Introduction
Few herbal remedies have conclusively demonstrated any positive effect on humans, possibly due to inadequate testing (Ernst, 2007). Many of the studies cited refer to animal model investigations or in-vitro assays and therefore cannot provide more than weak supportive evidence. However, examples of medicinal plants in use in other parts of the world that have demonstrable some interesting pharmacological results includes the following:
Medicinal Plants and their Applications
1. Aloe vera
It is traditionally used for the healing of burns and wounds (Maenthaisong et al., 2007). A systematic review (from 1999) states that the efficacy of Aloe vera in promoting wound healing is unclear, while a later review (from 2007) concludes that the cumulative evidence supports the use of Aloe vera for the healing of first to second degree burns (Ernst, 2007, Vogler and Ernst, 1999).
2. Boophone (Boophone disticha)
This highly toxic plant has been used in South African traditional medicine for treatment of mental illness (Stafford et al., 2008). Research demonstrated in vitro and in vivo effect against depression (Pedersen et al., 2008;Sandager et al., 2005; Neergaard et al., 2009).
3. Alligato pepper, Aframomism melegueta. K. Schum (Zingiberaceae)
The fruits, seeds, leaves are used as stimulant, and as remedy against cold.
4. Calendula (Calendula officinalis)
This is used traditionally for abdominal cramps and constipation (Gordon, 1998). In animal research an aqueous-ethanol extract of Calendula officinalis flowers was shown to have both spasmolytic and spasmogenic effects, thus providing a scientific rationale for this traditional use (Bashir et al., 2006).
5. Goat weed (Ageratum conyzoides L (Compositae)
The whole plant leaves and seeds are used in herbal formula. The juice from fresh plant is used for dressing wounds, ulcers, craw craw and as a remedy for inflammation. A decoction of the root is a remedy for abdominal pains and the raw root is chewed for digestive disorders.
6. Garlic (Allium sativum) L. Liliaceae,
The bulbs and leaves parts are used in ethnomedicine. It has diuretic properties and is given in fevers, coughs, flatulence, disorders of the nervous system. It has been used as a remedy for asthma and hoarseness of the chest. The bulb juice is used as a broad spectrum antibiotic against fungi and bacteria. It may also lower total cholesterol levels (Ackerman et al., 2001).
7. Echinacia (Echinacea angustifolia, Echinacea pallida, Echinacea purpurea)
The extracts of this plant is used for the treatment of rhinovirus colds (Shah et al., 2007).
8. Feverfew (Chrysanthemum parthenium)
This plant is sometimes used to treat migraine headaches (Shrivastava et al., 2007). Although many reviews of Feverfew studies show no or unclear efficacy, a more recent RTC showed favourable results (Silberstein, 2005). Feverfew is not recommended for pregnant women as it may be dangerous to the fetus (Yao et al., 2006;Modi and Lowder, 2006).
9. Gawo (Faidherbia albida),
Gawo is a traditional herbal medicine in West Africa, has shown promise in experimental animal tests (Tijani et al.,2008).
10. German Chamomile (Matricaria chamomilla)
This plant has demonstrated antispasmodic, anxiolytic, anti-inflammatory and some antimutagenic and cholesterol-lowering effects in animal research (Mckay et al., 2006). In vitro chamomile has demonstrated moderate antimicrobial and antioxidant properties and significant antiplatelet activity, as well as preliminary results against cancer. Essential oil of chamomile was shown to be a promising antiviral agent against herpes simplex virus type 2 (HSV-2) in vitro (Koch et al., 2008).
11. Ginger (Zingiber officinale)
Ginger is administered in 250 mg capsules for four days, and effectively decreased nausea and vomiting of pregnancy in a human clinical trial used for colds, toothaches, asthma, rheumatism, piles and headaches. The ripe fruit is given as laxative. Seeds boiled with milk are believed to be powerful abortificient and remedy for diabetes.
12. Grapefruit (Naringenin)
Grapefruit components may prevent obesity.
13. Green tea (Camelia sinensis)
Camelia components may inhibit growth of breast cancer cells and may heal scars faster (Belguise et al., 2007; Zhang et al., 2006). Honey may reduce cholesterol and wound healing (Al Walili, 2004).
14. Lemon grass (Cymbopogon citratus),
When administered daily, the aqueous extract of the fresh leaf, has lowered total cholesterol and fasting plasma glucose levels in rats, as well as increasing HDL cholesterol levels. Lemon grass administration had no effect on triglyceride levels (Adeneye and Agbaje, 2007).
15. Morinda citrifolia (noni)
Noni is used in the Pacific and Caribbean islands for the treatment of inflammation and pain (Pande et al., 2005). Human studies indicate potential cancer preventive effects (Wang et al., 2009).
16. Black cumin (Nigella sativa)
Black cumin has demonstrated analgesic properties in mice. The mechanism for this effect, however, is unclear. In vitro studies support antibacterial, antifungal, anticancer, anti-inflammatory and immune modulating effects (Hajhashemi et al., 2004).
17. Pawpaw (Carica papaya L Caricaceae)
Carica papaya is used as insecticide use for wound dressing (Regnault et al., 2004).
18. Peppermint oil
Peppermint oil is used in Nigerian ethnomedicine as remedy against irritable bowel syndrome (Capello et al., 2007).
19. Pomegranate (Punica granatum)
Pomegranate contains the highest percentage of ellagitannins of any commonly consumed juice. Punicalagin, an ellagitannin unique to pomegranate, is the highest molecular weight polyphenol known. Ellagitannins are metabolized into urolithins by gut flora, and have been shown to inhibit cancer cell growth in mice (Heber, 2008).
20. Rauvolfia serpentina
This has a high risk of toxicity if improperly used extensively for sleeplessness, anxiety and high blood pressure and has been widely used in Nigeria in the management of psychiatric problems. Rose hips – Small scale studies indicate that hips from Rosa canina may provide benefits in the treatment of osteoarthritis.
21. Saw Palmetto
Saw Palmetto can be used for (high blood pressure ) Benign prostate hyperplasia BPH. The fat soluble extract of this berry has become a leading natural treatment for BPH. This extract when used regularly, has been shown to help keep symptoms of BPH in check (Schneider et al., 1995).
22. Shiitake mushrooms (Lentinus edodes)
These are edible mushrooms that have been reported to have health benefits, including cancerpreventing properties (Fang et al., 2006). In laboratory research a shiitake extract has inhibited the growth of tumor cells through induction of apoptosis. Both a water extract and fresh juice of shiitake have demonstrated antimicrobial activity against pathogenic bacteria and fungi (Hearst et al., 2009).
23. St. John’s wort
St. John’s Wort has yielded positive results, proving more effective than a placebo for the treatment of mild to moderate depression in some clinical trials (Kuznetsov et al., 2005). A subsequent, large, controlled trial, however, found St. John’s wort to be no better than a placebo in treating depression (Gaster and Holroyd, 2000). However, more recent trials have shown positive results (Davidson or positive trends that failed significance. A 2004 meta-analysis concluded that the positive results can be explained by publication bias but later analyses have been more favorable. The Cochrane Database cautions that the data on St. John’s wort for depression are conflicting and ambiguous.
Stinging nettle in some clinical studies effective for benign prostatic hyperplasia and the pain associated with osteoarthritis. In-vitro tests show antiinflammatory action. In a rodent model, stinging nettle reduced LDL cholesterol and total cholesterol. In another rodent study it reduced platelet aggregation.
24. Umckaloabo (Pelargonium sidoides)
An extract of this plant showed efficacy in the treatment of acute bronchitis in a controlled trial and is approved for this use in Germany.
25. Willow bark (Salix alba)
Willow bark can be used for a variety of anti-inflammatory and antimicrobial purposes due to presence of salicylic acid and tannins. Has been in use for aprox. 6000 yrs and was described in the 1st century AD by Dioscorides (Mahdi et al., 2006).
26. Cam wood Baphia nilida Latal (Papilionaceae)
local name: Urhobo- orhua. In urhobo land, a tribe in Nigeria, a paste of its leaves is applied to the lower portion of the abdomen of pregnant women to prevent miscarriage.
27. Bitter leaf (Vernonia amygdalina, L (compositae)
A decoction of the leaves is used for stomach pains. Also used for skin infections, as an antipyretic, laxative and antidiabetic.
28. Ginkgo (Ginkgo biloba)
Ginkgo billba has been used in traditional medicine to treat circulatory disorders and enhance memory. Although not all studies agree, ginkgo may be especially effective in treating dementia (including Alzheimer’s disease) and intermittent claudication (poor circulation in the legs). It also shows promise for enhancing memory in older adults. Laboratory studies have shown that ginkgo improves blood circulation by dilating blood vessels and reducing the stickiness of blood platelets. By the same token, this means ginkgo may also increase the effect of some blood-thinning medications, including aspirin.
29. Kava kava (Piper methysticum)
Kava kava is said to elevate mood, well-being, and contentment, and produce a feeling of relaxation. Several studies have found that kava may be useful in the treatment of anxiety, insomnia, and related nervous disorders. However, there is serious concern that kava may cause liver damage. It’s not clear whether the kava itself caused liver damage in a few people or whether it was taking kava in combination with other drugs or herbs. It’s also not clear whether kava is dangerous at previously recommended doses, or only at higher doses. Some countries have taken kava off the market. It remains available in the United States, but the Food and Drug Administration (FDA) issued a consumer advisory in March of 2002 regarding the “rare” but potential risk of liver failure associated with kava-containing products.
30. Abere Seed
According to Veenna, Abere seed has been found useful in the treatment of many diseases such as:
- Diabetes
- Hypertension
- Low libido
- Weak Penile
- Quick Ejaculation
Veenna however emphasized on its use in the treatment of diabetes. Check it here