (100-1000 µg/mL) on TM3 Leydig cells were assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium (MTT) assay. Testosterone levels were measured using ELISA kit.

The methanol extracts of T. sambesiaca and X. caffra revealed higher total phenolic and flavonoid contents (102.13±2.32 mg/g gallic acid equivalent and 1.05±0.04 mg/g quercetin equivalent, respectively) than other plant extracts. The acetone and methanol extracts of P. africanum revealed the best IC50 values (12.50 ± 0.052 µg/mL) against DPPH compared to the other plant extracts and ascorbic acid. The MTT assay results showed that all concentrations of plant extracts maintained cell viability and were not cytotoxic with IC50 values of greater than 20 µg/mL. The methanol extract of T. sambesiaca had the higher 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 of P. africanum and T. sambesiaca had significantly high testosterone production of 0.147 and 0.188 ng/mL, respectively when compared with basal control.

The results reveal that these plants possess antioxidants and androgenic properties and suggest the potential use for the treatment of male infertility.

Aspilia africana is a plant commonly used to stop bleeding, heal wound, and manage various stomach complaints. This study aimed at evaluating the impact of aqueous and ethanol leaf extracts of A. africana on biochemical (liver function tests, renal function tests, and lipid profile), histopathological (kidney and liver) and haematological parameters of the female Wistar rats.

To study acute toxicity, the median lethal dose (LD50) was determined by oral administration of different doses of the extract to 8 groups of 3 rats each and the animals were observed for 24 hours for signs of toxicity. To evaluate the toxicological effect of the extract, 3 groups of 5 animals each received 0.5 mL normal saline (control), 250 or 500 mg/kg of the extracts for 2 consecutive weeks.

Data revealed the LD50 of the extract to be >5000 mg/kg.bw. There was no significant variation in organosomatic indices of the animals fed with aqueous and ethanol extracts of A. africana leaves. In comparison with the control, there were significant increase (P<0.05) in serum liver and kidney biomarkers, high density lipoprotein, and white blood cells while some red cells indices, platelets, some lipid profile levels reduced significantly (P<0.05). A marked alteration in hepatic and renal architectures was also observed.

The results of this study show that the A. africana leaves may not be safe as herbal medicine despite the outcome of LD50 acute toxicity studies. For it to be integrated in folk medicine, we recommend its use at minimal doses.

The ethyl acetate fraction of the Saudi Lavandula coronopifolia Poir has been previously reported to have hepatoprotective activity against ethanol-induced oxidative stress. The aim of the current study was to investigate the chemical composition, cytotoxic effect, and antioxidant activities of ethyl acetate fraction of the aerial parts of Saudi L. coronopifolia Poir.

Air dried aerial parts of L. coronopifolia were extracted using 90% ethyl alcohol. The dried extract was suspended in water, defatted with light petroleum and then fractionated with ethyl acetate. The ethyl acetate fraction was subjected to ultra performance liquid chromatography-tandem mass spectrometeric (UPLC-ESI/MS/MS) analysis in a negative ionization mode. The antioxidant activity of the fraction was determined using free radical 2,2-diphyenyl-picrylhydrazyl (DPPH) scavenging assay and its cytotoxic effect against HepG2 (human hepatocarcinoma) and MCF-7 (human breast carcinoma) cells were determined using (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium (MTT) cell viability assay.

The major components of the ethyl acetate fraction included carvacrol-O-diglucoside, (34.98%) and trihydroxy ursolic acid (12.07%). Moreover, the DPPH radical scavenging activity of ethyl acetate fraction was measured. The ethyl acetate fraction revealed an antioxidant potential with EC50 17.8 ± 1.3 µg/mL. Additionally, he ethyl acetate fraction showed cytotoxic activity against HepG-2 and MCF-7 cells with IC50=29.3 ± 0.9 µg/mL and 14.6 ± 0.3 µg/mL, respectively.

The ethyl acetate fraction of the Saudi L. coronopifolia has antioxidant activity and also cytotoxic activity against breast and liver cancer cells.

Despite the extensive use of herbal preparations for treatment of viral respiratory diseases in poultry, few studies have analyzed the effectiveness of these products. This study aimed to evaluate the effects of three different herbal respiratory symptom relieving agents in broiler chickens experimentally infected with H9N2 avian influenza (AI) and infectious bronchitis (IB) viruses.

A total of 175 broiler chickens were randomly assigned into 5 equal groups. Negative control (NC) group remained intact while others received H9N2-AI and IB viruses. Treatment groups (G1-G3) but not positive control (PC) birds were treated with three different herbal agents containing menthol. Clinical and pathological aspects were evaluated during the experiment.

Administration of these agents to challenged chickens not only did not notably decrease clinical severity, gross and histopathological lesions, but also markedly increased mortality rate in treated groups. In dead cases, cast/plug formation was a prominent feature in the trachea. Treatment with herbal agents induced an increase of more than twofold in the number of goblet cells compared to PC group. Significant ciliostasis was observed in all challenged groups regardless of treatment, while ciliary activity was not changed statistically in comparison with the mean values of PC.

In this study administration of herbal preparations adversely affected the tracheal epithelium via enhancement of goblet cell hyperplasia. It appears that hyper-secretion of mucosa along with ciliary incompetence causes mucus stagnation followed by tracheal or bronchial obstruction and death. These findings necessitate cautious use of these products.

This research aims to evaluate the anti-diabetic activity of the extracts from different parts of Cratoxylum formosum subsp. formosum.

The in vitro inhibitory activities of the hexane (HEX), dichloromethane (DCM) and ethyl acetate (EtOAc) extracts from the flowers, leaves, roots and stems on pancreatic α-amylase (pAA), Saccharomyces α-glucosidase (SAG), rat intestinal maltase (rIM), and sucrase (rIS) were investigated.

The DCM and EtOAc extracts from the flowers (IC50 5.4 ± 1.5 and 10.5 ± 0.6 µg/mL) displayed the similar inhibitory activities as acarbose (IC50 7.2 ± 0.4 µg/mL) in the pAA assay. The inhibitory activities of the DCM and EtOAc extracts from the flowers (IC50 56.7 ± 8.9 and 20.4 ± 0.4 µg/mL), EtOAc extract from leaves (IC50 45.0 ± 3.5 µg/mL), DCM and EtOAc extracts from roots (IC50 35.0 ± 6.7 and 16.7± 3.6 µg/mL), and EtOAc extract from stems (IC50 31.1 ± 7.3 µg/mL) were more potent than acarbose (IC50 431.4 ± 16.7 µg/mL) on SAG inhibitory assay (P<0.05). In the rIM assay, DCM and EtOAc extracts from the flowers (IC50 8.5 ± 0.2 and 12.4 ± 0.3 µg/mL) exhibited stronger inhibitory activity than acarbose (IC50 38.5 ± 7.2 µg/mL) (P<0.05). Moreover, the inhibitory activity of DCM extract from the flowers (IC50 16.9 ± 1.5 µg/ mL) was comparable to the acarbose (IC50 15.5 ± 1.2 µg/mL) on rIS assay.

The DCM and EtOAc extracts from the flowers were more active than the leaves, roots and stems in the inhibition of our defined target enzymes.

Renal ischemia reperfusion (IR) contributes to the development of acute renal failure (ARF). Free radicals are considered to be principal components involved in the pathophysiological alterations observed during IR. In this study, we evaluated the effects of vitamin D and erythropoietin (EPO) in IR–induced renal and liver damage.

Wistar rats were divided into five groups of 6 each. 1) The control, 2) IR, 3) VD3 (1,25-dihydroxyvitamin D3) + IR, 4) EPO+ IR, and 5) VD3+EPO+ IR groups. The rats were unilaterally nephrectomized and subjected to 45 minutes of renal pedicle occlusion followed by 24 h reperfusion. Vitamin D (10 mg/kg, IP) and EPO (1000 U/kg, IP) were administered prior to ischemia. After 24 hours reperfusion, the blood samples were collected for the determination of biochemical parameters and kidney and liver samples were taken for histological studies.

Renal ischemia significantly decreased kidney and liver functions. IR significantly increased blood urea nitrogen-creatinine (BUN-Cr), glucose, total protein and liver enzyme levels and significantly decreased hemoglobin (Hb) and hematocrit (Hct) values. Histopathological findings of the IR group confirmed that there were glomerular atrophy and acute tubular necrosis in the renal tissues and lymphocyte infiltration in the liver samples. Treatment with vitamin D and EPO boosted liver and kidney functions and improved the morphological changes.

It seems that vitamin D or EPO administration could protect the kidney and liver damage induced by IR. Also, the combination of vitamin D and EPO may exert more beneficial effects than either agent used alone.