Epidemiological studies have revealed that a diet rich in plant-derived foods has a protective effect on human health. Identifying bioactive dietary constituents is an active area of scientific investigation that may lead to new drug discovery. Kaempferol (3,5,7-trihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one) is a flavonoid found in many edible plants (e.g. tea, broccoli, cabbage, kale, beans, endive, leek, tomato, strawberries and grapes) and in plants or botanical products commonly used in traditional medicine (e.g. Ginkgo biloba, Tilia spp, Equisetum spp, Moringa oleifera, Sophora japonica and propolis). Some epidemiological studies have found a positive association between the consumption of foods containing kaempferol and a reduced risk of developing several disorders such as cancer and cardiovascular diseases. Numerous preclinical studies have shown that kaempferol and some glycosides of kaempferol have a wide range of pharmacological activities, including antioxidant, anti-inflammatory, antimicrobial, anticancer, cardioprotective, neuroprotective, antidiabetic, anti-osteoporotic, estrogenic/antiestrogenic, anxiolytic, analgesic and antiallergic activities. In this article, the distribution of kaempferol in the plant kingdom and its pharmacological properties are reviewed. The pharmacokinetics (e.g. oral bioavailability, metabolism, plasma levels) and safety of kaempferol are also analyzed. This information may help understand the health benefits of kaempferol-containing plants and may contribute to develop this flavonoid as a possible agent for the prevention and treatment of some diseases.

A review on the dietary flavonoid kaempferol.

Adaptogens comprise a category of herbal medicinal and nutritional products promoting adaptability, resilience, and survival of living organisms in stress. The aim of this review was to summarize the growing knowledge about common adaptogenic plants used in various traditional medical systems (TMS) and conventional medicine and to provide a modern rationale for their use in the treatment of stress-induced and aging-related disorders. Adaptogens have pharmacologically pleiotropic effects on the neuroendocrine-immune system, which explain their traditional use for the treatment of a wide range of conditions. They exhibit a biphasic dose-effect response: at low doses they function as mild stress-mimetics, which activate the adaptive stress-response signaling pathways to cope with severe stress. That is in line with their traditional use for preventing premature aging and to maintain good health and vitality. However, the potential of adaptogens remains poorly explored. Treatment of stress and aging-related diseases require novel approaches. Some combinations of adaptogenic plants provide unique effects due to their synergistic interactions in organisms not obtainable by any ingredient independently. Further progress in this field needs to focus on discovering new combinations of adaptogens based on traditional medical concepts. Robust and rigorous approaches including network pharmacology and systems pharmacology could help in analyzing potential synergistic effects and, more broadly, future uses of adaptogens. In conclusion, the evolution of the adaptogenic concept has led back to basics of TMS and a new level of understanding of holistic approach. It provides a rationale for their use in stress-induced and aging-related diseases.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/med.21743

Evolution of the adaptogenic concept from traditional use to medical systems: Pharmacology of stress- and aging-related diseases.

The great diversity of enzymatic reactions in plant secondary metabolism allows the continuous discovery of new natural compounds and derivatives. Flavonoids, for example, can be found as aglycone or as several sorts of glycosylated, acetylated, methylated, and sulphated derivatives. This review focuses on sulphated flavonoids, an uncommon group of flavonoid derivatives found in some plant families. This work presents a compilation of sulphated flavonoids and their natural sources reported in the literature. Biosynthetic aspects and biological activities have also been reviewed, showing that these particular kinds of natural compounds play an interesting role in plant metabolism, as well as being potential candidates for the development of new drugs.

/pdf/sulphated-flavonoids-biosynthesis-structures-and-biological-2zt9ktm0u5.pdf

Sulphated Flavonoids: Biosynthesis, Structures, and Biological Activities.

Tuberculosis, also called TB, is currently a major health hazard due to
 multidrug-resistant forms of bacilli. Global efforts are underway to
 eradicate TB using new drugs with new modes of action, higher activity, and
 fewer side effects in combination with vaccines. For this reason, unexplored
 new sources and previously explored sources were examined and around 353
 antimycobacterial compounds (Nat Prod Rep 2007; 24: 278–297) 7 have been previously reported. To develop
 drugs from these new sources, additional work is required for preclinical
 and clinical results. Since ancient times, different plant part extracts
 have been used as traditional medicines against diseases including
 tuberculosis. This knowledge may be useful in developing future powerful
 drugs. Plant natural products are again becoming important in this regard.
 In this review, we report 127 antimycobacterial compounds and their
 antimycobacterial activities. Of these, 27 compounds had a minimum
 inhibitory concentration of < 10 µg/mL. In some cases, the mechanism of
 activity has been determined. We hope that some of these compounds may
 eventually develop into effective new drugs against tuberculosis.

/pdf/plants-a-source-for-new-antimycobacterial-drugs-5cj69k0ww4.pdf

Plants: A Source for New Antimycobacterial Drugs

Ethnobotanical survey of Purulia district, West Bengal, India for medicinal plants used against gastrointestinal disorders.

The present study has been designed to evaluate the liver protective and in-vivo antioxidant role of Ethanolic extract (EtAS) and Ethyl acetate extract (EAAS) of roots of Argyreia speciosa, an important ‘rasayana’ herb in Indian System of medicine, in CCl4-induced hepatotoxicity and oxidative stress in rats. Animals were treated with EtAS and EAAS at doses of 200 mg and 400 mg / kg body weight p.o. along with CCl4 (0.7 ml / kg in olive oil, 1:1 v/v i.p. on every alternate days) for seven days. Serum biochemical parameters such as SGOT, SGPT, ALP, cholesterol, total and direct bilirubin were determined. Antoixidant status in liver was determined by measuring the activities of Super oxide dismutase (SOD), Catalase and Peroxidase. Histopathological study of isolated liver specimens was also carried out to know the protection offered by the extracts. There was a significant rise in the levels of serum GOT, GPT, and ALP and other biochemical parameters, decrease in the levels of SOD, Catalase and Peroxidase after administration of CCl4. Suspensions of EtAS and EAAS (200 and 400 mg/ kg) successfully prevented the alterations of these effects in rats (p< 0.001). Histopathological examination demonstrated that CCl4 treated group induces ballooning degeneration and centrilobular necrosis. Groups treated with EtAS and EAAS showed recovery on ballooning degeneration and centrlobular bridging necrosis was occasionally present. Data also showed that these extracts possessed strong antioxidant activity, and were comparable to Silymarin, a well known liver protecting herbal formulation.

/pdf/hepatoprotective-and-antioxidant-effects-of-argyreia-3onsfems8o.pdf

Hepatoprotective and antioxidant effects of argyreia speciosa in rats

Antimicrobial activity of flavanoid sulphates and different fractions of A. speciosa root was studied against bacteria, fungi and Mycobacterium tuberculosis H37 Rv sensitive strain by in vitro and in vivo assays. Flavanoid sulphates such as quercetin 3'7 di-O methyl 3- sulphate and kaempferol 7-O methyl 3-sulphate were isolated from the n-butanol fraction of 80% methanolic extract of the plant. The structures of the isolated flavanoids were confirmed by spectral studies. Ethyl acetate (EAAS) fraction and flavanoid sulphates inhibited the growth of M. tuberculosis Rv sensitive strain at MIC values 50 and 25 microg/ml, respectively. Ethanolic fraction (EtAS) showed significant inhibition of gram positive organism with a MIC of 31.25 microg/ml. More inhibition was observed with a less MIC (2 microg/ml) for flavanoid sulphates against Klebsiella pneumoniae, a gram negative organism and it is almost comparable with the standards. Interestingly, chloroform fraction alone exhibited significant antifungal activity with a MIC of 100 microg/ml. A synergistic effect between flavanoids sulphates and commercially available antitubercular drugs was observed with FIC index of 0.443 +/- 0.245, 0.487 +/- 0.247 for isoniazid and 0.468 +/- 0.333, 0.417 +/- 0.345 for rifampicin, whereas EAAS fraction showed partial synergistic effect. A synergistic effect was observed for EAAS fraction and flavanoids sulphates with FIC index < 0.5 with antibiotics. Hemolysis assay on RBCs suggested that EAAS and flavanoids sulphates exhibited least cellular toxicity to erythrocytes as compared to chloramphenicol. In vivo studies in mice infected with K. pneumoniae demonstrated that on day 10 post treatment of different fractions and isolated compounds of A. speciosa, about 60% of the animals treated with EAAS, 70% of animals treated with flavanoids sulphates and 40% of animals treated with EtAS were survived.

http://nopr.niscair.res.in/bitstream/123456789/3074/1/IJEB%2047%282%29%20121-128.pdf

Antimicrobial activity of flavanoid sulphates and other fractions of Argyreia speciosa (Burm.f) Boj.

Argyreia speciosa (sweet) (Burm.f.) Boj. is an Ayurvedic rasayana plant used as an adaptogen. The present study reports the investigations done on the adaptogenic property of ethanol (EtAS; 100 and 200 mg/kg; po), ethyl acetate (EAAS; 100 and 200 mg/kg; po) fraction and flavanoids such as quercetin and kaempferol (25 mg/kg; po) of the root. Immobilization induced acute stress (AS; 3 days) and chronic stress (CS; 7 days) and swimming induced stress models were used to screen the anti-stress effect of the plant fractions and isolated flavanoids. The tested doses of EtAS and isolated flavanoids were able to produce significant effects in normalizing altered serum biochemical parameters and the severity of ulcer in both AS and CS models. Higher dose of EtAS, quercetin and kaempferol (25 mg/kg; po) were found to be significant in restoring the hypertrophy of adrenal gland and atrophy of spleen and thymus gland only in CS model. Greater swimming time was noted in the mice pretreated with tested doses of flavanoids and EtAS. In addition, levels of adrenal ascorbic acid and cortisol were restored compared to stress control group. EtAS exhibited significant scavenging effect of DPPH, hydroxyl radical and LPO. Thus, EtAS, quercetin and kaempferol are capable of increasing the capacity to tolerate non-specific stress in experimental animals, as evident from restoration of large number of parameters in the stress models studied. Bioactivity of EtAS may be due to the synergetic action of isolated flavanoids. Improvement in stress markers may be due its prolong effect of resistance to stress and partly due to free radical scavenging activity.

http://nopr.niscair.res.in/bitstream/123456789/6964/1/IJEB%2048%281%29%2053-60.pdf

Adaptogenic and in vitro antioxidant activity of flavanoids and other fractions of Argyreia speciosa (Burm.f) Boj. in acute and chronic stress paradigms in rodents.

The present study was undertaken to evaluate the adaptogenic activity of ethanol (EtHI), ethyl acetate (EAHI) fractions of Habenaria intermedia D. Don, Orchidaceae (HI), tubers using immobilization induced acute stress (AS), chronic stress (CS) and swimming induced stress in experimental animals. The tested doses of EtHI (100 and 200 mg/kg, p.o.) and higher dose of EAHI (200 mg/kg, p.o.) normalized altered serum biochemical parameters and the severity of ulcers in both AS and CS. EAHI and EtHI restored the hyperthrophy of adrenal gland and atrophy of spleen and thymus gland in AS and CS. Greater swimming time was noted in the mice pretreated with EtHI and EAHI. Levels of adrenal ascorbic acid and cortisol were restored significantly. EAHI exhibited prominent scavenging effect of DPPH, hydroxyl radical and lipid peroxidation in vitro. Phytochemical studies resulted in the isolation of scopoletin and gallic acid as marker compounds. Our results proved the traditional claim of HI as anti-stress/adaptogen in Ayurvdea.

/pdf/protective-effect-of-habenaria-intermedia-tubers-against-49f8r8rjwh.pdf

Protective effect of Habenaria intermedia tubers against acute and chronic physical and psychological stress paradigms in rats.

Several ‘rasayana’ herbs that are enlisted in Indian system of medicine have been in use for the treatment of age-related neurodegenerative disorders including Alzheimer’s disease (AD). Roots of Argyreia speciosa are used in several Ayurvedic preparations as brain tonic and nervine tonic. The present work was undertaken to justify the traditional claim of the plant as nootropic and antiamnesic agent in mice. The ethyl acetate and ethanolic fractions (EtAS) of roots were selected for the study. Exteroceptive behavioural models such as elevated plus maze and Water maze were used to assess the short-term memory, whereas, scopolamine and natural ageing- induced amnesia served as interoceptive models. The whole brain acetyl cholinesterase activity was measured to assess the effect of A. speciosa on the central cholinergic system. Scopolamine (0.4 mg/kg, i.p.) increased the transfer latency significantly (P,0.01) in young mice on the first and second day as compared to control indicating the impairment of memory. Pretreatment with EAAS (100 and 200 mg/ kg, p.o.) significantly (P,0.01) attenuated scopolamine and ageing-induced amnesia. Escape latency time was recorded in the water maze model as an index of acquisition, and trials were conducted for 4 days. The mean time spent in target quadrant (TSTQ) during retrieval trial on fifth day was taken as the index of retrieval (memory). EAAS (100 and 200 mg/kg, p.o.) administered before the training trial (from day 1 to day 4), significantly (P,0.01) attenuated scopolamine and ageing-induced decrease in TSTQ during the retrieval test on the fifth day. EAAS (100 and 200 mg/kg, p.o.) significantly produced reduction in whole brain acetyl cholinesterase (AChE) activity of both young and aged mice thus exhibiting anti-AChE activity in whole brain homogenate compared to Piracetam, scopolamine and control groups of mice. The results indicate that A. speciosa has significant nootropic and antiamnesic activity, justifying its traditional use in Ayurveda. Key words: Antiamnesic, Argyreia speciosa, ayurveda, nootropic, rasayana

/pdf/antiamnesic-potentiality-of-argyreia-speciosa-burm-f-boj-in-1okpyw638x.pdf

R. A. Shastry

Papers

Hepatoprotective and antioxidant effects of argyreia speciosa in rats

Antimicrobial activity of flavanoid sulphates and other fractions of Argyreia speciosa (Burm.f) Boj.

Adaptogenic and in vitro antioxidant activity of flavanoids and other fractions of Argyreia speciosa (Burm.f) Boj. in acute and chronic stress paradigms in rodents.

Protective effect of Habenaria intermedia tubers against acute and chronic physical and psychological stress paradigms in rats.

Antiamnesic potentiality of Argyreia speciosa (Burm.f) Boj. in mice